Expert overviews covering the
science and technology of rubber
and plastics
ISSN: 0889-3144
Volume 15, Number 8, 2004
V. Goodship and E.O. Ogur
Polymer Processing with
Supercritical Fluids
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Item 1
Macromolecules
33, No.6, 21st March 2000, p.2171-83
EFFECT OF THERMAL HISTORY ON THE RHEOLOGICAL
BEHAVIOR OF THERMOPLASTIC POLYURETHANES
Pil Joong Yoon; Chang Dae Han
Akron,University
The effect of thermal history on the rheological behaviour of ester- and ether-
based commercial thermoplastic PUs (Estane 5701, 5707 and 5714 from
B.F.Goodrich) was investigated. It was found that the injection moulding
temp. used for specimen preparation had a marked effect on the variations
of dynamic storage and loss moduli of specimens with time observed
during isothermal annealing. Analysis of FTIR spectra indicated that
variations in hydrogen bonding with time during isothermal annealing very
much resembled variations of dynamic storage modulus with time during
isothermal annealing. Isochronal dynamic temp. sweep experiments indicated
that the thermoplastic PUs exhibited a hysteresis effect in the heating and
cooling processes. It was concluded that the microphase separation transition
or order-disorder transition in thermoplastic PUs could not be determined
from the isochronal dynamic temp. sweep experiment. The plots of log
dynamic storage modulus versus log loss modulus varied with temp. over
the entire range of temps. (110-190C) investigated. 57 refs.
GOODRICH B.F.
USA
Accession no.771897
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Volume 1
Report 1
Conductive Polymers, W.J. Feast
Report 2
Medical, Surgical and Pharmaceutical Applications of
Polymers, D.F. Williams
Report 3
Advanced Composites, D.K. Thomas, RAE,
Farnborough.
Report 4
Liquid Crystal Polymers, M.K. Cox, ICI, Wilton.
Report 5
CAD/CAM in the Polymer Industry, N.W. Sandland and
M.J. Sebborn, Cambridge Applied Technology.
Report 8
Engineering Thermoplastics, I.T. Barrie, Consultant.
Report 10
Reinforced Reaction Injection Moulding,
P.D. Armitage, P.D. Coates and A.F. Johnson
Report 11
Communications Applications of Polymers,
R. Spratling, British Telecom.
Report 12
Process Control in the Plastics Industry,
R.F. Evans, Engelmann & Buckham Ancillaries.
Volume 2
Report 13
Injection Moulding of Engineering Thermoplastics,
A.F. Whelan, London School of Polymer Technology.
Report 14
Polymers and Their Uses in the Sports and Leisure
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Polyurethane, Materials, Processing and Applications,
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Report 16
Polyetheretherketone, D.J. Kemmish, ICI, Wilton.
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Report 18
Agricultural and Horticultural Applications of
Polymers, J.C. Garnaud, International Committee for
Plastics in Agriculture.
Report 19
Recycling and Disposal of Plastics Packaging,
R.C. Fox, Plas/Tech Ltd.
Report 20
Pultrusion, L. Hollaway, University of Surrey.
Report 21
Materials Handling in the Polymer Industry,
H. Hardy, Chronos Richardson Ltd.
Report 22
Electronics Applications of Polymers, M.T.Goosey,
Plessey Research (Caswell) Ltd.
Report 23
Offshore Applications of Polymers, J.W.Brockbank,
Avon Industrial Polymers Ltd.
Report 24
Recent Developments in Materials for Food Packaging,
R.A. Roberts, Pira Packaging Division.
Volume 3
Report 25
Foams and Blowing Agents, J.M. Methven, Cellcom
Technology Associates.
Report 26
Polymers and Structural Composites in Civil
Engineering, L. Hollaway, University of Surrey.
Report 27
Injection Moulding of Rubber, M.A. Wheelans,
Consultant.
Report 28
Adhesives for Structural and Engineering
Applications, C. O’Reilly, Loctite (Ireland) Ltd.
Report 29
Polymers in Marine Applications, C.F.Britton, Corrosion
Monitoring Consultancy.
Report 30
Non-destructive Testing of Polymers, W.N. Reynolds,
National NDT Centre, Harwell.
Report 31
Silicone Rubbers, B.R. Trego and H.W.Winnan,
Dow Corning Ltd.
Report 32
Fluoroelastomers - Properties and Applications,
D. Cook and M. Lynn, 3M United Kingdom Plc and
3M Belgium SA.
Report 33
Polyamides, R.S. Williams and T. Daniels,
T & N Technology Ltd. and BIP Chemicals Ltd.
Report 34
Extrusion of Rubber, J.G.A. Lovegrove, Nova
Petrochemicals Inc.
Report 35
Polymers in Household Electrical Goods, D.Alvey,
Hotpoint Ltd.
Report 36
Developments in Additives to Meet Health and
Environmental Concerns, M.J. Forrest, Rapra
Technology Ltd.
Volume 4
Report 37
Polymers in Aerospace Applications, W.W. Wright,
University of Surrey.
Report 38
Epoxy Resins, K.A. Hodd
Report 39
Polymers in Chemically Resistant Applications,
D. Cattell, Cattell Consultancy Services.
Report 40
Internal Mixing of Rubber, J.C. Lupton
Report 41
Failure of Plastics, S. Turner, Queen Mary College.
Report 42
Polycarbonates, R. Pakull, U. Grigo, D. Freitag, Bayer
AG.
Report 43
Polymeric Materials from Renewable Resources,
J.M. Methven, UMIST.
Report 44
Flammability and Flame Retardants in Plastics,
J. Green, FMC Corp.
Report 45
Composites - Tooling and Component Processing, N.G.
Brain, Tooltex.
Report 46
Quality Today in Polymer Processing, S.H. Coulson,
J.A. Cousans, Exxon Chemical International Marketing.
Report 47
Chemical Analysis of Polymers, G. Lawson, Leicester
Polytechnic.
Report 48
Plastics in Building, C.M.A. Johansson
Volume 5
Report 49
Blends and Alloys of Engineering Thermoplastics, H.T.
van de Grampel, General Electric Plastics BV.
Report 50
Automotive Applications of Polymers II,
A.N.A. Elliott, Consultant.
Report 51
Biomedical Applications of Polymers, C.G. Gebelein,
Youngstown State University / Florida Atlantic University.
Report 52
Polymer Supported Chemical Reactions, P. Hodge,
University of Manchester.
Report 53
Weathering of Polymers, S.M. Halliwell, Building
Research Establishment.
Report 54
Health and Safety in the Rubber Industry, A.R. Nutt,
Arnold Nutt & Co. and J. Wade.
Report 55
Computer Modelling of Polymer Processing,
E. Andreassen, Å. Larsen and E.L. Hinrichsen, Senter for
Industriforskning, Norway.
Report 56
Plastics in High Temperature Applications,
J. Maxwell, Consultant.
Report 57
Joining of Plastics, K.W. Allen, City University.
Report 58
Physical Testing of Rubber, R.P. Brown, Rapra
Technology Ltd.
Report 59
Polyimides - Materials, Processing and Applications,
A.J. Kirby, Du Pont (U.K.) Ltd.
Report 60
Physical Testing of Thermoplastics, S.W. Hawley, Rapra
Technology Ltd.
Volume 6
Report 61
Food Contact Polymeric Materials, J.A. Sidwell,
Rapra Technology Ltd.
Report 62 Coextrusion, D. Djordjevic, Klöckner ER-WE-PA GmbH.
Report 63
Conductive Polymers II, R.H. Friend, University of
Cambridge, Cavendish Laboratory.
Report 64
Designing with Plastics, P.R. Lewis, The Open
University.
Report 65
Decorating and Coating of Plastics, P.J. Robinson,
International Automotive Design.
Report 66
Reinforced Thermoplastics - Composition, Processing
and Applications, P.G. Kelleher, New Jersey Polymer
Extension Center at Stevens Institute of Technology.
Report 67
Plastics in Thermal and Acoustic Building Insulation,
V.L. Kefford, MRM Engineering Consultancy.
Report 68
Cure Assessment by Physical and Chemical
Techniques, B.G. Willoughby, Rapra Technology Ltd.
Report 69
Toxicity of Plastics and Rubber in Fire, P.J. Fardell,
Building Research Establishment, Fire Research Station.
Report 70 Acrylonitrile-Butadiene-Styrene
Polymers,
M.E. Adams, D.J. Buckley, R.E. Colborn, W.P. England
and D.N. Schissel, General Electric Corporate Research
and Development Center.
Report 71
Rotational Moulding, R.J. Crawford, The Queen’s
University of Belfast.
Report 72
Advances in Injection Moulding, C.A. Maier, Econology
Ltd.
Volume 7
Report 73
Reactive Processing of Polymers, M.W.R. Brown,
P.D. Coates and A.F. Johnson, IRC in Polymer Science
and Technology, University of Bradford.
Report 74
Speciality Rubbers, J.A. Brydson.
Report 75
Plastics and the Environment, I. Boustead, Boustead
Consulting Ltd.
Report 76
Polymeric Precursors for Ceramic Materials,
R.C.P. Cubbon.
Report 77
Advances in Tyre Mechanics, R.A. Ridha, M. Theves,
Goodyear Technical Center.
Report 78
PVC - Compounds, Processing and Applications,
J.Leadbitter, J.A. Day, J.L. Ryan, Hydro Polymers Ltd.
Report 79
Rubber Compounding Ingredients - Need, Theory
and Innovation, Part I: Vulcanising Systems,
Antidegradants and Particulate Fillers for General
Purpose Rubbers, C. Hepburn, University of Ulster.
Report 80
Anti-Corrosion Polymers: PEEK, PEKK and Other
Polyaryls, G. Pritchard, Kingston University.
Report 81
Thermoplastic Elastomers - Properties and
Applications, J.A. Brydson.
Report 82
Advances in Blow Moulding Process Optimization,
Andres Garcia-Rejon,Industrial Materials Institute,
National Research Council Canada.
Report 83
Molecular Weight Characterisation of Synthetic
Polymers, S.R. Holding and E. Meehan, Rapra
Technology Ltd. and Polymer Laboratories Ltd.
Report 84
Rheology and its Role in Plastics Processing,
P. Prentice, The Nottingham Trent University.
Volume 8
Report 85
Ring Opening Polymerisation, N. Spassky, Université
Pierre et Marie Curie.
Report 86
High Performance Engineering Plastics,
D.J. Kemmish, Victrex Ltd.
Report 87
Rubber to Metal Bonding, B.G. Crowther, Rapra
Technology Ltd.
Report 88
Plasticisers - Selection, Applications and Implications,
A.S. Wilson.
Report 89
Polymer Membranes - Materials, Structures and
Separation Performance, T. deV. Naylor, The Smart
Chemical Company.
Report 90
Rubber Mixing, P.R. Wood.
Report 91
Recent Developments in Epoxy Resins, I. Hamerton,
University of Surrey.
Report 92
Continuous Vulcanisation of Elastomer Pro
À les,
A. Hill, Meteor Gummiwerke.
Report 93
Advances in Thermoforming, J.L. Throne, Sherwood
Technologies Inc.
Report 94
Compressive Behaviour of Composites, C. Soutis,
Imperial College of Science, Technology and Medicine.
Report 95
Thermal Analysis of Polymers, M. P. Sepe, Dickten &
Masch Manufacturing Co.
Report 96
Polymeric Seals and Sealing Technology, J.A. Hickman,
St Clair (Polymers) Ltd.
Volume 9
Report 97
Rubber Compounding Ingredients - Need, Theory
and Innovation, Part II: Processing, Bonding, Fire
Retardants, C. Hepburn, University of Ulster.
Report 98
Advances in Biodegradable Polymers, G.F. Moore &
S.M. Saunders, Rapra Technology Ltd.
Report 99
Recycling of Rubber, H.J. Manuel and W. Dierkes,
Vredestein Rubber Recycling B.V.
Report 100 Photoinitiated Polymerisation - Theory and
Applications, J.P. Fouassier, Ecole Nationale Supérieure
de Chimie, Mulhouse.
Report 101 Solvent-Free Adhesives, T.E. Rolando, H.B. Fuller
Company.
Report 102 Plastics in Pressure Pipes, T. Stafford, Rapra Technology
Ltd.
Report 103 Gas Assisted Moulding, T.C. Pearson, Gas Injection Ltd.
Report 104 Plastics Pro
À le Extrusion, R.J. Kent, Tangram
Technology Ltd.
Report 105 Rubber Extrusion Theory and Development,
B.G. Crowther.
Report 106 Properties and Applications of Elastomeric
Polysul
À des, T.C.P. Lee, Oxford Brookes University.
Report 107 High Performance Polymer Fibres, P.R. Lewis,
The Open University.
Report 108 Chemical Characterisation of Polyurethanes,
M.J. Forrest, Rapra Technology Ltd.
Volume 10
Report 109 Rubber Injection Moulding - A Practical Guide,
J.A. Lindsay.
Report 110 Long-Term and Accelerated Ageing Tests on Rubbers,
R.P. Brown, M.J. Forrest and G. Soulagnet,
Rapra Technology Ltd.
Report 111 Polymer Product Failure, P.R. Lewis,
The Open University.
Report 112 Polystyrene - Synthesis, Production and Applications,
J.R. Wünsch, BASF AG.
Report 113 Rubber-Modi
À ed Thermoplastics, H. Keskkula,
University of Texas at Austin.
Report 114 Developments in Polyacetylene - Nanopolyacetylene,
V.M. Kobryanskii, Russian Academy of Sciences.
Report 115 Metallocene-Catalysed Polymerisation, W. Kaminsky,
University of Hamburg.
Report 116 Compounding in Co-rotating Twin-Screw Extruders,
Y. Wang, Tunghai University.
Report 117 Rapid Prototyping, Tooling and Manufacturing, R.J.M.
Report 118 Liquid Crystal Polymers - Synthesis, Properties and
Applications, D. Coates, CRL Ltd.
Report 119 Rubbers in Contact with Food, M.J. Forrest and
J.A. Sidwell, Rapra Technology Ltd.
Report 120 Electronics Applications of Polymers II, M.T. Goosey,
Shipley Ronal.
Volume 11
Report 121 Polyamides as Engineering Thermoplastic Materials,
I.B. Page, BIP Ltd.
Report 122 Flexible Packaging - Adhesives, Coatings and
Processes, T.E. Rolando, H.B. Fuller Company.
Report 123 Polymer Blends, L.A. Utracki, National Research Council
Canada.
Report 124 Sorting of Waste Plastics for Recycling, R.D. Pascoe,
University of Exeter.
Report 125 Structural Studies of Polymers by Solution NMR,
H.N. Cheng, Hercules Incorporated.
Report 126 Composites for Automotive Applications, C.D. Rudd,
University of Nottingham.
Report 127 Polymers in Medical Applications, B.J. Lambert and
F.-W. Tang, Guidant Corp., and W.J. Rogers, Consultant.
Report 128 Solid State NMR of Polymers, P.A. Mirau,
Lucent Technologies.
Report 129 Failure of Polymer Products Due to Photo-oxidation,
D.C. Wright.
Report 130 Failure of Polymer Products Due to Chemical Attack,
D.C. Wright.
Report 131 Failure of Polymer Products Due to Thermo-oxidation,
D.C. Wright.
Report 132 Stabilisers for Polyole
À ns, C. Kröhnke and F. Werner,
Clariant Huningue SA.
Volume 12
Report 133 Advances in Automation for Plastics Injection
Moulding, J. Mallon, Yushin Inc.
Report 134 Infrared and Raman Spectroscopy of Polymers,
J.L. Koenig, Case Western Reserve University.
Report 135 Polymers in Sport and Leisure, R.P. Brown.
Report 136 Radiation Curing, R.S. Davidson, DavRad Services.
Report 137 Silicone Elastomers, P. Jerschow, Wacker-Chemie GmbH.
Report 138 Health and Safety in the Rubber Industry, N. Chaiear,
Khon Kaen University.
Report 139 Rubber Analysis - Polymers, Compounds and
Products, M.J. Forrest, Rapra Technology Ltd.
Report 140 Tyre Compounding for Improved Performance,
M.S. Evans, Kumho European Technical Centre.
Report 141 Particulate Fillers for Polymers, Professor R.N. Rothon,
Rothon Consultants and Manchester Metropolitan
University.
Report 142 Blowing Agents for Polyurethane Foams, S.N. Singh,
Huntsman Polyurethanes.
Report 143 Adhesion and Bonding to Polyole
À ns, D.M. Brewis and
I. Mathieson, Institute of Surface Science & Technology,
Loughborough University.
Report 144 Rubber Curing Systems, R.N. Datta, Flexsys BV.
Volume 13
Report 145 Multi-Material Injection Moulding, V. Goodship and
J.C. Love, The University of Warwick.
Report 146 In-Mould Decoration of Plastics, J.C. Love and
V. Goodship, The University of Warwick.
Report 147 Rubber Product Failure, Roger P. Brown.
Report 148 Plastics Waste – Feedstock Recycling, Chemical
Recycling and Incineration, A. Tukker, TNO.
Report 149 Analysis of Plastics, Martin J. Forrest, Rapra Technology
Ltd.
Report 150 Mould Sticking, Fouling and Cleaning, D.E. Packham,
Materials Research Centre, University of Bath.
Report 151 Rigid Plastics Packaging - Materials, Processes and
Applications, F. Hannay, Nampak Group Research &
Development.
Report 152 Natural and Wood Fibre Reinforcement in Polymers,
A.K. Bledzki, V.E. Sperber and O. Faruk, University of
Kassel.
Report 153 Polymers in Telecommunication Devices, G.H. Cross,
University of Durham.
Report 154 Polymers in Building and Construction, S.M. Halliwell,
BRE.
Report 155 Styrenic Copolymers, Andreas Chrisochoou and
Daniel Dufour, Bayer AG.
Report 156 Life Cycle Assessment and Environmental Impact
of Polymeric Products, T.J. O’Neill, Polymeron
Consultancy Network.
Volume 14
Report 157 Developments in Colorants for Plastics,
Ian N. Christensen.
Report 158 Geosynthetics, David I. Cook.
Report 159 Biopolymers, R.M. Johnson, L.Y. Mwaikambo and
N. Tucker, Warwick Manufacturing Group.
Report 160 Emulsion Polymerisation and Applications of Latex,
Christopher D. Anderson and Eric S. Daniels, Emulsion
Polymers Institute.
Report 161 Emissions from Plastics, C. Henneuse-Boxus and
T. Pacary, Certech.
Report 162 Analysis of Thermoset Materials, Precursors and
Products, Martin J. Forrest, Rapra Technology Ltd.
Report 163 Polymer/Layered Silicate Nanocomposites, Masami
Okamoto, Toyota Technological Institute.
Report 164 Cure Monitoring for Composites and Adhesives, David
R. Mulligan, NPL.
Report 165 Polymer Enhancement of Technical Textiles,
Roy W. Buckley.
Report 166 Developments in Thermoplastic Elastomers,
K.E. Kear
Report 167 Polyole
À n Foams, N.J. Mills, Metallurgy and Materials,
University of Birmingham.
Report 168 Plastic Flame Retardants: Technology and Current
Developments, J. Innes and A. Innes, Flame Retardants
Associates Inc.
Volume 15
Report 169 Engineering and Structural Adhesives, David J. Dunn,
FLD Enterprises Inc.
Report 170 Polymers in Agriculture and Horticulture,
Roger P. Brown.
Report 171 PVC Compounds and Processing, Stuart Patrick.
Report 172 Troubleshooting Injection Moulding, Vanessa Goodship,
Warwick Manufacturing Group.
Report 173 Regulation of Food Packaging in Europe and the USA,
Derek J. Knight and Lesley A. Creighton, Safepharm
Laboratories Ltd.
Report 174 Pharmaceutical Applications of Polymers for Drug
Delivery, David Jones, Queen's University, Belfast.
Report 175 Tyre Recycling, Valerie L. Shulman, European Tyre
Recycling Association (ETRA).
ISBN 1-85957-494-7
Polymer Processing with
Supercritical Fluids
V. Goodship and E.O. Ogur
(European Tyre Recycling Association (ETRA))
Polymer Processing with Supercritical Fluids
1
Contents
1.1
What is a Supercritical Fluid? ..........................................................................................................3
1.2
Solvent
Strength
...............................................................................................................................3
1.3
Advantages of Supercritical Fluids ..................................................................................................5
1.4
Polymers in Supercritical Carbon Dioxide (scCO
2
) .........................................................................5
1.4.1 Amorphous and Semi-Crystalline Polymers ........................................................................6
1.5
Supercritical Water (SCW) ...............................................................................................................6
1.5.1 Properties: Dielectric Constant ............................................................................................6
1.5.2 Properties: Ion Product ........................................................................................................7
1.6
Supercritical Methanol .....................................................................................................................9
1.7
Supercritical Nitrogen ......................................................................................................................9
2.1
Extraction and Puri
À cation ...............................................................................................................9
2.2
The Basic Principles of SCF Extraction of Polymers ....................................................................10
2.2.1 Choosing Solvent(s) for Supercritical Fluid Extraction (SFE) .......................................... 11
2.2.2 Applications of SFE ........................................................................................................... 11
2.3
Use of SCFs in Polymerisation ...................................................................................................... 11
2.3.1
Introduction
........................................................................................................................ 11
2.4
Impregnation
..................................................................................................................................13
2.5
Supercritical Fluid Dyeing (SFD) .................................................................................................14
2.6
Rapid Expansion of Supercritical Fluid Solutions (RESS Process) ...............................................15
2.7
Supercritical Anti-Solvents Precipitation (SASP) ..........................................................................15
3.1
Plasticisation of Polymers ..............................................................................................................16
3.2
Extrusion
........................................................................................................................................17
3.2.1 Microcellular Foams ..........................................................................................................17
3.2.2
MuCell
Extrusion
Technology
...........................................................................................19
3.3
Injection Moulding .........................................................................................................................19
3.3.1 Trexel: The MuCell
TM
System ............................................................................................20
3.3.2
Ergocell
..............................................................................................................................20
3.3.3 Optifoam Process ...............................................................................................................22
3.3.4
Foamold
.............................................................................................................................22
3.3.5 Applications and Properties of Microcellular Foams ........................................................23
3.4
Microcellular Blow Moulding ........................................................................................................23
3.5
Blending
.........................................................................................................................................23
5.1
Mechanical Recycling ....................................................................................................................24
5.2
Chemical Recycling .......................................................................................................................24
Polymer Processing with Supercritical Fluids
2
The views and opinions expressed by authors in Rapra Review Reports do not necessarily re
Á ect those
of Rapra Technology Limited or the editor. The series is published on the basis that no responsibility or
liability of any nature shall attach to Rapra Technology Limited arising out of or in connection with any
utilisation in any form of any material contained therein.
Polymer Processing with Supercritiical Fluids
3
1 Supercritical Fluids
In the polymer industry supercritical
Á uids are currently
the subjects of intense research and commercial interest.
They can be used for a variety of processes, for example
as solvents in polymer synthesis, as plasticising agents or
for chemical recycling. Supercritical
Á uids of materials
such as carbon dioxide and water also offer a ‘green’
solution, in that they do not harm the earth’s environment
(181).
The development and application of supercritical
Á uid (SCF) technology has actually been quite slow,
however it is unlikely that the pioneering researchers
into supercritical
Á uid properties in the early 1900s
envisioned the wide-ranging impact supercritical
materials would have later in the century, with
applications in a variety of industries. Interest really
began in the 1960s and 1970s with research into
extraction techniques. These experiments used mainly
supercritical carbon dioxide in their research and
concentrated in the food industry for the extraction of
Á avours and essential oils from materials such as hops
and herbs and for decaffeinating coffee and tea.
The decaffeination of coffee is the process most
commonly associated with supercritical fluids and
was
À rst carried out on a large production scale, in
Germany in 1978. Here, the combined properties of
the supercritical
Á uid carbon dioxide were realised in a
cost competitive and environmentally superior process.
The major driver for the development of the SCF
process was in the elimination of residual solvents in
the products, especially methylene chloride, which had
previously been used to decaffeinate coffee. Increasing
regulatory attention to solvent residues in food products
drove this, which is also driving current research in
many polymer
À elds today.
However there were also other advantages in employing
supercritical fluids in these fields. Extraction by
supercritical
Á uid also gave improved Á avour and aroma
characteristics in comparison to standard extraction
practices.
In the eighties, interest was heightened in the special
solvent properties of supercritical fluids. Now,
applications such as the RESS process, which will be
described in more detail later on in this review, are part
of standard industrial practice.
In view of their ever growing importance in the polymer
industry there is a need to fully comprehend how
supercritical
Á uids interrelate with polymeric materials
in order to fully realise the potential that can be gained
from their use. This review will therefore begin with a
quick introduction to supercritical
Á uids.
1.1 What is a Supercritical Fluid?
A supercritical
Á uid (SCF) is a substance (liquid or gas)
which is in a state above its critical temperature (T
c
) and
critical pressure (P
c
). At this critical point liquids and
gases coexist, and a supercritical
Á uid shows unique
properties that are different from those of either liquids
or gases under standard conditions. The relationship
between temperature, pressure and the formation of
a supercritical
Á uid can be seen in Figure 1. This is a
phase diagram for carbon dioxide, a SCF of particular
interest to polymer scientists, which will be discussed
in more detail later on in this review.
An unusually large compressibility means that the
density can be manipulated by small changes in
pressure. One enormous benefit being that a SCF
exhibits a pressure-tuneable dissolving power that is
ideally suited for developing processes for extracting,
purifying and recrystallising substances and producing
new product forms that at present cannot be obtained
by conventional processing technologies.
A SCF gives unusual properties, for example a viscosity
like that of a gas, a density like that of a liquid, and a
diffusion coef
À cient that lies between that of gas and
liquid. In addition, it has the gaseous property of being
able to penetrate porous and
À brous solids and the
liquid property of being able to dissolve materials into
their components. It possesses no surface tension hence
no capillary forces will appear during extraction. The
solvating power of the SCF follows the changes in the
density. The bene
À ts accrued from using supercritical
Á uids (especially water and carbon dioxide) include but
are not limited to the following: (i) environmentally
benign solvents, (ii) the ability to selectively tune
chemical reactions and solvents, (iii) the ability to
enhance reaction rates due to their low viscosities and
high diffusivities. The parameters of some commonly
used supercritical
Á uids are summarised in Table 1.
1.2 Solvent Strength
At the critical point the density is extremely sensitive
to changes in temperature and pressure. Whilst the
densities may be similar to those of organic liquids,
the solubility can be orders of magnitude higher. Since
the solvent strength is directly related to the density,
by control or regulation of the pressure, the solvent
Polymer Processing with Supercritical Fluids
4
strength can be manipulated to simulate (and replace)
the properties of many organic solvents. For example
they can replace solvents such as hexane, methanol,
methylene chloride and chloroform. Even the non-polar
nature of supercritical (sc) CO
2
material can also be
overcome by adding a modi
À er in the form of a polar
organic co-solvent. Thus SCFs have the potential to
replace numerous chemicals in a variety of industries,
apart from the polymer industry.
A supercritical
Á uid exhibits physical and chemical
properties intermediate between those of liquids and
gases. Characteristics of a supercritical fluid are:
(i) dense gas, (ii) solubilities approaching liquid phase,
and (iii) diffusivities approaching gas phase. These
Á uids have densities and diffusivities similar to liquids
and viscosities comparable to gases as outlined in
Table 2.
Figure 1
Phase diagram for carbon dioxide
(NB: At the boiling curve: gas and liquid phases co-exist. At the triple point: all three phases co-exist)
Table 1. Guide to physical parameters of commonly used supercritical solvents
Compound
Boiling point
(ºC)
Critical temp.
(ºC)
Critical pressure
(bar)*
Critical density
(g/cm³)
Nitrogen
–195.9
-147.0
34.0
0.314
Ethylene
–10.8
9.2
50.4
0.218
Carbon dioxide
–78.5
31.0
73.8
0.464
Ethane
–88.7
32.2
48.8
0.203
Nitrous oxide
–88.5
36.4
72.5
0.452
Butane
–17.8
91.8
46.2
0.232
Propane
–42.1
96.6
42.5
0.217
Ammonia
–33.5
132.5
112.8
0.235
Acetone
56.0
235.0
46.9
0.277
Methanol
64.6
239.4
81.0
0.272
Ethanol
78.3
243.0
63.8
0.276
Tetrahydrofuran (THF)
65.0
267.0
51.8
0.321
Toluene
110.6
318.6
41.0
0.291
Water
100.0
374.1
220.5
0.322
* 1 bar=15 psi=100 kPa=0.99 atm
supercritical
Á uid
Polymer Processing with Supercritiical Fluids
5
Mass transfer with supercritical
Á uids is usually fast.
Their active viscosities are nearer to those found in
normal gaseous states. In the zone of the critical point,
the diffusion coef
À cient is more than ten times that
of a liquid and both the viscosity and diffusivity are
dependent on temperature and pressure. Changes in
viscosity and diffusivity are more marked in the area of
the critical point. Also at high pressures, viscosity and
diffusivity are considerably less than that of a liquid.
Therefore, the properties of gas-like diffusivity, gas-
like viscosity, and liquid-like density combined with
pressure-dependent recovery control have provided
the drive for applying supercritical
Á uid technology to
a variety of problems.
The ability to improve solubility by using a material in
a supercritical state has been known since the 1870s,
therefore supercritical
Á uid technology is not entirely a
new technology. The unique properties of supercritical
Á uids were reported slightly over one hundred years ago
by the observation that at high pressures, gases such as
carbon dioxide and ethylene, dissolved complex organic
compounds and that this dissolving power of these
Á uids
was a strong function of pressure. However, it was not
until the second half of the 1900s that the
À rst commercial
scale supercritical processing of polymers was utilised to
manufacture tonnes of LDPE per year using supercritical
ethylene (a.1). As stated in the introduction, for many
years, SCFs have been used in food processing industries
to extract compounds such as caffeine, and the ability to
purge polymer materials of unwanted contaminants is
a new application with growing interest in this area of
supercritical
Á uid technology.
1.3 Advantages of Supercritical Fluids
The advantages of using a SCF can therefore be
summarised as follows:
1. SCFs have similar solvating powers to liquid
organic solvents, but their higher diffusivities, lower
viscosity and lower surface tension make them more
effective in many cases.
2. Since their density is pressure-tuneable, separation
of substances from solvents is easy to achieve.
3. The ability to add modi
À ers to a SCF, for example
to change the polarity, gives them more selective
separation power.
4. Little harm is done to the environment in terms
of residues from processes using SCF compared
to volatile organic compounds (VOCs) and ozone
depleting substances (ODSs).
5. SCFs are generally cheap, safe to use and have
minimal disposal costs associated with their
operation in industrial processes.
By far and away the most widely used SCF of interest
to polymer scientists is scCO
2
which will now be
considered in greater detail.
1.4 Polymers in Supercritical Carbon Dioxide
(scCO
2
)
Carbon dioxide (CO
2
) is the most commonly used
supercritical
Á uid because of its low critical temperature,
low toxicity and high purity at a low cost. It is non-
Á ammable and its use does not contribute to the net
global warming effect. In addition, CO
2
is the second
most abundant and the second least expensive solvent in
the planet. Being a gas under ambient conditions favours
its easy removal from polymeric products, thus saving
costs on other secondary operations such as drying and
solvent removal.
This material has a relatively low operating pressure
and temperature, which makes obtaining supercritical
conditions less expensive then many other SCF
materials. For example it is supercritical in a range often
already experienced by polymers during manufacturing
processes such as extrusion or injection moulding. It can
also be easily removed by simply reducing the pressure.
It can be easily recovered for recycling and can be used
to replace harmful or toxic materials such as Freons. It is
miscible with a variety of organic solvents, and can also
be used to replace some organic solvents. With a few
notable exceptions, most polymers with high molecular
weights are not soluble in this material, an exception is
Á uoropolymers which do dissolve. However, polymers
can take up a signi
À cant quantity of the material in
Table 2. Fluid densities and diffusivities
Mobile Phase
Density (g/cm³)
Viscosity (Poise)
Diffusivity (cm²/s)
Gas
–10³
0.5–3.5(E-4)
0.01–1.0
SCF
0.2–0.9
0.2–1.0(E-3)
0.1–3.3(E-4)
Liquid
0.8–1.0
0.3–2.4(E-2)
0.5–2.0(E-5)
Polymer Processing with Supercritical Fluids
6
a supercritical state. Amorphous polymers behave
differently to semi-crystalline materials, this difference
will now be discussed further.
1.4.1 Amorphous and Semi-Crystalline Polymers
At near critical conditions amorphous materials absorb
CO
2
to a greater extent than semi-crystalline polymers
and a greater amount of plasticisation is found to occur.
This is because CO
2
is absorbed only into amorphous
regions and not crystalline regions. As the concentration
of the fluid increases, sorption and swelling in
amorphous polymers (or amorphous regions of semi-
crystalline materials) can cause a phase transition from
glass to liquid. The glass transition temperature (T
g
) of
the polymer drops signi
À cantly, a property which can
be exploited in polymer processing. Quantities in the
region of 10-30% by weight can be absorbed by these
materials and treatment with just 8-10% can depress a
T
g
of 80 °C to below room temperature. The amount of
absorption is increased by increases in temperature and
pressure, however the polarity of the polymer and the
structure of the polymer also determine the solubility
of any particular polymer being used.
Plasticisation of the polymer also causes an increase in
crystallinity, which causes an increase in the melting
temperature and induces changes in the mechanical
properties of the materials.
The different response to scCO
2
means that amorphous
and semi-crystalline polymers may be more suited to
some applications than others. Certainly within the
scope of this review it is amorphous polymers that are
of most interest.
There have been numerous attempts to quantify the
plasticisation effects of scCO
2
on various polymers,
e.g., (72, 90, 94, 101, 113). However, it is dif
À cult to
de
À nitively state exact levels of either Á uid uptake or
level of plasticisation effect for any given polymer,
given the many different processes, conditions, and
types of the same material which have been tested. All
these factors make any comparison virtually impossible.
Despite this however, in the
À eld of polymer processing,
supercritical technology has already established its
effectiveness. Due to their small size, supercritical
Á uids penetrate into polymers more easily than do
larger liquid solvents. This property facilitates the
controlled rapid sorption of SCF through the adjustment
of pressure and temperature. Supercritical
Á uid used for
polymer plasticisation has signi
À cant effects on polymer
processing activities which include: (i) separation and
fractionation of polymers for extraction of impurities,
(ii) impregnation and extraction of impurities, (iii)
membrane conditioning, (iv) production of micro-
particles, foams, gels and
À bres and (v) polymerisation
reactions.
Changes in the physical and mechanical properties of
polymers are readily observed through the sorption of
supercritical carbon dioxide, with the resultant effect of
reduction of the glass-transition temperature. The major
effects of supercritical carbon dioxide on amorphous
polymers are summarised in Figure 2. Table 3
summarises the effects of scCO
2
on both amorphous
and semi-crystalline polymers.
1.5 Supercritical Water (SCW)
Like carbon dioxide, water is readily available and
hence of interest as a supercritical
Á uid. It is now
widely acknowledged that SCW possesses a massive
capacity for the destruction of both toxic and hazardous
materials.
Whilst this interest is currently focused mainly in
waste water treatment and the conversion of poorly
biodegradable substances to less toxic and more
degradable substances, it has also come to the attention
of chemists. This is as a potential medium for chemical
synthesis and also as a means of polymer recycling.
This is because of its special pressure, volume and
temperature (PVT) dependencies. As a supercritical
Á uid it has a number of interesting and unique properties
which are related to its dielectric properties and the ion
product.
1.5.1 Properties: Dielectric Constant
It can be seen from Figure 3 that supercritical water
is able to operate at a range of dielectric constants as
the temperature and pressure is changed. The dielectric
constant can be varied in a useful region from about 2 to
30 (although higher values can be obtained) dependent
on the pressure and/or temperature. The SCW can be
controlled to give a dielectric constant representing polar
to non-polar properties across this range, mimicking
the polarities of numerous common solvents which
occur. In comparison to common solvents, hexane
(non-polar) is 1.8, carbon tetrachloride has a dielectric
constant of 2.2 and methanol 32.6 (polar). It therefore
has a higher solubility for organic substrates than water
under atmospheric conditions and can dissolve paraf
À n,
aromatics and gases. At the critical point, it will appear
as a weak polar solvent.
Polymer Processing with Supercritiical Fluids
7
1.5.2 Properties: Ion Product
The catalytic properties are also enhanced in the
supercritical state. The proton concentration increases
greatly, by about 30 times, which allows the SCW to
replace other acid catalysts. This change in activity is
represented by the ion product which is the product of
the hydrogen ion concentration and the hydroxy-ion
concentration.
This is de
À ned as K
w
= [H+][OH-]
Under standard temperature and pressure, this has a
value of 1 x 10
-7
mol/l for both molecules, the value
for K
w
will therefore be 1 x 10
-14
(mol/l)
2
. Under high
temperatures and pressures, the value of the ion product
will be considerably increased, giving the acid catalysis
effect. The relationship to the dielectric constant at
400 °C is shown in Figure 4.
It can be seen from the unique properties of SCW, that
the ability to vary the properties of the reaction medium
over a wide range of conditions can be achieved simply
by changing the pressure and temperature. A reaction
can be optimised without changing the solvent, which
offers many advantages to chemists. This versatility can
be clearly seen in the ability to vary the relative static
dielectric constant (
¡) and the K
w
value with changes
to temperature and pressure, since these two physical
properties have such a major impact on both the polarity
and acid/base-catalytic properties.
Figure 2
Effect of supercritical carbon dioxide on amorphous polymers
Table 3 Summary of the effects and applications of scCO
2
on amorphous and semi-crystalline polymers
Semi-crystalline
Amorphous
Gas absorption
Low (only in amorphous regions)
High
Plasticisation effect
Low (only in amorphous regions)
High
Crystallinity
Small increases may be seen (only in
amorphous regions)
Increased
Common examples
Nylon 66, PVDF, PP, HDPE
ABS, HIPS, PC, PMMA, PET
Potential applications
Replacements for CFCS in cleaning
applications (limited applications as
amorphous dependent on degree of
crystallinity)
Foaming and production of
microcellular structures, impregnation,
surface modi
À cation, introduction of
crystallisation
Polymer Processing with Supercritical Fluids
8
Figure 3
The dielectric constant of water as a function of density and temperature
Figure 4
Changes in ion product and dielectric constant as pressure changes at 400 °C
Polymer Processing with Supercritiical Fluids
9
With supercritical water high reaction rates can be
achieved, due to the combined properties of high
dissolving capacity and high transportability. This
means that any mass transfer restrictions due to phase
boundaries do not apply with compounds highly soluble
in SCW. This is because as a supercritical
Á uid it has a
high diffusivity and low viscosity to penetrate materials.
As well as this, the reaction kinetics can also be varied
by pressure. Its pressure and temperature tunability
enables good control as a reaction-causing solvent,
and has been used for applications such as extraction,
decomposition and removal of pollutants in waste water,
sludge, coal and oil applications. It has also been the
solvent of choice for recovery of waste plastics during
chemical recycling.
However, the use of SCW does have drawbacks. High
investment costs are required due to the high working
pressures, and the highly corrosive nature of SCW means
expensive barrier materials are required when working
with this material. However, despite these drawbacks
SCW has great potential for the future especially in the
À elds of chemical synthesis and recycling.
1.6 Supercritical Methanol
Supercritical methanol has mainly been used in the
chemical recycling of polymers, as an alternative to
SCW. It offers several advantages over SCW in selected
applications, these being:
•
Lower critical conditions
•
Easier separation of products from solvent (lower
boiling point).
1.7 Supercritical Nitrogen
Nitrogen (N
2
), is mainly found in the atmosphere, where
it accounts for 78% by volume of the air we breath.
Liquid nitrogen has a variety of uses, for example it is
the most common cryogenic
Á uid used to chill, freeze
or store various products and materials. It is also used
in various chemical reactions.
The use of high-pressure nitrogen gas in the gas assisted
injection moulding (GAIM) process is common, and
requires pressures of between 10 bar to 200 bar and
a nitrogen content of between 98.0% and 99.9%.
From Table 1 it can be seen that this is well within
the supercritical pressure range. Generally scCO
2
is
used instead of supercritical nitrogen; however there
are certain process advantages with microcellular
foaming which can make this the gas of choice (see
Section 3.2).
Whilst there are other supercritical
Á uids as shown in
Table 1, at the time of this review none has yet generated
any pertinent research or data to merit inclusion in this
review.
Now that supercritical
Á uids themselves have been
considered, discussion will now begin on how these
materials can be applied to various aspects of polymer
processing.
2 Polymer Applications of
Supercritical Fluids
2.1 Extraction and Puri
À cation
The increased analytical accuracy of modern equipment
for polymer analysis has inevitably increased the
scrutiny with which potential contaminants are detected
and viewed. This is especially true in the medical device
industry, where materials have intimate contact with the
body such as implants, catheters and grafts. A number
of polymers are used in medical applications, which
can contain residual raw materials or by-products of
production. In some cases, such as materials made of
silicone or polyester-based polymers, these unwanted
components can make up to several percent of the
material, although this can be removed to some extent
during manufacture. There are materials that can be
used to remove impurities by dissolution and extraction.
Hexane and methylene chloride are two such organic
solvents, however they themselves often leave unwanted
residues in the material and can alter its characteristics.
Therefore, it is obvious that the use of scCO
2
will be
extremely attractive in these applications and is already
currently used in the production of a number of medical
components.
The in
Á uence of scCO
2
swells the polymer molecules,
this allows the
Á uid to penetrate deep into the component
and dissolve any unwanted materials or solute trapped
within it. The ability to dissolve materials increases
with an increase of density, controllable through
control of the system pressure and temperature. Of
course when the pressure is reduced, all the carbon
dioxide is also removed and unlike conventional liquid
extraction, the residual solvent in the extracted material
is negligible.
Polymer Processing with Supercritical Fluids
10
Generally extraction relies on the basic principle that
the solubility of a given compound (solute) in a solvent
varies with both temperature and pressure. At ambient
conditions (25 °C and 1 bar) the solubility of a solute in
a gas is generally negligible (and is related directly to
the vapour pressure of the solute). In a SCF, however,
solute solubilities of up to 10 orders of magnitude
greater than those predicted by ideal gas law behaviour
have been reported. This is because in supercritical
Á uids the solubility of a solute is not just a function
of pressure. Solute-solvent interaction as well as the
vapour pressure, controls the dissolution reaction.
Therefore volatile solids have a much higher solubility
in SCF in general, than for example in ideal gases.
The ability to further increase the solubility within a
SCF extraction process may also be desirable, in order
to reduce the amount of solvent required. This may be
achieved by adding another component to the mixture.
This may be referred as a co-solvent or entrainer. This
material will generally have a volatility intermediate
to that of the SCF and the solute which enables the
reaction to be controlled more precisely and selectively.
However, use of extra materials may also change the
chemical nature of the SCF and the ability to remove it
after reactions must also be taken into account.
2.2 The Basic Principles of SCF Extraction of
Polymers
The
Á uid is compressed to elevated pressures above its
critical pressure, to make it supercritical. The polymer
is then exposed to the supercritical
Á uid and swells. As
the free volume in the polymer is increased, the SCF
can penetrate deeply into the matrix and the impurities
are dissolved by the supercritical
Á uid. As any volatile
materials within the feed matrix will then partition
themselves within the supercritical phase, these are
removed with the SCF during the extraction from the
feed system. In the de-pressurisation phase the pressure
is quickly reduced and the supercritical fluid and
impurities diffuse out of the polymer. The SCF can then
be removed by changes to temperature and/or pressure,
leaving negligible SCF in the extracted material and the
SCF can be recycled by recompression. This system is
shown in Figure 5.
There are both advantages and disadvantages of using
SCFs when compared to conventional liquid solvents
for separations.
Some of the advantages are:
•
The dissolving power of the SCF is easily controlled
and manipulated by pressure and/or temperature,
• No harmful residue is left as solvents are non-
toxic,
•
The SCF is easily recovered and recycled from the
extract due to its volatility,
•
The ability to sometimes achieve separations that
are not possible by traditional processes,
• Heat sensitive materials can be extracted as low
temperatures can be employed.
Figure 5
Basic principle of SCF extraction
Polymer Processing with Supercritiical Fluids
11
Some of the disadvantages are:
• An elevated working pressure is required with
associated costs and hazards,
•
Whilst recycling and cost savings can be achieved
by a recompression of the solvent, equipment
installation can be costly and complex,
•
A high capital investment is therefore necessary for
equipment.
2.2.1 Choosing Solvent(s) for Supercritical Fluid
Extraction (SFE)
When choosing a solvent for SFE, many of the
parameters are similar to those used in more traditional
extraction methods, namely: has good properties, is
inert to the
À nal material, can be easily separated and
is economic to use. For SCF, this often means that the
critical parameters must be achievable without undue
cost or complexity.
For this reason carbon dioxide is the most commonly
used SCF in SFE, due primarily to its low critical
parameters, low-toxicity and low cost. Another
solvent with high potential is SCW, due to its ability
to dissolve organic compounds whilst leaving behind
inorganic salts. The opposite effect to its uncritical
state. This enables the same solvent to be used for both
extractions.
Several other SCFs such as hexane and methylene
chloride have been used commercially and in research.
For example, the petrochemical industry uses organic
solvents. However, these materials require explosion
proof equipment, increasing the expense of these
processes. Other restrictions on solvent choice may also
apply, for example the use of one set of highly effective
supercritical solvents (chloro
Á uorohydrocarbons, CFCs)
is limited due to their effect on the ozone layer.
Use of carbon dioxide or water in the form of supercritical
Á uids is used as a substitute for organic solvents in both
the food and medical industries. SCFs are used as safe
alternative solvents in the food processing industry.
They are also used in the rapid extraction of spirits and
other components at room temperature. Other areas of
application include:
(i) puri
À cation and fractionation of polymers such
as the removal of unaffected monomers from
polymers
(ii) puri
À cation and separation of substances such as
oil and grease and
(iii) removal of impurities in chemical materials (195).
Conventionally, the puri
À cation of polymers is carried
out by either vacuum, steam stripping or solvent
extraction. However, these methods are not always
adequate as they come short in reducing the residual
contents to the required permissible levels. Alternatively,
devolatilisation with supercritical
Á uids can improve
impurity removal due to an increased thermodynamic
driving force and improved molecular diffusivity. It is
therefore more effective.
This method can also be used to remove additives, residual
solvents, catalysts, and side reaction products which can
have a detrimental effect on the end-use properties.
Since supercritical
Á uids are ‘tuneable’, selective extractions
can be carried out providing the SCF has sufficient
solubilising power with the product to be puri
À ed.
2.2.2 Applications of SFE
Several applications for SFE outside the polymer
industry have been commercialised, for example
in the food industry to decaffeinate tea and coffee,
extraction of oils, hops and aromas. Tobacco can be
denicotined with this process. A process called Residum
Oil Supercritical Extraction (ROSE) is used to remove
impurities in the treatment of used oils and lubricants.
The pharmaceutical industry uses SFE to extract
ingredients from herbal plants, and also eliminate
harmful residual solvents from their products. It can also
be used to clean contaminated soil and remove residual
solvents from waste materials. Supercritical extraction
in polymer applications is not widely used yet, but the
potential seems high for the polymer industry. One
potential application may come in the mechanical
recycling
À eld where supercritical Á uids could be used
to remove low molecular weight contaminants from
recyclate before re-processing. (It is these that often
give recyclate such a distinctive smell.)
2.3 Use of SCFs in Polymerisation
2.3.1 Introduction
The many attributes of scCO
2
which have been
discussed earlier, have made it a viable alternative
Polymer Processing with Supercritical Fluids
12
solvent in a number of polymerisation reactions. It has
been intensively researched in a wide range of reactions
and used as the continuous phase for numerous step-
growth and chain-growth reactions. This includes free-
radical, ionic- and metal-catalysed process routes.
However, the long-term future of its use as a solvent
will be limited by the poor solubility of most long-
chain polymers. Its application is likely to be limited
to speci
À c special applications and materials such as
Á uorinated polymers, polysiloxanes, and where the
reaction involves soluble polymers such as those with
a low molecular weight.
Where SCFs have been used successfully, the ability to
tailor the properties with scCO
2
has enabled the synthesis
of polymers with precise control of molecular weight
and polydispersity, but with minimal contamination,
and at acceptable levels. The morphology can also be
controlled in some cases. ScCO
2
also offers a potential
process route to extremely low residue polymers by
acting as a solvent in a number of polymerisation
reactions.
In order to fully comprehend the application of SCFs
in polymerisation, a quick revision of the various
polymerisation routes is now provided.
Commercial polymer materials are made by a variety of
techniques depending on the required properties and the
type of
À nal product. Polymerisation mechanisms can
be simply classi
À ed into two classes: step and chain.
•
Step polymerisation proceeds with an increase of
one species at a time in any given chain. During
the reaction, any of the various sized polymer
species present can react with another. The
production of polyamides and polyurethane are
examples of commercially used step polymerisation
processes.
•
With chain polymerisation an initiator is used to
produce a reactive species such as a free radical,
cation or anion. Monomer then reacts with the
reactive species. Polystyrene and polyethylene are
two examples of materials that can be made by
undergoing chain polymerisation.
Radical polymerisation can be split into homogeneous
and heterogeneous types based on the initial mixture.
Mass and solution polymerisation are homogeneous;
suspension and emulsion polymerisation are
heterogeneous processes. A further type of radical chain
polymerisation is emulsion polymerisation, which uses
monomers in the form of colloidal dispersions.
Of all these processes it is the solution, suspension
and emulsion type reactions that have attracted most
attention for the application of SCF technology, because
of the possibility to reduce waste water and/or solvent
during polymerisation and to improve properties.
It should be noted that bulk polymerisation is by its
nature (solvent-free), of no interest to SCF technology,
since the objective is to replace solvents that are
toxic or reduce waste. However the use of a solvent,
as in solution polymerisation, often offers a number
of advantages (and some disadvantages too) to a
polymerisation process as summarised in Table 4.
A summary of various techniques covered in the
abstracts accompanying this review is given in Table 5.
It should be noted that all monomers could in theory
be processed by any one of the routes highlighted here.
However, there are often economic reasons why one or
two processes are favoured above others.
Fluoropolymers are already produced commercially
using scCO
2
. The polymerisation reaction is carried out
using the emulsion process. The use of SCF enabled the
replacement of water and was termed ‘Process G’ by the
manufacturers, DuPont. The materials produced were a
range of melt processable PTFE resins (151, 153).
Due to the higher solubility of materials in SCF
compared to some conventional solvents, the range
of polymers that can be produced by techniques like
solution polymerisation can be expanded somewhat.
However with this technique there is a requirement for
the materials to be soluble in the solvent, which still
means many polymers are not suitable for this route.
Generally, this means applications are limited to silicone
and
Á uoropolymers. For example, DuPont has produced
Á uorinated ethylene-propylene with scCO
2
as a solvent
using the solution polymerisation technique.
With dispersion polymerisation, SCF can be applied
for synthesis of polymers from monomers such as
acrylate and methacrylate (59, 67). Homogeneous
polymerisation with supercritical
Á uids has also been
studied for
Á uoroacrylates.
Table 4. Use of solvents in polymerisation
reactions
Advantages
Disadvantages
Diluent
Purity (residues)
Aids heat transfer
Chain transfer to solvent
Allows mixing
Better thermal control
Polymer Processing with Supercritiical Fluids
13
As well as the more commonly used scCO
2
, precipitation
polymerisation has also been studied using one of the
lesser-used SCFs, supercritical ethane. Unlike solution
polymerisation, in this type of reaction it is required that
the polymer is insoluble in the solvent being used. It has
been used to successfully produce styrene polymers.
Another important area of research is in the creation
of surfactants for use with SCFs. In dispersion and
emulsion polymerisation for example, the surfactants
play an essential role in preventing aggregation of
the growing polymer chain. With scCO
2
, many of the
traditional surfactants have been found to be insoluble.
Therefore increased uptake of scCO
2
technology has
led to much research, in
À nding suitable surfactants to
utilise this new technology.
2.4 Impregnation
The impregnation of polymeric materials with
supercritical fluids is an area of interest in the
preparation of novel materials (61, 108). The properties
of low surface tension, high diffusivity and the ability
to recover the solvent with ease, makes the application
of SCF achievable.
The impregnation process becomes feasible when the
material to be dispersed (the solute) can be dissolved in
the supercritical
Á uid. The material to be impregnated
then swells under the action of the SCF, and the solute
within the SCF is dispersed with it. Plasticisation,
with the associated reduction in the glass transition
temperature aids the impregnation process. Residual
Table 5. Types of polymerisation reactions
Polymerisation process
conditions
Description
Polymer types used or produced
Emulsion
This is when the monomer(s), initiator, (surfactant)
and stabiliser are mixed in the dispersion media
to form an inhomogeneous mixture capable of
polymerisation of the monomer.
PTFE, PVDF, PVA, ABS (88,
134, 150)
Precipitation
The polymer precipitates out on forming, as it
does not dissolve in the monomer or solvent
used. The initial mixture is homogeneous in
nature consisting of monomer, initiator and
solvent. On polymerisation the reaction becomes
heterogeneous.
MMA (polymers and copolymers
produced from monomer) (87),
acrylonitrile (54), PVDF (89)
Dispersion
This is a type of precipitation polymerisation
in which all the necessary ingredients, e.g.,
monomer(s), initiators(s) and stabiliser(s) are
added to a solvent to produce a homogeneous
mixture. The resulting polymerisation produces a
polymer which does not dissolve in the solvent.
This produces polymer particles.
PMMA, styrene (59, 86, 96, 304),
vinyl acetate, acrylamide
Solution
This process uses a liquid solvent to dissolve
the monomers and initiators. The resulting (co)
polymer is often also soluble in the solvent.
Vinyl acetate, acrylonitrile,
PVDF,
Á uorinated ethylene-
propylene, per
Á uoroalkoxy resins,
Nylon 6 (125)
Suspension
In this method, the monomer(s) droplets are
polymerised while being dispersed in a liquid
phase (usually water) by continuous mixing. It is
primarily utilised for PVC production.
PVDF, PVA, PE (57, 336)
Bulk
(can be batch-type or
continuous production)
This process is also known as mass
polymerisation. The monomer is polymerised
with an accelerator or catalyst, without any other
medium being present. Although the monomers
are commonly in a liquid form, they can also be
gases or solids if no solvents are present.
Ethylene, styrene, MMA
Polymer Processing with Supercritical Fluids
14
solvent recovery can be made relatively easily, when
compared to the cost of other solvent recovery options.
The process steps are illustrated in Figure 6.
Materials that are both miscible and immiscible can
become dispersed. A material with little af
À nity for the
matrix is dispersed and then trapped when it comes out
of solution, but has no molecular attraction with the
matrix. The scCO
2
appears not to aid compatibility in
these cases, in contrast to the effect seen in blending by
extrusion for example. A material with af
À nity for the
matrix has potential in a variety of applications such as
a drug delivery mechanism, for dye impregnation and
to produce polymer blends. In all cases it is necessary
that the matrix species is able to swell under scCO
2
.
The ability to replace current aqueous dying solvents
with an environmentally benign material could reduce
textile waste streams considerably. This will be further
discussed in Section 2.5.
scCO
2
can be used to obtain modifications to the
polymer molecules, by acting as a carrier for a second
impregnated material. By impregnating one material
with a monomer and an initiator, the matrix swollen
under the effects of the scCO
2
is modi
À ed, without
producing thermal stresses. This allows materials to be
manufactured that may be dif
À cult to obtain by more
common methods.
For example Lui and co-workers (107) have reported
the polymerisation of styrene monomer within a
polypropylene (PP) matrix. This was carried out by
impregnating a swollen PP matrix with the monomer
and an initiator using scCO
2
as the solvent. There has
been a similar study with the impregnation of LDPE
using styrene (224), again using the scCO
2
to swell
the LDPE substrate. After further treatment to induce
polymerisation some entanglement between the LDPE/
PS blends could be seen.
This technology has numerous possibilities, e.g., (55,
61), outside the range of melt mixing and with thermally
unstable materials. For example it is possible to take a
hydrophobic material such as PVC and generate a water-
soluble polymethacrylic acid (PMAA) within it.
2.5 Supercritical Fluid Dyeing (SFD)
A further application for SCF impregnation is to use
it as an aid to the dyeing of polymers (212, 214). It
offers a number of advantages when compared to the
current water processes that require water, surfactants
or dispersing aids and need a drying stage. With SFD
the production of waste water, which contains remnants
of all the additives and unused dye, can be eliminated,
as can the necessary drying stage. PP fibres dyed
using scCO
2
also have a higher dye uptake than with
conventional water-based dying systems. Aramid, PE
and PET (227) can also all be successfully dyed. Dye
molecules tend to be relatively large with slow diffusion
rates and they penetrate only into amorphous regions
of the polymer. In PP the plastication effect makes the
polymer molecules more mobile and this, combined
with the high diffusivity of scCO
2
, leads to higher
dye diffusion into the polymer. There has also been
considerable success in the dyeing of polyester (179,
200). The high initial investment for this technology
means it is the harder to dye materials that will most
likely utilise this technology
À rst.
Figure 6
The impregnation process
Polymer Processing with Supercritiical Fluids
15
2.6 Rapid Expansion of Supercritical Fluid
Solutions (RESS Process)
In the 1980s when a whole number of SCF applications
were being explored, one such technology was an exciting
new method to produce ultra
À ne particles. Even today, this
is still an area of intense development by pharmaceutical
companies and researchers in the US, Japan (70) and in
Europe. This is because the recrystallisation of materials
by supercritical
Á uid processing enables the manufacture
of specially structured products of signi
À cantly high
quality and function that simply cannot be produced with
conventional manufacturing methods. This is because
some pharmaceutical materials are too unstable to
micronise by methods such as simple grinding or milling,
as they either may form as amorphous materials or just
smear. This makes control of the particle size extremely
dif
À cult.
Two methods have been developed to overcome this
problem:
• Rapid expansion of supercritical
Á uid solutions
(RESS) and
•
Supercritical anti-solvent precipitation (SASP)
The RESS process can be used to produce thin
À lm
coating, polymer
À bres and À ne graining, by using
this process to manufacture whisker-shaped fine
particles of a submicrometre size. There is a wide
range of different materials that can be processed using
RESS technologies including organic and inorganic
compounds and pharmaceutical materials.
The RESS process is unique, as RESS products are
generated ‘dry’, meaning little or no residual solvent.
This is because the solvent changes phase during the
expansion phase, leaving the deposited supercritical
Á uid-soluble materials behind.
The process works by exploiting property changes bought
about by density changes. By passing supercritical
Á uid
solutions through a small ori
À ce, a rapid expansion
occurs, hence the acronym RESS.
In this process materials are dissolved in supercritical
Á uids that can then for example, be sprayed through a
nozzle head and deposited continuously or as required,
e.g., micrometre size powder coatings over relatively
large areas. In this way it can replace mechanical actions
such as grinding or milling to produce
À ne deposits,
hence preventing damage to delicate materials. Non-
polar materials can be dissolved in supercritical carbon
dioxide and then sprayed.
The powder size produced can be manipulated by
changes to parameters such as pressure, temperature
and concentration. The advantages of carbon dioxide
are the same as in other processes. It is cheap, non-toxic
and leaves no residue.
The rapid expansion stage causes a sudden drop in the
dissolving capacity of the solvent as the
Á uid comes out
of its supercritical state, causing nucleation and growth
of any low vapour pressure solute species that were
present in the solution prior to expansion. This rapid
crystallisation of the solute results in homogeneous
submicrometre particles. In many ways the process relies
on exploiting pressure drops, similar to the pressure
drops employed in a number of SCF technologies such
as in extrusion to produce foaming (which will be
discussed in the plastic processing section). However,
the products here can have a number of different forms
dependant on the process settings employed.
As in many current SCF applications, the solvent
of choice is carbon dioxide; however as in other
technologies it may be necessary to modify the
properties of the solvent to improve solubility. Therefore
modi
À ers may be required especially to improve the
solubility of polar molecules (e.g., MeOH), since
carbon dioxide is non-polar, (but does have a limited
af
À nity to polar materials). Co-solvents may also be
employed to enhance solubility. A further approach is
to add polarity with
Á uorinated substituents. However,
this can add expense to the process and also make
recycling necessary.
There are also a number of practical advantages
associated with the use of supercritical carbon dioxide
as a solvent such as the
À nal dryness achieved by
evaporation. This could be essential where residual
solvents are problematic such as in pharmaceutical
manufacture. This technique is currently employed in
the pharmaceutical industry to produce materials such
as antibiotics, steroids and controlled release drugs.
It is also possible to use supercritical carbon dioxide
where there is no solubility, in a complimentary process
to RESS called SASP.
2.7 Supercritical Anti-Solvents Precipitation
(SASP)
This process is also sometimes known as precipitation
of a compressed
Á uid anti-solvent (PCA).
The limited solubility of polar materials in supercritical
carbon dioxide has already been discussed. However,
Polymer Processing with Supercritical Fluids
16
supercritical carbon dioxide can still be employed in a
powder forming reaction. The SASP process involves
À rst dissolving the material in a suitable solvent. This
is then sprayed into the supercritical carbon dioxide,
contained in a high-pressure chamber. Droplets are
formed and the original solvent dissolves in the carbon
dioxide, leaving the insoluble material in powder
form. The size of the powder depends on the reaction
conditions such as temperature, pressure, and the
concentrations of the constituent reaction materials.
Like RESS this technique is currently employed in the
pharmaceutical industry (106).
A further advantage of both the RESS and SASP
processes are the extremely fast process times. Gas and
solution mixing and pressure reductions can take place
in times well below a second. Market opportunity is
likely to increase for these technologies and this should
also therefore enhance the economics of the process.
3 Processing Applications of SCF
Technology
3.1 Plasticisation of Polymers
Since it is the plasticisation of polymers using scCO
2
which
is of major interest in processing, a quick discussion on
the effects of plasticisation will now follow.
Plasticisers are additives sometimes mixed with
polymers to change the rheology and/or the mechanical
properties of the
À nal product. Perhaps the best-known
use of plasticisers is in PVC where plasticisers can be
used to reduce stiffness and lower the glass transition
temperature. The effect of this addition depends on the
nature of the additive and the structure of the polymer. If
the additive is soluble in the plasticiser, then absorption
will cause swelling and eventually it will dissolve.
The behaviour of molten thermoplastic polymers with
supercritical
Á uids is of great interest as a substitute for
plasticising agents in processing. This is particularly
of importance for thermally labile polymers with high
glass transition temperatures (T
g
) and for materials that
are highly viscous.
Plasticisation is generally characterised by changes in
the polymer system that result in:
•
a lowering of the glass transition temperature,
•
a lower rigidity at room temperature,
•
increased elongation and
Á exibility of individual
chains in the polymer,
• increased
toughness.
Amorphous materials and amorphous regions in semi-
crystalline materials are more easily penetrated than
crystalline regions in semi-crystalline polymers. The
degree of crosslinking also affects the ability of the
plasticiser to penetrate. This can be observed when
considering that elastomers (with a less dense network
of crosslinks) may swell in a solvent but a thermoset
(highly crosslinked) neither swells nor dissolves.
During polymer synthesis, plasticisation can generally
be achieved either during synthesis by adding a small
amount of co-monomer (to disturb the subsequent
crystallinity and chain packing), or by adding a low
molecular weight compound into a higher molecular
weight polymer. In both techniques the result is an
increase in the free volume leading to the described
changes in physical properties.
A further method to induce plasticisation is to include
a high-pressure gas, a process called gas-induced
plasticisation. When scCO
2
is dissolved into a polymer
melt the viscosity is observed to decrease. This is
obviously of great interest in trying to process high
viscosity melts. It also enables temperature-sensitive
polymers to be processed at lower temperatures, as
well as lower processing temperatures for materials
with high glass transition temperatures. As previously
described, amorphous polymers swell under the
in
Á uence of scCO
2
and can absorb carbon dioxide to a
greater extent than crystalline polymers, and therefore
amorphous polymers have an increased potential
for both plasticisation and foaming (which will be
discussed later).
For materials with high viscosities, a lowering of
viscosity during processing can be achieved by an
increase in the processing temperature. However an
increase in temperature can also cause heat degradation,
if this requires temperatures above the normal processing
range. Therefore an alternative method that could reduce
the viscosity of polymers is extremely attractive. This is
not only in terms of the drop in viscosity and therefore
improvements in processability, but also the ability
to reduce the processing temperatures. This allows a
drop in energy consumption and therefore leads to cost
reductions. Obviously therefore, this is a very attractive
proposition to material processors.
Polymer Processing with Supercritiical Fluids
17
The high pressures required for the containment of
SCF within the polymers, are similar to those already
encountered in processing operations such as injection
moulding and extrusion. Therefore, it is not a great
problem to modify these systems for use with a SCF
such as scCO
2
. Also the gas can be easily removed by
simply reducing the pressure. Processes developed for
use with supercritical
Á uids will now be discussed,
whilst they are primarily focused on foam applications,
the other major bene
À t of using supercritical Á uids
(for energy savings) should also be borne in mind
throughout.
3.2 Extrusion
Standard extruders generally need little modi
À cation
to incorporate scCO
2
as this can be introduced
through a venting port (114, 118, 228). The scCO
2
is
injected downstream after the plastic undergoes initial
plastication. The two materials then create a single
phase through the action of the screw and mixers. The
rapid pressure drop at the die initiates cell nucleation.
The use of supercritical
Á uids in extrusion has focused
on two distinct applications:
1. Insulation foams, low density (< 0.4 g/cm
3
).
2. Microcellular foams, high density (approximately
0.7 g/cm
3
).
The basic steps to foaming remain the same; the
differences are in the pressure drop requirements,
which control the
À nal cell sizes. For standard foams,
conventional equipment can generally be used providing
supercritical
Á uid is introduced and adequately mixed
prior to foaming. Under these conditions a standard
extruder would generally be expected to produce
low quality foam with large irregular cell sizes.
These extrusions would have the same drawbacks
as conventionally produced cellular materials using
chemical-blowing agents, i.e., poor and irregular surface
À nish.
For microcellular production, the pressure drop is more
tightly controlled, by design and modi
À cations to both
the screw and die. This enables maintenance of an
adequate pressure within the system and ensures that
a suf
À cient pressure drop is present when the material
exits through the die.
The
À rst step in extrusion is the injection of the physical
blowing agents in a supercritical state. Carbon dioxide
(CO
2
) is the most common blowing agent but nitrogen
(N
2
) is also used. This can be injected directly into the
molten polymer in the extruder. By using these gases in
supercritical states both a higher diffusivity and a higher
solubility in the polymer can be achieved. A variety of
injector systems are available, the main prerequisite
being that they can deliver a controlled dose of the
Á uid,
to the barrel of the machine.
The second step requires the saturation, mixing and
dissolving of the SCF into the molten polymer to create
a single-phase homogeneous polymer/gas solution. A
number of different methods of mixing the polymer
and gas have been studied. For example Rapra has done
work on dispersing the SCF in the polymer, using both
a static mixer and a cavity transfer mixer (CTM) (228).
The work proved to be successful and was later applied to
injection moulding for the Foamold process (see Section
3.3.4). Research has also been carried out to assess the
feasibility of making compounds of gas encapsulated
polymers, providing a gas/polymer ‘pre-mix’ to enable
processing/foaming to be carried out without the need for
further gas additions. The permeability of the polymer
and hence gas diffusion and potential shelf-life of these
compounds is obviously a limitation here.
In terms of the extrusion processing itself, it has been
found that the gas diffusion process depends on solubility,
diffusion rate and extrusion parameters such as foaming
temperature and saturation pressure (in order to promote
the development of a microcellular structure).
The
À nal step is the foaming as the material exits the
die. The die has a dual function as it must maintain an
adequate pressure in the extruder barrel to keep the
blowing agent from coming out of solution. It must
also provide the appropriate rapid pressure drop rate to
bring the SCF back out of solution. At this stage there is
nucleation, and gas nuclei form throughout the polymer
matrix as the materials are split back into two phases.
This is followed by a cell growth phase that relates to the
growth and development of the cells. This is controlled
by a combination of mass transfer and
Á uid dynamics
which is beyond the scope of this review. Depending on
the parameters employed during processing, a variety of
conventional size cells or microcellular cells will result.
Some of the important parameters in SCF foaming are
highlighted in Figure 7.
3.2.1 Microcellular Foams
Since microcellular foams are of such high commercial
interest, further discussion on their unique properties
will now follow.
Polymer Processing with Supercritical Fluids
18
A microcellular foam is characterised by its cell size
(smaller than 10
μm) and the cell density (density >109
cells/cm
3
). These materials have a more consistent and
homogeneous cell structure compared to the cell size
and structure of standard foam. These bring a number
of advantages, including better physical properties such
as improved impact strength and toughness. This means
that when compared to common structural foams these
materials have a higher weight to mechanical strength
ratio. They also bene
À t from an improved surface
appearance, low dielectric constant and improved
thermal insulation. Another important bene
À t of this
process is the ability to replace unfoamed applications
which do not require the full mechanical properties
achieved with unfoamed materials. This allows
manufactures to achieve both material and weight
savings.
In order for microcellular foaming to be achieved, the
supercritical
Á uid and polymer must À rst create a single-
phase solution. For this, the CO
2
needs to be dissolved
with the polymer at high pressure, the solubility being
pressure dependent. Lowering the pressure to below the
saturation point will bring the CO
2
out of solution.
To create microcellular foams it is necessary for a large
number of cells to be created before any increase in the
size of those cells occurs. This can only be produced
with a cell nucleation rate that is extremely high and
higher than the diffusion rate of the blowing agent into
cells (i.e., cell creation as opposed to cell growth). With
a large number of nucleation sites in place, growth can
then occur simultaneously and at the same rate. It is this
relationship that gives the evenly distributed, uniformly
sized, microscopic cells than characterise microcellular
moulding.
There is little data available on the critical pressure drop
required for microcellular foaming. For high impact
polystyrene (HIPS), it is reported as being around
109 Pa/s. However such critical pressures are likely
to be highly material dependant due to factors such
as crystallinity, branching and additives which can all
affect the number of available nucleation sites.
The pressure drop in a system can be calculated as
follows:
dp
dt
=
32
μD4V2
d
6
where D = screw diameter,
μ = material viscosity, d =
nozzle ori
À ce diameter, V = extrusion speed/injection
speed.
As the screw speed is increased the pressure drop
also increases. The critical pressure required to create
microcellular foams is however also related to the
gate size (in injection moulding), the material, the
gas percentage and the melt temperature. In injection
moulding, which will be further discussed later in this
review, there is a clear link between injection speed and
potential weight reduction. Higher speeds lead to more
foaming as there are considerably more cells produced
at a higher injection speed. This is due to an increased
pressure drop in the tool at a faster speed. At a further
increased injection speed the pressure drop would
continue to rise and more cells would be achieved until
a saturation point was reached. It is the rate of pressure
Figure 7
Important parameters in the extrusion foaming process
Polymer Processing with Supercritiical Fluids
19
reduction which controls the time period for nucleation
and growth. Under unsaturated process conditions, a
higher pressure drop may be required to increase the
nucleation rate. This can be achieved with the design
of the nozzle and with consideration of factors such
as tooling.
In terms of service strength, the compressive strength of
the foams depends on the cell size, as it has been found
that the compressive strength increases with increasing
cell size. The compressive force causes progressive
buckling of the microcellular cells (319).
3.2.2 MuCell Extrusion Technology
Microcellular foaming was
À rst offered for extrusion
commercially by Trexel under the trade name MuCell
Extrusion Technology. This system provides both the
equipment and processing technologies for producing
microcellular foams using thermoplastic materials and
can currently only be used under license. It can be
installed in both new and existing extrusion equipment.
As in conventional foaming, the MuCell Extrusion
Technology is based on three stages, but the process
requires the purchase and modi
À cation of several pieces
of proprietary equipment:
1. A Trexel SCF System provides the
Á uid pumping
and a MuCell
®
Injector Kit is used to inject the
supercritical
Á uid directly into the extruder barrel.
2. A proprietary screw design is used to disperse
and intimately mix the SCF and the polymer to
form a single-phase solution. A pressure pro
À le is
required to keep the SCF in solution and to ensure
the availability of suf
À cient nucleation sites when
the material exits the die.
3. A suitably designed die will ensure there is control
of the microcellular foaming when the material exits
the die.
A diagram of a potential setup is shown in Figure 8.
3.3 Injection Moulding
Trexel along with others, have also successfully
commercialised microcellular moulding in injection
moulding. As in extrusion, all the systems represented
here assume the creation of a single-phase of polymer
and gas with a solubility gradient.
scCO
2
and supercritical nitrogen are currently used
as foaming agents in injection moulding to produce
lightweight components with high mechanical strength.
The higher solubility of scCO
2
is advantageous, however
supercritical nitrogen can sometimes be used to produce a
better surface
À nish and smaller cells. As with extrusion,
to produce microcellular foams a higher pressure drop
is required than with conventional foaming. This is to
increase the number of nucleation sites.
Figure 8
Design for a MuCell
TM
system
Polymer Processing with Supercritical Fluids
20
3.3.1 Trexel: The MuCell
TM
System (166, 167)
An injection moulding system using scCO
2
is
commercially available by licence from Trexel Inc.,
Woburn, MA. The technology is known as MuCell
TM
.
There are numerous claims made for this process,
for example it is claimed that this technology can
lower the viscosity of the melt, allowing temperature
reductions of up to 78 °C (especially useful if processing
heat sensitive materials such as PVC leading to both
reduced energy consumption and less chance of material
degradation). There is also an associated reduction in
the cavity pressure that is produced in the tool. This can
allow an increase in the number of cavities, and hence
improved manufacturing ef
À ciency.
The MuCell
TM
process configuration includes a
speci
À cally conÀ gured screw and feed system designed
to optimise the thermodynamic instability necessary to
achieve rapid foaming. Carbon dioxide is introduced
into the injection barrel to form a single-phase solution
with the polymer melt.
The following equipment is required to run
MuCell
TM
:
•
metering system for the supercritical
Á uid (SCF) to
ensure the
Á uid is at the appropriate pressure and
volume.
•
A Trexel designed screw and possibly new barrel.
•
Software and system modi
À cations to create and
maintain the uniformity required of the single-phase
solution through the injection moulding cycle.
The screws are usually 22:1 or 24:1 L/D with the barrel
À tted with injector systems designed to match the screw
length. A shut-off nozzle and screw position control
modi
À cations are used to help maintain the pressure for
a single phase solution and prevent decompression. A
system is shown in Figure 9.
As with the Trexel extrusion technology, this system
also requires the purchase of both a licence for the
technology and any necessary machine modi
À cations.
The next system attempts to introduce the material into
the nozzle rather than the barrel, making the change to
foaming much simpler and cheaper. It is much newer
and therefore less established than the Trexel system,
but also enables further understanding of the basic
requirements for microcellular moulding.
3.3.2 Ergocell
In 2001, Demag Ergotech
À rst showed its new Ergocell
process for moulding microcellular foamed products.
To overcome any possible patent con
Á icts, they made
an agreement with Trexel that makes it necessary for
Ergocell customers to purchase a MuCell licence,
however these are offered at reduced cost. As part of
the agreement Demag also offer customers injection
presses with a MuCell option.
Figure 9
MuCell
TM
system
Polymer Processing with Supercritiical Fluids
21
Unlike MuCell, which injects the gas part way along a
specially modi
À ed screw, the Ergocell process injects
gas downstream of the plastication screw into an already
fully homogenised melt. This process works by splitting
the plasticising, gas mixing and injection stages into
separate functions. Plasticising proceeds as normal but
a mixing chamber is added on at the end of the screw
to inject the gas and blend the gas/polymer mixture. A
melt accumulator then holds the material under pressure
until it is injected. This is achieved using conventional
equipment: a standard injection cylinder and screw, and
a non-return valve. This is because all the necessary
work is carried out in a bolt-on unit
À tted to the end of
existing machinery.
Ergocell technology equipment is made up of:
•
A module for gas metering and mixing (including
a mixer, injection module and non-return valve).
•
An injection accumulator.
•
A gas station (a source of gas, carbon dioxide or
nitrogen is also required by the user).
•
A gas metering and mixing module.
The function of the module is to ensure effective
homogenising of the melt/gas mixture independent to
the plasticising stage. It consists of an injection plunger
which is attached to the existing plasticising screw. This
then leads to a mixer where the gas nozzles are arranged
opposite each other. The mixer external geometry is
splined to the plunger. A schematic of the module is
shown in Figure 10.
As the polymer is passed down the screw, gas delivery
takes place simultaneously with plasticising of the
next shot. Gas is fed from the metering station into the
melt as the screw draws feed material in, and is pushed
back by the back pressure. This feeding of material
pushes existing material into the mixer and injection
module. The melt here is intimately mixed with the
CO
2
. The melt accumulator then holds the mixture
under pressure until the nozzle valve is opened and the
plunger injects the melt into the mould. scCO
2
is the
recommended blowing agent with this process, due to
its high sorption capacity in polymers. Whilst nitrogen
can be used, lesser weight savings are obtainable. The
microcellular structure produced has realised material
savings of up to 40 percent. Also, as in other injection
moulding supercritical applications the gas reduces the
viscosity of the material enabling reductions in injection
pressure and clamping forces.
The main differences in the Ergocell and MuCell
systems are in the point of gas injection. Because of
the design of Ergocell, it can be retro
À tted to Ergotech
machines and also removed when necessary to use the
machine in its standard con
À guration. The hardware
itself does not require a licence as the MuCell system
does. There is also the likelihood of less shear damage
to the material, due to the nature of the mixing system,
as the melt is not mixed in the screw but by a mixer.
Figure 10
Ergocell module
spine
injection
piston
screw
polymer gas
(single phase)
gas injection
nozzle
melt
Polymer Processing with Supercritical Fluids
22
This also allows a wider processing window for many
material applications. As summarised in Table 6, the
other advantages of this process are the same as for
MuCell technology.
3.3.3 Optifoam Process
A further bolt-on system has been commercialised by
Sulzer Chemtech Ltd. In this system gas is introduced
in a specially designed injection nozzle rather than
the barrel as in the MuCell system. This nozzle is
shown schematically in Figure 11 and is mounted
between the plasticising unit and the shut-off nozzle
of a conventional machine in a similar manner to the
Ergocell system.
In order to produce a homogeneous distribution of gas in
the melt a ring shape die design and a torpedo is used at
the centre of the melt
Á ow channel to enlarge the mixing
area. This is manufactured using sintered metal which is
permeable to the gas. Static mixers downstream of the
Á uid entrance point ensure intimate polymer/gas mixing
is achieved. The results reported so far by IKV Aachen,
Germany who initially developed the process, relate
to the importance of the relative injection moulding
parameters. Injection speeds, melt temperature and the
concentration of the blowing agent are considered the
key machine settings with this system.
With an 8 mm wall thickness a density reduction of up to
66% was achieved using this system with polystyrene.
(However, generally with all foaming methods, larger
weight reductions can be achieved with thicker cavities.
This correlation seems independent of the material
type.)
A further application for the Optifoam process achieved
a 63% density reduction. This was on a thermoplastic
polyurethane shoe sole (a.2). Like the Ergocell design,
this can be retro
À tted to all injection moulding machines
but unlike any of the processes so far, is license free.
3.3.4 Foamold
The Foamold system by Rapra Technology Limited
claims to be the world’s
À rst portable injection moulding
machine with scCO
2
foaming capability(188). The gas
injection unit can be used either for foaming or as a
means of lowering the viscosity of the molten material
to allow easier mould
À lling and improved product
Table 6. Advantages of microcellular mouldings
over standard injection mouldings
Process
advantages
Reduction in part weight
Elimination of sink marks
Control of warpage
Lower internal stresses
Improved insulation (thermal and
acoustical)
Dimensional stability
Specially suited for decorating
techniques
Cost advantages Material savings
Reduction in clamping force
Reduction in cycle time
Figure 11
Optifoam gas injection nozzle schematic
Polymer Processing with Supercritiical Fluids
23
quality. Unlike other systems, the Foamold system
uses both a cavity transfer mixer (CTM) and an internal
static mixer to disperse the gas in the melt. Previous
research carried out by Rapra on extrusion had shown
the necessity to maintain uniform processing conditions.
This was achieved by separation of the screw pre-
plasticiser and the ram injection pot. The system, known
as Foamold includes a cavity transfer mixer (designed
and developed at Rapra) and a static internal mixer, to
ensure near perfect dispersion of the gas in the melt. The
small machine can deal in sample weights in the range
0.02-12 g. Lower processing temperatures (meaning
less thermal degradation), lower injection pressures and
shorter cycling times means there is a great potential
for energy savings.
3.3.5 Applications and Properties of Microcellular
Foams
Most materials can be produced with a microcellular
structure, including amorphous, semi-crystalline and
thermoplastic elastomer (TPE) materials (64). Therefore
there are numerous applications reported for this
technology of which some now follow: automotive
fasteners and door latches, automotive interior trim, air
distribution manifold, engine intake manifold gasket,
automotive fuse box, rear air blower base connector, fan
motor housing, printer components, electrical switches,
electrical box, electrical connector, cable ties, child gate
panel, thin-wall container, bottle cap, and thermoplastic
vulcanisate weatherstrips (82).
For the same reasons as stated in Section 1.4.1, it is
dif
À cult to deÀ nitively give the properties of microcellular
materials as they are so dependent on the particular
process and material combination. However, Table 7 is
a guide to the potential for the change of properties with
microcellular processing when compared to standard
techniques.
The weld-line properties of injection moulded
microcellular materials are affected by processing
conditions similar to conventional injection moulding
(129), that is increased strength with increasing melt
temperature, injection speed and shot size. The weld-
line strength of microcellular materials also showed
a lesser dependency on the supercritical
Á uid level
employed in processing.
3.4 Microcellular Blow Moulding
Microcellular blow moulding has also been proposed
by Trexel Inc. (196). Like the injection moulding and
extrusion processes already commercialised by Trexel,
the SCF is injected into the extruder. The process
is preformed in the normal sequence and foaming
controlled by modi
À cations to the die and screw.
3.5 Blending
Blends are extremely important materials, which can
provide materials with properties not available from
using a single material. Blends are produced by mixing
or blending polymers together. Examples of common
commercial blends are PVC-ABS or PC-ABS. These
materials are not to be confused with copolymers,
which are polymeric materials composed of one or
more monomers in the same chain, e.g., high impact
polystyrene (HIPS) or ABS which is a terpolymer
(three different monomer groups), made up of a blend
of acrylonitrile, butadiene and styrene. These types of
materials would be produced by polymerisation routes
as dealt with in Section 2.
Successful polymer blending often depends on the very
different viscosities of the polymers. For example a low
viscosity polymer with a small quantity of high viscosity
polymer can improve a number of properties such as
the impact strength or the tear strength. Blends can be
of two types: miscible (one phase) and have a single
glass transition temperature or immiscible (two phases)
with two glass transition temperatures.
Most useful blends of two polymers are immiscible
and hence form two phase systems (one phase rich
with one material and another phase rich in the other
material). The blend may be made up predominately
of one of these materials, whilst the second component
is dispersed within it. The level of dispersion plays an
important part in determining the blend properties,
Table 7. Microcellular plastic compared to unfoamed (solid) material
Properties
Unfoamed plastic
Microcellular plastic
Speci
À c density ratio
1.0
0.05-0.95
Glass transition reduction, T
g
(°C)
100
35 (PS with 10% CO
2
)
Viscosity ratio (viscosity foamed/viscosity unfoamed)
1.0
0.20 (PS with 4% CO
2
)
Polymer Processing with Supercritical Fluids
24
particularly the particle size of the dispersed material.
This is determined by the shearing action at blending but
also depends on the surface tension of the material.
Additives can be used to improve the stability of the
material interface, they are called compatibilisers.
They work by reducing the surface tension and hence
the particle size between the dominant phase and the
dispersed phase. They also help to prevent the particles
from coalescing.
When used in the creation of blends using an extruder,
scCO
2
can enable the bene
À ts of compatibilisation to
be achieved. Namely, whilst it does not dissolve most
polymers, it is a very effective plasticiser affecting both
the viscosity and the morphology.
When a SCF is absorbed it causes swelling, reduced
chain entanglement and the free volume is increased.
Due to the properties of both the SCF (high diffusivity)
and the polymer (swelling under SCF), a high level of
penetration of the SCF is possible. Interfacial tension
is reduced, reducing the strength between phases. The
plasticising effect of the SCF also causes a reduction
in the viscosity. This plasticising effect tends to cause
polymer speci
À c viscosity reductions so in some cases
reduces one component more than the other. This
enables the viscosity ratio of the two components to be
in
Á uenced. A matching of viscosity ratio is beneÀ cial
to mixing and therefore also affects the dispersion
parameters. These properties all lead to a reduction
in particle size of the dispersed phase, thus improving
the blend.
With PS/LDPE blends extruded with 4% wt scCO
2
, it
was found that the SCF reduced the size of the dispersed
phase (103). However the current problem with using
extrusion blending technology using SCF is that once
the SCF is vented, the blends show the properties of
untreated blends.
4 Hardening of Polymers
A further application for supercritical
Á uids has been
reported by Rosti Medical Plastics (25). They have
announced a new product called Hard-Plas. This aims to
replace traditional metal materials, primarily in medical
applications, by producing disposable polymer scalpels
to replace metal ones. This would remove the current
contamination problem. It is reported that a hardness
equivalent to quartz has been achieved.
The process details have yet to be published, subject
to patent applications. From reports that are available
it appears they are using SCF as a plasticiser and are
using scCO
2
and methane as solvents in a process
to ultimately deposit a ceramic on the surface of the
polymer via a sol-gel process. Whilst the creation of
a polymer-ceramic matrix is not new, incorporation of
SCF into the process would suggest that a large process
and hardness improvement should be achievable.
5 Recycling and Recovery
With worldwide consumption of plastics increasing
annually, and with
À fty percent of the mixed solid waste
stream consisting of these materials, the opportunities
for recycling and recovery of polymeric materials are
high. In this regard SCF technology has been applied
to these areas (102, 402).
5.1 Mechanical Recycling
One application of SCF that may prove commercially
viable to the recycling industry is as a cleaning agent
to remove contamination from the polymer prior or
during mechanical recycling. For example, supercritical
Á uids can be used to clean polyethylene automotive fuel
tanks of residual gasoline or diesel (56). A gas tank may
absorb up to 5% by weight of fuel over the course of
its service life. By pressurising the shredded materials
and exposing them to scCO
2
, the gas acts as a solvent
to extract the residual fuel.
Supercritical fluids can also be used during re-
compounding to remove contaminants (373). Controlled
experiments with naphthalene doped plastics found
95% or greater of the naphthalene could be removed
by introducing SCF into a 34 mm counter-rotating,
intermeshing twin-screw extruder.
5.2 Chemical Recycling
Unlike mechanical recycling, which collects and uses
waste plastics without any further chemical treatment,
chemical recycling uses the waste products to turn
them into their monomers (or other useful chemicals)
by means of chemical reactions. Common examples
of chemical recycling processes include cracking and
hydrogenation. Thermal conversion technologies on
the other hand generate conversion products and heat.
Polymer Processing with Supercritiical Fluids
25
These are used for both a volume reduction in the waste
and for energy recovery. There are three common types
of categories of reactions, distinguished by their air
requirements:
• Pyrolysis: thermal processing in the absence of
oxygen. (Pyrolysis conditions have found few
commercial applications because of high viscosities
and low heat transfer rates.)
•
Hydrogenation: as pyrolysis but in a high hydrogen
or carbon monoxide environment.
• Gasi
À cation: partial combustion with a limited air
supply.
In this respect chemical recycling would appear to offer
ideal recycling routes for thermoset resins that cannot
be recycled by reprocessing like thermoplastics can.
However, their highly crosslinked nature can make
them dif
À cult to depolymerise and generally chemical
recycling is more suited to polymers such as PET, PA
and PU.
An alternative disposal method for hazardous or toxic
materials is the supercritical oxidation processes. These
are ‘green’ technologies since they operate as closed
processes and hence no emissions to the atmosphere
occur. Epoxy resin, polyetheretherketones and xylene
resin can all be decomposed back into monomers using
SCW (73). Likewise, phenol resin can be recycled using
SCW and supercritical methanol.
Using SCW with appropriate oxidisers under
hydrothermal conditions, components can be
decomposed to simpler materials such as carbon
dioxide, nitrogen and water. This is a highly ef
À cient
‘combustion’ system with ef
À ciencies >99.9%. Since
the critical point of water is relatively high (374 °C)
and its properties vary signi
À cantly as discussed in
Section 1.5, easy control can be achieved over reaction
pathways and reaction rate.
Polyethylene has been decomposed using SCW in a
reaction using pyrolysis and partial oxidation (164);
silane-crosslinked PE was likewise decomposed using
supercritical methanol (160).
Thermoplastic polyethylene terephthalate (PET) can
be decomposed by hydrolysis. Conversion methods
proceed by methanolysis or glycolysis. The hydrolysis
of PET generates terephthalic acid and ethylene
glycol. By using hydrolysis with supercritical water
or supercritical methanol (171) the reaction time
can be considerably improved, also no additive or
compatibilisers are required with SCW. This should lead
to a process that is more ef
À cient than the conventional
process for PET decomposition. Recently the effect of
supercritical ammonia on polycarbonates has also been
studied (52).
Polyamide (161) has also been decomposed with
SCW, as have flame retardant additive containing
epoxy materials (162). In this case the SCW enabled
accelerated bromine abstraction for the plastic to be
achieved.
6 Conclusions
The use of supercritical
Á uids in the polymer industry
presents an opportunity to create unique products both
now and in the future as demand and usage of the
technology further develops. The choice to change
to supercritical processing technology will depend
primarily on the demands of the marketplace and the
economics of the technology versus existing processes.
A switch to a high-pressure technology requires both
investment cost and the desire to tackle what may
be a highly complex process. Market demand may
come in the form of improved product performance/
speci
À cations or environmental legislation affecting
factors such as purity and/or recycling and disposal. A
market may also exist for products which realistically
cannot be manufactured by alternative process routes.
The extent to which SCF technology will be applied
in the polymer industry has yet to be realised, but the
massive research effort currently being put into the
numerous and varied potential applications makes
further utilisation of these processes highly likely.
Polymer Processing with Supercritical Fluids
26
Additional References
a.1 K.M.
Scholsky,
Process Polymers with
Supercritical Fluids, Chemtech, 1987.
a.2
Sulzer Technical Review, Sulzer Chemtech Ltd.,
2004.
References and Abstracts
© Copyright 2005 Rapra Technology Limited
27
Abstracts from the Polymer Library Database
Item 1
GPEC 2004: Plastics - Helping Grow A Greener
Environment. Proceedings of a conference held Detroit,
Mi., 18th-19th Feb.2004.
Brook
À eld, Ct., SPE, 2004, Paper 27, pp.6, CD-ROM,
012
AROMATIC HYDROCARBON CONTENT OF
COMMON PLASTIC PACKAGING MATERIALS
Ezrin M; Lavigne G
Connecticut,University
(SPE,Environmental Div.)
Various plastics packaging materials containing readily
detected levels of aromatic hydrocarbons were subjected to
supercritical
Á uid extraction with carbon dioxide to remove
the hydrocarbons and then exposed to atmosphere to allow
them to reabsorb hydrocarbons from the air either in a
Á ask
or garage. The plastics packaging materials were analysed
before extraction, after extraction and after exposure to
hydrocarbons in the atmosphere by thermal desorption gas
chromatography/mass spectroscopy using heat to evolve
volatile compounds onto the chromatography column.
The materials were found to absorb hydrocarbons from
the atmosphere. The most likely source of the absorbed
hydrocarbons was identi
À ed as gasoline vapours.
USA
Accession no.923279
Item 2
GPEC 2004: Plastics - Helping Grow A Greener
Environment. Proceedings of a conference held Detroit,
Mi., 18th-19th Feb.2004.
Brook
À eld, Ct., SPE, 2004, Paper 49, pp.10, CD-ROM,
012
DEVULCANIZATION OF RECYCLED TIRE
RUBBER USING SUPERCRITICAL CARBON
DIOXIDE
Tzoganakis C; Zhang Q
Waterloo,University
(SPE,Environmental Div.)
An investigation was carried out into the devulcanisation
of crumb rubber from recycled truck tyres in a twin-
screw extruder into which supercritical carbon dioxide
was injected to swell the crumb rubber. The effects of the
supercritical carbon dioxide on extrusion and of processing
conditions (
Á ow rate, carbon dioxide concentration, screw
speed and con
À guration and temperature) on the viscosity
and degree of devulcanisation of the rubber were examined
and chemical changes occurring during devulcanisation
assessed using FTIR spectroscopy. 14 refs.
CANADA
Accession no.923300
Item 3
Polymer Science Series A
46, No.4, April 2004, p.377-80
SYNTHESIS OF POLYIMIDES IN
SUPERCRITICAL CARBON DIOXIDE
Said-Galiyev E E; Vygodskii Y S; Nikitin L N; Vinokur
R A; Khokhlov A R; Potoskaya I V; Kireev V V;
Schaumburg K
Russian Academy of Sciences; Mendeleev University of
Chemical Technology; Roskilde,University
High molecular-mass polyimides are synthesised in
supercritical carbon dioxide by the one-step polycyclisation
of diamines and tetracarboxylic dianhydrides under batch
and
Á ow regimes. The effect of various reaction parameters
(including the content of water in the reaction system)
on the structure, molecular mass and yield of polymers
is studied. It is shown that the solubility of monomers
in supercritical CO2 is indecisive for polymer growth.
It is hypothesised that CO2 exhibits catalytic activity
when polyimides are prepared in the presence of water.
11 refs.
DENMARK; EU; EUROPEAN COMMUNITY; EUROPEAN
UNION; RUSSIA; SCANDINAVIA; WESTERN EUROPE;
WESTERN EUROPE-GENERAL
Accession no.922515
Item 4
Journal of Cellular Plastics
40, No.5, Sept.2004, p.371-82
CELL DEVELOPMENT IN MICROCELLULAR
INJECTION MOLDED POLYAMIDE-6
NANOCOMPOSITE AND NEAT RESIN
Chandra A; Gong S; Turng L-S; Gramann P
Wisconsin-Madison,University; Madison Group
The effects of processing parameters and nanofillers
(nanoclay) on cell nucleation and cell growth during
the injection moulding of microcellular polyamide-
6 nanocomposites were investigated using various
techniques. A fractional four-factorial, three level, L9
Taguchi design of experiments was performed to minimise
the number of trials and facilitate the analysis of the
results and morphology development of cell structure was
analysed by scanning electron microscopy. Processing
parameters studied included melt temperature, injection
speed, supercritical
Á uid concentration and shot size.
(ANTEC 2004, Chicago, Illinois, 16th-20th May) 8 refs.
USA
Accession no.922671
References and Abstracts
28
© Copyright 2005 Rapra Technology Limited
Item 5
Macromolecules
37, No.11, 1st June 2004, p.4241-6
CHARACTERIZATION OF POLYETHYLENES
PRODUCED IN SUPERCRITICAL CARBON
DIOXIDE BY A LATE-TRANSITION-METAL
CATALYST
de Vries T J; Kemmere M F; Keurentjes J T F
Eindhoven,University of Technology
Polymerisation of ethylene in a supercritical carbon dioxide
(scCO2) medium, using a palladium based catalyst, was
studied over a range of temperatures, pressures and
ethylene concentrations. Polymers were characterised
using gel permeation chromatography, differential scanning
calorimetry, and nuclear magnetic resonance spectroscopy.
High molecular weight amorphous polymers with narrow
molecular weight distribution and a high degree of
branching were obtained, similar to those obtained from
solution polymerisation in dichloromethane. Degree of
short chain branching was higher when sc CO2 was used,
and evidence of a new branch-on-branch structure was
observed. Molecular weight, but not short chain branching
were affected by polymerisation temperature and ethylene
concentration. 22 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; WESTERN EUROPE
Accession no.921548
Item 6
ANTEC 2003. Proceedings of the 61st SPE Annual
Conference held Nashville, Tn., 4th-8th May 2003.
Brook
À eld, Ct., SPE, 2003, Volume 1-Processing
Session M13-Recycling, p.2811-5, CD-ROM, 012
MELT PROCESSING OF THERMALLY
UNSTABLE POLYMERS PLASTICIZED WITH
CO2
Bortner M J; Wilding M D; Baird D G
Virginia,Polytechnic Institute & State University
(SPE)
An acrylonitrile copolymer was plasticised using
supercritical carbon dioxide, so as to reduce the melt
viscosity and allow melt spinning at temperatures below
those at which signi
À cant crosslinking occurred. The
copolymer (65 mol% acrylonitrile, 25 mol% methyl
acrylate and 10 mol% rubber), in pellet form, was exposed
to carbon dioxide at 11 MPa and 120 C for various
time periods and characterised by differential scanning
calorimetry and capillary rheometer measurements. A
plasticising effect was observed, with a nonlinear pressure
dependence, indicating that further plasticisation would
occur at higher pressures. 14 refs.
USA
Accession no.920541
Item 7
Journal of Applied Polymer Science
93, No.2, 15th July 2004, p.545-9
NEW PDMS MACROMONOMER STABILIZER
FOR DISPERSION POLYMERIZATION OF
STYRENE IN SUPERCRITICAL CARBON
DIOXIDE
Ruolei Wang; Cheung H M
Akron,University
A polydimethylsiloxane(PDMS) macromonomer was used
as a stabiliser for free radical dispersion polymerisation
of PS in supercritical carbon dioxide. The reactions were
conducted in a 225 mL stainless steel autoclave over the
temperature range 60 to 80C and under pressures of 1500
to 3000 psi. The effects of the stabiliser concentration
on conversion, molec.wt. and product morphology
were investigated. After 2 to 12 h of polymerisation, the
conversion determined by the gravimetric method was
between 20 and 80%. These preliminary results indicated
that the macromonomer provided satisfactory stabilisation
for the styrene system. 14 refs.
USA
Accession no.920957
Item 8
E-Polymers
No.2, 2004, p.1-7
SOLVATION OF POLY(METHYL ACRYLATE)
AND POLY(VINYL ACETATE) BY CO2 STUDIED
VIA ATOMISTIC MONTE CARLO SIMULATION
TECHNIQUES
Beuermann S; Buback M; Drache M; Nelke D;
Schmidt-Naake G
Clausthal,Technical University; Gottingen,Georg-
August-Universitat
The differences in solubility of PVAc and polymethyl
acrylate(PMA) were studied by using atomistic Monte
Carlo simulation techniques. Polymer segments consisting
of nine monomer units served as model compounds
for polymer chains. As a measure of intermolecular
interactions with the solvent environment, cohesion
energies of the polymer segments embedded in either
the corresponding monomer or in carbon dioxide were
calculated. Speci
À c interactions between polymer segments
were identi
À ed only in the case of PMA segments in carbon
dioxide environment. This result was in agreement with
experimental results on phase behaviour and propagation
kinetics. 15 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.920167
References and Abstracts
© Copyright 2005 Rapra Technology Limited
29
Item 9
E-Polymers
No.3, 2004, p.1-14
REVERSIBLE ADDITION FRAGMENTATION
CHAIN TRANSFER(RAFT) POLYMERIZATION
OF STYRENE IN FLUID CO2
Arita T; Beuermann S; Buback M; Vana P
Gottingen,Georg-August-Universitat
RAFT polymerisations of styrene in liquid carbon
dioxide were carried out at 80C and 300 bar using cumyl
dithiobenzoate as the controlling agent in the concentration
range 0.0035 to 0.021 mol/L. The polymerisation rates
were retarded, depending on the concentration of added
RAFT agent, with no significant difference between
the RAFT polymerisation performed in liquid carbon
dioxide and in toluene. Full chain length distributions
were analysed with respect to peak molec.wts., indicating
the successful control of radical polymerisation in liquid
carbon dioxide. A characterisation of the peak widths
indicated a minor in
Á uence of liquid carbon dioxide on the
addition reaction of macroradicals on the dithiobenzoate
group. 29 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.920168
Item 10
Macromolecules
37, No.12, 15th June 2004, p.4580-9
GRAFTING OF MALEIC ANHYDRIDE ONTO
ISOTACTIC POLYPROPYLENE IN THE
PRESENCE OF SUPERCRITICAL CARBON
DIOXIDE AS A SOLVENT AND SWELLING FLUID
Galia A; De Gregorio R; Spadaro G; Scialdone O;
Filardo G
Palermo,University
Grafting of maleic anhydride(MA) onto isotactic PP(iPP)
was carried out by thermal decomposition of dicumyl
peroxide(DCP) using supercritical carbon dioxide (scCO2)
as a solvent and swelling
Á uid. As long as the initial
concentration of anhydride dissolved in scCO2 was higher
than 1% w/w, the grafting occurred without signi
À cant
molec.wt. modi
À cation of the polymer and, with proper
selection of the operative conditions, a grafting level
higher than 0.5% w/w with respect to the polymer mass
was obtained. The amount of grafted MA was determined
by FTIR spectroscopy and polymer degradation was
monitored by dynamic mechanical tests in the melt state.
The effect of MA and DCP concentration, of scCO2 density
and of the reaction time on the grafting yield and on the
melt
Á ow behaviour was studied. MA homopolymerisation
during the grafting was indicated by the FTIR spectra. The
maleated iPP synthesised was an effective compatibilising
agent in the preparation of iPP/nylon-6 blends. 42 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.920303
Item 11
ANTEC 2003. Proceedings of the 61st SPE Annual
Conference held Nashville, Tn., 4th-8th May 2003.
Brook
À eld, Ct., SPE, 2003, Volume 1-Processing
Session M16-Interface and Compatibilization, p.2271-5,
CD-ROM, 012
EFFECTS OF SUPERCRITICAL CO2
ON THE INTERFACIAL REACTION OF
MALEIC ANHYDRIDE FUNCTIONALIZED
POLYETHYLENE AND POLYAMIDE-6
Xue A; Tzoganakis C
Waterloo,University
(SPE)
Blends of maleic anhydride-functionalised polyethylene and
polyamide-6 (PA-6) were prepared by reactive extrusion
using a co-rotating twin-screw extruder, with injections of 1-4
wt% carbon dioxide. Nonreactive low density polyethylene
was added to some blends to reduced the maleic anhydride
(MA) concentration. The degree of interfacial reaction was
determined by measuring the amount of unreacted MA by
Fourier transform infrared spectroscopy. The MA conversion
increased with increasing carbon dioxide concentration. This
was attributed to interfacial reactions between the two melt
phases. It is proposed that dissolution of carbon dioxide into
the polymer melt increased the free volume, which enhanced
segmental chain mobility and promoted reorientation of
the chain con
À guration, so facilitating contact of reactive
functional groups. The in
Á uence of carbon dioxide on the
MA conversion was less pronounced with increasing PA-6
content in the blend. At high PA-6 concentrations (70%), MA
conversions as high as 80% were achieved without the use
of carbon dioxide. This was attributed to the development
of a crosslinked interfacial region, or to the saturation of
copolymers at the interface. 19 refs.
CANADA
Accession no.919057
Item 12
Asian Plastics News
July-Aug.2004, p.13-4
NEW TECHNOLOGIES FROM JAPAN
Japanese
À rms have been working on processes to improve
the surface
À nish of plastics parts and obviate the need
for coating. Munekata employs supercritical CO2 in a
process to improve the surface
À nish of moulded products.
Supercritical CO2 is also being used in microcellular
foam extrusion. For parts that have been coated, various
recycling technologies are available to enable the reuse
of plastics. Idemitsu Techno
À ne has developed a system
to recycle plated parts by employing a magnetic force to
remove metals from recycled plastics after it has been
finely powdered. Nanotechnology is another active
research area in Japan. Unitika has applied nanotechnology
to realise a biodegradable polylactic acid compound with
mechanical properties superior to PS, PP and ABS.
JAPAN
Accession no.917826
References and Abstracts
30
© Copyright 2005 Rapra Technology Limited
Item 13
Polymer Materials Science and Engineering
20, No.2, March 2004, p.65-8
Chinese
STUDY OF POLYPROPYLENE DEGRADATION
IN SUPERCRITICAL WATER
Wang Jun; Shen Mei-qing; Gong Yan-ling;
Ma Pei-sheng
Tianjin,University
The degradation of PP in supercritical water was studied
with particular reference to the in
Á uence of conditions such
as temperature, pressure, reaction time and ratio of water
to PP. The results obtained are discussed in relation to the
development of guidelines for degradation of PP and other
waste plastics materials in supercritical water. 8 refs.
CHINA
Accession no.918212
Item 14
Polymer Materials Science and Engineering
20, No.2, March 2004, p.155-7
Chinese
INVESTIGATION OF SORPTION AND
DESORPTION OF SUPERCRITICAL CARBON
DIOXIDE INTO POLYSTYRENE
Chen Cun-she; Xu Hui; Li Xiao-juan
Beijing,University of Technology & Business
The interaction of supercritical carbon dioxide with PS
was investigated systematically. PS
À lms of 0.67 mm
thickness were treated with carbon dioxide at pressures
between 15 MPa and 30 MPa, at temperatures between 40
and 80C and for soaking times between 6 and 10 h. During
carbon dioxide sorption, the formerly transparent PS
samples became opaque. The gravimetric desorption data
were kinetically evaluated, assuming Fickian diffusion.
The sorbed amount of carbon dioxide ranged from 9.7%
(80C, 15 MPa) to 13.5% (40C, 25 MPa). The desorption
diffusivities decreased with decreasing concentrations of
carbon dioxide inside the polymer. 7 refs.
CHINA
Accession no.918236
Item 15
Journal of Materials Chemistry
14, No.11, 7th June 2004, p.1663-78
MATERIALS PROCESSING IN SUPERCRITICAL
CARBON DIOXIDE: SURFACTANTS,
POLYMERS AND BIOMATERIALS
Woods H M; Silva M M C G; Nouvel C; Shakesheff K
M; Howdle S M
Nottingham,University
Supercritical carbon dioxide (scCO2) is a unique solvent
with a wide range of interesting properties. Recent
advances in the use of scCO2 in materials synthesis
and materials processing are reviewed. In particular, the
advances made in three major areas are considered. First of
all, the design and application of new surfactants for use in
scCO2 which enable the production of metal nanoparticles,
porous polymers and polymers of high molecular weight
with excellent morphology. Secondly, the development of
new polymer processing and polymer blend technologies
in scCO2 which enable the synthesis of some very complex
polymer composites and blends. Finally, the application of
scCO2 in the preparation of novel biomedical materials,
e.g. biodegradable polymer particles and scaffolds. The
examples described highlight the fact that scCO2 allows
facile synthesis and processing of materials, leading to
new products with properties that would otherwise be very
dif
À cult to achieve. 180 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.917005
Item 16
Macromolecules
37, No.10, 18th May 2004, p.3564-8
EFFECTS OF PRESSURE AND TEMPERATURE
ON THE KINETICS OF L-LACTIDE
POLYMERIZATION IN SUPERCRITICAL
CHLORODIFLUOROMETHANE
Pack J W; Kim S H; Park S Y; Lee Y-W; Kim Y H
Korea,Institute of Science & Technology;
Seoul,National University
The ring-opening polymerisation of L-lactide initiated
by stannous 2-ethylhexanoate in the presence or absence
of 1-dodecanol in supercritical chlorodi
Á uoromethane
was studied at a range of pressures and temperatures, and
the polymers characterised by GPC (molecular weight,
polydispersity). The effects of pressure and temperature
on polymerisation kinetics are discussed. 37 refs.
KOREA
Accession no.917051
Item 17
Journal of Applied Polymer Science
92, No.4, 15th May 2004, p.2363-8
DEPOLYMERIZATION OF
POLY(TRIMETHYLENE TEREPHTHALATE) IN
SUPERCRITICAL METHANOL
Hao-Hong Zhang; Hong-Wei Xiang; Yong Yang; Yuan-
Yuan Xu; Yong-Wang Li
Chinese Academy of Sciences
The depolymerisation of poly(trimethylene terephthalate)
(PTT) was carried out in supercritical methanol in a batch
reactor at temperatures between 280 and 340C, at pressures
between 2.0 and 14.0 MPa and a reaction time of up to
60 min. The degradation products of PTT were dimethyl
terephthalate (DMT) and 1,3-propane diol (PDO). The
yields of DMT and PDO increased greatly with increasing
temperature and the monomer yields increased with
increasing pressure up to 10 MPa and then levelled off at
References and Abstracts
© Copyright 2005 Rapra Technology Limited
31
higher pressures. PTT seemed to completely depolymerise
to monomers at 320C after 30 min or more. The
À nal
yields of DMT and PDO at 320C and 10.0 MPa with a
10:1 weight ratio of methanol to PTT reached 98.2%. A
kinetic model for the simulation of the depolymerisation
reaction agreed well with the experimental data. In this
model, the scission of one PTT ester linkage by a methanol
molecule resulted in the formation of one carboxymethyl
group and one hydroxyl group. 29 refs.
CHINA
Accession no.917303
Item 18
Macromolecules
37, No.7, 6th April 2004, p.2450-3
ENZYME-CATALYZED RING-OPENING
POLYMERIZATION OF EPSILON-
CAPROLACTONE IN SUPERCRITICAL
CARBON DIOXIDE
Loeker F C; Duxbury C J; Kumar R; Wei Gao;
Gross R A; Howdle S M
Nottingham,University; Brooklyn,Polytechnic
University
The ring-opening polymerisation of epsilon-caprolactone
was carried out in supercritical carbon dioxide using an
enzyme catalyst (Novozym-435, which is lipase B from
Candida antarctica supported on macroporous beads).
The molecular weights of the poly(epsilon-caprolactone)
obtained were very similar to those obtained using toluene
but in supercritical carbon dioxide, the polydispersity of
the polymer was lower and the yields were higher. The
enzyme catalyst could be cleaned and recycled using
supercritical carbon dioxide while still producing a high
molecular weight polymer. Thus, it was not necessary to
use organic solvents. 34 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; USA;
WESTERN EUROPE
Accession no.917368
Item 19
Journal of Cellular Plastics
40, No.3, May 2004, p.229-41
SUPERCRITICAL CO2 PROCESSED
POLYSTYRENE NANOCOMPOSITE FOAMS
Strauss W; D’Souza N A
North Texas,University
The preparation of cellular PS nanocomposites containing
various amounts of montmorillonite-layered silicate using
carbon dioxide supercritical
Á uid, as a solvent and blowing
agent, is reported. The characterisation of compression
moulded laminates based on the foams by scanning
electron microscopy, DSC and X-ray diffraction is also
reported. The effects of the silicate on foam nucleation,
growth and microstructure are assessed and the thermal
properties of the nanocomposite foams before and after
processing tabulated. 24 refs. (SAMPE 2003, Long Beach,
California; ANTEC 2003, Nashville, Tennessee, 4-8 May,
2003)
USA
Accession no.916790
Item 20
Polymer Science Series B
46, No.3-4, March-April 2004, p.61-5
COPOLYMERIZATION OF PROPYLENE
OXIDE AND CARBON DIOXIDE UNDER
SUPERCRITICAL CONDITIONS
Rakhimov T V; Said-Galiev E E; Vinokur R A;
Nikitin L N; Khokhlov A R; Il’in V V; Nysenko Z N;
Sakharov A M; Schaumberg K
Moscow,Institute of Organoelement Compounds;
Moscow,Institute of Organic Chemistry;
Roskilde,University
The copolymerisation of propylene oxide with supercritical
carbon dioxide using zinc adipate as catalyst was
investigated at different comonomer ratios. The product
poly(propylene carbonate) was characterised by proton
NMR (copolymer structure) and GPC (molecular
weight), and the effects of carbon dioxide concentration
on copolymer yield and polydispersity are discussed. 21
refs.
DENMARK; EU; EUROPEAN COMMUNITY; EUROPEAN
UNION; RUSSIA; SCANDINAVIA; WESTERN EUROPE;
WESTERN EUROPE-GENERAL
Accession no.915631
Item 21
ANTEC 2003. Proceedings of the 61st SPE Annual
Conference held Nashville, Tn., 4th-8th May 2003.
Brook
À eld, Ct., SPE, 2003, Volume 1-Processing
Session T7-Polymerisation Catalysis and Application of
New Polymers, p.1794-8, CD-ROM, 012
KINETIC STUDY OF THE POLYMERIZATION
OF METHYL METHACRYLATE UNDER
SUPERCRITICAL FLUID CO2
Lu S; Zhang Z; Nawaby A V; Day M
Canada,National Research Council
(SPE)
High pressure differential scanning calorimetry was
used to study the kinetics of the in-situ polymerisation of
methyl methacrylate using supercritical carbon dioxide as
solvent and benzoyl peroxide as initiator. The steady state
polymerisation obeyed
À rst-order reaction kinetics, with
rates similar to those observed for polymerisation in air, but
the molecular weight 34% was higher. The polymerisation
kinetics increased and the induction time decreased with
increasing initiator concentration. 14 refs.
CANADA
Accession no.915676
References and Abstracts
32
© Copyright 2005 Rapra Technology Limited
Item 22
ANTEC 2003. Proceedings of the 61st SPE Annual
Conference held Nashville, Tn., 4th-8th May 2003.
Brook
À eld, Ct., SPE, 2003, Volume 1-Processing
Session W7-Thermoplastic Foams Applications Part I,
p.1812-6, CD-ROM, 012
EFFECT OF MONTMORILLONITE ON
FORMATION OF POLYSTYRENE FOAMS
USING SUPERCRITICAL CO2
Strauss W; Ranade A; D’Souza N A; Reidy R F;
Paceley M
North Texas,University
(SPE)
Styrene monomer, benzoyl peroxide initiator and
various concentrations of montmorillonite clay were
mixed and heated to initiate in-situ polymerisation. The
nanocomposites were compression moulded into sheets
of 1.1 mm thickness, which were immersed in liquid
carbon dioxide at temperatures in the range 60-85 C at
pressures of 7.6-12.0 MPa. After soaking for a set time,
the pressure was reduced to atmospheric and the samples
cooled at a rate of 1 C/min to room temperature. Rapid
carbon dioxide absorption rates were observed, compared
with polystyrene, and foams were successfully prepared
at temperatures in the range 75-85 C, at pressures of 8-12
MPa. The key process parameters were temperature and
depressurisation rate. The cell morphology was strongly
dependent upon the clay concentration and dispersion,
and preferred orientation was observed round the foam
cells. 24 refs.
USA
Accession no.915679
Item 23
Journal of Applied Polymer Science
92, No.3, 5th May 2004, p.2008-12
EFFECT OF SUPERCRITICAL CARBON
DIOXIDE DYEING CONDITIONS ON THE
CHEMICAL AND MORPHOLOGICAL CHANGES
OF POLY(ETHYLENE TEREPHTHALATE)
FIBERS
Hou A; Xie K; Dai J
Shanghai,Donghua University
The effects of supercritical carbon dioxide dyeing
conditions at various temperatures on the chemical and
morphological properties of poly(ethylene terephthalate)
À bres were investigated using FTIR, x-ray diffraction,
DSC and SEM. The results are discussed in terms of
changes in crystal size, melting temperature, crystallinity
and surface morphology. 14 refs.
CHINA
Accession no.914028
Item 24
Polyurethanes Expo 2003. Proceedings of a conference
held Orlando, Florida, 1st-3rd Oct.2003.
Arlington, VA, Alliance for the Polyurethanes Industry,
2003, p.61-6, 28 cm, 012
SUPERCRITICAL OR SUBCRITICAL CO2
ASSISTED WATER BLOWN SPRAY FOAMS
Ohnuma Y; Mori J
Achilles Corp.
(American Plastics Council; Alliance for the
Polyurethanes Industry)
In Japan, spray foams occupy about 40 % of the rigid
PU (PUR) foam market. HCFC-141b used as a blowing
agent in this segment is scheduled to be phased out by
the end of 2003. Potential substitutes include HFC-245fa,
HCF-365mfc and water. The Ministry of Economy,
Trade & Industry commenced research on recovery and
processing technology of CFCs from thermal insulations
for building in 2001. The bank of CFCs in existing rigid
PUR foams has been estimated at 29,000 to 36,000
tonnes; there is greater interest in all water or hydrocarbon
blown foams. Japanese spray foams are mostly used in
the building envelope area where thermal conductivity is
not the most critical requirement, so water is considered
to be the preferred blowing agent. All water blown PUR
foams suffer from poor dimensional stability and poor
adhesion to substrates besides high thermal conductivity.
Rigid polyisocyanurate (PIR) spray foams using aromatic
polyester polyol are widely used in Japan. In this case, if
water is used, B-component degradation occurs in a short
period. An attempt is made to solve these dif
À culties using
supercritical or subcritical CO2. With some equipment
modification, proprietary water blown spray systems
are developed. Adding 1.5% of CO2, isotropic cells are
obtained which lead to dimensionally stable foams at the
density comparable to HCFC-141b blown foams. Not
only is a conventional foam system developed, but also
an aromatic polyester polyol-based
Á ame-retardant foam
system in which water is added as a separate stream.
These foams can be processed as well as HCFC-141b
blown foams and good adhesion is shown even at low
temperature. 4 refs.
JAPAN
Accession no.914048
Item 25
Materials World
12, No.7, July 2004, p.9-10
ROSTI MEDICAL PLASTICS ANNOUNCES
CUTTING EDGE POLYMER ENGINEERING
Wilkes S
Hard-Plas is a unique polymer hardening process
developed by Rosti that looks set to take on products
that are traditionally manufactured from metals in a wide
variety of
À elds. It is the medical area that will probably be
the
À rst to beneÀ t from the process, as disposable polymer
scalpels hardened using the technique would overcome
References and Abstracts
© Copyright 2005 Rapra Technology Limited
33
problems of possible contamination faced by multiple-
use stainless steel scalpels. The process itself is carried
out within a pressure vessel that can withstand pressures
exceeding 20 bar and temperatures above 120C. The Hard-
Plas process can achieve a surface hardness of at least 7
Mohs or 178 Brinell, equivalent to quartz.
Rosti Medical Plastics
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; WESTERN EUROPE
Accession no.914369
Item 26
ANTEC 2003. Proceedings of the 61st SPE Annual
Conference held Nashville, Tn., 4th-8th May 2003.
Brook
À eld, Ct., SPE, 2003, Volume 1-Processing
Session W5-Recent Advances in Polymer Structure,
Properties and Morphology, p.1610-4, CD-ROM, 012
PROCESSING OF INTRACTABLE POLYMERS
USING HIGH-PRESSURE CARBON DIOXIDE
Garcia-Leiner M; Lesser A J
Massachusetts,University
(SPE)
To facilitate the processing of polymers with high
melt viscosities such as
Á uorinated ethylene-propylene
copolymer, polytetrafluoroethylene and syndiotactic
polystyrene, the feed section of a single screw extruder
was modi
À ed so that the polymer could interact with
carbon dioxide (CO2) under conditions close to or in
the supercritical regime prior to extrusion. It was shown
that cell nucleation was controlled by the diffusion rate
of CO2 in the polymer melt, so that the provision of a
saturation time prior to extrusion facilitated foaming. Cell
nucleation was also enhanced by operating with the die
temperature close to the polymer melting point. Increasing
the saturation pressure gave higher cell densities and
lower average cell sizes. The enhanced processability was
attributed to a plasticisation effect and to a hydrostatic
contribution. 23 refs.
USA
Accession no.914651
Item 27
Macromolecular Bioscience
4, No.3, 15th March 2004, p.340-5
RING-OPENING POLYMERIZATION OF
LACTIDE AND PREPARATION OF ITS
MICROSPHERE IN SUPERCRITICAL FLUIDS
Pack J W; Kim S H; Park S Y; Lee Y-W; Kim Y H
Korea,Institute of Science & Technology;
Seoul,National University
The ring-opening polymerisation of lactide initiated
by stannous octoate was carried out in supercritical
chlorodi
Á uoromethane at various reaction conditions and
reactant concentrations. Polylactide microspheres were
prepared by using a continuous supercritical antisolvent
process. Molecular weights and MWDs were determined
using GPC. Characterisation was also undertaken using
proton NMR and SEM. 20 refs.
KOREA
Accession no.912715
Item 28
Colloid and Polymer Science
282, No.6, April 2004, p.569-74
PRODUCTION OF POLY(METHYL
METHACRYLATE) PARTICLES BY DISPERSION
POLYMERIZATION WITH MERCAPTOPROPYL
TERMINATED POLY(DIMETHYLSILOXANE)
STABILIZER IN SUPERCRITICAL CARBON
DIOXIDE
Fujii S; Minami H; Okubo M
Kobe,University
PMMA particles were produced by dispersion
polymerisation of methyl methacrylate in the presence of
mercaptopropyl-terminated polydimethylsiloxane(MP-
PDMS) in supercritical carbon dioxide with AIBN initiator
at about 30 MPa for 24 h at 65C. The particle diameter
could be controlled in a size range of submicron to micron
by varying MP-PDMS concentration. The MP-PDMS was
shown to work not only as a chain transfer agent but also
as a colloidal stabiliser. 26 refs.
JAPAN
Accession no.912886
Item 29
International Polymer Processing
19, No.1, March 2004, p.77-86
DEVELOPMENT OF A HYBRID SOLID-
MICROCELLULAR CO-INJECTION MOLDING
PROCESS
Turng L-S; Kharbas H
Wisconsin-Madison,University
The development of a hybrid solid-microcellular co-
injection moulding process, which employs a modi
À ed
two-colour injection moulding machine equipped with
an interfacial platen and a supercritical
Á uid unit for
co-injection moulding, is reported. The production of co-
injection moulded PS parts having a microcellular core
encapsulated by a solid skin layer is demonstrated and
the effects of process conditions and core-skin volume
ratios on penetration and morphology of the core are
examined. The cell structure and morphology of the
parts, as determined by scanning electron microscopy, are
compared with microcellular injection moulded PS parts
and the potential bene
À ts of the process are discussed.
24 refs.
USA
Accession no.911353
References and Abstracts
34
© Copyright 2005 Rapra Technology Limited
Item 30
ANTEC 2003. Proceedings of the 61st SPE Annual
Conference held Nashville, Tn., 4th-8th May 2003.
Brook
À eld, Ct., SPE, 2003, Volume 1-Processing
Session T34-Shear Rheology, p.986-90, CD-ROM, 012
RHEOLOGICAL CHANGES IN CO2
IMPREGNATED POLYSTYRENE REINFORCED
WITH NANOCLAYS
Wingert M J; Han X; Zeng C; Li H; Lee L J;
Tomasko D L; Koelling K W
Ohio,State University
(SPE)
The combined effects of montmorillonite and carbon
dioxide additions on the melt rheology of polystyrene (PS)
was studied using an extrusion slit die rheometer. In the
absence of carbon dioxide, the nanocomposite viscosity
increased with increasing clay content. However, the melt
viscosity of PS containing carbon dioxide decreased with
increasing clay content. It was considered that this may
be due to the adsorption of carbon dioxide onto the clay
surface, so lubricating the
Á ow and creating a unique
particle layering structure. 21 refs.
USA
Accession no.911397
Item 31
ANTEC 2003. Proceedings of the 61st SPE Annual
Conference held Nashville, Tn., 4th-8th May 2003.
Brook
À eld, Ct., SPE, 2003, Volume 1-Processing
Session W22-Microcellular Molding, p.686-90, CD-
ROM, 012
MICROCELLULAR INJECTION MOLDING
Turng L-S
Wisconsin-Madison,University
(SPE)
In the microcellular injection moulding process,
supercritical nitrogen or carbon dioxide is introduced
into the polymer melt in the machine barrel. The gas
and polymer phases separate during moulding to
form microcells. The bene
À ts include lower operating
temperatures and pressures, the ability to mould thin walls,
reduced cycle times and improved dimensional stability.
Samples of a variety of polymers and
À ller systems were
prepared by microcellular injection moulding using
nitrogen gas and a range of processing parameters. The
samples were characterised by microstructural studies
and by measurements of mechanical properties. The cell
size decreased with increasing supercritical gas content,
injection speed and melt plastication pressure. The cell size
was signi
À cantly reduced by the presence of exfoliated
nanoclay. The microcellular structure generally resulted
in reductions in tensile, impact and weld line strength.
10 refs.
USA
Accession no.910802
Item 32
ANTEC 2003. Proceedings of the 61st SPE Annual
Conference held Nashville, Tn., 4th-8th May 2003.
Brook
À eld, Ct., SPE, 2003, Volume 1-Processing
Session W22-Microcellular Molding, p.691-5, CD-
ROM, 012
MICROCELLULAR NANOCOMPOSITE
INJECTION MOLDING PROCESS
Yuan M; Turng L-S; Spindler R; Caul
À eld D; Hunt C
Wisconsin-Madison,University; Kaysun Corp.;
US,Dept.of Agriculture,Forest Products Laboratory
(SPE)
Tensile and impact test bars of several polyamides
and polyamide-clay nanocomposites were prepared by
microcellular injection moulding using nitrogen as the
supercritical
Á uid. The presence of the supercritical Á uid
enhanced the clay exfoliation and dispersion during
moulding. Compared with the corresponding microcellular
polyamides, the microcellular nanocomposites exhibited
superior mechanical properties, cell structures and cell
distributions. 4 refs.
USA
Accession no.910803
Item 33
ACS Polymeric Materials: Science and Engineering.
Spring Meeting 2003. Volume 88. Proceedings of a
conference held New Orleans, La., 23rd-27th March
2003.
Washington, D.C., ACS,Div.of Polymeric Materials
Science & Engineering, 2003, p.92-3, CD-ROM, 012
POLYMER-CLAY NANOCOMPOSITES
PREPARED IN SUPERCRITICAL CARBON
DIOXIDE
Garcia-Leiner M; Lesser A J
Massachusetts,University
(ACS,Div.of Polymeric Materials Science & Engng.)
The preparation of nanocomposites based on either
HDPE or polytrimethylene terephthalate and modi
À ed
or unmodified montmorillonite nanoparticles in the
presence of supercritical carbon dioxide is described. The
effects of the clay nanoparticles on the morphology and
crystallisation of the polymers and on the foaming process
are discussed and the in
Á uence of supercritical carbon
dioxide on melt intercalation is assessed. 10 refs.
USA
Accession no.909399
Item 34
Polymer Preprints. Volume 44. Number 1. March
2003. Papers presented at the ACS meeting held New
Orleans,Lo., 23rd-27th March 2003.
Washington, DC, ACS, Div.of Polymer Chemistry,
2003, p.1216-7, 28CM, 012
DEGRADATION OF PET UNDER
SUPERCRITICAL METHANOL
References and Abstracts
© Copyright 2005 Rapra Technology Limited
35
Hanfu Wang; Xiaogang Zhao; Xincai Liu; Yubin Zheng;
Zhongwen Wu; Yunchun Zhou
Jilin,University; Changchun,Institute of Applied
Chemistry
A method for degradation of polyethylene terephthalate,
and recovery of its constituent parts, using degradation/
depolymerisation under supercritical methanol is described.
Recovery of ethylene glycol and dimethyl terephthalate
approached 95 percent, under the correct operating
conditions of the reactor. Polymers and liquids were
characterised by fourier transform infrared spectroscopy
and gas chromatography. 5 refs
CHINA
Accession no.908541
Item 35
Polymer Preprints. Volume 44. Number 1. March
2003. Papers presented at the ACS meeting held New
Orleans,Lo., 23rd-27th March 2003.
Washington, DC, ACS, Div.of Polymer Chemistry,
2003, p.1218-9, 28CM, 012
DEGRADATION OF PBT UNDER
SUPERCRITICAL METHANOL
Hanfu Wang; Yubin Zheng; Zhongwen Wu; Yunchun
Zhou
Jilin,University; Changchun,Institute of Applied
Chemistry
A method for degradation of polybutylene terephthalate,
using degradation/depolymerisation under supercritical
methanol is described. Recovery of a blend of 1,4-butanyldiol
and dimethyl terephthalate as a fluid, and dimethyl
terephthalate as a solid, approached 100 percent under the
correct operating conditions of the reactor. Polymers and
liquids were characterised by fourier transform infrared
spectroscopy and gas chromatography. 2 refs
CHINA
Accession no.908542
Item 36
Journal of Polymer Science: Polymer Chemistry
Edition
42, No.3, 1st Feb.2004, p.416-31
UNIFORM POLYMER IN SYNTHETIC
POLYMER CHEMISTRY
Hatada K; Kitayama T; Ute K; Nishiura T
Fukui,University of Technology
The preparation of uniform polymers, polymers composed
of molecules uniform with regard to molecular weight
and constitution, typically by a combination of living
polymerisation and supercritical
Á uid separation, and their
applications are reviewed. Examples discussed include
the study of complex formation between isotactic and
syndiotactic poly(methyl methacrylate)s using GPC and
NMR. 44 refs.
JAPAN
Accession no.908825
Item 37
Polymer Degradation and Stability
83, No.3, 2004, p.389-93
STUDIES ON THE DECOMPOSITION
BEHAVIOR OF NYLON-66 IN SUPERCRITICAL
WATER
Meng L; Zhang Y; Huang Y; Shibata M; Yosomiya R
Harbin,Institute of Technology; Chiba,Institute of
Technology
Polyamide-6,6 was decomposed in supercritical water and
the decomposition products analysed by gas chromatography
and mass spectroscopy. The effects of reaction conditions
on reaction rate and product yield were examined and the
decomposition of polyamide-6,6 in the presence of adipic
acid studied. Addition of adipic acid was found to result in
an increase in the decomposition rate. 14 refs.
CHINA; JAPAN
Accession no.909009
Item 38
Polymer Degradation and Stability
83, No.3, 2004, p.481-5
DECOMPOSITION REACTIONS OF PLASTIC
MODEL COMPOUNDS IN SUB- AND
SUPERCRITICAL WATER
Shibasaki Y; Kamimori T; Kadokawa J-I; Hatano B;
Tagaya H
Yamagata,University
Model compounds of PEEK and PEK having ether
linkages, such as dibenzyl ether, dinaphthylether, diphenyl
ether, 1,4-diphenoxybenzene and p-phenoxyphenol, were
decomposed in subcritical water and supercritical water
and the optimum conditions required for decomposition
to monomeric compounds investigated. 9 refs.
JAPAN
Accession no.909022
Item 39
Biomaterials
25, No.13, 2004, p.2611-7
GENERATION OF POROUS MICROCELLULAR
85/15 POLYLACTIDE-CO-GLYCOLIDE FOAMS
FOR BIOMEDICAL APPLICATIONS
Singh L; Kumar V; Ratner B D
Washington,University
Porous lactide-glycolide copolymer foams were produced
by the pressure quench method using supercritical carbon
dioxide as the blowing agent. The rate of carbon dioxide
uptake and carbon dioxide equilibrium concentration in
the copolymer at different processing conditions were
studied by performing sorption experiments. The effects
of saturation pressure and temperature on average cell
size and relative density of the resulting foams were also
studied. 17 refs.
USA
Accession no.906946
References and Abstracts
36
© Copyright 2005 Rapra Technology Limited
Item 40
Journal of Materials Science. Materials in Medicine
15, No,2, Feb.2004, p.123-8
LASER STEREOLITHOGRAPHY AND
SUPERCRITICAL FLUID PROCESSING FOR
CUSTOM-DESIGNED IMPLANT FABRICATION
Popov V K; Evseev A V; Ivanov A L; Roginski V V;
Volozhin A I; Howdle S M
Russian Academy of Sciences; Nottingham,University
Details are given of the laser photo polymerisation of
a liquid mixture of polyfunctional acrylic monomer,
photoinitiator and hydroxyapatite. Pure polymeric
and composite materials were fabricated by laser
stereolithography based on images derived from 3-D
computer modelling. The materials were treated with
supercritical carbon dioxide to remove toxic residues and
to improve interconnectivity microporosity. Samples were
implanted to study living tissue response and processes of
osteointegration and osteoinduction. 20 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; RUSSIA; UK;
WESTERN EUROPE
Accession no.906934
Item 41
Cellular Polymers
23, No.1, 2004, p.25-37
MICROCELLULAR FOAMING WITH
SUPERCRITICAL CARBON DIOXIDE IN
INJECTION MOULDING
Goodship V; Stewart R L; Hansell R; Ogur E O; Smith G F
Warwick,University
Commercial systems for microcellular injection moulding
are reviewed. The design considerations for nozzle
systems for microcellular foaming with supercritical
carbon dioxide in injection moulding of polystyrene were
investigated. The results are discussed in terms of the
effects of pressure drop, weight reduction and injection
speed, and recommendations for design modi
À cations
are made. 13 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.906826
Item 42
European Plastics News
31, No.2, Feb.2004, p.16-8
FOAM ADVANTAGE
Smith C
Trexel launched its MuCell microcellular foam moulding
technology in 1997 and is gradually building a worldwide
network of licensees. Polytec Reisselmann is among the
most recent European
À rms to take on the technology, which
it is using to manufacture non-visible structural interior trim
parts for the Porsche Cayenne and VW Tuareg vehicles.
Trexel’s process is based on development work carried
out at MIT during the early 1990s exploring supercritical
Á uids. Under the right circumstances, a relatively uniform
microcellular closed-cell structure can be created. It is this
structure that Trexel claims sets its MuCell technology
apart from alternative internal gas technologies. Sulzer
Chemtech’s Optifoam foam injection moulding process is
based on technology originally developed at IKV. Sulzer
holds exclusive rights to use this technology and plans to
market it as a licence-free alternative to the Trexel MuCell
system. Demag Ergotech has reached an agreement with
Trexel that allows it to supply its Ergocell technology
hardware with a discounted Trexel licence.
TREXEL INC.; SULZER CHEMTECH AG; DEMAG ERGOTECH
GMBH
WORLD
Accession no.906319
Item 43
Patent Number: US 6642330 B2 20031104
SUPERCRITICAL FLUID PRESSURE
SENSITIVE ADHESIVE POLYMERS AND THEIR
PREPARATION
McGinniss V D; Vijayendran B R; Spahr K B;
Shibata K; Yamamoto T
Nitto Denko Corp.
Pressure sensitive adhesive (PSA) polymers, especially
low Tg, high tack, non-polar and polar polymers useful
in formulating PSA, can be solubilised or dispersed
in a supercritical
Á uid (SCF), such as liquid CO2 or
supercritical CO2, using an organic cosolvent, such as
toluene. PSA polymers can be polymerised in SCF
Á uids to
make unique adhesive products. Inclusion of a
Á uorinated
reactant in the SCF polymerisation process yields a PSA
with improved resistance to mineral oil.
USA
Accession no.906285
Item 44
Macromolecular Symposia
No.204, 2003, p.141-9
EFFECT OF SUPERCRITICAL CO2 ON BULK
HYDROGENATION OF NITRILE BUTADIENE
RUBBER CATALYZED BY RHCL(PPH3)3
Li G; Pan Q; Rempel G L; Ng F T T
Waterloo,University
The results are reported of a study of the influence of
supercritical carbon dioxide on the bulk hydrogenation of
nitrile rubber catalysed with RhCl(PPh3)3. The effects of
various parameters, such as reaction time, reaction temperature,
hydrogen pressure, catalyst loading and film thickness,
on the process are examined. A method for measuring the
degree of dissolution or apparent solubility of the catalyst in
supercritical carbon dioxide is also reported. 6 refs. (IUPAC
10th International Symposium on Macromolecule-Metal
Complexes, Moscow, 18th-23rd May, 2003)
CANADA
Accession no.906232
References and Abstracts
© Copyright 2005 Rapra Technology Limited
37
Item 45
Rubber Chemistry and Technology
76, No.4, Sept.-Oct.2003, p.957-68
DEVULCANIZATION OF SULFUR-CURED
ISOPRENE RUBBER IN SUPERCRITICAL
CARBON DIOXIDE
Kojima M; Ogawa K; Mizoshima H; Tosaka M;
Kohjiya S; Ikeda Y
Toyo Tire & Rubber Co.Ltd.; Kyoto,University;
Kyoto,Institute of Technology
The effectiveness of supercritical carbon dioxide as
a swelling solvent in the devulcanisation of unfilled
polyisoprene vulcanisates with different crosslink densities
was evaluated. Devulcanisation was carried out at different
temperatures for a period of 60 min. in the presence of
various devulcanising agents. The effects of cure time and
curing agent on devulcanisation were examined and the
chemical structure of the devulcanised rubber analysed by
NMR spectroscopy. The degradation of the main chains
due to devulcanisation was also examined. 27 refs.
JAPAN
Accession no.906201
Item 46
Polymer
44, No.13, 2003, p.3627-32
THIN FLUOROPOLYMER FILMS AND
NANOPARTICLE COATINGS FROM THE RAPID
EXPANSION OF SUPERCRITICAL CARBON
DIOXIDE SOLUTIONS WITH ELECTROSTATIC
COLLECTION
Fulton J L; Deverman G S; Yonker C R; Grate J W;
De Young J; McClain J B
Paci
À c Northwest National Laboratory; Micell
Technologies
The application of nanometer thick
Á uoropolymer À lms
onto metal and semiconductor substrates is described.
Nanometer-sized polymer particles were generated by
homogeneous nucleation during the rapid expansion of
supercritical
Á uid solutions. Charged nanoparticles were
collected on a solid surface forming uniform coatings
with thicknesses from tens of nanometers to several
micrometers thick. Supercritical carbon dioxide solutions
of three different
Á uoropolymers were used to generate
different types of coatings. 18 refs.
USA
Accession no.905933
Item 47
Journal of Polymer Science: Polymer Physics Edition
42, No.2, 15th Jan.2004, p.280-5
EFFECT OF SUPERCRITICAL CARBON
DIOXIDE ON THE CRYSTALLIZATION AND
MELTING BEHAVIOR OF LINEAR BISPHENOL
A POLYCARBONATE
Xia Liao; Jin Wang; Gang Li; Jiasong He
Beijing,State Key Laboratory of Engineering Plastic
The crystallisation and melting behaviour of bisphenol A
polycarbonate treated with supercritical carbon dioxide for
various times at a range of temperatures and pressures was
investigated using DSC and wide-angle x-ray diffraction.
The effects of the various processing conditions on the
crystallisation temperature and the multiple melting
behaviour are discussed. 28 refs.
CHINA
Accession no.905893
Item 48
Industrial and Engineering Chemistry Research
42, No.25, 10th Dec.2003, p.6431-56
REVIEW OF CO2 APPLICATIONS IN THE
PROCESSING OF POLYMERS
Tomasko D L; Li H; Liu D; Han X; Wingert M J;
Lee L J; Koelling K W
Ohio,State University
The use of supercritical carbon dioxide as a processing
solvent for the physical processing of polymeric
materials is reviewed. Fundamental properties of carbon
dioxide/polymer systems are discussed with an emphasis
on available data and measurement techniques, the
development of theory or models for a particular property,
and an evaluation of the current state of understanding for
that property. Applications such as impregnation, particle
formation, foaming, blending and injection moulding are
described. 319 refs.
USA
Accession no.904409
Item 49
Journal of Polymer Science: Polymer Chemistry
Edition
42, No.1, 1st Jan.2004, p.173-85
SYNTHESIS OF HYDROPHILIC POLYMERS
IN SUPERCRITICAL CARBON DIOXIDE
IN THE PRESENCE OF A SILOXANE-
BASED MACROMONOMER SURFACTANT:
HETEROGENEOUS POLYMERIZATION OF
1-VINYL-2 PYRROLIDONE
Galia A; Giaconia A; Iaia V; Filardo G
Palermo,University
The free radical, particle forming polymerisation of vinyl
pyrrolidone in supercritical carbon dioxide in the presence
of a reactive polysiloxane surfactant was studied. The
reaction was initiated by the thermal decomposition of
AIBN. The phase behaviour of the mixture was studied
by subjecting the mixture in a high-pressure cell to a
progression of stepwise increases in temperature to
record the pressure temperature pro
À le. The polymers
were characterised by their solubility, yields determined
gravimetrically and particle size determined by SEM. The
polymerisation was followed at various concentrations
of the surfactant, then at various concentration of AIBN
References and Abstracts
38
© Copyright 2005 Rapra Technology Limited
initiator, monomer and at different reaction mixture
densities. The Hildebrand parameter of the
Á uid phase
suggests that vinyl pyrrolidone acts as a cosolvent for the
polysiloxane chains. Analysis of the kinetics suggested
that, for this system, a nucleation mechanism different to
that proposed for pure dispersion polymerisation processes
was involved. 33 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.904133
Item 50
Journal of Materials Chemistry
13, No.11, Nov.2003, p.2838-44
THE PREPARATION OF NOVEL NANO-
STRUCTURED POLYMER BLENDS OF ULTRA
HIGH MOLECULAR WEIGHT POLYETHYLENE
WITH POLYMETHACRYLATES USING
SUPERCRITICAL CARBON DIOXIDE
Busby A J; Zhang J; Naylor A; Roberts C J;
Davies M C; Tendler S J B; Howdle S M
Nottingham,University
Several methacrylates were polymerised in an ultrahigh
molec.wt. PE matrix using supercritical carbon dioxide
and the in
Á uence of side chain length on the loading
of the methacrylate phase and the morphology of the
resulting polymer blends investigated. It was found that the
methacrylates were located in nanoscalar phase separated
domains within the PE and that these blends could not
be fabricated in the absence of the supercritical carbon
dioxide. 35 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.901742
Item 51
Polymer Preprints. Volume 44. Number 1. March 2003.
Papers presented at the ACS meeting held New Orleans,
La., 23rd-27th March 2003.
Washington, D.C., ACS,Division of Polymer Chemistry,
2003, p.744-5, 28cm, 012
SOLID STATE POLYMERIZATION
OF POLYBISPHENOL A CARBONATE
FACILITATED BY SUPERCRITICAL CARBON
DIOXIDE
Shi C; Gross S M; DeSimone J M; Roberts G W;
Kiserow D J
North Carolina,State University; Micell Technologies
(ACS,Div.of Polymer Chemistry)
Details are given of the reaction kinetics of the solid-
state polymerisation of polycarbonate with supercritical
carbon dioxide as the sweep fluid. Reaction rate
constants and phenol diffusivity in the polymer were
determined and compared with results obtained for
solid-state polymerisation with nitrogen as the sweep
gas. The controlling reaction mechanism under different
polymerisation conditions was determined by comparing
the activation energies for chemical reaction and phenol
diffusion. 9 refs.
USA
Accession no.901299
Item 52
Polymer Preprints. Volume 44. Number 1. March 2003.
Papers presented at the ACS meeting held New Orleans,
La., 23rd-27th March 2003.
Washington, D.C., ACS,Division of Polymer Chemistry,
2003, p.738-9, 28cm, 012
CHEMICAL RECYCLING OF
POLYCARBONATES WITH (SUPERCRITICAL)
AMMONIA
Mormann W; Spitzer D
Siegen,Universitat
(ACS,Div.of Polymer Chemistry)
The behaviour of aliphatic and aromatic polycarbonates
towards liquid and supercritical ammonia was investigated.
The use of ammonolysis for the chemical recycling of
bisphenol-A polycarbonate-containing composites such as
compact disks or car windows is discussed. 5 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.901296
Item 53
Macromolecules
36, No.19, 23rd Sept.2003, p.6967-9
SUPERCRITICAL CARBON DIOXIDE-
MEDIATED INTERCALATION OF PEO IN CLAY
Qian Zhao; Samulski E T
North Carolina,University
A model system of polyethylene oxide (PEO) and sodium
montmorillonite was utilised to provide unambiguous
evidence for the supercritical carbon dioxide (scCO2)
mediated intercalation of the polymer into silicate
nanolayers. X-ray diffraction, differential scanning
calorimetry and thermogravimetric analysis were used to
examine the model system, and the swelling of PEO in
scCO2 indicated the strong plasticising effect of the CO2,
indicating an enthalpically driven intercalation mechanism
similar to that found during melt intercalation. 26 refs.
USA
Accession no.901148
Item 54
Colloid and Polymer Science
281, No.10, Oct.2003, p964-72
PRODUCTION OF POLYACRYLONITRILE
PARTICLES BY PRECIPITATION
POLYMERIZATION IN SUPERCRITICAL
CARBON DIOXIDE
Okubo M; Fujii S; Maenaka H; Minami H
References and Abstracts
© Copyright 2005 Rapra Technology Limited
39
Kobe,University
Polyacrylonitrile particles were produced by precipitation
polymerisation of acrylonitrile in supercritical carbon
dioxide. The effects of initiation rate of the polymerisation
and acrylonitrile concentration on the conversion, the
Á uidity of powder, the degree of coagulation, the viscosity-
average molecular weight and the crystallinity were
examined in detail. 41 refs.
JAPAN
Accession no.900163
Item 55
Journal of Applied Polymer Science
90, No.8, 21st Nov.2003, p.2040-4
SUPERCRITICAL CO2-ASSISTED SYNTHESIS
OF POLY(ACRYLIC ACID)/NYLON1212 BLEND
Chang Y; Xu Q; Liu M; Wang Y; Zhao Q
Zhengzhou,University
Blends of polyacrylic acid and polyamide-12,12 were
prepared by the infusion of acrylic acid into and radical
polymerisation within the polyamide-12,12 using
supercritical carbon dioxide as a substrate-swelling agent
and monomer/initiator carrier and characterised by DSC,
FTIR spectroscopy and scanning electron microscopy. The
sorption of carbon dioxide into the polyamide-12,12 and
effects of impregnation conditions on the preparation of
the blends investigated. 24 refs.
CHINA
Accession no.899792
Item 56
Modern Plastics International
33, No.11, Nov.2003, p.18
NEW WAY TO RECYCLE AUTO PLASTICS
A group of seven industrial
À rms led by the Fraunhofer
Institute for Chemical Technology has developed an
economical and safer way to recycle PE fuel tanks from
end-of-life vehicles. Over the course of their working
lives, the tanks absorb up to 5% of their weight in gasoline
or diesel. The research group is studying the use of
supercritical carbon dioxide to separate fuel from plastic,
it is brie
Á y reported. The shredded fuel tanks are placed
in pressurised vessels and diffused with CO2 gas. At a
speci
À c pressure and temperature, the gas acts as a highly
ef
À cient solvent, extracting the fuel that has inÀ ltrated
the plastic.
FRAUNHOFER-INSTITUT FUER CHEMISCHE TECHNOLOGIE
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.898687
Item 57
Macromolecules
36, No.16, 12th Aug.2003, p.5908-11
SUSPENSION POLYMERIZATION OF L-
LACTIDE IN SUPERCRITICAL CARBON
DIOXIDE IN THE PRESENCE OF A TRIBLOCK
COPOLYMER STABILIZER
Bratton D; Brown M; Howdle S M
Nottingham,University; Smith & Nephew
Details are given of the preparation of a well-de
À ned
Á uorinated triblock copolymer surfactant for suspension
polymerisation of polylactide in supercritical carbon
dioxide. Data concerning the ether-caprolactone copolymer
and their interaction with polylactide particles in suspension
polymerisation are discussed. Molecular structures and
morphological properties were determined. 27 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.898508
Item 58
Journal of Applied Polymer Science
90, No.4, 24th Oct.2003, p.1113-6
PREPARATION OF CONDUCTING
COMPOSITES OF POLYPYRROLE USING
SUPERCRITICAL CARBON DIOXIDE
Abbett K F; Teja A S; Kowalik J; Tolbert L
Georgia,Institute of Technology
Pyrrole was polymerised in several host polymers (PCTFE,
crosslinked PDMS, PMMA and porous crosslinked PS)
using supercritical carbon dioxide as the transport medium
and reaction medium for in-situ polymerisation and the
morphology and electrical conductivity of the resulting
composites determined. It was found that conductive
composites were formed using PMMA and porous
crosslinked PS as host polymers, the level of pyrrole
polymerised on the surface or in the pores of the host
polymer being suf
À cient to produce the interconnected
conducting polymer networks. 17 refs.
USA
Accession no.898131
Item 59
Macromolecules
36, No.13, 1st July 2003, p.4779-85
DISPERSION POLYMERIZATION OF MMA
IN SUPERCOOLED CARBON DIOXIDE
IN THE PRESENCE OF COPOLYMERS
OF PERFLUOROOCTYLETHYLENE
METHACRYLATE AND POLY(PROPYLENE
GLYCOL) METHACRYLATE
Lunhan Ding; Olesik S V
Ohio,State University
Radical copolymerisation was used to prepare a
series of random copolymer dispersants based on
perfluorooctylethylene methacrylate and propylene
References and Abstracts
40
© Copyright 2005 Rapra Technology Limited
glycol methacrylate. These dispersants were then used
for the dispersion polymerisation of methyl methacrylate
in supercritical carbon dioxide. Yield and morphology
of the resulting polymethyl methacrylate was shown to
have a high dependence on composition of the dispersant
The effects on the polymerisation process of varying
dispersant and monomer concentrations, and the reaction
pressure were also examined. Polymers were characterised
using scanning electron microscopy, nuclear magnetic
resonance spectroscopy, dynamic light scattering and high
performance liquid chromatography. 25 refs.
USA
Accession no.897575
Item 60
European Polymer Journal
39, No.9, Sept.2003, p.1785-90
THE POLYMERISATION OF FUNCTIONALISED
METHACRYLATE MONOMERS IN
SUPERCRITICAL CARBON DIOXIDE
Giles M R; Grif
À ths R M T; Irvine D J; Howdle S M
Nottingham,University
I s o b o r n y l m e t h a c r y l a t e a n d p o l y ( e t h y l e n e
glycol)methacrylate were homopolymerised in
supercritical carbon dioxide and copolymerised with
methyl methacrylate using, as stabiliser systems,
poly(dimethyl siloxane) monomethylacrylate and Krytox
157FSL. The effects of initiator (AIBN) concentration
and copolymer composition on polymer and copolymer
properties, such as solubility, were examined and the
performance of the stabilisers compared. 24 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.896214
Item 61
Polymer
44, No.18, 2003, p.5449-54
SUPERCRITICAL CARBON DIOXIDE-ASSISTED
SYNTHESIS OF POLY(ACRYLIC ACID)/NYLON6
AND POLYSTYRENE/NYLON6 BLENDS
Qun Xu; Yuning Chang; Jinling He; Buxing Han;
Yukun Liu
Zhengzhou,University; Chinese Academy of Sciences
Poly(acrylic acid)/nylon 6 and PS/nylon 6 blends were
prepared by the infusion of acrylic acid or styrene into,
and radical polymerisation within, solid nylon 6 using
supercritical carbon dioxide as a carrier. The content of
the incorporated polymers could be controlled by adjusting
the reaction conditions. The poly(acrylic acid)/nylon 6
blend had better thermal stability than the original nylon
6. Supercritical carbon dioxide-induced crystallisation
was found in carbon dioxide-treated nylon 6 and blend
samples. 25 refs.
CHINA
Accession no.895482
Item 62
ACS Polymeric Materials: Science and Engineering.
Fall Meeting 2002. Volume 87. Proceedings of a
conference held Boston, Ma., 18th-22nd Aug. 2002.
Washington, D.C., ACS,Div.of Polymeric Materials
Science & Engng., 2002, p.409-10, CD-ROM, 012
TOTALLY “DRY” MICROLITHOGRAPHY IN
CARBON DIOXIDE
Flowers D; Hoggan E; Carbonell R G; DeSimone J M
North Carolina,University; North Carolina,State
University
(ACS,Div.of Polymeric Materials Science & Engng.)
It is proposed that the use of carbon dioxide for the
manufacture of integrated circuits would reduce the
environmental, wetting and image collapse problems
associated with current solvents, whilst acting as a good
solvent for the highly
Á uorinated polymers proposed for
157 nm photolithography. Liquid carbon dioxide solutions
of a random copolymer of per
Á uorooctylmethacrylate and
tetrahydropyranyl methacrylate (a 193 nm resist system)
were used to spin-coat wafers, using ionic and non-ionic
photoacid generators (PAG). It is shown that CO2 was
able to replace organic and aqueous solvents at each step
of the microlithography process. When used in conjunction
with an ionic PAG, the system was able to produce images
which were developed and stripped in CO2. 5 refs.
USA
Accession no.895291
Item 63
Advanced Materials
15, No.13, 4th July 2003, p.1049-59
POROUS MATERIALS AND SUPERCRITICAL
FLUIDS
Cooper A I
Liverpool,University
Porous materials are used in a wide variety of applications,
including catalysis, chemical separation and tissue
engineering. The synthesis and processing of these
materials is frequently solvent intensive. In addition to
reducing organic solvent emissions, supercritical
Á uids
(SCFs) offer a number of speci
À c physical, chemical and
toxicological advantages as alternative solvents for the
production of functional porous materials. The review
shows that there is number of speci
À c beneÀ ts that can
be derived from the use of supercritical
Á uids for the
synthesis and modi
À cation of porous materials. SCFs are
useful for the production of microcellular foams, both
by expansion and by using crystallisation or anti-solvent
phase separation routes. In the case of biocomposite
foams, the introduction of toxic solvent residues into the
À nal product can be avoided. The potential of reducing
organic solvent usage in the production of porous materials
and composites is offered. This is particularly important
for processes that currently use large volumes of organic
solvents. SCF routes to porous materials that exploit more
than one of these speci
À c advantages are likely to be
References and Abstracts
© Copyright 2005 Rapra Technology Limited
41
pro
À table subjects for future research. 126 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.895234
Item 64
Blowing Agents and Foaming Processes 2003.
Proceedings of a conference held Munich, Germany,
19th-20th May 2003.
Shawbury, Rapra Technology Ltd., 2003, Paper 11,
p.101-25, 29 cm, 012
NEW DEVELOPMENTS IN MUCELL MARKETS
Traut H
Trexel
(Rapra Technology Ltd.)
The latest developments and commercial applications
of the MuCell microcellular foam injection moulding
process are presented. In particular, advancements in the
MuCell screw design combined with the simple ability to
upgrade a standard electric or hydraulic injection moulding
machine into a fully capable MuCell moulding machine
are described. The MuCell process has been adopted as a
core plastics manufacturing technology to achieve higher
productivity weight reduction, quality improvement and
cost savings. The microcellular foam injection moulding
process results in plastic components that are lighter,
Á atter, straighter and more dimensionally stable at extreme
operating temperatures compared to conventionally
moulded parts. The MuCell process can be applied to a
wide variety of
À lled and unÀ lled materials, including many
high temperature engineering resins and thermoplastic
elastomers (TPEs). Today there are MuCell products in
various markets, including automotive, business equipment,
electric/electronic, consumer and medical industries. The
MuCell process uses supercritical
Á uids (SCF) of inert gases,
typically nitrogen or carbon dioxide, to evenly distributed
and uniformly sized microscopic cells throughout a polymer.
In injection moulding the microcellular foam process
enhances product design, improves processing ef
À ciency
and reduces costs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.895001
Item 65
Polymer Composites
24, No.4, Aug.2003, p.545-54
EVALUATING THE MECHANICAL
PERFORMANCE OF SUPERCRITICAL CO2
FABRICATED POLYAMIDE 6,6/PMMA, FIBER
REINFORCED COMPOSITES
Caskey T C; Lesser A J; McCarthy T J
Massachusetts,University
The mechanical properties of a polyamide-6,6
À bre/PMMA
composite made by a novel supercritical carbon dioxide
assisted process under compressive force were investigated.
Tests were carried out to determine the
Á exural and tensile
properties of the composites and an analysis was made of
the evolution of damage and energy dissipation using a
combination of cyclic loading and optical microscopy of
post-stressed composite cross-sections. The relationship
between the structure and properties of the composites was
also analysed to provide a better understanding of the overall
performance of the composites. 16 refs.
USA
Accession no.894131
Item 66
Macromolecules
36, No.9, 6th May 2003, p.3380-5
QUANTIFYING PLASTICIZATION AND
MELTING BEHAVIOR OF POLY(VINYLIDENE
FLUORIDE) IN SUPERCRITICAL CARBON
DIOXIDE UTILIZING A LINEAR VARIABLE
DIFFERENTIAL TRANSFORMER
Shenoy S L; Fujiwara T; Wynne K J
Virginia,Commonwealth University
The plasticisation and melting behaviour of PVDF in
supercritical carbon dioxide were studied by measuring
linear dilation as a function of temperature (75-130C) and
pressure (138-670 bar) using a linear variable differential
transformer. In constant temperature experiments at 75
and 99C, the carbon dioxide density or solvent quality
determined the degree of swelling. At lower pressures,
the rate of change of dilation with pressure increased
rapidly up to 414 bar and then attenuated. At 117 and
130C, the rate of change of dilation with pressure was
almost linear. Reasons for the higher swelling of PVDF
above 100C were discussed. PVDF swelling was measured
as a function of temperature at constant pressure. With
increasing pressure, the melting temperature decreased to
a minimum of 135C at 483 bar. Above 483 bar, hydrostatic
effects predominated over plasticisation and the melting
temperature increased. 54 refs.
USA
Accession no.893374
Item 67
Polymer
44, No.14, June 2003, p.3803-9
HOMO AND COPOLYMERISATION OF 2-
(DIMETHYLAMINO)ETHYL METHACRYLATE
IN SUPERCRITICAL CARBON DIOXIDE
Wenxin Wang; Giles M R; Bratton D; Irvine D J; Armes
S P; Weaver J V W; Howdle S M
Nottingham,University; Uniqema; Sussex,University
The free-radical dispersion homopolymerisation of
2-(dimethylamino)ethyl methacrylate(DMA) and
copolymerisation of DMA with methyl methacrylate(MMA)
in supercritical carbon dioxide were studied. The
polymerisations were performed in the presence of two
commercially-available stabilisers, poly(dimethylsiloxane)
References and Abstracts
42
© Copyright 2005 Rapra Technology Limited
monomethacrylate macromonomer and the carboxylic
acid-terminated per
Á uoropolyether (Krytox 157FSL).
Dry,
À ne powdered polymer product was produced for the
copolymer under optimised conditions, but only aggregated
solid was formed for homo poly(DMA). The effect of
reaction time, stabiliser, copolymer composition and
reaction pressure on the yield, molec.wt. and morphology
of the copolymers was investigated. 31 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.893235
Item 68
Patent Number: US 6590053 B2 20030708
SUPERCRITICAL FLUID PRESSURE
SENSITIVE ADHESIVE POLYMERS AND THEIR
PREPARATION
McGinniss V D; Vijayendran B R; Spahr K B;
Shibata K; Yamamoto T
Nitto Denko Corp.
Pressure sensitive adhesive (PSA) polymers, especially
low Tg, high tack, non-polar and polar polymers, can
be solubilised or dispersed in a supercritical
Á uid, such
as liquid carbon dioxide or supercritical carbon dioxide,
using an organic cosolvent, such as toluene. The polymers
can be polymerized in supercritical
Á uids to make unique
adhesive products. Inclusion of a
Á uorinated reactant in
the polymerisation process yields a pressure-sensitive
adhesive with improved resistance to mineral oil.
USA
Accession no.892878
Item 69
Polymer Engineering and Science
43, No.6, June 2003, p.1261-75
EXTRUSION OF POLYSTYRENE
NANOCOMPOSITE FOAMS WITH
SUPERCRITICAL CARBON DIOXIDE
Han X; Zeng C; Lee L J; Koelling K W; Tomasko D L
Ohio,State University
Intercalated and exfoliated PS-nanoclay composites were
prepared by mechanical blending and in situ polymerisation.
The composites were foamed by using carbon dioxide as
the foaming agent in an extrusion foaming process. Foam
structures were measured. 59 refs.
USA
Accession no.891650
Item 70
Journal of Applied Polymer Science
89, No.3, 18th July 2003, p.742-52
FORMATION OF MICROCAPSULES OF
MEDICINES BY THE RAPID EXPANSION
OF A SUPERCRITICAL SOLUTION WITH A
NONSOLVENT
Matsuyama K; Mishima K; Hayashi K I; Ishikawa H;
Matsuyama H; Harada T
Fukuoka,University; Kyoto Institute of Technology;
Mitsubishi Gas Chemical Co.Inc.
The rapid expansion from a supercritical solution with
a non-solvent(RESS-N) was used to produce polymeric
microcapsules of medicines such as p-acetamidophenol,
acetylsalicylic acid, 1,3-dimethylxanthine,
Á avone and
3-hydroxy
Á avone without agglomeration. The cosolvent
ethanol was much less toxic than most organic solvents and
no surfactant was required. The solubilities of the polymers
(polyethylene glycol(PEG), PMMA, ethylcellulose and
PEG-polypropylene glycol-PEG copolymer) increased
signi
À cantly with addition of a small amount of a lower
alcohol. The microcapsules had a globular form and a fairly
monodispersed particle size distribution. The average
particle diameter and standard deviation of the particle
diameter were 14.6 micrometres and 0.41. The particle size
distribution of the microcapsules could be controlled by
changes in the polymer concentration. It changed very little
with the pre-expansion pressure, temperature, injection
Á ow rate, injection distance and polymer molec.wt. The
feed compositions were more effective than other factors
for controlling the particle size. 44 refs.
JAPAN
Accession no.891295
Item 71
Journal of Polymer Science: Polymer Physics Edition
41, No.12, 15th June 2003, p.1375-83
DRAWING OF ULTRAHIGH MOLECULAR
WEIGHT POLYETHYLENE FIBERS IN THE
PRESENCE OF SUPERCRITICAL CARBON
DIOXIDE
Garcia-Leiner M; Song J; Lesser A J
Amherst,Massachusetts University; US,Army Soldier
Systems Command
The in situ drawing behaviour and the physical and
mechanical properties of ultrahigh molecular weight
polyethylene
À bres drawn uniaxially in supercritical carbon
dioxide are compared to those observed for the process
carried out in air. Signi
À cant differences in thermal and
mechanical properties were observed, and the results of
DSC and wide-angle x-ray scattering studies are discussed
in terms of the crystallinity of the
À bres. 23 refs.
USA
Accession no.889949
Item 72
Journal of Polymer Engineering
23, No.1, Jan.-Feb.2003, p.1-22
RHEOLOGICAL PROPERTIES OF
POLYSTYRENE/SUPERCRITICAL CO2
SOLUTIONS FROM AN EXTRUSION SLIT DIE
Xue A; Tzoganakis C
Waterloo,University
References and Abstracts
© Copyright 2005 Rapra Technology Limited
43
Recent advances in the use of supercritical CO2 (ScCo2) in
polymer processing (i.e. injection moulding and extrusion)
have increased the need for rheological data of polymer/
ScCO2) solutions at high pressures. A slit die with a sudden
contraction is used to investigate the entrance drop as well
as the shear and extensional viscosities of a PS melt and of
a PS/scCO2 solution. Dissolution of CO2 into the PS melt
is shown to reduce its entrance pressure drop as well as its
shear and extensional viscosities. The entrance pressure
drop of PS and PS/CO2 is found to be a strong (exponential)
function of pressure. The entrance pressure drop as a function
of wall shear stress can be
À tted with a master curve for all
experiments at different temperature, pressure and CO2
concentrations. Shear viscosities of PS as well as PS/CO2
are described using the model and the Doolittle equation and
different free volume models are compared. 24 refs.
CANADA
Accession no.889376
Item 73
ISFR 2002. Proceedings of a conference held Ostend,
Belgium, 8th-11th Sept.2002.
Brussels, Belgium, Vrije University, 2002, Paper A39,
pp.4, CD-ROM, 012
DECOMPOSITION REACTIONS OF PLASTICS
AND THEIR MODEL COMPOUNDS IN SUB- AND
SUPERCRITICAL WATER
Tagaya H; Shibasaki Y; Kato C; Kadokawa J; Hatano B
Yamagata,University
(Brussels,Free University; Japan,Research Assn.for
Feedstock Recycling of Plastics)
Plastics such as xylene resin, epoxy resin and
polyetheretherketone resin were decomposed into their
monomers such as phenol and cresols by the thermal
treatment of them in sub- and supercritical water by using
10ml tubing bomb reactor. The addition of basic compounds
such as Na2CO3 was effective on the reaction. In the reaction
of xylene resin, the total yield of identi
À ed products reached
near 40% in the reaction at 703K for 5 h. The reactions of
model compounds containing methylene, ether or carbonyl
bonds suggested the chemical participation of water on the
decomposition reaction of them including the scission of
bonds between aromatic polymer units. 10 refs.
JAPAN
Accession no.889108
Item 74
ISFR 2002. Proceedings of a conference held Ostend,
Belgium, 8th-11th Sept.2002.
Brussels, Belgium, Vrije University, 2002, Paper A33,
pp.4, CD-ROM, 012
DESIGN AND OPTIMISATION OF A
SEPARATION, PURIFICATION AND
UPGRADING PROCESS FOR POLYMERS FROM
ELECTRONIC AND ELECTRIC EQUIPMENT
van Schijndel P P A J; van Kasteren H J M N
Eindhoven,University of Technology
(Brussels,Free University; Japan,Research Assn.for
Feedstock Recycling of Plastics)
This study reports a new route for the recycling of
consumer electronic plastics. Electronic plastics are either
thermoplastic, containing low amounts of additives or
thermo-set, normally containing high amounts of additives
e.g. heavy metals. Upgrading experiments have shown
that thermoplastic electronic parts, like ABS casings,
can be recycled, although mechanical properties have
degraded because of ageing. It is possible to improve these
properties by extruding the recyclates together with certain
silanes. For the thermo-set resins a depolymerisation/
extraction route is proposed, which makes molecular
recycling possible. This depolymerisation/extraction
process is based on the use of supercritical CO2 as
extraction medium, which makes separation of wastes
and pure monomers recovery technical, economical and
environmental feasible. 3 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; WESTERN EUROPE
Accession no.889103
Item 75
Journal of Polymer Science: Polymer Physics Edition
41, No.11, 1st June 2003, p.1143-56
EFFECT OF SUPERCRITICAL CARBON
DIOXIDE ON THE DIFFUSION COEFFICIENT
OF PHENOL IN POLY(BISPHENOL A
CARBONATE
Shi C; Roberts G W; Kiserow D J
North Carolina,State University; US,Army Research
Of
À ce
The diffusion coef
À cient of phenol in poly(bisphenol A
carbonate) was measured during solid state polymerisation
of the polymer under diffusion-limited conditions to establish
the reason for the faster rate of polymerisation in supercritical
carbon dioxide. Phenol diffusivities were determined between
135 and 180C in the presence of atmospheric nitrogen and
supercritical carbon dioxide as sweep
Á uids and diffusion
coef
À cients of condensate molecules calculated from a proÀ le
of molec.wt. versus time. 32 refs.
USA
Accession no.888592
Item 76
Macromolecular Rapid Communications
24, No.7, 7th May 2003, p.457-61
WELL-CONTROLLED BIODEGRADABLE
NANOCOMPOSITE FOAMS. FROM
MICROCELLULAR TO NANOCELLULAR
Fujimoto Y; Ray S S; Okamoto M; Ogami A;
Yamada K; Ueda K
Toyota Technological Institute; Unitika Ltd.
The foaming process of polylactide and polylactide-silicate
nanocomposites were conducted using supercritical carbon
References and Abstracts
44
© Copyright 2005 Rapra Technology Limited
dioxide as a foaming agent. The morphological correlation
between the dispersed silicate particles with nanometer
dimensions in the bulk and the obtained closed-cell
structure of the foam is discussed. 9 refs.
JAPAN
Accession no.888565
Item 77
Chemistry of Materials
15, No.10, 20th May 2003, p.2061-9
STRUCTURAL CONTROL IN POROUS
CROSSLINKED POLYMETHACRYLATE
MONOLITHS USING SUPERCRITICAL
CARBON DIOXIDE AS A PRESSURE-
ADJUSTABLE POROGENIC SOLVENT
Hebb A K; Senoo K; Bhat R; Cooper A I
Liverpool,University
The synthesis of permanently porous, highly crosslinked
polymethacrylate resins using supercritical carbon dioxide
is described. The pressure-adjustable solvent properties
were exploited to
À ne-tune the average pore size and
surface area of the materials. Pore size distributions were
recorded by mercury intrusion porosimetry. Morphologies
were examined using SEM. 71 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.888558
Item 78
Macromolecules
36, No.5, 11th March 2003, p.1603-8
HIGHLY CONCENTRATED, INTERCALATED
SILICATE NANOCOMPOSITES: SYNTHESIS
AND CHARACTERIZATION
Zerda A S; Caskey T C; Lesser A J
Massachusetts,University
Nanocomposites of poly(methyl methacrylate) containing
in excess of 20 wt% organically modi
À ed montmorillonites
were prepared using a custom-made high pressure
apparatus. Monomer, radical initiator and clay were added
to the apparatus along with supercritical carbon dioxide,
which lowered the viscosity of the system, homogeneously
distributed the monomer and facilitated clay intercalation.
The d spacing of intercalated nanocomposites containing
less than 40 wt% clay was commensurate with the
dimensions of the fully extended surfactant chains. Larger
clay additions decreased the d spacing as the composite
volume became saturated with the inorganic material. A
model to estimate this transition concentration is given.
A 50% increase in modulus was obtained for a 40 wt%
clay addition, whilst the glass transition temperature was
unchanged. Orientation achieved by subsequent melt
processing increased the tensile modulus, as determined by
dynamic mechanical thermal analysis, by 220%. 29 refs.
USA
Accession no.888394
Item 79
High Performance Plastics
June 2003, p.8
SUPERCRITICAL CARBON DIOXIDE PROCESS
A novel recycling process for some of the most common
kinds of polymers has been developed by researchers at
North Carolina State University in the USA. This short
article provides scant details of the new process, which
involves the use of supercritical carbon dioxide combined
with ethylene glycol or methanol, which reduces the
viscosity of the polymer to be recycled, making it easier
to process.
NORTH CAROLINA,STATE UNIVERSITY
USA
Accession no.888308
Item 80
Polymer Preprints. Volume 43. Number 2. Fall 2002.
Papers presented at the ACS Meeting held Boston, Ma.,
18th-22nd Aug.2002.
Washington, DC, ACS, Div.of Polymer Chemistry,
2002, p.1252-3, 28cm, 012
TREATMENT OF PEEK UNDER
SUPERCRITICAL ETHANOL
Hanfu Wang; Xincai Liu; Liang Chen; Zhongwen Wu;
Yunchun Zhou
Jilin,University; Changchun,Institute of Applied
Chemistry
(ACS,Div.of Polymer Chemistry)
The treatment of PEEK under supercritical ethanol was
studied and the properties of the treated polymer were
examined by techniques such as IR spectroscopy, X-ray
diffraction, DSC and rheological measurements. It was
shown that supercritical
Á uid had an extraction effect
on PEEK and that this effect provided evidence for the
model of melting-recrystallisation with a double melting
peak. 2 refs.
CHINA
Accession no.888084
Item 81
Polymer Preprints. Volume 43. Number 2. Fall 2002.
Papers presented at the ACS Meeting held Boston, Ma.,
18th-22nd Aug.2002.
Washington, DC, ACS, Div.of Polymer Chemistry,
2002, p.956, 28cm, 012
SUPERCRITICAL CO2 POST-PLASTICIZATION
MORPHOLOGIES OF PVDF AND PVDF-
COPOLYMER
Fujiwara T; Shenoy S LWvnne K J
Virginia,Commonwealth University
(ACS,Div.of Polymer Chemistry)
Super-critical CO2 has attracted considerable attention
in polymer processes such as fractionation and swelling
because of its non-toxic, non-corrosive and non-
Á ammable
References and Abstracts
© Copyright 2005 Rapra Technology Limited
45
properties. Processing behaviour as a function of
temperature and pressure has been studied by various
methods. However, there are few studies on the post-
plasticised morphologies. The conformation change of
syndiotactic PS after SCCO2 plasticisation by using X-
ray technique has been reported. Recently, a programme
to study plasticisation of semicrystalline polymers as a
function of pressure and temperature approaching melting
point (Tm) has been initiated. Unique post-plasticised
thermal behaviour is described and the morphologies
of PVDF and PVDF copolymer, vinylidene
Á uoride-
co-5 mol.% hexafluoropropylene (PVDF-HFP), are
investigated. 9 refs.
USA
Accession no.887894
Item 82
Plastics and Rubber Weekly
2nd May 2003, p.9
JYCO SEALING USES MUCELL PROCESS FOR
AUTOMOTIVE FOAM SEALS
Proving that the MuCell microcellular foaming technology
is not just for injection moulders, US-based Jyco Sealing
Technologies is using the process to manufacture
foamed thermoplastic vulcanisate (TPV) weatherstrips
for the automotive sector. According to chief executive
of
À cer Sam Jyawook, the foaming process is critical in
the production of weather seals because an open-cell
structure will not meet the demanding automotive industry
standards. The MuCell technique, which uses supercritical
Á uids to create the foam structure, has proved to give
good control of cell structure, reducing surface porosity
and preventing moisture uptake. MuCell developer Trexel
now has a commercial TPV foaming process. TPVs are
predicted to continue replacing EPDM in weather-seal
applications, where they are claimed to provide easier
recyclability, colourability and improved design
Á exibility.
The company claims its process is consistent in high-
output manufacturing processes with a range of material
formulations.
JYCO SEALING TECHNOLOGIES; TREXELL INC.
USA
Accession no.887869
Item 83
Polymer Preprints. Volume 43. Number 2. Fall 2002.
Papers presented at the ACS Meeting held Boston, Ma.,
18th-22nd Aug.2002.
Washington, DC, ACS,Div.of Polymer Chemistry, 2002,
p.1338, 28cm, 012
MICROCELLULAR FOAMING OF AMORPHOUS
HIGH-TG POLYMER USING CARBON DIOXIDE
Wang D; Jin Y; Jiang Z; Wu Z
Jilin,University
(ACS,Div.of Polymer Chemistry)
The preparation and SEM characterisation of microcellular
foams from high-Tg fluorinated aromatic PEEK are
described. These foams, produced using supercritical
carbon dioxide, as blowing agent, are closed-cell foams
with low dielectric constants and better thermal insulation
properties than their matrix. A SEM micrograph of the
microcellular polymer is illustrated. 4 refs.
CHINA
Accession no.886331
Item 84
Polymer
44, No.8, 2003, p2201-11
CARBOXYLIC ACID END GROUP
MODIFICATION OF POLY(BUTYLENE
TEREPHTHALATE) IN SUPERCRITICAL
FLUIDS
de Gooijer J M; Scheltus M; Jansen M A G; Koning C E
Eindhoven,University of Technology; DSM Research
Modi
À cation of polybutylene terephthalate carboxylic end
groups by 1,2-epoxybutane was carried out at different
temperatures and pressures in supercritical carbon dioxide,
and mixtures of this with an added 10 mol percent of
dioxane. Highest modi
À cation was achieved in the mixed
solvent at the highest experimental temperature, resulting
in much improved hydrolytic stability of the polymer as
observed by molecular weight measurements and intrinsic
viscosity change with respect to hydrolysis time. An
increase in crystallinity was observed, using differential
scanning calorimetry, due to the plasticising effect of the
mixed solvents. 27 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; WESTERN EUROPE
Accession no.885760
Item 85
Journal of Applied Polymer Science
88, No.9, 31st May 2003, p2189-93
PLASTICISATION OF POLYMERS WITH
SUPERCRITICAL CARBON DIOXIDE:
EXPERIMENTAL DETERMINATION OF GLASS
TRANSITION TEMPERATURES
Alessi P; Cortesi A; Kikic I; Vecchione F
Trieste,University
A method for the study of the plasticisation effect of
supercritical carbon dioxide on polymers, including
polymethyl methacrylate, polystyrene and polycarbonate,
and its effect on glass transition temperature was shown to
be high-pressure partition chromatography, a modi
À cation
to inverse gas chromatography. Experimental results were
compared with published
À gures for each polymer, and
shown to be in good agreement. 14 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.885711
References and Abstracts
46
© Copyright 2005 Rapra Technology Limited
Item 86
European Polymer Journal
39, No.3, March 2003, p.423-8
MONITORING DISPERSION
POLYMERISATIONS OF METHYL
METHACRYLATE IN SUPERCRITICAL
CARBON DIOXIDE
Wang W; Grif
À ths R M T; Giles M R; Williams P;
Howdle S M
Nottingham,University; UK,Health and Safety
Laboratory
Details are given of the development of power compensation
calorimetry equipment to monitor the dispersion
polymerisation of methyl methacrylate in supercritical
carbon dioxide. The effect of initiator concentration and
stabiliser on the reaction was studied and the enthalpy of
polymerisation obtained from the apparatus was found to
correlate with other reported data. 21 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.884200
Item 87
Journal of Applied Polymer Science
88, No.5, 2nd May 2003, p.1393-8
MOLECULAR WEIGHT AND SPINNABILITY
OF POLYACRYLONITRILE PRODUCED BY
PRECIPITATION POLYMERIZATION IN
SUPERCRITICAL CO2
Teng X-R
Tongji,University
Details are given of the precipitation polymerisation of
acrylonitrile in supercritical carbon dioxide. The effects
of monomer and initiator concentration, total reaction
time, temperature and carbon dioxide pressure on polymer
molecular weight were investigated. Processability is
discussed. 25 refs.
CHINA
Accession no.884127
Item 88
Revista de Plasticos Modernos
83, No.550, April 2002, p.409-18
Spanish
POLYMERISATION AND SUPERCRITICAL
SOLVENTS
Trabelsi S; Ajzenberg N; Recasens F
Catalunya,Universitat Politecnica
The characteristics of supercritical
Á uids are examined,
and their possible use as solvents in solution, suspension
and emulsion polymerisation reactions is discussed.
The application of such
Á uids in plastics recycling by
depolymerisation reactions is also considered. 47 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN;
WESTERN EUROPE
Accession no.884067
Item 89
Polymer Preprints. Volume 43. Number 2. Fall 2002.
Papers presented at the ACS Meeting held Boston, Ma.,
18th-22nd Aug.2002.
Washington, D.C., ACS,Div.of Polymer Chemistry,
2002, p.889, 28cm, 012
POLYMERIZATION OF VINYLIDENE
FLUORIDE IN DENSE CARBON DIOXIDE
Wojcinski L M; Saraf M K; Charpentier P;
DeSimone J M; Roberts G W
North Carolina,State University; North Carolina,Chapel
Hill University
(ACS,Div.of Polymer Chemistry)
Vinylidene
Á uoride was polymerised via free radical
precipitation polymerisation in supercritical carbon
dioxide in a continuous stirred tank reactor. The initiator
was diethyl peroxydicarbonate. The resulting PVDF was
highly porous with a novel bimodal molecular weight
distribution which varied with reaction conditions such
as monomer concentration, temperature and pressure.
No refs.
USA
Accession no.883973
Item 90
Polymer Preprints. Volume 43. Number 2. Fall 2002.
Papers presented at the ACS Meeting held Boston, Ma.,
18th-22nd Aug.2002.
Washington, D.C., ACS,Div.of Polymer Chemistry,
2002, p.888, 28cm, 012
SUPERCRITICAL AND LIQUID CARBON
DIOXIDE: POLYMER SWELLING AND
EFFECTS ON MELTING BEHAVIOR
Wynne K J; Shenoy S; Fujiwara T; Irie S;
Woerdeman D; Sebra R; Garach A; McHugh M
Virginia,Commonwealth University
(ACS,Div.of Polymer Chemistry)
A linear variable differential transformer method was used
to measure the dilation of polymer samples by supercritical
and liquid carbon dioxide. Results obtained with SBS,
PS, PMMA and PVDF showed that each polymer had a
characteristic pattern of swelling behaviour. The linear
dilation for SBS was very low and was complicated by
compression. However, “in
Á ation” of the sample occurred
when the pressure was released. The solubility of carbon
dioxide in PS was very low, although the glass transition
temperature was greatly affected. The solubility of
carbon dioxide in PMMA was much greater and the glass
transition temperature of PMMA was also sharply lowered
by supercritical carbon dioxide. Semicrystalline PVDF
showed complex swelling behaviour which was sensitive
to temperature. 7 refs.
USA
Accession no.883972
References and Abstracts
© Copyright 2005 Rapra Technology Limited
47
Item 91
Polymer Preprints. Volume 43. Number 2. Fall 2002.
Papers presented at the ACS Meeting held Boston, Ma.,
18th-22nd Aug.2002.
Washington, D.C., ACS,Div.of Polymer Chemistry,
2002, p.887, 28cm, 012
PLASTICIZATION AND MELTING BEHAVIOR
OF PVDF AND PVDF COPOLYMERS IN
SUPERCRITICAL CARBON DIOXIDE
Shenoy S L; Fujiwara T; Wynne K J
Virginia,Commonwealth University
(ACS,Div.of Polymer Chemistry)
PVDF and poly(vinylidene fluoride-co-4.9 mol%
hexa
Á uoropropylene) were plasticised by supercritical
carbon dioxide. The degree of plasticisation depended
strongly on the temperature and the pressure. The
hexa
Á uoropropylene groups resulted in a much larger
swelling of the copolymer. The melting temperatures of
both the homopolymer and the copolymer were lowered
by polymer-supercritical carbon dioxide interactions.
However, above about 540 bar, there was a modest increase
in the melting temperature due to the hydrostatic pressure.
Thus, the melting behaviour was a balance between the
lowering of the melting temperature due to plasticisation
and increasing it due to the hydrostatic pressure. 12 refs.
USA
Accession no.883971
Item 92
Journal of Applied Polymer Science
88, No.2, 11th April 2003, p.522-30
SURFACE MODIFICATION OF
POLYBUTADIENE FACILITATED BY
SUPERCRITICAL CARBON DIOXIDE
Ngo T T; McCarney J; Brown J S; Lazzaroni M J;
Counts K; Liotta C L; Eckert C A
Georgia,Institute of Technology
The hydrophilicity of polybutadiene was increased by
treating the polymer surface with hydrophilic monomers
(such as 3-vinylbenzoic acid and crotonic acid) in the
presence of a photoinitiator in a supercritical carbon
dioxide environment. The carbon dioxide acted as the
swelling agent for the polymer and the transport medium
for solutes to diffuse on to the polymer surface. The
carbon dioxide pressure had a substantial effect on the
partitioning of the solute between the polymer and the
Á uid phase and a smaller effect on the diffusivity of the
solute onto the polymer surface. Based on these results,
the operating conditions of the process could be optimised
to obtain the required surface properties. The dimerisation
kinetics of carboxylic acids in carbon dioxide solution
were examined. This dimerisation behaviour signi
À cantly
affected the solubility and diffusivity of the acids in
solution. 15 refs.
USA
Accession no.883780
Item 93
Polymer Preprints, Volume 43. Number 2. Fall 2002.
Papers presented at the ACS Meeting held Boston, Ma.,
18th-22nd Aug. 2002.
Washington, DC, ACS,Div. of Polymer Chemistry,
2002, p.938-9, 28 cm, 012
ELECTROCHEMICAL SYNTHESIS AND
CHARACTERIZATION OF CONDUCTING
POLYPYRROLE FILMS IN SUPERCRITICAL
CARBON DIOXIDE
Badlani R N; Mayer J L; Anderson P E; Mabrouk P A
Northeastern University
(ACS,Div.of Polymer Chemistry)
Pyrrole polymers were synthesised by the electrochemical
polymerisation of pyrrole in supercritical carbon dioxide on
gold disks and indium tin oxide/glass working electrodes.
They were characterised by cyclic voltammetry, four-point
probe conductivity, scanning electron microscopy and
UV vis spectroscopy and found to exhibit relatively high
conductivity and distinct surface morphology. 21 refs.
USA
Accession no.883668
Item 94
ANTEC 2002. Proceedings of the 60th SPE Annual
Technical Conference held San Francisco, Ca., 5th-9th
May 2002.
Brook
À eld, Ct., SPE, 2002, Paper 611, Session
W17-Applied Rheology. Wall Slip, Instabilities and
Processing Aids, pp.5, CD-ROM, 012
RHEOLOGY AND EXTRUSION OF CO2
PLASTICIZED ACRYLIC COPOLYMERS
Bortner M J; Baird D G
Virginia,Polytechnic Institute & State University
(SPE)
The reduction of the glass transition temperature (Tg)
and hence the melt viscosity of poly(acrylonitrile-co-
methyl acrylate) (10 mol% methyl acrylate) by the
addition of carbon dioxide, to facilitate melt spinning,
was investigated. Copolymer pellets were saturated with
carbon dioxide in a sealed pressure vessel for various
time periods. Following depressurisation, dynamic and
steady shear measurements were made using a torsional
rheometer, and a modi
À ed capillary rheometer, pressurised
using nitrogen, was used to study both saturated and
unsaturated copolymer. Tg was determined by differential
scanning calorimetry. A reduction of approximately 40%
in melt viscosity was obtained on saturating the copolymer
with carbon dioxide, leading to a reduction in processing
temperature of up to 20 C. 7 refs.
USA
Accession no.883569
References and Abstracts
48
© Copyright 2005 Rapra Technology Limited
Item 95
Journal of Polymer Science: Polymer Physics Edition
41, No.4, 15th Feb.2003, p.368-77
PREPARATION AND CHARACTERIZATION
OF MICROCELLULAR POLYSTYRENE/
POLYSTYRENE IONOMER BLENDS WITH
SUPERCRITICAL CARBON DIOXIDE
Jin Wang; Xingguo Cheng; Xuejing Zheng;
Mingjun Yuan; Jiasong He
Beijing,Institute of Chemistry
Preparation of microcellular PS, lightly sulphonated
PS(SPS), zinc-neutralised lightly sulphonated PS(ZnSPS)
and blends of PS/SPS and PS/ZnSPS via supercritical
carbon dioxide was carried out using the pressure-quench
process. Both higher foaming temperature and lower
pressure resulted in larger cell sizes, lower cell densities
and lower relative density for microcellular ionomers and
blends than for microcellular PS. The difference between
the various microcellular samples was the change of cell
size with the sample composition. The cell size decreased
in the sequence from SPS, through PS/SPS blends, PS and
PS/ZnSPS blends, to ZnSPS. The diffusivity of carbon
dioxide in samples also decreased in the sequence from
SPS, through PS/SPS blends, PS and PS/ZnSPS blends,
to ZnSPS. For this series of samples with similar structure
and identical solubility of carbon dioxide, the varying
diffusivity was responsible for the difference of cell sizes.
36 refs.
CHINA
Accession no.882238
Item 96
Industrial and Engineering Chemistry Research
42, No.3, 5th Feb.2003, p.448-55
DISPERSION COPOLYMERIZATION OF VINYL
MONOMERS IN SUPERCRITICAL CARBON
DIOXIDE
Galia A; Muratore A; Filardo G
Palermo,University
An investigation was carried out into the free-radical
copolymerisation of methyl methacrylate and N,N-
dimethylacrylamide initiated by the thermal decomposition
of AIBN in supercritical carbon dioxide in the presence
of polysiloxane surfactants. The phase behaviour of the
reaction mixture was examined by combining visual
observation of the mixture to the recording of the pressure
trend inside a
À xed-volume view cell during slow heating
and cooling of the reaction mixture. The effects of the
nature of the surfactant, feed composition and surfactant
concentration on dispersion copolymerisation were studied
and the end-use properties of the copolymers evaluated.
24 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.881794
Item 97
Polymer Engineering and Science
43, No.1, Jan.2003, p.157-68
EFFECT OF PROCESS CONDITIONS
ON THE WELD-LINE STRENGTH AND
MICROSTRUCTURE OF MICROCELLULAR
INJECTION MOLDED PARTS
Lih-Sheng Turng; Kharbas H
Wisconsin-Madison,University
The way in which the process conditions affected the weld-
line strength and microstructure of injection-moulded
microcellular parts was investigated. Experimental design
was used and polycarbonate tensile test specimens were
produced for tensile tests and microscopic analysis.
Injection moulding trials were performed by systematically
adjusting four process parameters, i.e. melt temp., shot size,
supercritical
Á uid level and injection speed. Conventional
solid specimens were also produced for comparison. The
TS was measured at the weld line and away from the
weld line. The weld-line strength of injection moulded
microcellular parts was lower than that of its solid
counterparts. It increased with increasing shot size, melt
temp. and injection speed and was weakly dependent
on the supercritical
Á uid level. The microstructures of
the moulded specimens at various cross-sections were
examined using SEM and optical microscopy in order to
study the variation of cell size and density with different
process conditions. 21 refs.
USA
Accession no.881046
Item 98
Journal of Applied Polymer Science
87, No.7, 14th Feb.2003, p.116-22
REACTIVE EXTRUSION OF POLYPROPYLENE
WITH SUPERCRITICAL CARBON DIOXIDE:
FREE RADICAL GRAFTING OF MALEIC
ANHYDRIDE
Dorscht B M; Tzoganakis C
Waterloo,University
Supercritical carbon dioxide was used in a reactive extrusion
process for the peroxide-initiated functionalisation of PP
with maleic anhydride. The use of supercritical carbon
dioxide led to improved free radical grafting of maleic
anhydride on to PP when high levels of maleic anhydride
were used. There was no evidence of improvement
in the homogeneity of the product and melt
Á ow rate
measurements showed a reduction in the degradation of
PP during the grafting reaction when low levels of maleic
anhydride were used. 26 refs.
CANADA
Accession no.880727
References and Abstracts
© Copyright 2005 Rapra Technology Limited
49
Item 99
Advanced Materials
14, No.24, 17th Dec.2002, p.1802-4
INCORPORATION OF PROTEINS INTO
POLYMER MATERIALS BY A NOVEL
SUPERCRITICAL FLUID PROCESSING
METHOD
Watson M S; Whitaker M J; Howdle S M;
Shakesheff K M
Nottingham,University
The preparation of porous tissue engineering poly(D,L-
lactide) scaffolds containing biologically active material
for controlled-release using a combination of solution and
supercritical
Á uid processing, which permits the accurate
dosing of biological agent and provides a very clean
route to porous materials, is described. The controlled
release of avidin tagged with rhodamine using these
scaffolds and retention of biological activity throughout
supercritical carbon dioxide reprocessing using the enzyme
ribonuclease A are demonstrated. 23 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.880165
Item 100
Polymer Preprints. Volume 42. Number 2. Fall 2001.
Papers presented at the ACS meeting held Chicago, Il.,
26th-30th Aug.2001.
Washington, DC, ACS,Div.of Polymer Chemistry, 2001,
p.817, 28cm, 012
POLYMERIZATION OF VINYL CHLORIDE IN
SUPERCRITICAL CARBON DIOXIDE
Li G; Johnston K P; Zhou H; Venumbaka S R;
Cassidy P
Texas,University
(ACS,Div.of Polymer Chemistry)
Details are given of the polymerisation of vinyl chloride
in supercritical carbon dioxide using AIBN as initiator.
Molecular weight was determined using GPC. 5 refs.
USA
Accession no.879641
Item 101
Journal of Polymer Research
9, No.3, 2002, p157-62
STUDY ON THE RHEOLOGICAL BEHAVIOR
OF PP/SUPERCRITICAL CARBON DIOXIDE
MIXTURE
Hung-Yu Lan; Hsieng-Cheng Tseng
Taiwan,National University of Science & Technology
An injection moulding machine was modi
À ed with gas
injection port and special screw to measure the rheological
behaviour of polypropylene (PP) mixed with supercritical
carbon dioxide. A reduction in viscosity of the polymer was
expected, compared to the pure PP, but this was found to
be greatest at low shear rates. As the shear rate increased,
viscosity reduction due to addition of supercritical carbon
dioxide became less. 22 refs.
TAIWAN
Accession no.879404
Item 102
RP Asia 2002: Composites in the global market.
Proceedings of a conference held Kuala Lumpur,
Malaysia, 5th-6th Sept.2002.
Oxford, Elsevier Science Ltd., 2002, Paper 14, p.263-6,
29cm, 012
COMPOSITES WASTE MANAGEMENT
Nomaguchi K
Japan,Society of Plastics Recycling
(Elsevier Science Ltd.)
Polymer composites are very durable, but eventually they
must
À nish their service life and become “waste”. The
author has been studying composite waste management and
trying to exchange information among North American,
European and Asian regions to
À nd the most efÀ cient
methods. This paper covers basic ideas on composite waste
management and the practical processes which have been
developed. 4 refs.
JAPAN
Accession no.879311
Item 103
ANTEC 2002. Proceedings of the 60th SPE Annual
Technical Conference held San Francisco, Ca., 5th-9th
May 2002.
Brook
À eld, Ct., SPE, 2002, Paper 487, Session T48-
Alloys & Blends. Morphology Development, pp.5,
CD-ROM, 012
EFFECTS OF SUPERCRITICAL CO2 ON THE
DISPERSED PHASE SIZE AND COCONTINUITY
OF PS/LDPE BLENDS
Xue A; Tzoganakis C
Waterloo,University
(SPE)
Blends of polystyrene and low density polyethylene
(LDPE), containing 10-90 vol% LDPE, were prepared
using a co-rotating twin-screw extruder, with 4 wt%
supercritical carbon dioxide injected into the barrel.
Scanning electron microscopy, and gravimetry following
selective extraction showed that the CO2 reduced the
dispersed phase size, and also reduced the region of co-
continuity, attributed to a reduction in melt viscosity. The
morphology at the die following CO2 venting was similar
to that of blends was no CO2 addition. In the co-continuous
region, very
À ne morphologies were observed during the
foaming process. 16 refs.
CANADA
Accession no.878322
References and Abstracts
50
© Copyright 2005 Rapra Technology Limited
Item 104
ANTEC 2002. Proceedings of the 60th SPE Annual
Technical Conference held San Francisco, Ca., 5th-9th
May 2002.
Brook
À eld, Ct., SPE, 2002, Paper 392, Session T32-
Engineering Properties and Structure. Polyole
À ns III:
Structure and Properties of Polyole
À ns, pp.5, CD-ROM, 012
DRAWING OF UHMWPE FIBERS IN THE
PRESENCE OF SUPERCRITICAL CO2
Garcia-Leiner M; Song J; Lesser A J
Massachusetts,University; US,Army Soldier Systems
Command
(SPE)
Ultra high molecular weight polyethylene
À bres were
drawn in air and in supercritical carbon dioxide (scCO2)
over a range of temperatures. The drawing properties
in air varied with temperature, whilst in scCO2 they
were temperature-independent. Differential scanning
calorimetry and wide angle X-ray scattering studies
showed that crystallisation of the air-drawn samples
occurred in an internally constrained manner which
resulted in changes in the thermal behaviour. However,
in scCO2, crystals grew without constraint, possibly due
to crystal-crystal transformation, allowing the processing
temperature to increase up to 110 C. 12 refs.
USA
Accession no.876482
Item 105
ANTEC 2002. Proceedings of the 60th SPE Annual
Technical Conference held San Francisco, Ca., 5th-9th
May 2002.
Brook
À eld, Ct., SPE, 2002, Paper 351, Session T25-
Applied Rheology, Extrusion I, Thermoplastic Materials
and Foams. Interactive Presentations, pp.5, CD-ROM,
012
VISCOSITY MEASUREMENTS ON
POLYPROPYLENE MIXED WITH
SUPERCRITICAL FLUID AT HIGH SHEAR
RATES
Hung-Yu Lan; Hsieng-Cheng Tseng
Taiwan,National University of Science & Technology
(SPE)
An injection moulding machine with a 36 mm diameter
screw was modi
À ed by À tting a carbon dioxide injector
port to the barrel and a slit die with pressure transducers
in front of the nozzle. Flow rates were determined by
measuring screw displacement. Reduction in the viscosity
of polypropylene by the introduction of supercritical
CO2 was investigated, the viscosity being determined
by applying Bagley and Rabinowitsch corrections to the
measured pressure and
Á ow rates. A 30% reduction in
viscosity was achieved at low shear rates, and stable values
were observed at high shear rates. 21 refs.
TAIWAN
Accession no.876441
Item 106
Industrial and Engineering Chemistry Research
41, No.24, 27th Nov.2002. p.6049-58
SUPERCRITICAL CO2 BASED PRODUCTION
OF MAGNETICALLY RESPONSIVE
MICRO- AND NANOPARTICLES FOR DRUG
TARGETING
Chattopadhyay P; Gupta R B
Auburn,University
A supercritical antisolvent technique was used to
produce magnetically responsive PMMA, lactide-
glycolide copolymer and Eudragit RS polymer particles
via coprecipitation of the polymer with a suspension
of magnetite particles in mineral oil and a fatty acid
surfactant, using dichloromethane as the solvent. The
supercritical antisolvent technique was used to precipitate
drug-loaded magnetically responsive polymer particles.
Size, morphology and drug-release kinetics of the particles
were studied. 33 refs.
USA
Accession no.875759
Item 107
Chemistry of Materials
14, No.11, Nov.2002, p.4619-23
COMPOSITES PREPARED BY THE
POLYMERIZATION OF STYRENE WITHIN
SUPERCRITICAL CARBON DIOXIDE-
SWOLLEN POLYPROPYLENE
Zhimin Liu; Zexuan Dong; Buxing Han; Jiaqui Wang;
Jun He; Guanying Yang
Beijing,Institute of Chemistry
The monomer styrene and the initiator AIBN dissolved
in supercritical(SC) carbon dioxide were impregnated
into SC carbon dioxide-swollen PP matrix at 35C and the
monomer was then polymerised within the PP substrates
at 70C, resulting in PP/PS composites. The Young’s
modulus and TS of the PP were improved signi
À cantly in
the presence of PS. TEM, DSC and IR spectroscopy were
used to characterise the morphology and microstructure of
the composites. The results showed that the PS was more
homogeneously dispersed in the blends and its phase size
was in the range of nanometers. Some of the PS entangled
with PP in the composites. The special microstructures
and morphology of the blends resulted in the enhanced
mechanical performances of PP/PS composites. 27 refs.
CHINA
Accession no.875594
Item 108
European Polymer Journal
39, No.1, Jan.2003, p.151-6
SYNTHESIS OF ELECTRICALLY CONDUCTIVE
POLYPYRROLE-POLYSTYRENE COMPOSITES
USING SUPERCRITICAL CARBON DIOXIDE. II.
EFFECTS OF THE DOPING CONDITIONS
References and Abstracts
© Copyright 2005 Rapra Technology Limited
51
Tang M; Wen T-Y; Du T-B; Chen Y-P
Chinese Culture University; Taipei,National Taiwan
University
A polymer composite was produced by impregnating a
pyrrole monomer within a PS substrate in supercritical
carbon dioxide followed by soaking the resulting composite
in a solution of a metal salt to form an electrically conductive
composite. The effects of doping solvent (acetonitrile or
water), doping temperature and nature of the oxidants
(iron chloride, iron sulphate, iron perchlorate or iron
nitrate) on the electrical conductivity of the composites
were investigated and the heat stability of the composites
determined by thermogravimetry. 18 refs.
TAIWAN
Accession no.875416
Item 109
Industrial and Engineering Chemistry Research
41, No.22, 30th Oct.2002, p.5393-400
HYDROTHERMAL DECHLORINATION AND
DENITROGENATION OF MUNICIPAL-WASTE-
PLASTICS-DERIVED FUEL OIL UNDER SUB-
AND SUPERCRITICAL CONDITIONS
Akimoto M; Ninomiya K; Takami S; Ishikawa M; Sato
M; Washio K
Niigata,University
The hydrothermal processing of municipal-waste-plastics-
derived fuel oil (kerosene fraction; Cl content = 62 ppm,
N content = 1150 ppm) under sub- and supercritical
conditions is investigated so as to demonstrate the possible
use of water and aqueous solutions of metal salts and
hydroxides for the dechlorination and denitrogenation
of the fuel oil. The hydrothermal processing is carried
out in a small SUS316 stainless steel batch reactor under
nitrogen atmosphere. Although the two reactions take place
in water, they proceed much more readily under basic
conditions, especially in aqueous solutions of alkaline
metal hydroxides. That is, the nitrogen content in the
product oil decreases to 297 ppm upon processing with
water for 15 min at 425 deg.C, whereas it decreases to
49 ppm when 0.10 mol/L NaOH is used instead of water
at 375 deg.C. Under these hydrothermal conditions, the
chlorine content in the product oil is always nearly 0 ppm.
Organic acids such as benzoic acid and phthalic acid in
the fuel oil can also be removed. 37 refs.
JAPAN
Accession no.875151
Item 110
Industrial and Engineering Chemistry Research
41, No.22, 30th Oct.2002, p.533-40
KINETICS OF DEGRADATION OF
POLYCARBONATE IN SUPERCRITICAL AND
SUBCRITICAL BENZENE
Silvalingam G; Madras G
Indian Institute of Science
The degradation kinetics of polycarbonate (poly(bisphenol
A carbonate)) in supercritical and subcritical benzene is
studied at various temperatures (523-618 K) at 50 atm.
The degradation is also investigated in other solvents at
573 K and 50 atm. The time evolution of molecular weight
distribution is obtained by gel permeation chromatography
and modelled with continuous distribution kinetics to
obtain the degradation rate coef
À cients. The activation
energy, determined from the temperature dependence of
the rate coef
À cient, increases from 16.7 to 20.4 kcal/mol
from the subcritical region to the supercritical region of the
solvent. The degradation rate coef
À cients at the supercritical
conditions are an order higher than the rate coef
À cients at
subcritical conditions, indicating enhanced degradation at
supercritical conditions. The Arrhenius plot shows a break at
the supercritical transition point, while the semilogarithmic
plot of rate coef
À cients with the density of the reaction
mixture shows a continuous linear variation. 17 refs.
INDIA
Accession no.875148
Item 111
Polymer
43, No.25, 2002, p.6653-9
PREPARATION OF CROSS-LINKED
MICROPARTICLES OF POLY(GLYCIDYL
METHACRYLATE) BY DISPERSION
POLYMERIZATION OF GLYCIDYL
METHACRYLATE USING A PDMS
MACROMONOMER AS STABILIZER IN
SUPERCRITICAL CARBON DIOXIDE
Wenxin Wang; Grif
À ths R M T; Naylor A; Giles M R;
Irvine D J; Howdle S M
Nottingham,University; Uniqema
The dispersion polymerisation of glycidyl methacrylate was
carried out using poly(dimethylsiloxane) monomethacrylate
macromonomer as the stabiliser in supercritical carbon
dioxide. Under optimised conditions, discrete crosslinked
polymer particles were produced with high monomer
conversion during a very short reaction time of less than
4 h. The reaction pressure and stabiliser concentration
affected the morphology of the
À nal product. 18 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.874632
Item 112
Macromolecules
35, No.23, 5th Nov.2002, p.8869-77
PREPARATION OF A POLYMETHYL
METHACRYLATE/ULTRAHIGH MOLECULAR
WEIGHT POLYETHYLENE BLEND USING
SUPERCRITICAL CARBON DIOXIDE
AND THE IDENTIFICATION OF A THREE-
PHASE STRUCTURE. AN ATOMIC FORCE
MICROSCOPY STUDY
Zhang J; Busby A J; Roberts C J; Chen X; Davies M C;
References and Abstracts
52
© Copyright 2005 Rapra Technology Limited
Tendler S J B; Howdle S M
Nottingham,University
Supercritical carbon dioxide was used as a processing
medium to facilitate impregnation and polymerisation of
methyl methacrylate in ultrahigh molecular weight PE.
Morphological structures were investigated using tapping
mode atomic force microscopy. DSC analysis was also
carried out. 37 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.873640
Item 113
Polymer Engineering and Science
42, No.11, Nov.2002, p.2234-45
MEASUREMENT AND PREDICTION OF LDPE/
CO2 SOLUTION VISCOSITY
Areerat S; Nagata T; Ohshima M
Kyoto,University
The melt viscosities of LDPE/supercritical carbon
dioxide solutions were measured with a capillary
rheometer equipped at a foaming extruder. The viscosity
measurements were performed by varying the content of
carbon dioxide and temperature. Melt viscosities were
measured by measuring the pressure drop and
Á ow rate of
polymer running through the tube. A mathematical model
was developed to predict viscosity reduction owing to
carbon dioxide dissolution. 34 refs.
JAPAN
Accession no.873543
Item 114
Polymer Engineering and Science
42, No.11, Nov.2002, p.2094-106
CONTINUOUS MICROCELLULAR
POLYSTYRENE FOAM EXTRUSION WITH
SUPERCRITICAL CO2
Han X; Koelling K W; Tomasko D L; Lee L J
Ohio,State University
The continuous production of PS microcellular foams
with supercritical carbon dioxide was achieved on a two-
stage single-screw extruder. Simulations related to the
foaming process were accomplished by modelling the
phase equilibria with the Sanchez-Lacombe equations of
state and combining the equations of motion, the energy
balance, and the Carreau viscosity model to characterise
the
Á ow À eld and pressure distribution in the die. The
position of nucleation in the die was determined from
the simulation results via a computational
Á uid dynamics
code. The effects of carbon dioxide concentration and die
pressure were investigated. 48 refs.
USA
Accession no.873530
Item 115
Silicones in Coatings IV. Proceedings of a conference
held Guildford, UK, 30th-31st May 2002.
Teddington, Paint Research Association, 2002, Paper 4,
pp.11, 29cm, 012
SUPERCRITICAL FLUIDS AND SILICONES - A
POTENTIAL REVOLUTION OF WOOD AND
OTHER POROUS MATERIALS - AN UPDATE
Johns K; Hay J N
Chemical & Polymer; Surrey,University
(Paint Research Association)
The use of silicone polymers and of supercritical carbon
dioxide technology in the coating of various substrates,
but particularly of wood, is described. The problems
of wood coating are considered and the selection of
suitable biocides and water repellents is discussed. The
environmental advantages of using supercritical
Á uid
systems are examined and their use in powder coatings,
inverse microemulsions and microporous coatings is
described. 36 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.873338
Item 116
Polymer Engineering and Science
42, No.9, Sept.2002, p.1907-18
FOAM PROCESSING AND CELLULAR
STRUCTURE OF POLYPROPYLENE/CLAY
NANOCOMPOSITES
Pham Hoai Nam; Maiti P; Okamoto M; Kotaka T;
Nakayama T; Takada M; Ohshima M; Usuki A;
Hasegawa N; Okamoto H
Toyota Technological Institute; Kyoto,University;
Toyota Central R & D Laboratories Inc.
PP/clay nanocomposites(PPCNs) were autoclave-foamed
in a batch process. Foaming was performed using
supercritical carbon dioxide at 10 MPa, within the temp.
range 130.6 to 143.4C, i.e. below the m.p. of either PPCNs
or maleic anhydride(MA)-modi
À ed PP matrix without
clay. The foamed PP-MA and PPCN2 (prepared at 130.6C
and containing 2 wt % clay) showed closed cell structures
with pentagonal and/or hexagonal faces, while foams of
PPCN4 and PPCN7.5 (prepared at 143.4C, 4 and 7.5 wt
% clay) had spherical cells. SEM con
À rmed that foamed
PPCNs had high cell density of 10,000,000 to 100,000,000
cells/mL, cell sizes in the range of 30 to 120 micrometres,
cell wall thicknesses of 5 to 15 micrometres and low
densities of 0.05 to 0.3 g/mol. TEM observations of the
cell structure showed biaxial
Á ow-induced alignment of
clay particles along the cell boundary. The correlation
between foam structure and rheological properties of the
PPCNs is also discussed. 15 refs.
JAPAN
Accession no.873198
References and Abstracts
© Copyright 2005 Rapra Technology Limited
53
Item 117
ACS Polymeric Materials: Science and Engineering.
Spring Meeting. Volume 84. Proceedings of a
conference held San Diego, Ca., 1st-5th April 2001.
Washington, D.C., ACS,Div.of Polymeric Materials
Science & Engng., 2001, Paper 343, p.625-6, 27cm, 012
SUPERCRITICAL CARBON DIOXIDE
INTERACTION WITH POLYMERIC
MATERIALS: SORPTION AND DESORPTION
DIFFUSION COEFFICIENT
Shuely W J; Ince B S
US,Research & Technology Directorate;
US,Army,Aberdeen Proving Ground
(ACS,Div.of Polymeric Materials Science & Engng.)
Sorption and desorption diffusion coef
À cient measurements
by means of TGA were carried out to characterise the
plasticisation of a range of polymers by supercritical
carbon dioxide, which is utilised as a cleaning
Á uid for
sensitive equipment. Polymers tested included PVC,
PPO, polycarbonate, PMMA and polydimethylsiloxane.
The time required to return to the unplasticised state
was estimated using diffusion coef
À cient equations and
continuous desorption curve measurements permitted
adjustment and correction for extractables and zero-time
sorption measurement lag after decompression. 3 refs.
USA
Accession no.872806
Item 118
Foams 2002. Proceedings of a conference held Houston,
Tx., 22nd-23rd Oct.2002.
Brook
À eld, Ct., 2002, Session VII, p.163-8, 27cm, 012
INNOVATIVE FOAMING TECHNOLOGIES
Reedy M E
Reedy International Corp.
(SPE,Thermoplastic Materials & Foams Div.;
SPE,South Texas Section)
Many new innovative technologies are now being
introduced and reintroduced for foamed injection moulding
processing. Often called microcellular foaming, the new
technologies utilise a number of approaches to achieve
À ne cellular structures with double-digit weight and cycle
time reductions. The key to the innovative technologies is
computerised process control, good tool design including
counter pressure, static melt mixing and new chemical
blowing agents. These technologies have subtle differences,
which are very important for optimum part performance.
Technologies include a microcellular injection moulding
process using supercritical gas and polymer mixtures, which
reduce part weight while creating a swirled surface
À nish.
A class A surface is obtained with the use of Textron’s
IntelliMould, a process control system that decreases part
weight and cycle time while eliminating surface irregularities.
In addition, new compact gas counter pressure modules are
providing signi
À cantly improved structural foam processing.
Processors are also using new tailored static mixers to create
highly uniform melt components at constant temperatures.
New chemical blowing agents (CBAs) are making dramatic
strides in achieving reproducible cell distributions and cell
size in microcellular foaming. New applications include
automotive mouldings, such as foamed bumpers and fascia.
CBAs now utilise microencapsulated small particle size
components with very narrow distributions to achieve both
signi
À cant weight reduction and cycle time improvement.
Trials show that these improvements can be achieved on
conventional equipment. 11 refs.
USA
Accession no.871809
Item 119
162nd ACS Rubber Division Meeting - Fall 2002.
Proceedings of a conference held Pittsburgh, Pa., 8th-
11th Oct. 2002.
Akron, Oh., ACS Rubber Division, 2002, Paper 116,
pp.17, 28cm, 012
DEVULCANIZATION OF UNFILLED NATURAL
RUBBER IN SUPERCRITICAL CARBON
DIOXIDE
Kojima M; Tosaka M; Kohjiya S; Ikeda Y
Kyoto,University; Kyoto,Institute of Technology
(ACS,Rubber Div.)
Sulphur cured un
À lled NR was devulcanised in supercritical
carbon dioxide using diphenyl disulphide, as devulcanising
agent, and the product fractionated into sol and gel
fractions. The structure and properties of the devulcanised
rubber were determined by rheometry, viscometry,
swelling measurements, NMR spectroscopy, GPC and
DSC. The dependence of devulcanisation on the amount
of devulcanising agent, pressure and time was examined
and the effect of crosslink distribution in the vulcanisate
on devulcanisation evaluated. 20 refs.
JAPAN; USA
Accession no.871413
Item 120
Journal of Applied Polymer Science
86, No.9, 28th Nov.2002, p.2338-41
MOLECULAR WEIGHT DISTRIBUTION
OF POLYACRYLONITRILE PRODUCED IN
SUPERCRITICAL CARBON DIOXIDE
Xin-rong Teng; Hui-li Shao; Xue-chao Hu
Shanghai,Donghua University
An effectively linear molec.wt. calibration curve of
PAN was obtained using a copolymer standard with a
single broad MWD. The molec.wts. and MWDs of PAN
obtained from precipitation polymerisation of acrylonitrile
in supercritical carbon dioxide were quanti
À ed by the
calibration curve. The effects of monomer concentration,
initiator concentration, carbon dioxide pressure and total
reaction time on the molec.wt. and MWD were studied
in detail. 28 refs.
CHINA
Accession no.871260
References and Abstracts
54
© Copyright 2005 Rapra Technology Limited
Item 121
Journal of Applied Polymer Science
86, No.9, 28th Nov.2002, p.2272-8
IMPROVEMENT IN THE WATER-ABSORBING
PROPERTIES OF SUPERABSORBENT
POLYMERS (ACRYLIC ACID-CO-ACRYLAMIDE)
IN SUPERCRITICAL CARBON DIOXIDE
Li Ma; Le Zhang; Ji-Chu Yang; Xu-Ming Xie
Tsinghua,University
Superabsorbent resins prepared from acrylic acid and
acrylamide were prepared by UV polymerisation and
were treated with supercritical carbon dioxide(SC-CO2).
The water-absorbing properties of the treated resins were
found to be signi
À cantly improved. The water-absorbing
properties of resins treated with SC-CO2 in a pressure
range of 10 to 35 MPa and a temp. range of 40 to 60C were
studied. The effects of treatment time and depressurising
speed of carbon dioxide after treatment were also
examined. Different results were found for particles of
different sizes, smaller particles being more ef
À cient under
the same treatment conditions. The samples were tested
using DSC. The results showed that the plasticising effect
of carbon dioxide reduced the Tg of the polymer and it was
suggested that the plasticisation effect might have led to
polymer chain redistribution and better
Á exibility. Minor
changes in the surface morphology of the particles were
observed by SEM. The extraction of the unpolymerised
monomers by SC-CO2 was also studied. 13 refs.
CHINA
Accession no.871251
Item 122
Macromolecules
35, No.21, 8th Oct.2002, p.7976-85
CONTINUOUS PRECIPITATION
POLYMERIZATION OF VINYLIDENE
FLUORIDE IN SUPERCRITICAL CARBON
DIOXIDE: FORMATION OF POLYMERS
WITH BIMODAL MOLECULAR WEIGHT
DISTRIBUTIONS
Saraf M K; Gerard S; Wojcinski L M; Charpentier P A;
DeSimone J M; Roberts G W
North Carolina,State University; North
Carolina,University
The polymerisation of vinylidene
Á uoride in supercritical
carbon dioxide was studied in a continuous stirred tank
reactor using diethylperoxydicarbonate as the free radical
initiator. The effect of inlet monomer concentration, temp.,
average residence time and stirring on the polymerisation
rate, average molec.wts. and MWD of the PVDF. A
homogeneous kinetic model that included inhibition due
to chain transfer to monomer predicted the polymerisation
rates reasonably well. Imperfect mixing rather than a
chemical effect could, however, have caused the apparent
inhibition observed at high monomer concentrations. At
inlet monomer concentrations greater than about 1.5M,
broad and bimodal MWDs were observed. An extended
homogeneous kinetic model that included chain transfer
to polymer predicted the polydispersities reasonably
well. This model also predicted a region of inoperability
that matched the experimental results. The extended
homogeneous model could not, however, account for the
bimodal distributions. 26 refs.
USA
Accession no.871097
Item 123
ANTEC 2002. Proceedings of the 60th SPE Annual
Technical Conference held San Francisco, Ca., 5th-9th
May 2002.
Brook
À eld, Ct., SPE, 2002, Paper 235, Session M44-
Applied Rheology. Experimental And Numerical Flow
Modeling, pp.4, CD-ROM, 012
MELT PROCESSING OF POLYMERS USING
SUPERCRITICAL FLUIDS
Matthews S O; Dhadda K S; Hornsby P R
Brunel University
(SPE)
Low density polyethylene, with and without additions of
glass beads, was processed using single screw and co-rotating
twin-screw extruders
À tted with slit dies carrying pressure
transducers and thermocouples for rheometry measurements.
Supercritical carbon dioxide injected into the polymer during
processing signi
À cantly reduced viscosity, the reduction being
greater than theoretical predictions. 8 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.870783
Item 124
Polymer Preprints. Volume 41, Number 1. Proceedings
of a conference held San Francisco, Ca., March 2000.
Washington D.C., ACS,Div.of Polymer Chemistry,
2000, p.14-5, 28cm, 012
SYNTHESIS OF LINEAR
POLY(TETRAFLUOROETHYLENE-CO-VINYL
ACETATE) IN SUPERCRITICAL CARBON
DIOXIDE
Lausenberg R D; Shoichet M S
Toronto,University
(ACS,Div.of Polymer Chemistry)
Linear copolymers of tetra
Á uoro ethylene and vinyl acetate
were prepared in supercritical carbon dioxide solution with
different initiator and tetra
Á uoroethylene concentrations.
The linearity of the polymers was proven by attempted
hydrolysis of the vinyl acetate to vinyl alcohol, where only
a slight change in molar mass was observed. Causes of this
mass change were discussed. Polymers were characterised
using gel permeation chromatography, fourier transform
infrared and nuclear magnetic resonance analysis, and
elemental analysis. 13 refs.
CANADA
Accession no.868858
References and Abstracts
© Copyright 2005 Rapra Technology Limited
55
Item 125
Polymer Preprints. Volume 42, Number 1. Spring 2001.
Papers presented at the ACS meeting held San Diego,
Ca., 1st-5th April 2001.
Washington D.C., ACS,Div.of Polymer Chemistry,
2001, p.159-60, 28cm, 012
HYDROSILATION POLYMERIZATIONS WITH
DIALLYL MONOMER-BENZENE SOLUTION VS
SUPERCRITICAL CARBON DIOXIDE
Welsch R; Blanda M T; Venumbaka S R; Cassidy P E;
Fitch J W
Southwest Texas,State University
(ACS,Div.of Polymer Chemistry)
Comparison was made of the use of supercritical carbon
dioxide (SC CO) or benzene as solvent for the solution
polymerisation of a new class of
Á uorine and silicone
containing polymers. Polymers were prepared from
synthesised diallyl
Á uorine containg monomers and a
dihydrosilane or a siloxane using a platinum complex
catalyst. Molecular weights of polymers obtained when
using SC CO were equivalent or higher than when benzene
was used. Polymers had good thermal stability in both air
and argon. Polymers were characterised using infrared and
nuclear magnetic resonance spectroscopy, gel permeation
chromatography, differential scanning calorimetry and
thermogravimetric analysis. 6 refs
USA
Accession no.868798
Item 126
Polymer Journal (Japan)
34, No.7, 2002, p.534-8
STUDY ON THE STEREOREGULARITY OF
POLYACRYLONITRILE PRODUCED BY
PRECIPITATION POLYMERIZATION IN
SUPERCRITICAL CARBON DIOXIDE
Xin-Rong Teng; Xue-Chao Hu; Hui-Li Shao
Tongji,University; Shanghai,Donghua University
The triad and pentad tacticities of PAN obtained by
precipitation polymerisation in supercritical carbon dioxide,
using AIBN as initiator (referred to as CO2-PAN), were
analysed by carbon-13 NMR and IR spectroscopies. The
pentad tacticities of CO2-PAN from the intensities of cyano
peaks were examined by statistical methods. It was found
that CO2-PAN was completely random in stereoregularity
and its sequence distributions obeyed Bernoullian statistics.
Comparisons were made with the aqueous phase suspension
polymerisation of acrylonitrile, using AIBN as initiator
(referred to as S-PAN), and aqueous phase precipitation
polymerisation of acrylonitrile, using redox-type initiator
(R-PAN), and it was found that the isotacticity of CO2-PAN
was lower than that of S-PAN and R-PAN, although the
three types of PAN were all random in stereoregularity. The
cause was probably the different polarities of the solvents
used. The relation between IR data and stereoregularity of
PAN was also used to calculate the isotactic triad units of
CO2-PAN and the result was shown to be in agreement with
the carbon-13 NMR method used. 19 refs.
CHINA
Accession no.868607
Item 127
Polymer
43, No.20, 2002, p.5511-20
GENERATION OF MICROCELLULAR
FOAMS OF PVDF AND ITS BLENDS USING
SUPERCRITICAL CARBON DIOXIDE IN A
CONTINUOUS PROCESS
Siripurapu S; Gay Y J; Royer J R; DeSimone J M;
Spontak R J; Khan S A
North Carolina,State University
Supercritical carbon dioxide was used as a blowing agent
to generate microcellular foams of PVDF and its blends
with PS or PMMA in a continuous process. Foams of neat
PVDF and immiscible blends with PS showed poor cell
characteristics but miscible blends of PVDF with PMMA
produced foams with greatly improved morphologies.
The PVDF/PMMA melt viscosity, decreased markedly
with increasing PMMA content and supercritical carbon
dioxide concentration. The cell density of microcellular
PVDF/PMMA foams increased with increasing PMMA
fraction and decreasing foaming temperature. 32 refs.
USA
Accession no.868068
Item 128
Polymer Preprints. Volume 42. Number 1. Spring 2001.
Papers presented at the ACS Meeting held San Diego,
Ca., 1st-5th April 2001.
Washington, D.C., ACS,Div.of Polymer Chemistry,
2001, p.518-9, 28cm, 012
RING-OPENING METATHESIS
POLYMERIZATION OF NORBORNENE IN
SUPERCRITICAL CARBON DIOXIDE
Xiaochuan Hu; Blanda M T; Venumbaka S R; Cassidy P E
Southwest Texas,State University
(ACS,Div.of Polymer Chemistry)
Ring-opening metathesis polymerisation of norbornene
was carried out in supercritical carbon dioxide. The
molecular weight, molecular weight distribution and
thermal stability of the polynorbornenes synthesised by
this method were similar to those of polynorbornenes
synthesised in the conventional THF solvent. A high
trans structure was obtained in all the polynorbornenes
prepared using the Grubbs catalyst and the trans/cis ratio
could be adjusted by adding co-solvent (THF and toluene).
However, when the Schrock’s catalyst was used, a high cis
structure was obtained. Temperature had no effect on the
cis/trans ratio of the polymers but affected the molecular
weights and their distribution; Pressure had no signi
À cant
effect on the microstructure of the polynorbornenes
prepared in supercritical carbon dioxide. 9 refs.
USA
Accession no.867542
References and Abstracts
56
© Copyright 2005 Rapra Technology Limited
Item 129
ANTEC 2002. Proceedings of the 60th SPE Annual
Technical Conference held San Francisco, Ca., 5th-9th
May 2002.
Brook
À eld, Ct., SPE, 2002, Paper 131, Session M28-
Injection Moulding Analysis, pp.5, CD-ROM, 012
STUDY OF WELD-LINE STRENGTH AND
MICROSTRUCTURE OF INJECTION MOLDED
MICROCELLULAR PARTS
Kharbas H; Turng L-S; Spindler R; Burhop B
Wisconsin-Madison,University; Kaysun Corp.
(SPE)
The in
Á uence of process parameters on the weld line
strength and microstructure of polycarbonate processed
by microcellular injection moulding was investigated.
The mould temperature and the melt back pressure were
maintained constant at 71.1 C and 17.2 MPa, respectively.
The weld line strength increased with increasing melt
temperature, injection speed, and shot size, and also
exhibited a weak dependence on the supercritical
Á uid
level. 5 refs.
USA
Accession no.867335
Item 130
Journal of Materials Chemistry
12, No.9, Sept.2002, p.2688-91
SYNTHESIS OF COMPOSITES OF SILICON
RUBBER AND POLYSTYRENE USING
SUPERCRITICAL CO2 AS A SWELLING AGENT
Liu Z; Wang J; Dai X; Han B; Dong Z; Yang G;
Zhang X; Xu J
Chinese Academy of Sciences
The heterogeneous free-radical polymerisation of styrene
within supercritical carbon dioxide swollen silicon
rubber
À lm is conducted to prepare silicone rubber/PS
(SR/PS) polymer blends. The PS content in the blends
can be controlled by adjusting the soaking time and the
concentration of styrene in the supercritical
Á uid. Scanning
electron microscopy (SEM) indicates that the PS phase is
uniformly distributed in the blends, and the phase size is
very small, although the two polymers are very different
and incompatible. The mechanical properties of the blends
and the average molecular weight of the PS polymerised in
the matrix are also measured. The results indicate that the
average molecular weight of the PS in the blend depends
on the PS content or its phase size. The tensile strength of
the blends is higher than that of original SR substrate, and
there is a maximum in tensile strength in.vs. PS content.
Young’s modulus of the blends increases monotonously
with PS content in the blends. 23 refs.
CHINA
Accession no.866646
Item 131
Polymer
43, No.19, 2002, p.5363-7
PREPARATION OF NANOMETER DISPERSED
POLYPROPYLENE/POLYSTYRENE
INTERPENETRATING NETWORK USING
SUPERCRITICAL CO2 AS A SWELLING AGENT
Dan Li; Zhimin Liu; Buxing Han; Liping Song;
Guanying Yang; Tao Jiang
Chinese Academy of Sciences
Nanometer dispersed polypropylene/polystyrene
interpenetrating networks are prepared. These IPNs are
then characterised in terms of thermal and mechanical
properties, and the features of the IPNs formed are studied.
The IPNs are prepared by the radical polymerisation and
crosslinking of styrene within supercritical CO2-swollen
PP substrates. Styrene, divinyl benzene (crosslinking
agent) and benzoyl peroxide (initiator) were impregnated
into a polypropylene matrix using supercritical CO2
as a solvent and swelling agent at 35 degree C, then
polymerisation and crosslinking were carried out at 120
degree C. The compositions of the IPNs can be controlled
by the supercritical CO2 pressure, styrene concentration
and divinyl benzene concentration. The impact strength,
tensile strength and elongation-at-break of the IPNs
increases with the content of polystyrene. 26 refs.
CHINA
Accession no.866550
Item 132
Macromolecular Symposia
Vol.184, 2002, p.215-28
POLYMERS AND SUPERCRITICAL FLUIDS:
OPPORTUNITIES FOR VIBRATIONAL
SPECTROSCOPY
Kazarian S G
London,Imperial College of Science,Technology &
Medicine
A report is presented on the use of in-situ ATR-IR
spectroscopy to study changes in polymers subjected to
supercritical
Á uids. Experiments are conducted utilising an
ATR-IR cell with a diamond crystal accessory to measure
the spectra. Application of this technique to study the
sorption of high-pressure CO2 into polymers, swelling
of polymers in high-pressure CO2, impregnation of
polymers from supercritical CO2 solution, CO2-induced
polymer melting and PMMA stereocomplex formation and
polymers in near-critical water. 42 refs. (14th European
Symposium on Polymer Spectroscopy, Dresden, 2nd-5th
Sept., 2001, Germany)
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.866443
References and Abstracts
© Copyright 2005 Rapra Technology Limited
57
Item 133
Advanced Materials and Processes
160, No.6, June 2002, p.19-20
NANOCOMPOSITE DENSE PLASTIC FOAM
REPLACES SOLID PLASTIC
It is briefly reported that researchers at Ohio State
University claim to have developed nanocomposite
plastic foam that is strong enough to replace solid plastic
in structural applications such as car or airplane panels.
To make foam, manufacturers inject gases into hot liquid
plastic. The Ohio State researchers added nanometre-size
clay particles to the molten plastic, and small bubbles of the
injected gas about
À ve microns across formed around the
nanoparticles, adhering to them. With a foam that contains
5% clay particles, boards were made that are just as strong
as typical foam, but two thirds as thick.
OHIO,STATE UNIVERSITY
USA
Accession no.864095
Item 134
Polymer Preprints. Volume 43, Number 1. Spring 2002.
Papers presented at the ACS meeting held Orlando, Fl.,
7th-11th April 2002.
Washington D.C., ACS,Div.of Polymer Chemistry,
2002, p.744-5, 28cm, 012
EMULSION TEMPLATING USING
SUPERCRITICAL FLUID EMULSIONS
Butler R; Davies C M; Hopkinson I; Cooper A I
Liverpool,University; Cavendish Laboratory
(ACS,Div.of Polymer Chemistry)
A new technique for using supercritical carbon dioxide, at
volume fractions up to 80 percent, as the internal oil phase
in emulsion templating during the preparation of porous
polymers is described. Polymerisations of acrylamide
with methylene bisacrylamide or hydroxyethyl acrylate
and methylene bisacrylamide were carried out at different
monomer concentrations and carbon dioxide volume fractions
to illustrate the technique, and pore sizes were measured
using mercury intrusion porosimetry. Polymer area was
determined using nitrogen adsorption (BET method) and
scanning electron microscopy was used to examine polymer
morphology. Confocal microscopy was used to determine
cell sizes. The claimed advantage of this method over others
for preparation of porous monolithic polymers is the lack of
involvement of organic solvents. 8 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.862535
Item 135
Macromolecular Symposia
Vol.182, 2002, p.119-29
CONTINUOUS PRECIPITATION
POLYMERIZATION OF VINYLIDENE
FLUORIDE IN SUPERCRITICAL CARBON
DIOXIDE: MOLECULAR WEIGHT
DISTRIBUTION
Saraf M K; Wojcinski L M; Kennedy K A; Gerard S;
Charpentier P A; DeSimone J M; Roberts G W
North Carolina,State University
An investigation was carried out into the surfactant-free
precipitation polymerisation of vinylidene
Á uoride in
supercritical carbon dioxide using, as polymerisation
initiator, diethyl peroxydicarbonate. Polymerisation
was carried out in a continuous stirred autoclave at
temperatures from 65 to 85C and at pressures between
210 and 305 bar. Molecular weight distributions of the
polymers were determined by GPC and the effects of inlet
monomer concentration, total polymerisation pressure and
polymerisation temperature on MWD evaluated. A model,
which includes chain transfer to polymer, was developed
to predict the increase in polydispersity observed with
increasing monomer concentration and the reasons for the
formation of polymers with bimodal MWD at many of the
operating conditions investigated are brie
Á y considered.
(3rd IUPAC-Sponsored International Symposium on
Free-Radical Polymerization: Kinetics and Mechanism, Il
Ciocco (Lucca), Tuscany, Italy, 3rd-9th June, 2001)
USA
Accession no.860998
Item 136
Macromolecular Symposia
Vol.182, 2002, p.31-42
PROPAGATION KINETICS IN FREE-RADICAL
POLYMERIZATIONS
Beuermann S
Gottingen,Georg-August-Universitat
The effect of
Á uid or supercritical carbon dioxide on
the kinetics of propagation of a range of monomers in
bulk and solution was examined using a combination of
pulsed laser initiated polymerisation and size exclusion
chromatography. The role of local monomer concentrations
in the vicinity of the propagating radical is discussed and
the contribution of local monomer concentrations towards
a better understanding of increases in propagation rate
coef
À cients with ester size in acrylates and methacrylates
and the in
Á uence of initiating laser pulse repetition rate
on propagation rate coef
À cients is considered. 34 refs.
(3rd IUPAC-Sponsored International Symposium on
Free-Radical Polymerization: Kinetics and Mechanism, Il
Ciocco (Lucca), Tuscany, Italy, 3rd-9th June, 2001)
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.860992
References and Abstracts
58
© Copyright 2005 Rapra Technology Limited
Item 137
Macromolecules
35, No.12, 4th June 2002, p.4653-7
SOLUBILITY OF CF2-MODIFIED
POLYBUTADIENE AND POLYISOPRENE IN
SUPERCRITICAL CARBON DIOXIDE
McHugh M A; Park I-H; Reisinger J J; Ren Y;
Lodge T P; Hillmyer M A
Virginia,Commonwealth University; Kumoh,National
University of Technology; Minnesota,University
The cloud points of
Á uorinated polyisoprenes (FPI) and
Á uorinated polybutadienes (FBR) in supercritical CO2
were investigated over the temperature range 60-170 C and
the pressure range 100-300 MPa. Neither polyisoprene (PI)
nor hydrogenated PI were soluble in CO2 at temperatures
of up to 155 C and pressures of 260 MPa. Pressures in
excess of 100 MPa were required to obtain single phase
solutions of FPI and FBR. The cloud point curves of FPI
and FBR exhibited temperature minima at approximately
60 and 80 C, respectively, attributed to increased CO2-CO2
and polymer-polymer interactions relative to polymer-CO2
interactions. The cloud point curves for FPI moved to
higher pressures and temperatures with decreasing
Á uorine
content. It was concluded that the incorporation of
Á uorine
into macromolecules results in a signi
À cant increase of
solubility in CO2. 25 refs.
KOREA; USA
Accession no.857463
Item 138
Polymer Preprints. Volume 43, Number 1. Spring 2002.
Papers presented at the ACS meeting held Orlando, Fl.,
7th-11th April 2002.
Washington D.C., ACS, Div.of Polymer Chemistry,
2002, p.473, 28 cm, 012
STUDY ON DEGRADATION OF PET IN
SUPERCRITICAL ETHYLENE GLYCOL
Hanfu Wang; Liang Chen; Xincai Liu; Yubin Zheng;
Zhongwen Wu; Yunchun Zhou
Jilin,University; Changchun,Institute of Applied
Chemistry
(ACS,Div.of Polymer Chemistry)
The degradation of PETP in supercritical ethylene glycol
was studied. Degradation products of different molecular
weights could be obtained by controlling the system
pressure, temperature or ratio of polymer to ethylene
glycol. The oligomeric degradation products could be
converted into unsaturated polyesters by reacting with
maleic anhydride. 7 refs.
CHINA
Accession no.857005
Item 139
Industrial and Engineering Chemistry Research
41, No.11, 29th May 2002, p.2617-22
REDUCTION OF RESIDUAL MONOMER
IN LATEX PRODUCTS BY ENHANCED
POLYMERIZATION AND EXTRACTION IN
SUPERCRITICAL CARBON DIOXIDE
Kemmere M; van Schilt M; Cleven M; van Herk A;
Keurentjes J
Eindhoven,University of Technology
The reduction of methyl methacrylate in a PMMA latex was
studied. Pulsed electron beam experiments were performed
to study the effect of supercritical carbon dioxide on the
monomer concentration inside the polymer particles during
the polymerization reaction. The partitioning behaviour of
methyl methacrylate between water and carbon dioxide
was measured as a function of pressure and temperature.
28 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; WESTERN EUROPE
Accession no.856799
Item 140
ACS POLYMERIC MATERIALS SCIENCE AND
ENGINEERING. SPRING MEETING 2001. VOLUME
84. Proceedings of a conference in San Diego, Ca..
Washington, D.C., 2001, p.280-1, 012
EVALUATING THE SWELLING OF POLYMERS
IN SUPERCRITICAL CARBON DIOXIDE
Shenoy S L; Sebra R; Woerdeman D; Wynne K
Virginia,Commonwealth University
A simple and inexpensive technique to accurately
determine the degree of swelling of the commercially
available polymer Kraton in carbon dioxide. At ambient
temperature and 2000 psi Kraton swells by approximately
7% in liquid carbon dioxide. A microcellular morphology
is obtained on sudden depressurisation. The use of
supercritical carbon dioxide to control and manipulate
the properties of polymeric melts is rapidly becoming an
important area of research. 7 refs.
USA
Accession no.855570
Item 141
ACS POLYMERIC MATERIALS SCIENCE AND
ENGINEERING. SPRING MEETING 2001. VOLUME
84. Proceedings of a conference in San Diego, Ca..
Washington, D.C., 2001, p.279, 012
RHEOLOGY OF POLYMER MELTS SWOLLEN
WITH DISSOLVED SUPERCRITICAL FLUIDS
Manke C W; Gulari E; Smolinski J M; Kwag C
Wayne State,University
The effects of dissolved gases on the rheology of polymer
melts are important to applications such as the production of
polymer foams and the synthesis and processing of polymers
in supercritical
Á uids. Dissolved supercritical gases can
reduce the viscosity of polymer melts by 2 to 3 orders of
magnitude under suitable conditions. Viscosity measurements
for several polymer-supercritical
Á uid systems are presented,
including polystyrene, polymethyl methacrylate, and
References and Abstracts
© Copyright 2005 Rapra Technology Limited
59
polydimethyl siloxane with dissolved carbon dioxide, and
polystyrene with the refrigerant gases 1,1-di
Á uoroethane
(R152a) and 1,1,1,2-tetra
Á uoroethane (R134a). For each
system, conventional viscoelastic scaling techniques were
used to reduce the composition-dependent viscosity versus
shear rate relationships to master curves identical to the
viscosity curve for the pure polymer. The dependence of
the viscoelastic scaling factors on dissolved gas content is
correlated by a simple free volume theory, combined with
an equation-of-state model for the polymer-gas mixture. Also
considered is the effect of dissolved gas on the glass transition
temperature of the polymer-gas mixture.
USA
Accession no.855569
Item 142
ACS POLYMERIC MATERIALS SCIENCE AND
ENGINEERING. SPRING MEETING 2001. VOLUME
84. Proceedings of a conference in San Diego, Ca..
Washington, D.C., 2001, p.276-8, 012
CO2-ASSISTED POLYMER PROCESSING:
ACCESSING NEW PROCESSING WINDOWS
AND NOVEL MORPHOLOGIES
Royer J R; Siripurapu S; DeSimone J M; Spontak R J;
Khan S A
North Carolina,State University; North
Carolina,University
A detailed rheological investigation to help elucidate the
advantages of carbon dioxide-induced plasticisation is
presented. Several example cases, speci
À cally microcellular
foaming and extrusion technology are discussed to
demonstrate the utilisation of supercritical carbon
dioxide as a plasticiser. Experimental measurements of
viscosity as a function of shear rate, pressure, temperature
and carbon dioxide concentration were carried out for
various commercial polymer resins using an extrusion
slit die rheometer. Carbon dioxide was demonstrated
to be an excellent plasticiser for all samples measured,
lowering the viscosity of the polymer melts by 25-80%
depending on pressure, temperature and carbon dioxide
concentration. A free-volume model was developed to
predict the effects of carbon dioxide on melt rheology,
using existing theories for viscoelastic scaling of polymer
melts and the prediction of glass transition temperature
depression by a diluent. Conventional viscoelastic scaling
and data corrections were formed using the predictive
free-volume model developed. Utilising only the free-
volume theory, the experimental data was collapsed to a
single master curve independent of pressure and carbon
dioxide concentration for each of the three polymer resins.
A predictive tool to quantify the viscosity reduction of
polymer melts due to plasticisation by carbon dioxide or
other diluents is therefore possible from the combination
of conventional viscoelastic scaling and free volume theory
with thermodynamic models. This prediction assists in the
design of novel extrusion processes and in understanding
the ability of carbon dioxide to act as a processing aid for
carbon dioxide-assisted extrusion and as a blowing agent
in the microcellular foaming process. 7 refs.
USA
Accession no.855568
Item 143
Modern Plastics International
32, No.5, May 2002, p.35
NEW SOLVENT PROVES CRITICAL TO
MAKING IMPROVED FLUOROPOLYMERS
Rosenzweig M
DuPont Fluoropolymers is introducing what it claims
are the first commercial fluoropolymers made using
supercritical carbon dioxide. The nine grades now debuting
globally are similar to
Á uorinated ethylene propylene
polymers, but are terpolymers containing some vinyl ether.
The materials, designated Te
Á on G, are much tougher than
FEP. Toughness at 100C is 4.6 kJ/m3 versus 1.7 kJ/m3
for Te
Á on FEP. Tensile strength retention with increasing
temperature exceeds all current FEP polymers, while
ultimate elongation also is much higher. The new polymers
are particularly suitable for extrusion. Initial applications
will focus on heat-shrink tubing, wire and cable insulation
and industrial
À lm.
DUPONT FLUOROPOLYMERS
USA
Accession no.855046
Item 144
Blowing Agents and Foaming Processes 2002.
Proceedings of a conference held Heidelberg, 27th-28th
May 2002.
Shawbury, Rapra Technology Ltd., 2002, Paper 8, p.79-
85, 29cm, 012
NEW DEVELOPMENTS IN MUCELL
MICROCELLULAR FOAM MOULDING
TECHNOLOGY AND COMMERCIAL
APPLICATIONS
Janisch R
Trexel USA
(Rapra Technology Ltd.)
The MuCell microcellular foam injection moulding
process, which provides plastics components that
are lighter,
Á atter, straighter and more dimensionally
stable at extreme operating temperatures compared to
conventionally moulded components, and the hardware
necessary to adapt the process are brie
Á y described. The
cost bene
À ts of the process are indicated and a range
of products manufactured using the process, which
employs supercritical fluids of inert gases to create
evenly distributed and uniformly sized microscopic cells
throughout the polymer, by companies from as far a
À eld
as Australia and Singapore are illustrated. 5 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; USA;
WESTERN EUROPE
Accession no.854592
References and Abstracts
60
© Copyright 2005 Rapra Technology Limited
Item 145
Polymer Preprints, Volume 42, No.2, Fall 2001,
Conference proceedings.
Chicago, Il., Fall 2001, p.554-5
CONTINUOUS AND BATCH
POLYMERISATIONS OF VINYLIDENE
FLUORIDE IN DENSE CARBON DIOXIDE
Wojeiski L M; Saraf M K; Roberts G W; DeSimone J M
North Carolina,State University; North Carolina,Chapel
Hill University
(ACS,Div.of Polymer Chemistry)
As an environmentally benign solvent, supercritical
carbon dioxide (scCO2) has shown potential as a viable
medium for a number of chemical processes, including
the polymerisation of
Á uorinated oleÀ ns. A green process
has been developed, which allows for the continuous
polymerisation of
Á uorinated monomers via free radical
precipitation polymerisation in scCO2 in a continuous
stirred tank reactor (CSTR). It was hoped that by carrying
out these polymerisations in a CSTR, the environmental
bene
À ts of CO2-based polymerisations could be coupled
with the process advantages of using a continuous
system. Although it has been possible to achieve desirable
conversions of monomer, molecular weight of the polymers
produces in this system has been lower than desired. A
small-scale polymerisation system is implemented which
allows for rapid screening of polymerisation conditions
and initiators, in this case, for the free radical precipitation
polymerisation of vinylidene
Á uoride. The Á uorinated
initiators examined are active at lower temperatures
relative to non-
Á uorinated initiators, which opens up the
possibility of preparing high molecular weight polymer
under reasonably mild reaction conditions. These lower
reaction temperatures lead to an increase in the Tm of the
polymer to one comparable with commercially available
PVDF. NMR analysis of these polymers shows a reduced
tendency to reverse added monomer units, and shows a
lower concentration of end-groups, indicating that these
materials have higher Mn’s relative to those prepared at
high temperatures. 3 refs.
USA
Accession no.853927
Item 146
Macromolecules
35, No.10, 7th May 2002, p.3866-9
PRESSURE AND TEMPERATURE
DEPENDENCE OF THE PROPAGATION RATE
COEFFICIENT OF FREE-RADICAL STYRENE
POLYMERIZATION IN SUPERCRITICAL
CARBON DIOXIDE
Beuermann S; Buback M; Isemer C; Lacik I; Wahl A
Gottingen,University; Slovak Academy of Sciences
Free radical polymerisation of styrene in homogeneous
phase of supercritical carbon dioxide was studied at
temperatures between 40 and 80 C and pressures between
300 and 1500 bar. Propagation rate coef
À cients were
obtained using pulsed-laser polymerisation in conjunction
with size-exclusion chromatography. The points of
inflection were determined from maxima of the first
derivative curve of the experimental MWD. 11 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
SLOVAK REPUBLIC; SLOVAKIA; WESTERN EUROPE
Accession no.853624
Item 147
Macromolecules
35, No.9, 23rd April 2002, p.3653-61
KINETICS OF THE EARLY STAGE OF
DISPERSION POLYMERIZATION IN
SUPERCRITICAL CARBON DIOXIDE AS
MONITORED BY TURBIDIMETRY. II.
PARTICLE FORMATION AND LOCUS OF
POLYMERIZATION
Fehrenbacher U; Ballauff M
Karlsruhe,University
The dispersion polymerisation of methyl methacrylate was
studied in supercritical carbon dioxide at 330 bar in situ
by turbidimetry. All the experiments were conducted in
the presence of the macromonomer polydimethylsiloxane-
monomethacrylate which acted as a stabiliser. The
formation of particles of PMMA was monitored
quantitatively by turbidimetry because the degree of
swelling by supercritical carbon dioxide, as well as the
refractive index of these particles, was known accurately.
The turbidity spectra were measured in the range 400 to
950 nm. The number density and the diameter could be
obtained as a function of time in the earliest stage of the
dispersion polymerisation with a time resolution of about
0.1 s. Furthermore, the mass of polymer could be deduced
and thus a full kinetic analysis performed. Particular
attention was paid to the size distribution of particles
which was shown to play an essential role in the treatment
of turbidimetric data. 30 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.853390
Item 148
Macromolecules
35, No.9, 23rd April 2002, p.3569-75
SYNTHESIS OF FLUOROCARBON-VINYL
ACETATE COPOLYMERS IN SUPERCRITICAL
CARBON DIOXIDE: INSIGHT INTO BULK
PROPERTIES
Baradie B; Shoichet M S
Toronto,University
A series of
Á uorocarbon-vinyl acetate(VAc) copolymers
was prepared in supercritical carbon dioxide with a broad
range of compositions, high yields and high molec.
wts. It was shown that surfactant-free carbon dioxide
polymerisation of all three
Á uorocarbons studied (tetraf
luoroethylene(TFE), chlorotri
Á uoroethylene(CTFE) and
References and Abstracts
© Copyright 2005 Rapra Technology Limited
61
vinylidene
Á uoride(VDF)) with VAc was possible and
that P(TFE-VAc) was linear. All the TFE-VAc copolymers
had high yields and high molec.wts., suggesting good
solubility in carbon dioxide. CTFE-VAc copolymers
were synthesised in high yield when less than 50 mol
% CTFE was in the feed. At higher concentrations of
CTFE, the gradual consumption of VAc resulted in lower
polymer yields and molec.wts., suggesting that CTFE
was less soluble than TFE in carbon dioxide. VDF-VAc
copolymers were synthesised with the lowest yields of the
three
Á uorocarbons studied due to the decreased reactivity
(and probably carbon dioxide solubility) of VDF relative
to VAc. 35 refs.
CANADA
Accession no.853379
Item 149
Macromolecules
35, No.9, 23rd April 2002, p.3325-7
RIGID PORE STRUCTURE FROM HIGHLY
SWOLLEN POLYMER GELS
Winter H H; Gappert G; Ito H
Massachusetts,University
A crosslinked PE specimen, when exposed to a suitable
pressure-temp. cycle in the presence of supercritical
propane, was shown to increase its size several fold and to
develop an open-pore structure. The process was genuine
and was expected to be applicable to other semicrystalline
polymers which could be crosslinked and swollen. It
provided a relatively simple method for obtaining high
value-added materials from commodity polymers such
as PE or from approved biopolymers. When supercritical
Á uids were used as the swelling Á uid, the process was
capable of producing extremely high-purity materials with
zero emissions. 15 refs.
USA
Accession no.853346
Item 150
Polymer Preprints. Volume 42, Number 2, Fall 2001.
Proceedings of a conference held Chicago, Il., 26th-30th
August 2001.
Washington D.C., ACS,Div.of Polymer Chemistry,
2001, p.340-1
LIVING ANIONIC POLYMERISATIONS OF
WELL-DEFINED SUGAR-CONTAINING
DIBLOCK FLUOROCOPOLYMER AND
ITS APPLICATION IN CO2 EMULSION
POLYMERISATIONS
Ye W; DeSimone D M
North Carolina,University
(ACS,Div.of Polymer Chemistry)
Carbon dioxide as a useful processing
Á uid is limited
by its inability to solubilise highly polar compounds.
This problem can be alleviated by the addition of CO2-
philic amphiphiles. The primary objective is to design
and synthesise novel materials with both strongly polar
groups and highly CO2-philic segments. Synthetic
polymers with pendent carbohydrate moieties and a stable
C-C backbone are referred to as glycopolymers, which
are water-soluble and have many potential applications
in biochemical and biomedical
À elds. Novel amphiphilic
block copolymers with well-defined glycopolymer
and fluoropolymer blocks are reported using living
anionic polymerisation. Both protected (hydrophobic/
CO2-philic) and deprotected (hydrophilic/CO2-philic)
copolymers are CO2 amphiphiles and their solubility in
CO2 is heavily in
Á uenced by the amphiphilic structure.
The emulsion polymerisation of N-ethylacrylamide in
CO2 is successfully performed by using the hydrophilic
deprotected block copolymer. 7 refs.
USA
Accession no.849822
Item 151
Plastics and Rubber Weekly
5th April 2002, p.9
SUPERCRITICAL DEBUT
Smith C
DuPont has launched a range of six high-performance
melt processable PTFE resins, the first commercial
products to be manufactured using its supercritical CO2
polymerisation technology. Process G uses supercritical
CO2 in place of water used in traditional emulsion
polymerisation of
Á uoropolymers. The À rst Process G
resins are targeted at heat shrink tubing, high-performance
À lms and high temperature cable sleeving. Property data
are presented.
DUPONT CO.
USA
Accession no.849679
Item 152
Macromolecules
35, No.3, 29th Jan.2002, p.934-40
POLY(METHYL METHACRYLATE) AND
POLY(BUTYL METHACRYLATE) SWELLING IN
SUPERCRITICAL CARBON DIOXIDE
Nikitin L N; Said-Galiyev E E; Vinokur R A;
Khokhlov A R; Gallyamov M O; Schaumburg K
Russian Academy of Sciences; Moscow,Lomonosov
University; Copenhagen,University
The swelling of PMMA and poly(butyl methacrylate) in
supercritical carbon dioxide was studied by means of direct
optical observation. The diffusion coef
À cients of carbon
dioxide molecules in the polymers were determined by
analysing the diffusion front propagation in the polymers
and by volumetric measurements of the swelling kinetics
for different temperatures and pressures. The results from
the two methods were in good agreement. A difference in
the appearance of diffusion fronts in these polymers with
different glass transition temperatures was observed. The
References and Abstracts
62
© Copyright 2005 Rapra Technology Limited
results were discussed. 26 refs.
DENMARK; EUROPEAN COMMUNITY; EUROPEAN UNION;
RUSSIA; SCANDINAVIA; WESTERN EUROPE
Accession no.848202
Item 153
Chemical and Engineering News
80, No.10, 11th March 2002, p.17
DUPONT DEBUTS FLUOROPOLYMERS
DuPont has introduced the
À rst commercial Á uoropolymers
made with a new polymerisation process based on
supercritical carbon dioxide. The products, melt-
processable polymers for applications such as wire and
cable insulation, are produced at a 40m US dollars facility
in Fayetteville, N.C., that started up in late 2000. The
technology was developed jointly by scientists at DuPont
and at the University of North Carolina, Chapel Hill.
This abstract includes all the information contained in
the original article.
DUPONT CO.
USA
Accession no.847773
Item 154
ACS POLYMERIC MATERIALS SCIENCE AND
ENGINEERING. SPRING MEETING 2001. VOLUME
84. Proceedings of a conference in San Diego, Ca..
Washington, D.C., 2001, p.270-1, 012
PROGRESS IN RESEARCH OF RAPID
EXPANSION OF SUPERCRITICAL SOLUTIONS
(RESS) TECHNIQUE OF DROPLET FORMATION
OF PERFLUOROPOLYETHER FOR COATING
APPLICATION
Montero G A; Robert H B; Carbonell R G;
DeSimone J M
North Carolina,State University; North
Carolina,University
(AMERICAN CHEMICAL SOCIETY)
A discussion is given of progress in research into the rapid
expansion of supercritical solutions (RESS) technique
of droplet formation of per
Á uoropolyether for coating
applications. The objective was to gain an understanding
of the relationship between morphology of precipitate,
droplet size, spray characteristics and RESS process
conditions. It was demonstrated that small droplet size
and a narrow droplet size distribution can be achieved in
the system by using the RESS technique. RESS is a very
promising technology because in principle small droplets
and particles can be obtained with a narrow (mono-
disperse) size distribution. The technique for droplet
size formation that has been demonstrated avoids the
use of organic solvents for polymer coating applications.
3 refs.
USA
Accession no.846723
Item 155
ACS POLYMERIC MATERIALS SCIENCE AND
ENGINEERING. SPRING MEETING 2001. VOLUME
84. Proceedings of a conference in San Diego, Ca..
Washington, D.C., 2001, p.203, 012
MULTICOMPONENT POLYMER SYSTEMS IN
THE PRESENCE OF SUPERCRITICAL CARBON
DIOXIDE
Walker T A; Siripurapu S; Young J L; Hirsch S G;
Khan S A; DeSimone J M; Spontak R J
North Carolina,State University; North
Carolina,University
(AMERICAN CHEMICAL SOCIETY)
The presence of supercritical carbon dioxide, which
plasticises a broad range of polymers, can greatly affect
the phase behaviour of multicomponent polymer systems.
This effect was studied by investigating three related areas.
The
À rst was an investigation into the extent to which
supercritical carbon dioxide shifts the phase boundaries
of polymethyl methacrylate/polyvinylidene fluoride
(PMMA/PVDF) and polymethyl mercaptoacetamide/
polyvinylidene
Á uoride (PEMA/PVDF) blends, which
display lower critical solution temperature (LCST)
behaviour. The second area was the extent to which
supercritical carbon dioxide and high-pressure nitrogen
in
Á uence the cloud point of polydimethyl siloxane(PEMS)
(upper critical solution temperature, UCST) blends.
Within the context of microcellular polymer foams,
polymer miscibility issues were considered. Through the
liberal addition of PMMA, microcellular polymer foams
of PVDF have been generated continuously in batch
mode with very good homogeneity. The third area was a
study of polystyrene/PMMA latex particles produced by
emulsion polymerisation in supercritical carbon dioxide.
A presentation is given of morphological characteristics
discerned by transmission electron microtomography.
USA
Accession no.846684
Item 156
ACS POLYMERIC MATERIALS SCIENCE AND
ENGINEERING. SPRING MEETING 2001. VOLUME
84. Proceedings of a conference in San Diego, Ca..
Washington, D.C., 2001, p.195-6, 012
RELATIONSHIP BETWEEN MACROSCOPIC
SCF-POLYMER PHASE BEHAVIOUR AND
SOLUTION MICROSTRUCTURE
Hugh M A M; van Zanten J H; DiNoia T P
Virginia,Commonwealth University; North
Carolina,State University
(AMERICAN CHEMICAL SOCIETY)
The relationship between macroscopic supercritical
fluid- (SCF)-polymer phase behaviour and solution
microstructure was investigated. The aim was to identify
whether differences exist on a microscopic level between
the quality of a liquid and an SCF solvent. Analysis
was carried out using small angle neutron scattering of
References and Abstracts
© Copyright 2005 Rapra Technology Limited
63
polyethylene butene in dimethyl ether. It was found that
very high pressures are required to dissolve most polymers
in SCF solvents. Typical SCF solvents are low molecular,
high volatility gases at room temperature, which is an
indication of very low cohesive energy. Pressure can be
used to modulate the strength of interactions with an SCF
solvent, however, whereas pressure has very little impact
on liquid solvent strength. The concentration
Á uctuations
in an SCF solvent environment are larger than those in a
liquid solvent environment even at similar distances to the
phase boundary. 10 refs.
USA
Accession no.846680
Item 157
Colloid and Polymer Science
280, No.2, Feb. 2002, p.183-7
PRODUCTION OF SUBMICRON-SIZED
POLYMETHYL METHACRYLATE PARTICLES
BY DISPERSION POLYMERIZATION WITH
A POLYDIMETHYLSILOXANE-BASED
AZOINITIATOR IN SUPERCRITICAL CARBON
DIOXIDE
Okubo M; Fujii S; Maenaka H; Minami H
Kobe,University
Details are given of the preparation of submicron-sized
PMMA particles by dispersion polymerisation using a
PDMS-based azo initiator in supercritical carbon dioxide.
The initiator was found to operate not only as a radical
initiator but also as a colloidal stabiliser. Characterisation
was undertaken using SEM, proton NMR and X-ray
photoelectron spectroscopy. 19 refs.
JAPAN
Accession no.845782
Item 158
Kobunshi Ronbunshu
58, No.12, 2001, p.714-7
Japanese
SORPTION PROPERTIES OF SUPERCRITICAL
CARBON DIOXIDE IN POLY(ETHYLENE
GLYCOL) AND POLY(ETHYLENE OXIDE) WITH
HIGH-PRESSURE THERMOGRAVIMETRY-
DIFFERENTIAL THERMAL ANALYSIS
Hata K-A
Japan,Chemical Innovation Institute
An in-situ high-pressure TGA-DTA method based on
magnetic suspension was employed to investigate the
sorption of and plasticisation effect of supercritical carbon
dioxide in molten PEG and PEO. It was found that sorption
of carbon dioxide increased almost linearly with pressure
and that compressed carbon dioxide depressed the melting
points of the polymers, which decreased linearly with the
pressure of the carbon dioxide. 11 refs.
JAPAN
Accession no.845103
Item 159
Kobunshi Ronbunshu
58, No.12, 2001, p.710-3
INFUSION OF THE ORGANOMETALLIC
COMPOUND INTO ORGANIC MATERIALS
USING SUPERCRITICAL CARBON DIOXIDE
Nakanishi T
Japan,Chemical Innovation Institute
The results are reported of a study of the infusion of Ti(O-
i-C3H7)4 into PMMA using supercritical carbon dioxide.
The titanium compound was infused into the surface of
the polymer at low temperatures and diffused further
into the polymer with increasing pressure under constant
temperature. It reacts to produce clusters, which could be
controlled by temperature and pressure. 7 refs.
JAPAN
Accession no.845102
Item 160
Kobunshi Ronbunshu
58, No.12, 2001, p.703-9
Japanese
DECOMPOSITION OF SILANE-CROSSLINKED
POLYETHYLENE FOR MATERIAL RECYCLING
BY USING SUPERCRITICAL METHANOL
Goto T; Yamazaki T; Okajima I; Sugeta T; Miyoshi T;
Hayashi S; Sako T
Hitachi Cable Ltd.; Shizuoka,University; Japan,National
Institute of Advanced Industrial Science & Technology
Silane-crosslinked PE was decomposed using supercritical
water and supercritical methanol and decomposition
investigated by means of NMR spectroscopy and FTIR
spectroscopy. Heating of the crosslinked PE in supercritical
methanol at 300 to 340C and 8 to 10 MPa for 30 min. gave
rise to a thermoplastic PE having a number-average molec.
wt. of about 40,000 and no gel fraction. The data obtained
indicated that the decomposition of PE using supercritical
methanol was suitable for recycling silane-crosslinked
polyethylene. 17 refs.
JAPAN
Accession no.845101
Item 161
Kobunshi Ronbunshu
58, No.12, 2001, p.697-702
Japanese
DECOMPOSITION OF AROMATIC POLYAMIDE
USING SUPERCRITICAL WATER
Takahashi K; Sato Y; Kato K; Nishi S
Lifestyle & Environmental Technology Laboratories;
Nippon Telegraph & Telephone Corp.
Poly(p-phenylene terephthalamide) was decomposed
using supercritical water in a batch reactor at temperatures
ranging from 300 to 600C and at temperatures ranging from
10 to 60 mins. Decomposition products were identi
À ed by
HPLC and gas chromatography-mass spectrometry and
References and Abstracts
64
© Copyright 2005 Rapra Technology Limited
compared with those obtained when decomposition was
performed in a
Á ow reactor. The data obtained indicated
that the mass-scale feedstock recycling of polyamide is
possible. 4 refs.
JAPAN
Accession no.845100
Item 162
Kobunshi Ronbunshu
58, No.12, 2001, p.692-702
Japanese
DECOMPOSITION AND DEBROMINATION OF
FLAME-RESISTANT POLYMERS CONTAINING
BROMINE ATOMS WITH SUBCRITICAL WATER
Okajima I; Sugeta T; Sako T
Shizuoka,University; Japan,National Institute of
Advanced Industrial Science & Technology
The decomposition and debromination of tetrabrominated
bisphenol A epoxy resin were investigated using subcritical
and supercritical water. Decomposition products were
identi
À ed and hydrolysis with subcritical water compared
with the pyrolysis of brominated epoxy resin. Hydrolysis
with subcritical water inhibited carbonisation and
accelerated bromine abstraction from the epoxy resin.
6 refs.
JAPAN
Accession no.845099
Item 163
Kobunshi Ronbunshu
58, No.12, 2001, p.661-73
Japanese
CONVERSION OF POLYETHYLENE TO
OIL USING SUPERCRITICAL WATER
AND DONATION OF HYDROGEN IN
SUPERCRITICAL WATER
Moriya T; Enomoto H
Tohoku Electric Power Co.Inc.; Tohoku,University
Thermal cracking and cracking in supercritical water of
PE were carried out and the species, yields and structures
of the cracked products investigated. The mechanism
of degradation was also studied and supercritical water
cracking compared with thermal cracking. Experiments
were also carried out using D2O as a tracer and the stages
involved in the donation of hydrogen from the supercritical
water to the oil identi
À ed. 28 refs.
JAPAN
Accession no.845098
Item 164
Kobunshi Ronbunshu
58, No.12, 2001, p.631-41
Japanese
POLYETHYLENE DECOMPOSITION VIA
PYROLYSIS AND PARTIAL OXIDATION IN
SUPERCRITICAL WATER
Watanabe M; Adschiri T; Arai K
Tohoku,University
Polyethylene was degraded in a batch reactor at 420C for
30 min. and the effect of supercritical water on degradation
investigated. The enhancement of decomposition
observed was attributed to the dissolution of high molec.
wt. hydrocarbons in the supercritical water and diffusion
of water into the molten PE phase. The yield of partial
oxidation products increased with the increasing density
of supercritical water and partial oxidation was affected
by the area of the interface between the molten PE and
water-oxygen phase. 17 refs.
JAPAN
Accession no.845096
Item 165
160th ACS Rubber Division Meeting - Fall 2001.
Cleveland, Oh., 16th-18th October 2001, Paper 38,
pp.24, 012
DEVULCANIZATION OF SULFUR-CURED
ISOPRENE RUBBER IN SUPERCRITICAL
CARBON DIOXIDE
Kojima M; Ogawa K; Mizoshima H; Tosaka M; Kohjiya S
Toyo Tire & Rubber Co.Ltd.; Kyoto,University
(ACS,Rubber Div.)
The devulcanisation of un
À lled isoprene rubber using
devulcanising reagents in supercritical carbon dioxide was
studied. In the supercritical gas, thiophenol/-n-butylamine
and diphenyl disulphide devulcanised the vulcanisates
effectively into chloroform-soluble polymer with molec.
wt. of tens of thousands. The vulcanisates were degraded
to sol fractions more easily with higher contents of
polysulphidic crosslink using thiophenol/n-butylamine
as a devulcanising reagent. Supercritical carbon dioxide
assisted the diffusion of devulcanising reagents into the
vulcanisates. The devulcanisation made progress more
ef
À ciently in supercritical Á uid of carbon dioxide than in
the gaseous state. 24 refs.
USA
Accession no.842975
Item 166
Revue Generale des Caoutchoucs et Plastiques
78, No.796, June/July 2001, p.40-5
French
INJECTION MOULDING OF TECHNICAL
PARTS: FOUR PROCESSES UNDER
EXAMINATION
Delannoy G
An examination is made of developments in four recently
introduced plastics injection moulding processes, including
sequential, two-material/multi-material and water-assisted
injection moulding and the MuCell process developed by
Trexel for the injection moulding of microcellular products
References and Abstracts
© Copyright 2005 Rapra Technology Limited
65
using supercritical gases as blowing agents. Types of
polymers processed and products manufactured by these
techniques are reviewed.
TREXEL
USA; WORLD
Accession no.842593
Item 167
Plastics Engineering
57, No.5, May 2001, p.46-51
INJECTION MOULDING INNOVATION: THE
MICROCELLULAR FOAM PROCESS
Pierick D; Jacobsen K
Trexel Inc.; Engel North America
The microcellular foam moulding method known as the
MuCell process uses supercritical
Á uids of atmospheric
gases to create evenly distributed and uniformly sized
microscopic cells throughout a polymer. Suitable for
injection moulding, the microcellular foam process
enhances product design, improves processing ef
À ciency
and reduces product costs. The technology offers weight
reduction, cycle time improvements, reduced injection
pressures and clamp tonnage, and energy savings. A
polystyrene case study is presented which investigates
À ve
primary variables: injection speed, melt temperature, gas
type, mould temperature and gas level in weight percent.
CANADA; USA
Accession no.842319
Item 168
ACS Polymeric Materials Science and Engineering.
Spring Meeting 2001. Volume 84. Proceedings of a
conference in San Diego, Ca..
Washington, D.C., 2001, p.45-6. 012
FREE-RADICAL COPOLYMERIZATIONS
OF STYRENE AND METHACRYLIC ACID
ESTERS IN HOMOGENEOUS PHASE OF
SUPERCRITICAL CARBON DIOXIDE
Beuermann S; Buback M; Jurgens M
Gottingen,Georg-August-Universitat
Phase behaviour measurements and copolymer syntheses
show that free-radical binary and ternary copolymerisations
of styrene with functional methacrylates such as, for example,
glycidyl methacrylate, 2-hydroxypropyl methacrylate or i-
bornyl methacrylate might be carried out in homogeneous
phase in the presence of supercritical carbon dioxide up to
high degrees of monomer conversion. Terpolymerisations of
styrene with methyl methacrylate and glycidyl methacrylate
were modelled using the software program PREDICI.
Currently developed are strategies either for a batch or a
continuous polymerisation process leading to a uniform
copolymer composition. 7 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.841552
Item 169
ACS Polymeric Materials Science and Engineering.
Spring Meeting 2001. Volume 84. Proceedings of a
conference in San Diego, Ca..
Washington, D.C., 2001, p.39-43. 012
PHARMACEUTICAL MATERIAL PRODUCTION
VIA SUPERCRITICAL FLUIDS EMPLOYING
THE TECHNIQUE OF PARTICLES FROM GAS-
SATURATED SOLUTIONS (PGSS)
Mandel F S; Wang J D; McHugh M A
Ferro Corp.,Technical Center; Virginia,Commonwealth
University
For the production of many performance materials at Ferro
Corp. A versatile and
Á exible supercritical carbon dioxide
manufacturing process, SF MicronMix, was developed
and deployed. The supercritical
Á uid-aided processing
exploits the change in polymer properties that occurs when
the polymer is contacted with an SCF solvent. Polymers
considered include polylactide-co-glycolide. It is usually
not necessary to dissolve the polymer to be processed,
which is advantageous because the high pressures and
temperatures required to dissolve polymers in supercritical
Á uids have a severe negative impact on process economics.
By interpretation using the principles of molecular
thermodynamics, guidelines for the type of repeat groups
that leads to polymer solubility in supercritical
Á uid solvents
at low temperatures and pressures are obtained. 58 refs.
USA
Accession no.841551
Item 170
ACS Polymeric Materials Science and Engineering.
Spring Meeting 2001. Volume 84. Proceedings of a
conference in San Diego, Ca..
Washington, D.C., 2001, p.37-8. 012
OPEN-PORE MORPHOLOGIES BY
CRYSTALLIZATION OF CROSSLINKED,
POLYETHYLENE GELS SWOLLEN WITH
SUPERCRITICAL PROPANE
Gappert G; Ito H; Winter H H
Massachusetts,University
Crosslinked polyethylene was crystallised from supercritical
propane to create open-pore structures in pre-shaped
samples. A metallocene LLDPE was moulded from pellet
into a
Á at sheet and then radiation crosslinked in an inert
atmosphere. The shaped, crosslinked sample was then
swollen with its critical point to prevent the formation
of a liquid phase during pore evacuation. Samples which
contained a fraction of uncrosslinked chains were partially
extracted during the swelling step. All samples displayed
a rise in volume and decrease in density and maintained
their original moulded shape. Scanning electron microscopy
reveals pore sizes ranging from about 0.25 microns to 10
microns. Propane is recovered completely in high purity and
leaves no residue in the porous polyethylene. 10 refs.
USA
Accession no.841550
References and Abstracts
66
© Copyright 2005 Rapra Technology Limited
Item 171
Polymer Degradation and Stability
75, No.1, 2002, p.185-91
STUDY ON METHANOLYTIC
DEPOLYMERIZATION OF PET WITH
SUPERCRITICAL METHANOL FOR CHEMICAL
RECYCLING
Yong Yang; Yijun Lu; Hongwei Xiang; Yuanyuan Xu;
Yongwang Li
Chinese Academy of Sciences
Polyethylene terephthalate (PET) was subjected to
methanolytic depolymerisation with supercritical methanol
in a stirred stainless steel autoclave at temperatures of 523-
543 deg.C, pressure 8.5-14.0 MPa, and a 3-8 methanol to
PET weight ratio. The solid products obtained, consisting
mainly of dimethyl terephthalate and small amounts of
methyl-(2-hydroxyethyl) terephthalate, bis(hydroxyethyl)
terephthalate, dimers, and oligomers, were analysed by
high performance liquid chromatography (HPLC), and the
liquid products, mainly ethylene glycol and methanol were
analysed by gas chromatography (GC). The temperature,
weight ratio of methanol to PET, and the reaction time
had a very marked effect on dimethyl terephthalate yield
and the degree of PET depolymerisation, but the effect
of pressure was insigni
À cant above the methanol critical
point. The optimum PET depolymerisation conditions
were: temperature 533-543 K, pressure 9.0-11.0 MPa, and a
methanol to PET weight ratio of 6-8. The depolymerisation
of several PET wastes from the Chinese market was
studied under the optimum conditions. 28 refs.
CHINA
Accession no.841527
Item 172
Asia Paci
À c Coatings Journal
14, No.6, Dec. 2001, p.557-63
DECOMPOSITION OF FIBER REINFORCED
PLASTICS USING FLUID AT HIGH
TEMPERATURE AND PRESSURE
Sugeta T; Nagaoka; Otake K; Sako T
Japan,National Institute of Advanced Industrial Science
& Technology; Kumamoto,Industrial Research Institute;
Shizuoka,University
An investigation is reported of the decomposition of
À bre-reinforced plastics, being refractory waste, using a
supercritical water and alkali solution with alcohol at high
temperature and pressure. Fibre-reinforced unsaturated
polyester was treated by supercritical water at 380 degrees
C and most of the matrix was decomposed during 5 minutes
reaction time. The main products were carbon dioxide and
carbon monoxide in gas phase, and styrene derivatives
and phthalic acid in liquid phase. After the treatment
with supercritical water for 5 minutes, no signi
À cant
change in the
À bre recovered was detected using scanning
electron microscopy or infrared spectroscopy. On the
other hand, phenolic resin used as a matrix of CFRP was
not decomposed using only supercritical water, but was
promoted by supercritical water with alkali. Futhermore,
with used of alcohol-alkali aqueous solution at a high
temperature, phenolic resin was found to be mostly broken
down to soluble products. 15 refs.
JAPAN
Accession no.840528
Item 173
Asia Paci
À c Coatings Journal
14, No.6, Dec. 2001, p.552-6
POLYMERIZATION OF GLYCIDYL
METHACRYLATE IN SUPERCRITICAL
CARBON DIOXIDE
Matsuyama K; Mishima K; Hirabaru T; Takahashi K
Fukuoka,University; Konoshima Chemical Co.Ltd.
Polyglycidyl methacrylate was synthesised in supercritical
carbon dioxide and its solubility in carbon dioxide was
measured by observing the cloud point. The in
Á uences of the
reaction pressure, monomer and initiator concentrations were
investigated. Furthermore, the effects of methacrylic acid and
a
Á uorous surfactant on the polymer morphology were also
discussed. Polymer particles were obtained by the addition of
methacrylic acid and the
Á uorous surfactant. Spherical particles
were produced by the addition of methacrylic acid. 16 refs.
JAPAN
Accession no.840527
Item 174
Kobunshi Ronbunshu
58, No.10, 2001, p.548-51
Japanese
MONOMERIZATION OF NYLON 6 IN SUB-AND
SUPERCRITICAL WATER
Goto M; Umeda M; Kodama A; Hirose T; Nagaoka S
Kumamoto,University; Kumamoto,Industrial Research
Institute
Nylon-6, a polymer synthesised by ring-opening
polymerisation of epsilon-caprolactam, was decomposed
by hydrolysis in sub- and supercritical water. Nylon 6
and degassed water were charged into a batch reactor and
heated to a reaction temperature in the range of 573~673
K for 5 to 60 mins. In a salt bath. The liquid phase of the
product was analysed by HPLC and GC-MS. As a result
of HPLC analysis, epsilon-caprolactam and epsilon-
aminocaproic acid were detected in the product liquid
phase. The yields of monomer components were plotted
as a function of reaction time and temperature. The total
yields of these monomers were about 100% for reactions
at 573 K in 60 mins. and at 603 K in 30 mins. The yield
of e-aminocaproic acid decreased rapidly as reaction
time increased. Nylon 6 was decomposed by hydrolyis to
epsilon-aminocaproic acid followed by cyclodehydration
to epsilon-caprolactam or decomposition further to smaller
molecules in sub- and supercritical water. 6 refs.
JAPAN
Accession no.840526
References and Abstracts
© Copyright 2005 Rapra Technology Limited
67
Item 175
Kobunshi Ronbunshu
58, No.10, 2001, p.533-40
Japanese
NONCATALYTIC ORGANIC SYNTHESIS
OF EPSILON-CAPROLACTAM AND
DECOMPOSITION OF NYLON 6 USING
SUPERCRITICAL WATER
Sato O; Ikushima Y
Japan,National Institute of Advanced Industrial Science
& Technology
Non-catalytic Beckmann rearrangement of cyclohexanone-
oxime into epsilon-caprolactam was con
À rmed to be
signi
À cantly promoted near the critical temperature in
subcritical and supercritical water. High temperature, high
pressure FTIR was further used to study the reactivities,
in which it was demonstrated that supercritical water
acts effectively in place of conventional acid catalysts.
The rate constant in the
Á ow reaction system nylon 6
was successfully decomposed to epsilon-caprolactam in
supercritical water at 653 K and 25 Mpa, in which the
yield of epsilon-caprolactam reached 91%, even in short
reaction times ranging from 6-7 minutes. 23 refs.
JAPAN
Accession no.840525
Item 176
Kobunshi Ronbunshu
58, No.10, 2001, p.521-6
Japanese
FLUID DENSITY DEPENDENCE OF THE
PARTITION COEFFICIENT OF DISPERSE
DYES BETWEEN SYNTHETIC FIBER AND
SUPERCRITICAL CARBON DIOXIDE IN
SUPERCRITICAL DYEING
Tataba I; Miyagawa S; Lyu J H; Cho S M; Hori T
Fukui,University; Pusan,National University
PETP and PP fibres were dyed with two different
disperse dyes in supercritical carbon dioxide
Á uid. The
partition coef
À cients of dyes between polymer phase
and supercritical carbon dioxide phase were calculated
from the equilibrium dye uptake and the solubilities of
dyes in supercritical carbon dioxide. A liner relation
was found, and the slope of the plots was shown to be
roughly dependent on the solvation number of the dye in
supercritical carbon dioxide for all polymer-dye systems.
These thermodynamic analyses for the equilibrium dyeing
are claimed to offer some important information regarding
dye selection, the design of dyeing equipment and the
optimisation of the dyeing process. In addition, the results
are applicable for impregnation processes of polymers
using supercritical carbon dioxide. 24 refs.
JAPAN; KOREA
Accession no.840524
Item 177
Kobunshi Ronbunshu
58, No.10, 2001, p.489-94
Japanese
PREPARATION OF POLY(PHENYLACETYLENE)
USING SUPERCRITICAL OR LIQUID CARBON
DIOXIDE
Hori H; Six C; Leitner W
Max-Planck-Institut fuer Kohlenforschung;
Japan,National Institute of Advanced Industrial Science
& Technology
Polymerisation of phenylacetylene was carried out with
high ef
À ciency in supercritical or liquid carbon dioxide
using rhodium catalysts. The polymerisation rate in carbon
dioxide is higher than in conventional solvents such as
THF or hexane. The polymers consist of cis-transoidal and
cis-cisoidal species. The surface morphology, molecular
weight, IR and NMR spectroscopic properties of the
resulting polymers are compared to those obtained by
polymerisation in conventional solvents, and discussed in
terms of the microstructure of the polymers. 32 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
JAPAN; WESTERN EUROPE
Accession no.840522
Item 178
Journal of Injection Molding Technology
5, No.3, Sept.2001, p.152-9
MICROCELLULAR FOAM PROCESSING
IN RECIPROCATING-SCREW INJECTION
MOLDING MACHINES
Jingyi Xu; Pierick D
Trexel Inc.
A microcellular foam processing system for the
reciprocating-screw injection moulding machine was
developed. The design criteria derived provided the
necessary conditions for creating and maintaining a single-
phase solution in the overall system of the plasticising unit,
supercritical
Á uid(SCF) delivery unit and hydraulic unit.
An overall systems approach was the key to successful
implementation of a microcellular foam process. These
modi
À cations are described, together with the component
designs required for a microcellular foam moulding
machine. The important components discussed are the
plasticising unit, injection unit, hydraulic unit, clamp unit
and SCF unit. The general guidelines for designing an
injection moulding machine for microcellular foam are
listed as the conclusions. 18 refs.
USA
Accession no.840081
References and Abstracts
68
© Copyright 2005 Rapra Technology Limited
Item 179
Journal of Industrial Textiles
31, No.1, July 2001, p.43-56
PROGRESS IN SUPERCRITICAL CO2 DYEING
Hendrix W A
North Carolina,State University
Supercritical
Á uids have special properties that could lead
to substantial improvement when utilised as replacements
for water in wet processing of textiles. These
Á uids have
densities and solvating powers similar to liquid solvents
combined with viscosity and diffusion coef
À cients like those
observed for gases. In particular these make supercritical
carbon dioxide (SC-CO2) one of the most bene
À cial and
acceptable solvents used in manufacturing processes
today. Therefore it is anticipated that commercial textile
processes using SC-CO2 will have many advantages when
compared to conventional aqueous processes. Successful
commercialisation of SC-CO2 in processing will improve
the economics of dyeing and other textile chemical
processes by eliminating wastewater discharges, reducing
consumption, eliminating drying and reducing air emissions.
As a result, the use of SC-CO2 is expected to make textile
processing more economical and environmentally friendly.
An overview of the status of the research is presented,
together with the technical and economic factors important
to the successful commercialisation of an SC-CO2 polyester
yarn package dyeing process. 34 refs.
USA
Accession no.839799
Item 180
Polymer Preprints. Volume 41. Number 2. Conference
proceedings.
Washington, D.C., 20th-24th Aug.2000, p.1838-9
PATTERNABLE LOW-K DIELECTRICS
DEVELOPED USING SUPERCRITICAL CO2
Weibel G L; Pryce-Lewis H-G; Gleason K K; Ober C K’
Cornell University; Massachusetts,Institute of
Technology
(ACS,Div.of Polymer Chemistry)
Processing used in microelectronics is increasingly
designed with environmental impact in mind. As
technologies change, new process insertion points occur.
The role of polymers in microelectronics has traditionally
been con
À ned to photoresist materials, but is expanding
to include low dielectric constant (low-k) materials. A
collaboration is presented, intended to merge the role of
resist and dielectric material, resulting in directly-patterned
low-k
À lms. These patterned À lms serve as insulating
material compatible with metallisation schemes including
the damascene process. In examining this all-dry process
that involves CVD deposition and supercritical CO2
pattern development, it is shown that it may be possible to
eliminate the multiple steps presently required in current
manufacturing for generating patterned insulators. A new
processing tool, supercritical CO2, has gained increasing
interest as a developer, drying solvent and cleaning agent in
efforts to capitalise on the unique properties of supercritical
Á uids (SCF). SCF CO2 has high diffusivity comparable
to gas, has negligible surface tension and has density near
that of a liquid that can be tuned by minor temperature and
pressure adjustments. SCF CO2 is found to be suitable
as a developer for CVD
Á uorocarbon systems, as well
as for
Á uorinated resists patterned with small and high
aspect ratio features that may otherwise experience pattern
collapse due to surface tension from aqueous developers.
Positive-tone contrast is demonstrated in
Á uorocarbon
CVD
À lms by 1.0 mu m line and space features patterned
from e-beam exposure. Investigations of polymer and
CVD
À lm solubility/dissolution and minimum achievable
feature sizes are discussed. 12 refs.
USA
Accession no.839742
Item 181
Polymer Preprints. Volume 41. Number 2. Conference
proceedings.
Washington, D.C., 20th-24th Aug.2000, p.1817
CO2 TECHNOLOGY PLATFORM FOR
SUSTAINABLE MANUFACTURING
DeSimone J
North Carolina,University; North Carolina,State
University
(ACS,Div.of Polymer Chemistry)
Regulations on the release of toxic chemicals to the
environment have steadily increased over the years. Organic
or halogenated solvents account worldwide for more than
30 billion lb of solvent usage each year. Manufacturing and
service industries are faced with the dilemma of avoiding
the production, use and subsequent release of contaminated
water, volatile organic solvents, chlorofluorocarbons
and other noxious solvents and contaminants into the
environment. The need to develop a more environmentally
responsible and energy ef
À cient solvent technology platform
is paramount and the leading candidate is liquid and
supercritical carbon dioxide. 4 refs.
USA
Accession no.839731
Item 182
ACS POLYMERIC MATERIALS SCIENCE AND
ENGINEERING. SPRING MEETING 2001. VOLUME
84. Proceedings of a conference in San Diego, Ca..
Washington, D.C., 2001, p.138. 012
SUPERCRITICAL FLUID-ASSISTED
SYNTHESIS AND PROCESSING OF
POLYMERIC MATERIALS: KINETIC AND
THERMODYNAMIC CONSIDERATIONS
Watkins J J; Brown G; Gupta R; Ortelli D;
Ramachandra Rao V; Vogt B
Massachusetts,University
Case studies are presented which describe the preparation of
precisely ordered nanocomposites and reactive blending in
References and Abstracts
© Copyright 2005 Rapra Technology Limited
69
the presence of carbon dioxide. It was demonstrated that in
multi-component polymer systems, carbon dioxide sorption
not only in
Á uences molecular mobility, but also has a very
signi
À cant effect on polymer/polymer compatibility. The
phase behaviour of polymer blends and block copolymers
in the presence of carbon dioxide was determined using
complimentary techniques including in situ small angle
neutron scattering, high pressure
Á uorescence spectroscopy,
and measurements of optical birefringence. Results suggest
that near upper critical solution transitions, carbon dioxide
sorption can promote polymer miscibility through inter-
segment screening in analogy with liquid diluents, but near
lower critical sorption transitions, sorption of carbon dioxide
can induce phase segregation at temperatures hundreds
of degrees below the ambient pressure transition. In all
instances, the location of the transitions can be tuned over
broad-ranges through pressure-mediated adjustments in
solvent density. Small molecule diffusion in carbon dioxide-
dilated polymers using in situ
Á uorescence non-radiative
energy transfer techniques are also reported. The results
indicate enhancement in probe diffusivities that exceed
À ve orders of magnitude upon sorption of carbon dioxide
in polystyrene.
USA
Accession no.839631
Item 183
ACS POLYMERIC MATERIALS SCIENCE AND
ENGINEERING. SPRING MEETING 2001. VOLUME
84. Proceedings of a conference in San Diego, Ca..
Washington, D.C., 2001, p.134-5. 012
INTERFACE STUDIES ON SUPERCRITICAL
CO2 WELDED SEMI-CRYSTALLINE
POLYMERS
Caskey T C; Lesser A J; McCarthy T
Massachusetts,University
Studies were carried out on the interface of supercritical
carbon dioxide welded semi-crystalline linear low density
polyethylene (LLDPE) polymer films in order to more
completely describe the mechanisms of adhesion. The samples
were tested in a T-Peel geometry to determine the strength
of adhesion. The integrity of the weld line was analysed
using atomic force microscopy and optical microscopy. The
morphological nature of the interface region was characterised
using transmission electron microscopy and scanning electron
microscopy. The interfaces were demonstrated to be seamless
and to have good physical integrity. The interface is highly
amorphous, as revealed by transmission electron microscopy
and etching results. Adhesion was attained at temperatures
below the melting temperature which allows the retention of
the original morphology and crystal structure after processing,
as revealed by differential scanning calorimetry and wide
angle X-ray scattering. It is evident that the most consistent
mechanism of adhesion is amorphous diffusion of chains
across the interface. 5 refs.
USA
Accession no.839628
Item 184
ACS POLYMERIC MATERIALS SCIENCE AND
ENGINEERING. SPRING MEETING 2001. VOLUME
84. Proceedings of a conference in San Diego, Ca..
Washington, D.C., 2001, p.125-6. 012
SYNTHESIS OF MACROPOROUS POLYMER
BEADS BY SUSPENSION POLYMERIZATION
USING SUPERCRITICAL CARBON DIOXIDE AS
A PRESSURE-ADJUSTABLE POROGEN
Wood C D; Cooper A I
Liverpool,University
Investigations were carried out into the possibility
of preparing macroporous polymer beads by oil-in-
water suspension polymerisation using supercritical
carbon dioxide as the porogenic solvent. Suspension
polymerisation of trimethylol propane trimethacrylate was
carried out under various conditions. Polymer morphology
was studied using scanning electron microscopy. Nitrogen
adsorption/desorption and mercury intrusion porosimetry
results were also obtained. It was demonstrated that well-
de
À ned macroporous polymer beads can be synthesised
in the absence of any organic solvents using supercritical
carbon dioxide as the porogen. It is possible that these
initial results are the most signi
À cant yet of a system
where polymer properties can be tuned by varying the
supercritical
Á uid solvent density. 11 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.839624
Item 185
Polymer Engineering and Science
41, No.12, Dec. 2001, p.2259-65
SUPERCRITICAL CO2 WELDING OF
LAMINATED LINEAR LOW DENSITY
POLYETHYLENE FILMS
Caskey T; Lesser A J; McCarthy T J
Massachusetts,University
Supercritical carbon dioxide was used as a reversible
plasticising agent to promote solvent welding of quasi-
isotropic, highly oriented laminated LLDPE films.
The interfacial adhesion between individual plies,
morphological properties, crystal structure, tensile
properties, puncture resistance and tear resistance of the
laminated
À lms were investigated and the data obtained
compared with those for unoriented LLDPE
À lms. 15
refs.
USA
Accession no.839391
References and Abstracts
70
© Copyright 2005 Rapra Technology Limited
Item 186
Industrial and Engineering Chemistry Research
40, No.23, 14th Nov. 2001, p.5570-7
PROCESSING OF POLYAMIDE 11 WITH
SUPERCRITICAL CARBON DIOXIDE
Martinache J D; Royer J R; Siripurapu S; Henon F E;
Genzer J; Khan S A; Carbonell R G
North Carolina,State University; Ato
À na Chemicals Inc.
The supercritical carbon dioxide induced swelling and
plasticisation of polyamide 11 were investigated. The
diffusion coefficient of carbon dioxide in polyamide
11 was calculated from the initial slope of the swelling
kinetics data. The use of carbon dioxide as a blowing agent
was also investigated and preliminary foaming attempts
using a batch process are reported. 52 refs.
USA
Accession no.838726
Item 187
Synthetic Metals
123, No.3, 24th Sept.2001, p.509-14
SYNTHESIS OF CONDUCTIVE ELASTOMERIC
FOAMS BY AN IN SITU POLYMERIZATION OF
PYRROLE USING SUPERCRITICAL CARBON
DIOXIDE AND ETHANOL COSOLVENTS
Shenoy S L; Kaya I; Erkey C; Weiss R A
Connecticut,University
Conductive polyurethane/polypyrrole composite foams
were prepared using supercritical carbon dioxide to
impregnate a polyurethane foam with ferric tri
Á uoromethane
sulphonate or ferric tri
Á uoroacetate, followed by in situ
polymerisation of pyrrole. A small amount of ethanol was
added to the supercritical carbon dioxide and this greatly
improved the solubility of the oxidants in the supercritical
carbon dioxide. The conductivity of the composite foams
was 0.0000001- 0.01 S/cm depending on how much
ethanol was used and the impregnation time. The amount
of polypyrrole formed depended on the amount of oxidant
absorbed by the foam. When low ethanol concentrations
and/or short impregnation times were used, the polypyrrole
produced was concentrated at or near the surfaces of the
foam sample. By increasing the amount of ethanol and the
impregnation time the dispersion of the polypyrrole in the
foam was improved. The use of the ferric tri
Á uoroacetate
resulted in foams with much lower conductivity than
those using tri
Á uoromethane sulphonate. The electrically
conductive polymers formed have uses in technologies,
such as rechargeable batteries, sensors, EMI shielding and
biomaterials. 19 refs.
USA
Accession no.836773
Item 188
Polymer Engineering
1, No.8, Nov.2001, p.24-5
FARADAY PORTABLE INJECTION MOULDER
In response to signi
À cant industrial interest in liquid and
supercritical CO2 as a ‘green solvent’ and processing
aid, a demonstration unit has been developed to exploit
the technology for in-situ plasticisation and foaming of
plastics. This development is part of a Faraday Plastics
project, in collaboration with Rapra Technology. This
fully automated, user-friendly machine is believed to be
the world’s
À rst portable injection moulding machine to
incorporate supercritical CO2 foaming technology. The
gas-injection facility can be used as a foaming agent or
as a means to lower the viscosity of the melt in order
to case
Á ow and improve product quality. Rapra had
taken a standard bench-top injection moulder from MCP
Equipment of Stone, Staffordshire, in order to carry out the
conversion. MCP was chosen as a partner for this project
as the company manufactures a range of mini-moulding
and blow moulding machines ideal for R & D work due to
their small footprint and portability. Details are given.
FARADAY PLASTICS; MCP EQUIPMENT LTD.; RAPRA
TECHNOLOGY LTD.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.835596
Item 189
Nippon Gomu Kyokaishi
74, No.5, May 2001, p.173-8
Japanese
CHEMICAL RECYCLING PROCESS FOR
WASTE PLASTICS USING SUPER-CRITICAL
WATER
Fukuzato R
The reaction-catalysing properties of super-critical
Á uids
are described, and some examples are demonstrated of the
chemical recycling of waste plastics. 16 refs. Articles from
this journal can be requested for translation by subscribers
to the Rapra produced International Polymer Science and
Technology.
Accession no.834123
Item 190
Macromolecular Chemistry and Physics
202, No.14, 28th Sept. 2001, p.2857-63
FREE-RADICAL POLYMERIZATIONS
OF STYRENE IN CO2/ETHANOL MIXED
SUPERCRITICAL FLUID
Mingotaud A-F; Begue G; Cansell F; Gnanou Y
CNRS
The free radical polymerisation of styrene was studied in
carbon dioxide/ethanol mixed supercritical
Á uid. Results
were compared with those generated in the presence of
mesitylene or pure ethanol used as solvent. 29 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.833958
References and Abstracts
© Copyright 2005 Rapra Technology Limited
71
Item 191
Polymer Science Series B
43, Nos.7-8, July/Aug.2001, p.227-9
SYNTHESIS OF POLYIMIDES IN
SUPERCRITICAL CARBON DIOXIDE
Said A-Galiev E E; Vygodskii Y S; Nikitin L N;
Vinokur R A; Gallyamov M O; Khokhlov A R
Russian Academy of Sciences
Polyimides with a quantitative yield are produced by the
polycyclocondensation of dianhydride 6F, diamine 6F and
9,9-bis(4’-aminophenyl)
Á uorene in supercritical carbon
dioxide (32.5 MPa, 180 deg.C). The synthesised polymers
have an inherent viscosity up to 0.43 dl/g, Mw = 12.4 x
10 3, Mn = 4.7 x 10 3 and Mw/Mn = 2.6. It is suggested
that, in the presence of traces of water, supercritical carbon
dioxide plays the role of a catalyst in the formation of
polyimides. 4 refs.
RUSSIA
Accession no.831630
Item 192
Plast’ 21
No.102, May 2001, p.32-4
Spanish
MORE ECONOMICAL GAS INJECTION
MOULDING
The MuCell process developed by Husky for injection
moulding microcellular plastics and thermoplastic
elastomer foam components is described. The advantages
of this process, which uses supercritical
Á uids of nitrogen
or carbon dioxide as blowing agents, are examined in
comparison with conventional gas injection moulding
techniques.
HUSKY INJECTION MOULDING SYSTEMS LTD.;
TREXEL
CANADA; USA
Accession no.831352
Item 193
Revista de Plasticos Modernos
81, No.535, Jan.2001, p.92-8
Spanish
USE OF SUPERCRITICAL FLUID
TECHNOLOGY IN THE PREPARATION OF
SYSTEMS FOR THE CONTROLLED RELEASE
OF DRUGS
Fanovich M A; Fraile J; San Roman J;
Rodriguez-Clemente R; Domingo C
Barcelona,Institut de Ciencia de Materials; Instituto de
Ciencia y Tecnologia de Polimeros
The basic concepts of supercritical
Á uid technology are
examined, and the use of supercritical carbon dioxide as
a solvent in processes for the preparation of polymeric
microcapsules and microspheres for controlled drug
release is discussed. The different preparation processes
are classi
À ed as a function of the solubility of polymers
and drugs in the solvent. 50 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN;
WESTERN EUROPE
Accession no.831307
Item 194
Industrial and Engineering Chemistry Research
40, No.19, 19th Sept. 2001, p.4058-68
COATING OF METAL POWDERS WITH
POLYMERS IN SUPERCRITICAL CARBON
DIOXIDE
Glebov E M; Yuan L; Krishtopa L G; Usov O M;
Krasnoperov L N
New Jersey,Institute of Technology
Supercritical carbon dioxide was used as a solvent to
produce PVDF and polyvinyl biphenyl
À lms on fused silica
plates and metal powders. Protective properties of the
À lms
were quanti
À ed based on the dissolution rate. The average
thickness of the
À lms was evaluated using UV absorption
spectroscopy. A technique to measure the solubilities of
poorly soluble polymers in supercritical carbon dioxide
was developed. 47 refs.
USA
Accession no.831141
Item 195
Journal of Biomedical Materials Research (Applied
Biomaterials)
58, No.5, 2001, p.505-10
ASSESSMENT OF PARAMETERS ASSOCIATED
TO THE RISK OF PVC CATHETER REUSE
Granados D L; Jimenez A; Cuadrado T R
San Juan,National University; Alicante,University; Mar
del Plata,Universidad Nacional
Details are given of the identi
À cation of material parameters
that could contribute to the health risks associated with the
practice of reprocessing PVC catheters. supercritical
Á uid
extraction was used to determine the total percentage
of extractables and off-line gas chromatography-
Á ame
ionisation detection was used for the identi
À cation and
quanti
À cation of bisethylhexyl phthalate. Data are also
presented for Tg, storage modulus, dissipation factor, and
surface roughness. 24 refs.
ARGENTINA; EUROPEAN COMMUNITY; EUROPEAN UNION;
SPAIN; WESTERN EUROPE
Accession no.831095
References and Abstracts
72
© Copyright 2005 Rapra Technology Limited
Item 196
Antec 2001.Conference proceedings.
Dallas, Texas, 6th-10th May, 2001, paper 670
COMMERCIALIZATION OF MICROCELLULAR
BLOW MOLDING
Straff R; Anderson J; Blizard K; Chapman B
Trexel Inc.
(SPE)
Microcellular blow moulding is brie
Á y discussed. It is
proposed that the technology may be used to reduce bottle
weight whilst maintaining other important performance
characteristics. The process involves the injection of a
precise amount of supercritical
Á uid blowing agent into
the extruder, forming a single phase solution with the
polymer melt. Nucleation is initiated by a rapid pressure
drop followed by expansion of the cells, the size of which
is controlled by controlling the process conditions. The
À nal stage is the shaping of the part. Process technology
has been developed, including extruder screw design,
Á uid
injectors and metering systems, and die design to control
cell nucleation. Conventional moulding techniques are
used.
USA
Accession no.830102
Item 197
Journal of Applied Polymer Science
81, No.9, 29th August 2001, p.2102-8
DEPOLYMERIZATION OF POLYETHYLEN
ETEREPHTHALATE IN SUPERCRITICAL
METHANOL
Kim B-K; Hwang G-C; Bae S-Y; Yi S-C; Kumazawa H
Hanyang,University
The depolymerisation of PETP in supercritical methanol
was caried out using a batch-type autoclave reactor. The
conversion and yield of dimethyl terephthalate (DMT)
increased with rising temperature. The yield of DMT
exceeded 50% above 280C and the
À nal yield of DMT
at 300 and 310C reached 97.0% and 97.7% respectively.
the yield of ethylene glycol was slightly lower than that
of DMT. the yield of DMT increased markedly when the
methanol density was 0.08 g/cc and levelled off at higher
densities. A kinetic model to simulate the depolymerisation
of PETP in supercritical methanol was suggested. The
values of the forward reaction rate constants at different
temperatures were determined by comparing the observed
time dependence with that calculated by the proposed
model. The activation energy was found to be 49.9 kJ/mol,
which was close to a previously published value of 55.7
kJ/mol. 4 refs.
KOREA
Accession no.828757
Item 198
Advanced Materials
13, No.14, 18th July 2001, p.1111-4
RECENT DEVELOPMENTS IN MATERIALS
SYNTHESIS AND PROCESSING USING
SUPERCRITICAL CO2
Cooper A I
Liverpool,University
Some recent studies involving the use of supercritical
carbon dioxide, as a solvent, in the synthesis and
processing of various advanced materials, including porous
organic materials, coatings, lithographic resists, metal
nanoparticles and biomaterials, are reviewed. 16 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.826341
Item 199
Antec 2001.Conference proceedings.
Dallas, Texas, 6th-10th May, 2001, paper 331
SUPERCRITICAL CARBON DIOXIDE
ASSISTED POLYMER BLENDING IN TWIN-
SCREW EXTRUSION: PHASE INVERSION,
MORPHOLOGY, AND MECHANICAL
PROPERTIES
Elkovitch M D; Lee L J; Tomasko D L
Ohio,State University
(SPE)
The in
Á uence of supercritical carbon dioxide additions
during the twin-screw extrusion blending of polystyrene
(PS) with poly(ethylene-co-methyl acrylate) impact
modi
À er, and of poly(methyl methacrylate) (PMMA) with
the impact modi
À er, was investigated. Phase inversion,
morphology and mechanical properties were studied
for a CO2 addition of 2.0 wt%. The CO2 increased the
phase inversion rate by reducing the glass transition
temperatures of PS and PMMA. The increased inversion
rate, in conjunction with a reduced viscosity ratio, led to
enhanced dispersion of the impact modi
À er phase. The
use of CO2 gave an increase in impact strength and a
reduction in the
Á exural modulus, indicating the enhanced
dispersion of the rubber impact modi
À er phase into the
brittle polymer matrices. The morphology was not changed
by reprocessing. 17 refs.
USA
Accession no.825955
Item 200
Journal of Macromolecular Science B
40, No.2, 2001, p.189-97
DYEING BEHAVIOR OF HIGH-SPEED SPUN
POLY(ETHYLENE TEREPHTHALATE) FIBERS
IN SUPERCRITICAL CARBON DIOXIDE
Kawahara Y; Yoshioka T; Sugiura K; Ogawa S;
Kikutani T
Kyoto,Institute of Technology; Kyoto,Municipal Textile
Research Institute; Tokyo,Institute of Technology
The dyeing behaviour of several types of high-speed
and normal speed spun PETP
À bres was compared in
References and Abstracts
© Copyright 2005 Rapra Technology Limited
73
supercritical carbon dioxide
Á uid. At lower temp. and
pressure, the high-speed spun
À bres, which had inherently
larger crystallite sizes and lower birefringence, showed
a larger dye uptake than the other fibres. When the
supercritical conditions were elevated to 125C and 230
bar, the dye uptake of both types increased markedly
and the difference in dye uptake between the fibres
became small. This indicated that the swelling of
À bres
in supercritical carbon dioxide
Á uid exceeded a certain
level and the diffusion of dye molecules was then
promoted. The swelling also promoted the rearrangement
of molecular chains and permitted cold crystallisation to
occur. The modi
À cation of À bre structure through dyeing
in supercritical carbon dioxide fluid was significant,
particularly for the
À bres whose inherent structure was
not so well developed. 20 refs.
JAPAN
Accession no.825008
Item 201
Antec 2001.Conference proceedings.
Dallas, Texas, 6th-10th May, 2001, paper 200
SUPERCRITICAL FLUID ASSISTED POLYMER
PROCESSING
Matthews S O; Hornsby P R
Brunel University
(SPE)
A single screw extruder with a direct injection port for
supercritical carbon dioxide was used to study the in
Á uence
of CO2 additions on the processing of polyethylene (PE)
and PE containing silicon nitride. The extruder was
À tted
with a slit die for in-line rheometry. The injection of CO2
gave an average reduction in viscosity of 25%. Negligible
foaming was observed, and was dependent upon screw
speed, temperature, and the rate of CO2 injection and
pressure. Removal of the PE from the composite materials
by thermal treatment yielded ceramics of controlled
porosity which could be successfully sintered. 8 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.823412
Item 202
Antec 2001.Conference proceedings.
Dallas, Texas, 6th-10th May, 2001, paper 199
MEASUREMENT OF ENTRANCE PRESSURE
DROP OF POLYSTYRENE/SUPERCRITICAL
CO2 SOLUTIONS
Xue A; Tzoganakis C
Waterloo,University
(SPE)
The in
Á uence of pressure and supercritical carbon dioxide
content on the entrance pressure drop and rheological
properties of polystyrene/CO2 solutions was investigated
using a twin screw extruder
À tted with 180 degree entrance
angle slit dies with contraction ratios of 4:1 and 18:1.
Pressure was measured using transducers before and after
the die contraction. The introduction of CO2 into the
polystyrene melt reduced the entrance pressure drop, and
the shear and extensional viscosities. The entrance pressure
drops as a function of wall shear stress
À tted a master curve
for different CO2 contents and pressure levels. 10 refs.
CANADA
Accession no.823411
Item 203
Blowing Agents ‘99. Proceedings of a conference
held at the conference centre UMIST, UK, 9th.-10th
December 1999..
Shawbury, 1999, Paper 11, p.59-63. 012
MICROCELLULAR FOAM MOLDING
TECHNOLOGY
Pierick D; Janisch R
Trexel Inc.
(Rapra Technology Ltd.)
The MuCell foam moulding technology, invented by
the Massachusetts Institute of Technology’s Mechanical
Engineering Department, and licenced exclusively by Trexel
Inc., is described. The proprietary process uses supercritical
Á uids of atmospheric gases to create evenly distributed and
uniformly sized microscopic cells throughout a polymer.
The process is suitable for injection moulding, blow
moulding and extrusion, providing advantages in product
design, processing ef
À ciency and cost reduction. The use of
MuCell technology permits moulders to reduce raw material
consumption and cycle time whilst producing strong, lighter
weight products, the ability to foam thin-walled parts,
reduce processing temperatures, injection pressure and
clamp tonnage. In addition, the process enables moulders
to foam materials that previously could not be foamed
successfully using conventional foaming technologies,
such as high temperature polysulphone, polyetherimide,
liquid crystalline polymers and thermoplastic elastomers.
These advantages and features of the MuCell technology
are further discussed, and examples of applications are
described.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; USA;
WESTERN EUROPE
Accession no.818864
Item 204
Blowing Agents ‘99. Proceedings of a conference
held at the conference centre UMIST, UK, 9th.-10th
December 1999..
Shawbury, 1999, Paper 10, p.53-57. 012
CARBON DIOXIDE AS BLOWING AGENT
IN THE EXTRUSION OF THERMOPLASTIC
FOAMS
Gale M
Rapra Technology Ltd.
(Rapra Technology Ltd.)
The use is discussed of carbon dioxide as a blowing agent
in the extrusion of thermoplastic foams, in particular,
References and Abstracts
74
© Copyright 2005 Rapra Technology Limited
polyole
À ns and polystyrene. The paper summarises some
of the work carried out at Rapra Technology Ltd., into
the use of carbon dioxide with a conventional single
screw extruder, retro
À tted with a Cavity Transfer Mixer
and a static mixer heat exchanger. Estimates are included
of potential cost savings for a proposed commercial
applications, and an indication of the type of equipment
which will probably be used. 9 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.818863
Item 205
Industrial and Engineering Chemistry Research
40, No.3, 7th Feb.2001, p.756-67
DEPOLYMERISATION OF STYRENE-
BUTADIENE COPOLYMER IN NEAR-CRITICAL
AND SUPERCRITICAL WATER
Park Y; Hool J N; Curtis C W; Roberts C B
Auburn,University
Many conventional solvents do not suf
À ciently dissolve
crosslinked polymers such as SBR to allow ef
À cient
polymerisation. Supercritical and near-critical water
provides an alternative benign solvent for this application.
Supercritical water oxidation and thermal gradation
under supercritical water conditions provide a means to
break down rubbery materials into organic compounds
that can then be recovered as a chemical feedstock.
Depolymerisation reactions of SBR are examined in
a semi-continuous reactor. A statistical experimental
analysis technique is used to investigate the effect of
various operating conditions: temperature, pressure and the
presence of hydrogen peroxide as an oxidant. The results
demonstrate the ability of supercritical and near-critical
water to break down the SBR into a range lower molecular
weight organic compounds for potential recovery. Analysis
of variance shows that the temperature and oxidant
concentration are signi
À cant at the 1% level for destruction
efficiency. Benzene, toluene, ethylbenzene, styrene,
phenol, acetophenone, benzaldehyde and benzoic acid are
identi
À ed as liquid products using gas chromatography in
both and semi-continuous reactors. The gas products are
comprised of carbon monoxide, carbon dioxide and water
as determined by Fourier transform IR spectroscopy. The
ef
À ciency and a semi-quantitative analysis of the liquid
products show that both pyrolysis and oxidation products
are observed, and low molecular weight oxidation products
are to be primary. 7 refs.
USA
Accession no.810172
Item 206
Polymer Science Series C
42, No.1, 2000, p.78-101
POLYMER PROCESSING WITH
SUPERCRITICAL FLUIDS
Kararian S G
London,Imperial College of Science,Technology &
Medicine
Supercritical
Á uids have a unique and valuable potential
for the enhanced processing of many materials. Research
in the applications of supercritical fluids to polymer
processing are reviewed. The ability of supercritical
carbon dioxide to swell and plasticise polymers is crucial
to impregnation, extraction and modi
À cation of polymeric
materials. This plasticisation also reduces viscosity and
facilitates the processing of polymers due to lower shear
stresses. Spectroscopy plays an important role in probing
these interactions at a molecular level and to follow in
situ the processes of CO2-induced plasticisation and
the crystallisation of polymers. Opportunities exist for
improving the processing of many polymeric-based
materials ranging from textile to food and biomaterials.
The implications of interactions between supercritical
carbon dioxide and polymers for drying, dyeing, foaming
and extrusion are also discussed with an outlook for
further opportunities in this and related areas of polymer
processing. 312 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.809650
Item 207
Macromolecules
34, No.4, 13th Feb.2001, p.775-81
RING-OPENING POLYMERIZATION
OF EPSILON-CAPROLACTONE IN
SUPERCRITICAL CARBON DIOXIDE
Stasssin F; Halleux O; Jerome R
Liege,University
The ring-opening polymerisation of epsilon-caprolactone
was investigated in supercritical carbon dioxide at 40 C
and 210-215 bar, with dibutyltin dimethoxide initiator.
The polymer molecular weight was dependent upon
the monomer:tin alkoxide molar ratio and the degree of
monomer conversion. First-order reaction kinetics were
observed, the kinetics being lower than for polymerisation
in toluene and in bulk. This was attributed to the
competitive coordination of CO2 onto tin. 21 refs.
BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION;
WESTERN EUROPE
Accession no.808638
Item 208
Polymer Engineering and Science
41, No.2, Feb.2001, p.135-44
DRAWING IN HIGH PRESSURE CARBON
DIOXIDE - A NEW ROUTE TO HIGH
PERFORMANCE FIBERS
Hobbs T; Lesser A J
Massachusetts,University
A new draw technique for polymer orientation was
developed and applied to different polymer
À bres (PETP,
References and Abstracts
© Copyright 2005 Rapra Technology Limited
75
nylon-66 and UHMWPE). In this technique, a polymer
was drawn uniaxially in supercritical carbon dioxide
using a custom high-pressure apparatus. This technique
could be used as a replacement for the traditional drawing
process or as a post-treatment process. With PETP,
the technique was not effective at temps. at or below
130C. In contrast, the process was highly effective for
nylon-66, where carbon dioxide drawn
À bres showed
signi
À cantly higher crystallinity and orientation, together
with improved mechanical properties. While the
À bres
were plasticised, the drawability of the
À bres was only
slightly dependent on temp. High pressure carbon dioxide
drawing of UHMWPE fibres was equally effective.
Commercial high performance
À bres could be drawn
up to a ratio of 1.9 in a second stage, resulting in large
increases in tensile modulus and small improvements in
TS. 40 refs.
USA
Accession no.807502
Item 209
Journal of the Textile Institute - Part 3: Textile
Design: Technology, Management and Marketing
Vol.91, 2000, p.166-7
NOTES ON FUTURE DEVELOPMENTS FOR
TEXTILE FINISHING PROCESSES
Knittel D; Schollmeyer E
German Textile Research Institute North-West eV
A brief description is presented of textile
À nishing processes
that are liable to gain broad technical application in the
near future and on other processes that require intensive
research work but promise bene
À cial new ecological
and economical treatment procedures. The processes
discussed include supercritical
Á uid dyeing of synthetic
À bres (particularly PETP), electric dyeing, liquid ammonia
treatment of cellulosic
À bres, enzymatic processes, and
processes for conductive
À bres, liquid crystal À bres and
À bres derived from new bioresources.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.807440
Item 210
Chemical and Engineering News
79, No.5, 29th Jan.2001, p.34-5
ONE STEP TO BIOACTIVE POLYMERS
Brennan M B
A report is presented on studies led by S.M.Howdle at the
University of Nottingham in which supercritical carbon
dioxide is used to incorporate inorganic materials and
enzymes into the biodegradable polymers poly(lactide-
co-glycolide) and poly(DL-lactide). Particular attention
is paid to the incorporation of hydroxyapatite in order to
create arti
À cial bone and to the incorporation of catalase,
ribonuclease A and beta-D-galactosidase.
NOTTINGHAM,UNIVERSITY
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.807333
Item 211
Industrial and Engineering Chemistry Research
40, No.2, 24th Jan.2001, p.536-43
LATEXES FORMED BY RAPID EXPANSION OF
POLYMER/CARBON DIOXIDE SUSPENSIONS
INTO WATER. I. HYDROPHILIC SURFACTANT
IN SUPERCRITICAL CARBON DIOXIDE
Jae-Jin Shim; Yates M Z; Johnston K P
Texas,University
The rapid expansion of poly-2-ethylhexyl acrylate
suspensions in supercritical carbon dioxide containing a
hydrophilic as well as a carbon dioxide-philic surfactant
produced stable aqueous latices. The hydrophilic
surfactants were soluble in both carbon dioxide and
water. The aqueous latices could also be formed after
depressurisation and resuspension of the polymer
dispersion in carbon dioxide. Latices in basic buffer
solutions were stable for a few weeks for concentrations
up to 15.6% and for several months after sonication. The
synthesis of water-dispersible polymer particles in carbon
dioxide, which could be transferred to water without the
need for organic solvents, could be used for preparation
of new environmentally-benign coatings and adhesives.
28 refs.
USA
Accession no.807153
Item 212
Journal of Polymer Research
7, No.3, Sept.2000, p.155-9
ANALYSIS ON THE DYEING OF
POLYPROPYLENE FIBERS IN SUPERCRITICAL
CARBON DIOXIDE
Liao S K; Chang P S; Lin Y C
Feng Chia,University
PP
À bres were dyed in a supercritical carbon dioxide
system and the results were compared with those for
À bres dyed in water system. Dye uptake value calculated
by UV spectroscopy indicated that PP
À bre dyeing was
much better in carbon dioxide than in water. Optical
microscopic analysis showed that dye molecules had
diffused thoroughly into
À bre in carbon dioxide because
of the good compatibility between the dye and the carbon
dioxide. X-ray and birefringence analysis demonstrated
that plasticisation caused by the introduction of carbon
dioxide made the molecular chain more mobile and led
to an increase in the dyeing of PP
À bres. Furthermore, a
mechanical test and DSC analysis indicated that the
À bre
structure was not damaged when the fabric was dyed at
100C. 23 refs.
TAIWAN
Accession no.807128
References and Abstracts
76
© Copyright 2005 Rapra Technology Limited
Item 213
Macromolecules
33, No.25, 12th Dec.2000, p.9222-7
FREE RADICAL POLYMERIZATION
OF METHYL METHACRYLATE IN
SUPERCRITICAL CARBON DIOXIDE USING
A PSEUDO-GRAFT STABILIZER: EFFECT OF
MONOMER, INITIATOR, AND STABILIZER
CONCENTRATIONS
Christian P; Giles M R; Grif
À ths R M T; Irvine D J;
Major R C; Howdle S M
Nottingham,University; Uniqema
The free radical polymerisation of methyl methacrylate
in supercritical carbon dioxide was described, using a
commercially available acid-terminated per
Á uoropolyether
as a polymerisation stabiliser. The effects of varying the
concentrations of monomer, stabiliser and initiator (AIBN)
on the molecular weight, yield and morphology of the
resulting PMMA were studied. Unusual morphologies
occurred at high initiator concentration and low stabiliser
concentration. Remarkably high polymer yields were
produced even at very low stabiliser concentrations. No
detectable stabiliser residues were found in the PMMA,
even when very high stabiliser concentrations were used.
24 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.803578
Item 214
ACS Polymeric Materials Science and Engineering.
Volume 75. Conference Proceedings.
Orlando, FL., Fall 1996, p.73. 012
SUPERCRITICAL FLUID IMPREGNATION OF
DYE INTO GLASSY POLYMERS
Kazarian S G; Brantley N H; Vincent M F; West B L;
Liotta C L; Eckert C A
Georgia,Institute of Technology
(ACS,Div.of Polymeric Materials Science & Engng.)
It is known that supercritical carbon dioxide (scCO2) can
be used to swell and plasticise glassy polymers for solvent-
free incorporation of additives. For example, although
Disperse Red 1 dye (DR1) is relatively insoluble in
scCO2, the high partition coef
À cient in scCO2 has enabled
incorporation of about 3 weight percent into a PMMA
matrix. This is likely to be attributable to hydrogen bonding
between the hydroxyl moiety of DR1 and the carbonyl
groups of PMMA. The enhanced diffusion process was
observed in situ using FTIR and UV/vis spectroscopy.
Among the other applications of tunable, solvent-free
scCO2 impregnation into glassy polymers might be dyeing
processes or non-linear optical materials.
USA
Accession no.803056
Item 215
Journal of Polymer Science: Polymer Physics Edition
38, No.23, 1st Dec.2000, p.3168-80
HIGH-PRESSURE RHEOLOGY OF
POLYSTYRENE MELTS PLASTICISED WITH
CO2: EXPERIMENTAL MEASUREMENT AND
PREDICTIVE SCALING RELATIONSHIPS
Royer J R; Gay Y J; Desimone J M; Khan S A
North Carolina,State University
A high-pressure extrusion slit die rheometer is constructed
to measure the viscosity of polymer melts by liquid
and supercritical CO2. A novel gas injection system is
devised to accurately meter the follow of CO2 into the
extruder barrel. Measurements of pressure drop, within
the die, con
À rm the presence of a one-phase mixture and
a fully-developed
Á ow during viscosity measurements.
Experimental measurements of viscosity as a function of
shear rate, pressure, temperature and CO2 concentration
are conducted for three commercial PS melts. The
CO2 is shown to be an effective plasticiser for PS,
lowering the viscosity of the polymer melt by as much
as 80%, depending of the process conditions and CO2
concentration. Existing theories for viscoelastic scaling
of polymer melts and the prediction of Tg depression by
a diluent are used to develop a free volume model for
predicting the effects of CO2 concentration and pressure on
polymer melt rheology. The free volume model, dependent
only on material parameters of the polymer melt and pure
CO2, is shown to accurately collapse the experimental
data onto a single master curve independent of pressure
CO2 concentration for each of the three PS a samples.
This model constitutes simple predictive set of equations
to quantify the effects of gas-induced plasticisation on
molten polymer systems. 47 refs.
USA
Accession no.802457
Item 216
ACS Polymeric Materials: Science and Engineering.
Fall Meeting 2000. Volume 83.
Washington, D.C., 20th-24th Aug.2000, p.538-9
CHEMICALLY SENSITIVE NANOPARTICLES
DEVELOPED FROM RAPID EXPANSION OF
SUPERCRITICAL SOLUTIONS
Pestov D; Levit N; Colby D; Tepper G
Virginia,Commonwealth University
(ACS,Div.of Polymeric Materials Science & Engng.)
Rapid expansion of supercritical solutions (RESS) is a
versatile technique capable of particle size tuning over a
range of 4-5 orders of magnitude. It takes advantage of the
enormous solubility change that occurs by rapidly expanding
a supercritical solution through a restriction (small ori
À ce
or capillary nozzle) in order to form precipitates with
narrow and tunable size distributions. Silicone polymers
are attractive for chemical sensor applications because of
their favourable physical and chemical properties as well
as the possibility for chemical modi
À cation. The most
References and Abstracts
© Copyright 2005 Rapra Technology Limited
77
interesting family of silicone polymers are the silicone
rubbers - ready for curing compounds, that overcome
the poor mechanical properties of raw silicones after
intermolecular net formation. Siloxane based polymers are
known to be soluble in supercritical carbon dioxide over
a wide range of concentrations. The main disadvantage
of raw siloxanes in sensor applications is the loss of
surface integrity over time due to inadequate viscosity.
A new approach is described combining RESS and room
temperature gas-phase curing to produce siloxane based,
chemically active and physically stable polymer particles
with a wide range of morphologies. 5 refs.
USA
Accession no.802377
Item 217
Antec 2000.Conference proceedings.
Orlando, Fl., 7th-11th May, 2000, paper 488
SUPERCRITICAL CARBON DIOXIDE
ASSISTED POLYMER BLENDING IN
TWIN-SCREW EXTRUSION: RELATIONS
BETWEEN MORPHOLOGY EVOLUTION AND
MECHANICAL PROPERTIES
Elkovitch M D; Lee L J; Tomasko D L
Ohio,State University
(SPE)
The in
Á uence of additions of 0.5-3.0 wt% of supercritical
carbon dioxide to blends of polystyrene (PS) and
poly(methyl methacrylate) (PMMA) was investigated
during compounding using a twin screw extruder.
Viscosity reductions of up to 80% and 70% were observed
for PMMA and PS, respectively. The dispersed phase
exhibited a sharp decrease in size adjacent to the injection
point, but further compounding resulted in its coalescence,
and demixing occurred when the CO2 was vented. The
À nal morphology was similar to that observed without the
addition of CO2. Small additions of
À llers slowed down
the demixing on release of the CO2. 12 refs.
USA
Accession no.802018
Item 218
Popular Plastics and Packaging
46, No.1, Jan. 2001, p.77-9
REVIEW ON THE APPLICATIONS OF
SUPERCRITICAL FLUIDS IN POLYMER
PROCESSING
Tipnis S J
The use of supercritical
Á uids and in particular supercritical
carbon dioxide is examined with respect to the bene
À ts it
provides in polymer processing and polymerisation. The
viability of using supercritical carbon dioxide as a solvent
medium for homogeneous solution of polymerisation in
place of ecologically dangerous solvents such as CFC
was demonstrated in the homogeneous synthesis of
Á uorinated telomers. A further development in the use
of supercritical carbon dioxide is in the direct formation
of microcellular thermoplastic parts, in which the direct
addition of supercritical
Á uid is done in an extruder to
produce foamed plastic parts. 6 refs.
INDIA
Accession no.801405
Item 219
Industrial and Engineering Chemistry Research
39, No.12, Dec.2000, p.4891-6
NEW CHELATE COMPLEXES OF COPPER AND
IRON: SYNTHESIS AND IMPREGNATION INTO
A POLYMER MATRIX FROM SOLUTION IN
SUPERCRITICAL CARBON DIOXIDE
Said-Galiyev E; Nikitin L; Vinokur R; Gallyamov M;
Kurykin M; Petrova O; Lokshin B; Volkov I;
Khokhlov A; Schaumburg K
Nesmeyanov Institute of Organo-Element Compounds;
Copenhagen,University
Chelate complexes of copper diiminate and iron diiminate
were synthesised and their physical characteristics were
studied. The diffusion of supercritical(SC) carbon dioxide
into polyarylate(PAR)
À lms and their impregnation with
diiminates were investigated. The equilibrium degree
of PAR swelling in SC carbon dioxide was about 10%.
The conditions of impregnation were determined. The
impregnation was con
À rmed by the FTIR spectroscopic
data. Thermal reduction of metal ions was investigated.
Transformations of the chelate complexes on the polymer-
À lm surface were studied by ESCA. The value of the Auger
factor indicated that, after thermal reduction, the copper
ion was in a nearly univalent state. The copper content in
À lms was as large as 6.3 wt % and the iron content was 4.5
wt %. The FTIR and ESCA spectroscopic studies showed
that, in the course of impregnation, chelate complexes
interacted with functional groups of the polymer.
Subsequent thermal reduction of metal in air resulted in
diiminate evaporation and thermooxidative degradation
with ligand decomposition and enrichment of the surface
with metal atoms. According to the SAXS data, the size
distribution of metal-containing particles ranged from 20
to 60 nm with a maximum at 34 nm. 23 refs.
DENMARK; EUROPEAN COMMUNITY; EUROPEAN UNION;
RUSSIA; SCANDINAVIA; WESTERN EUROPE
Accession no.800608
Item 220
Industrial and Engineering Chemistry Research
39, No.12, Dec.2000, p.4707-13
COMPARISON OF DYE DIFFUSION IN
POLY(ETHYLENE TEREPHTHALATE) FILMS
IN THE PRESENCE OF A SUPERCRITICAL OR
AQUEOUS SOLVENT
Sicardi S; Manna L; Banchero M
Torino,Politecnico
The diffusion coefficients of a solute (a dyestuff)
permeating a PETP
À lm in a supercritical impregnating
References and Abstracts
78
© Copyright 2005 Rapra Technology Limited
system were measured for different working conditions
and the results were compared with similar data obtained
with the same solute in the same material but in a
traditional aqueous system. The experimental technique
used was that of the ‘
À lm roll method’ for the experiments
conducted in the supercritical system. For the aqueous
system, the sorption kinetics of the dyestuff on plane PETP
sheets were measured. The results con
À rmed the high gain
in the rate of diffusion obtained with the supercritical
impregnating system, related to the high plasticising
power of supercritical carbon dioxide towards synthetic
polymers. Comparison was made with the data obtained
by operating with supercritical carbon dioxide at different
working pressures and temps. and in the presence of a
proper modi
À ed (ethanol). 25 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY;
WESTERN EUROPE
Accession no.800602
Item 221
Industrial and Engineering Chemistry Research
39, No.12, Dec.2000, p.4622-6
PRODUCTION OF ENGINEERING PLASTICS
FOAMS BY SUPERCRITICAL CARBON
DIOXIDE
Ming-Tsai Liang; Chang-Ming Wang
I-Shou,University
Foams of PETP and polycarbonate(PC) were prepared
by rapid depressurisation of carbon dioxide-saturated
molten resin. It was found that the attainable expansion
ratio of the foam produced was generally less than 10. The
effect of saturation temp. on the nucleation was mainly a
result of the competition between the viscosity effect and
the solubility effect. The effect of saturation pressure on
the nucleation was, however, two-fold, i.e. the degree of
supersaturation and the rate of depressurisation. The effect
of lowering the depressurisation rate and changing the
depressurisation pattern on the polymeric foams was also
investigated. By careful observation of the microstructure,
it was concluded that the foaming process was dominated
by the nucleation kinetics. This study provided several
alternative techniques for controlling the microstructure
and the expansion ratio of PETP and PC foams. 12 refs.
TAIWAN
Accession no.800596
Item 222
Industrial and Engineering Chemistry Research
39, No.12, Dec.2000, p.4588-96
CONTINUOUS PRECIPITATION
POLYMERIZATION OF VINYLIDENE
FLUORIDE IN SUPERCRITICAL CARBON
DIOXIDE: MODELING THE RATE OF
POLYMERIZATION
Charpentier P A; DeSimone J M; Roberts G W
North Carolina,State University
The kinetics of the surfactant-free precipitation
polymerisation of vinylidene
Á uoride(VDF) in supercritical
carbon dioxide were studied in a continuous stirred
autoclave. Diethyl peroxydicarbonate was used as the
free-radical initiator. The stirring rate and agitator design
had no effect on the rate of polymerisation(Rp) or on the
weight-average molec.wt.(Mw) of the PVDF formed. The
fractional conversion of VDF ranged from 7 to 26% and Rp
was as high as 0.000027 mol/L.s at 75C and at a VDF feed
concentration of 2.5 mol/L. The PVDF was collected as a
dry, free-
Á owing powder and had Mws up to 150 kg/mol
and melt
Á ow indices as low as 3.0 at 230C. Homogeneous,
free-radical kinetics provided a reasonable basis for
describing the Rp, despite the heterogeneous nature of
the system. The order of the reaction with respect to the
monomer was found to be 1.0 and the order with respect
to the initiator was 0.5. The experimental data suggested
that an inhibitor was present in the monomer or that the
monomer itself acted as an inhibitor. 31 refs.
USA
Accession no.800595
Item 223
Industrial and Engineering Chemistry Research
39, No.12, Dec.2000, p.4564-6
SYNTHESIS OF SUGAR-CONTAINING
AMPHIPHILES FOR LIQUID AND
SUPERCRITICAL CARBON DIOXIDE
Weijun Ye; DeSimone J M
North Carolina,University
The use of liquid and/or supercritical carbon dioxide as a
processing
Á uid is limited by its inability to solubilise highly
polar compounds. This problem can be alleviated by the
addition of carbon dioxide-philic amphiphiles. The main
aim of this study was to design and synthesise materials that
had both strong polar moieties and highly carbon dioxide-
philic segments. Sugar-containing hydrophobic/hydrophilic
Á uorinated copolymers were synthesised by free-radical
polymerisation. The degree of solubility of the amphiphiles
in carbon dioxide was found to be strongly in
Á uenced by
the amphiphilic structure, including the polarity of the sugar
head (acetal protected and deprotected) and the fraction of
carbon dioxide-philic groups. It was also found that the
presence of water in the carbon dioxide phase could decrease
the solubility of the hydrophilic copolymer. The dispersion
polymerisation of 2-hydroxyethyl methacrylate in carbon
dioxide was tested by using the hydrophilic amphiphile as
a stabiliser. Spherical particles in the submicron size range
were obtained. 14 refs.
USA
Accession no.800594
Item 224
Industrial and Engineering Chemistry Research
39, No.12, Dec.2000, p.4506-9
IMPREGNATION OF POLYETHYLENE(PE)
References and Abstracts
© Copyright 2005 Rapra Technology Limited
79
WITH STYRENE USING SUPERCRITICAL
CARBON DIOXIDE AS THE SWELLING AGENT
AND PREPARATION OF PE/POLYSTYRENE
COMPOSITES
Dan Li; Buxing Han
Beijing,Institute of Chemistry
The impregnation of LDPE with styrene using
supercritical(SC) carbon dioxide as the swelling agent
was studied at 35C in the pressure range from 90 to 160
bar. The concentration of styrene in the
Á uid phase ranged
from 0 to 1.668 mol/l. The soaking time varied from 4 to 36
h. In the presence of AIBN initiator, styrene polymerised
to some extent in the soaking process, which resulted in
an increase in the mass uptake. LDPE/PS composites were
prepared by the further polymerisation of styrene in SC
carbon dioxide-swollen LDPE substrates at higher temp.
Using this method, the composition of the composites
could be controlled by the soaking time, pressure and
styrene concentration in the
Á uid phase. Some of the PS
molecules in LDPE/PS blends entangled with the PE
molecules, which caused signi
À cant improvement in the
impact strength, the TS and the EB. 23 refs.
CHINA
Accession no.800592
Item 225
Industrial and Engineering Chemistry Research
39, No.12, Dec.2000, p.4445-9
POLYMER DEPOSITION FROM
SUPERCRITICAL SOLUTIONS FOR SENSING
APPLICATIONS
Tepper G; Levit N
Virginia,Commonwealth University
The feasibility and potential advantages of using
supercritical
Á uid technology for the development of
advanced coatings for chemical sensor applications was
demonstrated. Polydimethylsiloxane microspheres were
deposited onto the sensing surface of a surface acoustic
wave device using rapid expansion of supercritical
solutions. The sensor output was monitored during
repetitive exposure to dilute hexane vapour and was found
to exhibit fast reversible behaviour. 16 refs.
USA
Accession no.800589
Item 226
Patent Number: EP 1057855 A1 20001206
METHOD OF RECYCLING CROSSLINKED
SILICONE COMPOUND WASTE
Kawamoto T
Yazaki Corp.
This involves hydrolysing crosslinked silicone compound
waste by bringing the waste into contact with a solvent
having a hydroxyl group in a molecule under a supercritical
state or by bringing the waste into contact with an alcohol/
water mixture solvent under heating to thereby recover a
non-crosslinked silicone or silicone oil-like product from
the waste.
EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN;
WESTERN EUROPE-GENERAL
Accession no.800456
Item 227
International Journal of Polymeric Materials
47, No.4, 2000, p.657-65
EFFECT OF PRESSURE AND TEMPERATURE
ON SUPERCRITICAL CO2 DYEING OF PET-
DYEING WITH MIXTURES OF DYES
Tusek L; Golob V; Knez Z
Maribor,University
A study was made of the effects of pressure and
temperature on the dyeing of PETP in supercritical carbon
dioxide. The PETP was dyed with either one dye or with
mixtures of two or three dyes and the dyed samples studied
by colorimetry and extraction of the dyes from the fabric.
It was found that variations in pressure and temperature
gave rise to differences in colour, especially when mixed
dyes were employed, and that the amount of dye on the
fabrics increased with increasing temperature as a result
of more rapid molecular motion of the chains and free
volume formation in the
À bres. 12 refs.
SLOVENIA
Accession no.800194
Item 228
Antec 2000.Conference proceedings.
Orlando, Fl., 7th-11th May, 2000, paper 417
CARBON DIOXIDE EXTRUSION FOAMING OF
ENGINEERING THERMOPLASTICS
Gale M
Rapra Technology Ltd.
(SPE)
The direct injection of supercritical
Á uid carbon dioxide
was evaluated for the extrusion foaming of a number
of engineering thermoplastics (polyether-etherketone,
polyphenylsulphone, styrene-maleic anhydride terpolymer,
high temperature polycarbonate, polyphenylene oxide and
linear polypropylene). A cavity transfer mixer and a static
mixer were attached to an extruder to mix and homogenise
the liquid carbon dioxide into the molten polymer, and to
cool the polymer to the required foaming temperature. A
simple measuring system for melt strength measurement
was also evaluated. 8 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.799932
References and Abstracts
80
© Copyright 2005 Rapra Technology Limited
Item 229
Antec 2000.Conference proceedings.
Orlando, Fl., 7th-11th May, 2000, paper 414
MICROCELLULAR FOAM MOLDING:
ADVANTAGES AND APPLICATION EXAMPLES
Jacobsen K; Pierick D
Engel North America; Trexel Inc.
(SPE)
Proprietary injection moulding technology is described for
the production of microcellular components. Supercritical
carbon dioxide or nitrogen is injected into the extruder,
and forms evenly distributing, uniformly-sized cells (5-100
micrometre) in the product. Bene
À ts of the process include:
weight reduction, cycle time reduction, reduced injection
pressures and clamp forces. The production of
À lled nylon
mirror brackets and of nylon cable ties are described.
CANADA; USA
Accession no.799929
Item 230
Macromolecular Materials and Engineering
Vol.283, Nov.2000 p.120-5
A NOVEL, EFFICIENT ROUTE FOR THE
CROSSLINKING AND CREEP IMPROVEMENT
OF HIGH MODULUS AND HIGH STRENGTH
POLYETHYLENE FIBRES
Jacobs M; Heijnen N; Bastiaansen C; Lemstra P
DSM High Performance Fibers; Eindhoven,University
of Technology
A new route for the chemical crosslinking of solution-spun,
ultra-drawn Ultra-High-Molecular-Weight Polyethylene
(UHMW-PE)
À bres is described. Utilising supercritical
carbon dioxide as a carrier, UHMW-PE
À bres with a range
of draw ratio’s, Young’s moduli and tensile strengths,
were impregnated with a radical initiator. Following
impregnation, the drawn
À bres were crosslinked with
ultra-violet light and
À bres with a high gel content (greater
than 90 percent) were obtained. The results indicated that
the chemical crosslinking strongly reduces the plateau
creep rate of the
À bres and that the threshold stress for
irreversible creep is enhanced. Simultaneously, the high
Young’s modulus and the high tensile strength of the
drawn
À bres are preserved which shows that the long term
properties of the
À bres (i.e. creep) are improved without
a great deal of loss in terms of short term mechanical
properties, for example, Young’s modulus. 41 refs.
Accession no.798665
Item 231
Polymer Preprints. Volume 40. Number 2. August 1999.
Conference proceedings.
New Orleans, La., August 1999, p.671-2
SOLVENT INDUCED CRYSTALLISATION
AND SOLID STATE POLYMERISATION OF
POLYBISPHENOL A CARBONATE USING
SUPERCRITICAL CO2 AS A PROCESSING AID
Gross S M; Goodner M D; Roberts G W; Kiserow D J;
DeSimone J M
North Carolina,Chapel Hill University; US,Army; North
Carolina,State University
(ACS,Div.of Polymer Chemistry)
Polycarbonate prepolymer crystallised by supercritical
CO2 is rendered in a suitable morphology for solid-state
polymerisation, thereby reducing the need for organic
solvents in this step of the polymer processing. The solid-
state polymerisation of polycarbonate is explored using
N2 and supercritical CO2 as the sweep
Á uid. Supercritical
CO2 as a sweep
Á uid offers a few advantages over N2.
Supercritical CO2 plasticises polycarbonate, thereby
lowering the Tg of the polymer. This allows for lower
processing temperatures as solid-state polymerisation
needs to be above Tg but below Tm of the polymer. A
number of molecules display signi
À cant solubility in
liquid or supercritical CO2, including a number of step
growth reaction by other products. Although water has a
low solubility in supercritical CO2, common condensates,
such as acetic acid, neopentyl glycol and phenol have the
potential to be using supercritical
Á uid extraction methods
which would drive the reaction to completion. 10 refs.
USA
Accession no.797535
Item 232
Polymer Preprints. Volume 40. Number 2. August 1999.
Conference proceedings.
New Orleans, La., August 1999, p.551-2
EXPANSION OF POLYSTYRENE USING
SUPERCRITICAL CARBON DIOXIDE:
EFFECTS OF MOLECULAR WEIGHT AND LOW
MOLECULAR WEIGHT COMPONENTS
Stafford C M; Russell T P; McCarthy T J
Amherst,Massachusetts University
(ACS,Div.of Polymer Chemistry)
Recently a novel method of creating microcellular foams
by use of supercritical (SC) CO2 was reported. Using this
method, SC C02 is used to plasticise the polymer matrix and
lower the apparent Tg to near ambient temperatures. Upon
rapid depressurisation the polymer becomes supersaturated
with CO2 gas nucleation of cells occurs and growth of
these cells continue until the polymer vitri
À es. Studies on
PS foams prepared using this technique have been made. It
was found that temperature, initial pressure depth of pressure
quench, decompression rate, decompression pro
À le and
geometric constraints of the foaming vessel can be used
to control cell size, cell size distribution and cell shape as
well as the compressive properties of the foams. Several
other parameters that may affect the foaming process using
SC CO2 as the blowing agent are examined. The effects of
polymer molecular weight and polydispersity on the
À nal
structure of the foam using PS and blends of PS prepared by
mixing samples with narrow molecular weight distributions
are reported, as is the effect of a low molecular weight
component found in commercial PS; it is shown that its
References and Abstracts
© Copyright 2005 Rapra Technology Limited
81
presence dramatically changes resultant foam structure.
Varying the concentration of this oligomer allows control
of cell size in foams. 8 refs.
USA
Accession no.797474
Item 233
Polymer Preprints. Volume 40. Number 2. August 1999.
Conference proceedings.
New Orleans, La., August 1999, p.829-30
SYNTHESIS OF TWO-STAGE COMPOSITE
LATEX PARTICLES BY DISPERSION
POLYMERISATION IN CARBON DIOXIDE
Young J L; Spontak R J; DeSimone J M
North Carolina,Chapel Hill University; North
Carolina,State University
(ACS,Div.of Polymer Chemistry)
The synthesis of two-stage latex particles builds on earlier
research on dispersion polymerisations in supercritical
CO2. In this
À rst example of a two-stage latex synthesis in
CO2, composite particles containing PS and PMMA were
prepared and characterised. Two-stage latex particles are
prepared by sequential polymerisation of two monomers.
There are numerous possible particle morphologies,
or distributions of the two polymer phases in the
À nal
particles. For example, in a core-shell particle, the second-
stage polymer forms a shell around the
À rst polymer core.
Other morphologies include inverted, sandwich, raspberry
and half-moon. The notation ‘PS/PMMA’ indicates that
styrene was polymerised
À rst, followed by MMA. This
notation does not necessarily mean that PS will form
the core and PMMA will form the shell of the particles.
A balance between thermodynamic and kinetic factors
determines the morphology of the resulting particles. In
considering the particle morphology produced in CO2, a
non-polar solvent, it can be predicted that the more polar
PMMA should form the core with a PS shell. However,
there are other factors to be taken into account. PMMA
has been shown by FTIR to have speci
À c interactions with
CO2, and PMMA absorbs twice as much CO2 as PS under
the same conditions. While PMMA’s polarity should be a
driving force to form the core, the interactions with CO2
may be a driving force to form a PMMA shell. However,
both PMMA and PS are highly plasticised in CO2,
reducing the Tg of both polymers far below the typical
polymerisation conditions of 65 deg.C, 345 bar. As a result,
the mobility of both polymers may allow for rearrangement
of particle morphology during the polymerisation. All of
these in
Á uences make it difÀ cult to predict the morphology
of these two-stage latex particles in CO2. 6 refs.
USA
Accession no.797284
Item 234
Silicones in Coatings II. Conference proceedings.
Florida, USA, 24th-26th March 1998, paper 13
SUPERCRITICAL FLUIDS AND SILICONES:
OVER A DECADE OF APPLICATIONS
Wetmore P M; Krukonis V
Phasex Corp.
(Paint Research Association)
Supercritical
Á uids (SCFs) achieve improved processing
results that are dif
À cult, if not impossible, to attain using
traditional methods. Motivated by demands for product
and process improvements and by increasingly stringent
restrictions on liquid organic solvent use, SCFs have
been applied for over a decade to address and solve
scores of silicone-containing polymer problems. The
unique combination of gas-like and liquid-like properties
of SCFs is exploited for carrying out operations such as
extraction, fractionation, impregnation/deposition and
recrystallisation. A broad spectrum of applications with
silicone and siloxane polymers is examined and described,
including extraction of residual monomers and cyclics
from medical tubing and speciality lubricants, fractionation
of silicone adhesives and functional siloxane polymers for
improved performance, fractionation of copolymers for
chemical composition elucidation, and impregnation of
polycarbosilane polymers into composites for improving
oxidation resistance. 49 refs.
USA
Accession no.795777
Item 235
Silicones in Coatings II. Conference proceedings.
Florida, USA, 24th-26th March 1998, paper 12
SUPERCRITICAL FLUIDS:
ENVIRONMENTALLY ACCEPTABLE
REPLACEMENTS FOR ORGANIC SOLVENTS
- THE WAY AHEAD
Howdle S
Nottingham,University
(Paint Research Association)
Supercritical
Á uids are becoming increasingly attractive
as environmentally acceptable replacements for organic
solvents in chemical reactions and material processing. The
properties of supercritical
Á uids are highlighted, especially
those of supercritical CO2, which offers particular
advantages for the handling of silicones; including small
molecule reactants, polymers and stabilisers. 33 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.795776
Item 236
Silicones in Coatings II. Conference proceedings.
Florida, USA, 24th-26th March 1998, paper 11a
WHY SILICONES AND SUPERCRITICAL
FLUIDS?
Johns K
Chemical & Polymer
(Paint Research Association)
References and Abstracts
82
© Copyright 2005 Rapra Technology Limited
Supercritical
Á uid technology is an exciting but very much
ignored route to new methods of surface modi
À cation.
It is, however, a sister to the conventional alternatives
to hydrocarbon solvents such as radiation curing, high
solids, water-borne, powder coating. The technology can
be complementary to these as well as competitive. The
interest in SCF here arises from a previous need to develop
techniques to replace CFC solvents for the deposition of
thin
À lms of Á uorinated liquids. 15 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.795775
Item 237
Modern Plastics International
30, No.10, Oct.2000, p.25-7
CARBON DIOXIDE FOAMING IS EXPLORED
FOR THIN EXTRUSIONS
Leaversuch R D
We are told that the use of carbon dioxide as a foaming
agent in extruded products made with commodity resins
is gradually
À nding its market niche. This article discusses
carbon dioxide in foam extrusion in detail, with many
examples.
RAPRA TECHNOLOGY LTD.; TREXEL; ECLIPSE
BLING SYSTEMS; ALUSUISSE COMPOSITES;
DUMAPLAST; POLYMER PROCESSING
INSTITUTE; TORONTO,UNIVERSITY
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; USA;
WESTERN EUROPE
Accession no.795336
Item 238
Industrial and Engineering Chemistry Research
39, No.11, Nov.2000, p.4020-3
CONTINUOUS DISTRIBUTION KINETICS FOR
THE DEGRADATION OF POLYSTYRENE IN
SUPERCRITICAL BENZENE
Karmore V; Madras G
Indian Institute of Science
The degradation kinetics of PS in supercritical benzene
was studied at various temperatures. The time evolution
of the MWD was obtained by analysing the samples
with GPC. Activation energies were determined from the
temperature dependence of the rate coef
À cients. 24 refs.
INDIA
Accession no.794849
Item 239
Macromolecular Rapid Communications
21, No.15, 23rd Oct.2000, p.1019-23
COPOLYMERISATION OF METHYL AND
ETHYL METHACRYLATE IN SUPERCRITICAL
CARBON DIOXIDE
Giles M R; Hay J N; Howdle S M
Nottingham,University; Surrey,University
Details are given of the free radical polymerisation of
methyl methacrylate-ethyl methacrylate copolymers in
supercritical carbon dioxide. Mention is made of the use
of polydimethyl siloxane methacrylate as a stabiliser.
Characterisation was undertaken using NMR, SEM, DSC
and GPC. The effect of varying AIBN initiator on the
composition and molecular weights of the copolymers
was also studied. 19 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.793530
Item 240
Journal of Polymer Science: Polymer Physics Edition
38, No.21, 1st Nov.2000, p.2832-40
SOLUBILITY OF VINYLIDENE FLUORIDE
POLYMERS IN SUPERCRITICAL CARBON
DIOXIDE AND HALOGENATED SOLVENTS
Dinoia T P; Conway S E; Jong Sung Lim; McHugh M A
Johns Hopkins University; Korea,Institute of Science &
Technology; Virginia,Commonwealth University
The cloud point behaviours of PVDF and vinylidene
Á uoride-22 mol % hexaÁ uoropropylene copolymer were
studied at temps. up to 250C and pressures up to 3000 bar
in supercritical carbon dioxide and halogenated solvents.
Cloud point pressures for both polymers decreased as the
solvent polarisability, polar moment per molar volume and
density increased. It was, however, extremely dif
À cult to
dissolve either
Á uoropolymer in chlorotriÁ uoromethane,
which had a large polarisability and a small dipole
moment. Carbon dioxide was an effective solvent because
it complexed with the C-F dipole at low temps. where
energetic interactions
À xed the phase behaviour. Polymer
structure also had a marked effect on the cloud point
pressure. 47 refs.
KOREA; USA
Accession no.792538
Item 241
Analytical Chemistry
72, No.17, 1st Sept.2000, p.4230-4
POLYMER NMR CELL FOR THE STUDY OF
HIGH-PRESSURE AND SUPERCRITICAL FLUID
SOLUTIONS
Wallen S L; Schoenbachler L K; Blatchford M A
North Carolina,University
NMR offers researchers unique, highly localised
molecular information. The importance of this technique
is well established in studies using chemical shift, spin
coupling, and relaxation times providing detailed structural
information, determining chemical equilibria and kinetics,
and understanding molecular dynamic processes. However,
the widespread application of NMR spectroscopy to high-
pressure liquids and supercritical
Á uids has been limited
due to the complexity of the necessary instrumentation.
One approach to these studies is to build a dedicated
References and Abstracts
© Copyright 2005 Rapra Technology Limited
83
high-pressure probe. Another involves the utilisation
of a high-pressure cell designed to
À t in commercially
available probes. The design and implementation of a
simple, three-piece, high-pressure NMR cell constructed
of high-performance polymers is presented. The cell
has pressure capabilities of up to 400 bar; however, the
ultimate temperature and pressure limits are determined
by the speci
À c polymer chosen. High-resolution NMR
spectra of methanol modi
À ed and tributyl phosphate (TBP)
modi
À ed supercritical CO2 are presented. An example of
supercritical
Á uid phase behaviour monitored with NMR
is demonstrated for the TBP system in which the chemical
shift changes in the 31P nucleus as a function of density are
indicative of solution phase separation. The multi-nuclear
NMR data demonstrate the utility of this cell for studying
supercritical
Á uid solution systems relevant to analytical
separations and extractions. 41 refs.
USA
Accession no.792119
Item 242
Advances in Polymer Technology
19, No.4, Winter 2000, p.300-11
EFFECTS OF SUPERCRITICAL CARBON
DIOXIDE ON THE VISCOSITY AND
MORPHOLOGY OF POLYMER BLENDS
Lee M; Tzoganakis C; Park C B
Waterloo,University; Toronto,University
A PE/PS blend is investigated in the presence of supercritical
carbon dioxide using various extrusion con
À gurations.
These con
À gurations involving a twin-screw extruder and
a single-screw extruder, were specially designed for the
study of the rheological and morphological behaviour of this
system. The viscosities of the polymer/carbon dioxide and
the blend/carbon dioxide solutions were measured at various
concentrations of carbon dioxide and PE/PS blending ratios
using a wedge die mounted on the twin-screw extruder.
The effect of carbon dioxide on the morphology of the
PE/PS blends was also investigated using a twin/single-
screw tandem system. This system allowed for preferential
dissolution of the carbon dioxide into the matrix and/or
dispersed polymer phase. By introducing devolatisation to
the tandem system, the morphological behaviours of PE/
PS blends were investigated on unfoamed
À laments. It is
generally concluded that the mixing of the two polymers was
improved by the dissolution of carbon dioxide. 24 refs.
CANADA
Accession no.791802
Item 243
Fluorine in Coatings III. Conference proceedings.
Orlando, Fl., 25th-27th January 1999, paper 36
FLUOROPOLYMER COATINGS FROM LIQUID
AND SUPERCRITICAL CARBON DIOXIDE
DeYoung J; Romack T
MICELL Technologies
(Paint Research Association)
Liquid and supercritical CO2 have been studied as
environmentally sound alternatives for a variety of
solvent-based chemical processes. Of recent signi
À cance
is the development of liquid CO2-based commercial
dry-cleaning of garments. Complimentary technology
emerging in the application of low surface energy coatings,
that are derived from
Á uoropolymers, to textiles promises
several potential advantages over traditional aqueous and
solvent based textile treatment processes. Developmental
efforts in the area of textile coating from CO2 processes are
discussed with emphasis on these advantages and on the
support framework within Micelle Technologies’ Micare
dry clean system. 15 refs.
USA
Accession no.790209
Item 244
Fluorine in Coatings III. Conference proceedings.
Orlando, Fl., 25th-27th January 1999, paper 33
FLUOROCOPOLYMER COATINGS
FROM ENVIRONMENTALLY BENIGN
SUPERCRITICAL FLUIDS
McHugh M A; Coneay S E; Dinioa T P
John Hopkins University
(Paint Research Association)
The solubility of various
Á uorocopolymers is determined in
environmentally benign supercritical
Á uid (SCF) solvents
with an emphasis on CO2 and hydro
Á uorocarbons. The
objective is to investigate the in
Á uence of Á uorocopolymer
architecture on phase behaviour and to relate the differences
to properties of coatings obtained from
Á uoropolymer SCF
solutions. The principles of molecular thermodynamics are
used to interpret phase behaviour. Examples of coatings
are presented. 9 refs.
USA
Accession no.790206
Item 245
Polymer Process Engineering 99. Conference
proceedings.
London, June 1999, p.28-36
SUPERCRITICAL ENHANCED PROCESSING
Kazarian S G; Briscoe B J; Lawrence C J
London,Imperial College of Science,Technology &
Medicine
Edited by: Coates P D
(Institute of Materials; UK,Interdisciplinary
Research Centre in Polymer Science & Technology;
Bradford,University)
Supercritical
Á uids have a unique and valuable potential
for enhanced processing of polymeric based materials and
soft solids. This is especially important due to the need to
develop environmentally friendly chemical synthesis and
materials processing systems. As a consequence there is
References and Abstracts
84
© Copyright 2005 Rapra Technology Limited
a very real need to understand how supercritical
Á uids
interact with polymeric materials, in particular how this
medium may modify many facets of process operation.
This understanding will help engineers to utilise molecular
level information for improving macroscopic properties
of polymeric materials by supercritical
Á uid processing.
Spectroscopy is an economic tool to probe interactions at
a molecular level. The bene
À cial changes, in the context of
processing, in polymeric systems induced by supercritical
carbon dioxide are currently being elucidated via in situ
spectroscopic methods that provide a route to optimise
new supercritical enhanced polymer processing operations.
Spectroscopic data provide a fundamental understanding
of the origin of the plasticising effect of CO2 on glassy
polymers. This effect results, for example, in a viscosity
reduction which facilitates processing of polymers due
to lower shear stresses. Also, since supercritical CO2
can plasticise glassy polymers, it can also modify semi-
crystalline polymers by plasticising their amorphous
phase resulting in induced crystallisation. The use of
supercritical CO2 as a plasticiser therefore shows great
promise in assisting the production of many polymeric
based materials. In particular, an important application
of CO2-induced polymer plasticisation will be in the
processing of injection moulded or extruded polymer
materials. 43 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.790078
Item 246
Macromolecular Chemistry and Physics
201, No.13, 11th Sept.2000, p.1532-9
KINETICS OF THE EARLY STAGE OF
DISPERSION POLYMERIZATION IN
SUPERCRITICAL CARBON DIOXIDE
AS MONITORED BY TURBIDIMETRIC
MEASUREMENTS. I. METHOD
Fehrenbacher U; Muth O; Hirth T; Ballauff M
Karlsruhe,University; Fraunhofer-Institut fuer
Chemische Technologie
The dispersion polymerisation of methyl methacrylate
in supercritical carbon dioxide in the presence of
polydimethylsiloxane-monomethyl acrylate was monitored
in situ by turbidimetry at 330 bar and 60C. The turbidity
spectra were recorded directly in the autoclave to produce
the average number of particles per unit volume and the
average particle diameter developing with time. The
experimental set-up allowed the early stages of nucleation
and particle formation to be monitored. The morphology
of a quenched sample after 500 s reaction time was shown
by SEM imaging. 34 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.789341
Item 247
Journal of Macromolecular Science B
B39, No.4, 2000, p.561-7
DIFFUSION OF ORGANOMETALLIC
COMPOUNDS INTO HIGH-SPEED SPUN
POLY(ETHYLENE TEREPHTHALATE) FIBRE
IN SUPERCRITICAL CARBON DIOXIDE FLUID
Kawahara Y; Kikutani T
Kyoto,Institute of Technology
The dyeability of high-speed spun PETP
À bres, which
had higher crystallinity, larger crystallite sizes and
lower birefringence than conventional PETP
À bres, in
supercritical carbon dioxide
Á uid was investigated using
Fe3(CO)12, as a dye. The high-speed spun
À bres exhibited
a larger dye uptake, at temperatures between 50 and 80C
and a pressure of 18.2 to 19.3 MPa. The penetration
of the dye into the
À bres was inÁ uenced by the size of
the channels caused by
À brillation of the À bres in the
supercritical carbon dioxide
Á uid. 10 refs.
JAPAN
Accession no.786360
Item 248
Journal of Applied Polymer Science
77, No.14, 29th Sept.2000, p.3228-33
DEPOLYMERIZATION OF POLY(BUTYLENE
TEREPHTHALATE) USING HIGH-
TEMPERATURE AND HIGH-PRESSURE
METHANOL
Shibata M; Masuda T; Yosomiya R; Meng Ling-Hui
Chiba,Institute of Technology; Harbin,Institute of
Technology
PBTP was depolymerised in excess methanol under high
temperature (473-523 K) and high pressure (4-14 MPa)
conditions. Depolymerisation was carried out at 483 K and
4-12 MPa, and at 513 K and 6-14 MPa. The temperature
had a great effect on the depolymerisation rate, but the
reaction pressure did not. Under the former conditions,
depolymerisation took over 80 min, but only about 20 min
under the latter conditions. The se results showed that the
supercritical state of methanol was not a key factor in the
depolymerisation reaction. A kinetic study of the reaction
at 473-523 K and 12 MPa showed that the decomposition
rate constant of PBTP increased dramatically when the
reaction temperature was higher than the melting point of
PBTP (500 K). This indicated that partial miscibility of
the molten PBTP and methanol was an important factor
for the short-time depolymerisation. 9 refs.
CHINA; JAPAN
Accession no.784903
Item 249
Polymer International
49, No.7, July 2000, p.712-8
PREPARATION AND MORPHOLOGY
CHARACTERISATION OF MICROCELLULAR
References and Abstracts
© Copyright 2005 Rapra Technology Limited
85
STYRENE-CO-ACRYLONITRILE (SAN) FOAM
PROCESSED IN SUPERCRITICAL CO2
Lee K N; Lee H J; Kim J H
Yonsei,University
Microcellular polymeric foam structures are generated
using a pressure-induced phase separation in concentrated
mixtures of supercritical CO2 and SAN. The process
typically generates a microcellular core structure encased
by a non-porous skin. Pore growth occurs through two
mechanisms: diffusion of CO2 from polymer-rich into the
pores and also through CO2 gas expansion. The effects
of saturation pressure, temperature and swelling time on
the cell size, cell density and bulk density of the porous
materials are studied. Higher CO2 pressures (hence, higher
Á uid density) provide more CO2 molecules for foaming
generated lower interfacial tension and viscosity in the
polymer matrix, and thus produce low cell size but higher
cell densities. This trend is similar to what is observed in
swelling time series. While the average cell size increases
with increasing temperature, the cell density decreases.
The trend of bulk density is similar to that of cell size.
15 refs.
KOREA
Accession no.784067
Item 250
Polymer Engineering and Science
40, No.8, Aug.2000, p.1942-52
RECYCLING OF POLYETHYLENE
TEREPHTHALATE INTO CLOSED-CELL
FOAMS
Japon S; Leterrier Y; Manson J-A E
Lausanne,Ecole Polytechnique Federale
The increase of the elongational viscosity of recycled
PETP was investigated with the aim of producing
closed-cell foams by means of a cost-effective reactive
extrusion technique. A recycled PETP grade containing
contamination levels of PVC and PE was compared
with virgin bottle-grade PETP as a reference. Data are
presented for the microstructure of the foams obtained in
a high-pressure vessel using supercritical carbon dioxide.
38 refs.
SWITZERLAND; WESTERN EUROPE
Accession no.782997
Item 251
Polymer Engineering and Science
40, No.8, Aug.2000, p.1850-61
EFFECT OF SUPERCRITICAL CARBON
DIOXIDE ON MORPHOLOGY DEVELOPMENT
DURING POLYMER BLENDING
Elkovitch M D; Lee L J; Tomasko D L
Ohio,State University
Supercritical carbon dioxide was added during
compounding of PS and PMMA and the resulting
morphology development was observed. Viscosity
reduction of PS and PMMA were measured using a slit die
rheometer attached to a twin-screw extruder. 24 refs.
USA
Accession no.782988
Item 252
ACS Polymeric Materials: Science & Engineering.
Spring Meeting 2000.Volume 82.Conference
proceedings.
San Francisco, Ca., 26th-30th March 2000, p.41-2
DRAWING OF NYLON 6,6 IN HIGH PRESSURE
CARBON DIOXIDE
Hobbs T; Lesser A J
Massachusetts,University
(ACS,Div.of Polymeric Materials Science & Engng.)
Fibre bundles of polyamide-6,6 were drawn to a draw
ratio of 3.8 at room temperature and subsequently drawn
in supercritical carbon dioxide at a pressure of 238 atm at
temperatures of 95, 110, 130, and 145 C. Carbon dioxide
was used as both a plasticiser and a pressure transmitting
medium, high temperatures being used to promote
crystallisation. The maximum draw ratio achieved was
6.1 at 130 C. The
À bres had 25% higher crystallinity and
30% higher strength values compared with conventional
air-drawn
À bres. 11 refs.
USA
Accession no.782850
Item 253
Plastics in Building Construction
24, No.8, 2000, p.5
MICROCELLULAR FOAM TECHNOLOGY
USED FOR TWO PRODUCTS
Brief details are given of the applications of two companies
who are using the Mucell extrusion technology from
Trexel Inc. to manufacture building/construction products.
Alusuisse Composites Inc. is using the technology to
manufacture microcellular foam products for its line
of FOAM-X material laminated foam-centered boards
used for graphic arts and three-dimensional moulding.
Eclipse Blind Systems Inc. has begun distributing a range
of high-performance vertical blind slates manufactured
from PVC with this new process which uses supercritical
Á uids of atmospheric gases to create microscopic cells
throughout thermoplastic polymers to achieve improved
parts performance and a reduction of production costs.
TREXEL INC.; ALUSUISSE COMPOSITES INC.; ECLIPSE BLIND
SYSTEMS INC.
USA
Accession no.782788
References and Abstracts
86
© Copyright 2005 Rapra Technology Limited
Item 254
ACS, Polymeric Materials Science & Engineering Fall
Meeting 1999. Volume 81. Conference proceedings.
New Orleans, La., 22nd-26th Aug.1999, p.47-8
SPIN COATING AND PHOTOLITHOGRAPHY
USING LIQUID AND SUPERCRITICAL CARBON
DIOXIDE
Hoggan E N; Kendal J L; Flowers D; Carbonell R G;
DeSimone J M
North Carolina,State University
(ACS,Div.of Polymeric Materials Science & Engng.)
The conventional manufacturing of integrated circuits
utilises two solvent intensive steps, spin coating of a
photoresist layer and the development of the image after
exposure. The complexity of modern semiconductor
devices necessitates large numbers of material layers, thus
requiring these solvent intensive steps to be repeated 30
times or more in the processing of a single wafer. This
creates vast amounts of solvent waste. For example, a
typical semiconductor sing line which produces 5,000
wafers per day will generate 2,000 gallons of waste
developing solution and an equivalent amount of
contaminated water. This does not include the large amount
of organic waste generated by spin coating processes. The
health and environmental hazards posed by these solvents
has led to increased research on alternative processing
solvents. One promising alternative is carbon dioxide. CO2
is non-toxic non-
Á ammable, inexpensive, environmentally
benign and recyclable. Despite its promise, CO2 has not
become widely used due to several challenges. Work
conducted to resolve these issues is described. The
synthesis of suitable resists, the construction of a high-
pressure spin coating apparatus, and the results obtained
with these materials are reported. 8 refs.
USA
Accession no.780710
Item 255
Macromolecules
33, No.11, 30th May 2000, p.4008-14
IN-SITU INVESTIGATION ON THE
MECHANISM OF DISPERSION
POLYMERISATION IN SUPERCRITICAL
CARBON DIOXIDE
Li G; Yates M Z; Johnston K P; Howdle S M
Texas,University; Nottingham,University
The effect of stabilisers on the particle formation stage
in dispersion polymerisation of methyl methacrylate
in supercritical carbon dioxide was studied by in-situ
turbidimetry. The point at which the particle number
density becomes equivalent to the
À nal particle number
density was determined. 45 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; USA;
WESTERN EUROPE
Accession no.779858
Item 256
Macromolecular Symposia
Vol.153, March 2000, p.77-86
CATIONIC AND ANIONIC RING-OPENING
POLYMERISATION IN SUPERCRITICAL CO2
Mingotaud A-F; Dargelas F; Cansell F
CNRS
Details are given of the anionic and pseudoanionic
polymerisation of caprolactone in supercritical carbon
dioxide. Results are also presented for the cationic
polymerisation of octamethylcyclotetrasiloxane and
phenyloxazoline. 17 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.778920
Item 257
Macromolecules
33, No.10, 16th May 2000, p.3505-7
POLYMERIZATION OF VINYLPYRROLIDONE
IN SUPERCRITICAL CARBON DIOXIDE WITH
DIBLOCK COPOLYMER STABILIZER
Berger T; McGhee B; Scherf U; Steffen W
Max-Planck-Institut fuer Polymerforschung
Polystyrene-block-polydimethylsiloxane diblock
copolymers were evaluated as stabilisers for the radical
polymerisation of vinylpyrrolidone in supercritical
carbon dioxide. The presence of the stabiliser resulted
in the formation of uniform, spherical microparticles
of polymer, with a wide molecular weight distribution,
attributed to surface plasticisation of the growing particles
creating inhomogeneous polymerisation conditions.
The polymerisation was very sensitive to the reaction
parameters, particularly the stabiliser concentration. 12
refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.778276
Item 258
Biomaterials
21, No.15, 2000, p.1587-93
CHARACTERISATION OF COPOLYMERS
OF LACTIC AND GLYCOLIC ACID FOR
SUPERCRITICAL FLUID PROCESSING
Engwicht A; Girreser U; Muller B W
Kiel,Christian-Albrecht-University
Polymers of lactic and glycolic acid are often used for the
production of injectable microparticles with controlled
drug release. In the variety of processes used for the
microparticle formulation, the aerosol solvent extraction
system (ASES) is rather special. Microparticle formation
and drying take place in one step by precipitating a
methylene chloride solution of the polymer in supercritical
CO2. This process sets special requirements to the
polymers in crystallinity, solubility and thermal behaviour
References and Abstracts
© Copyright 2005 Rapra Technology Limited
87
that are best ful
À lled by blocked copolymers. A number
of lactide-co-glycolide polymers blocked distribution
of the co-monomers by NMR spectroscopy and powder
diffraction. The molar ratios are determined by 1H NMR
spectroscopy to verify the manufacturer’s declarations of
the purchased specimens. Additionally, the block length
is determined by application of 13C NMR. Therefore, a
method is modi
À ed and evaluated in order to calculate
the length of lactide and glycolide sequences in the
polymer. The impact of synthesis conditions on block
length and crystallinity, and the impact of the blocking
on both crystallinity and solubility of the polymers, are
examined. 11 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.778044
Item 259
Patent Number: EP 1006143 A1 20000607
APPARATUS FOR DECOMPOSITION AND
RECOVERY OF POLYURETHANE RESIN
Kodama K; Murayama K; Kumaki T; Kasuya F;
Nagase Y; Nakata M; Nishida S
Takeda Chemical Industries Ltd.; Kobe Seiko Sho KK
This includes a
Á uidiser, which Á uidises the polyurethane
resin as a target compound of hydrolysis decomposition,
a reactor, which hydrolyses the
Á uidised target compound
with either a supercritical water or high-temperature
high-pressure water to a decomposition product mixture,
a water supplier, which feeds either supercritical water or
high-temperature high-pressure water to the reactor and a
post-processor, which causes the decomposition product
mixture discharged from the reactor to be subjected to a
post treatment procedure, such as dehydration, addition,
distillation, separation, or liquid separation, to recover
a polyamine compound and/or a polyol compound.
The required energy cost is reduced as is the size of
the machine. Foreign substances are removed from the
shredder dust and the required quantities of substances
for decomposition are reduced.
EUROPEAN COMMUNITY; EUROPEAN UNION; JAPAN;
WESTERN EUROPE-GENERAL
Accession no.777712
Item 260
British Plastics and Rubber
May 2000, p.4-9
FOAM EXTRUSION OF ENGINEERING AND
COMMODITY POLYMERS USING CARBON
DIOXIDE AS A BLOWING AGENT
Gale M
Rapra Technology Ltd.
The use of carbon dioxide as blowing agent has been
shown to be feasible on a laboratory scale using a
conventional extruder retro
À tted with a Cavity Transfer
Mixer to mix gas and polymer with some cooling, followed
by further cooling in a static mixer heat exchanger. Using
this arrangement, foams can be extruded from a number
of engineering polymers including polyaryletherketone.
In addition to the ability to foam engineering polymers,
carbon dioxide as blowing agent should give considerable
economic savings for commodity plastics foaming in
comparison to chemical blowing agents. 5 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.777093
Item 261
Polymer Degradation and Stability
65, No.3, 1999, p.373-86
CHARACTERISTICS OF POLYETHYLENE
CRACKING IN SUPERCRITICAL WATER
COMPARED TO THERMAL CRACKING
Moriya T; Enomoto H
Tohoku Electric Power Co.Inc.; Tohoku,University
PE cracking obtained from hydrothermal experiments with
supercritical water was compared to water-free thermal
cracking. The degradation mechanism of HDPE and the
contribution of supercritical water to degradation were
also considered by analysing the products in the aqueous
phase after the reaction. 21 refs.
JAPAN
Accession no.776428
Item 262
Polymer Process Engineering ‘97. Conference
proceedings.
London, July 1997, p.197-201
CHEMICAL ASSIST FOAMING AND THE ROLE
OF SUPERCRITICAL FLUIDS IN EXTRUSION
Reedy M E
Reedy International Corp.
(Institute of Materials)
Processing and properties of polymers are the two
most important criteria that are many times in con
Á ict
with each other. The processor looks for the largest
processing window while the designer looks for good
surfaces, optimum density reduction, excellent thermal
properties and great impact behaviour. Now, chemical
foam assist (CFA) technology enables both commodity
and engineering polymers to process more easily and
with improved properties for a wide variety of extrusion
processes. Carbon dioxide is used extensively as a physical
blowing agent in the production of thermoplastic foams.
For example, in the extrusion of foam sheet, carbon
dioxide alone or in conjunction with other gases can
produce lightweight products with excellent physical
properties. Recent studies have shown that CO2 has
unique low pressure solubility. In most polymers, CO2
when pressurised to 1,700 psi becomes a supercritical
Á uid
and acts as a solvent resulting in a lowering of the glass
transition temperature and improved polymer melt
Á ow
References and Abstracts
88
© Copyright 2005 Rapra Technology Limited
characteristics. During transition between a supercritical
Á uid and a gas, the CO2 will absorb heat energy, improve
melt cooling and consequently facilitate increased
extrusion rates. The improved melt
Á ow characteristics
and heat energy absorption result in improved physical
properties of extruded board and sheet materials. 8 refs.
USA
Accession no.775992
Item 263
Materials World
8, No.5, May 2000, p.10-2
CO2 UNDER PRESSURE - A CLEAN SOLUTION
FOR POLYMER PROCESSING
Cooper A; Howdle S
Liverpool,University; Nottingham,University
The use of supercritical carbon dioxide during the
synthesis of polymers is examined, and its ability to
produce novel materials which are dif
À cult to obtain by
more conventional methods. Supercritical carbon dioxide,
as a solvent for polymer synthesis, also addresses concerns
over volatile organic solvent emissions and the generation
of aqueous waste streams. It can be used to produce
a variety of polymers with tailored properties such as
polymeric implants with modi
À ed bioproperties, and the
building macroporous monoliths.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.773641
Item 264
Patent Number: US 6025459 A1 20000215
SYNTHESIS OF POLYAMIDES IN LIQUID AND
SUPERCRITICAL CO2
DeSimone J; Givens R; Ni Y
North Carolina,University
A nylon salt is condensed in carbon dioxide to form
a polyamide and water. A polyamide is formed by
polymerising a lactam monomer in carbon dioxide to
form a polyamide.
USA
Accession no.773536
Item 265
Polymer Journal (Japan)
32, No.2, 2000, p.178-81
RECOVERY OF CONSTITUENT MONOMERS
FROM POLYETHYLENE TEREPHTHALATE
WITH SUPERCRITICAL METHANOL
Sako T; Okajima I; Sugeta T; Otake K; Yoda S;
Takebayashi Y; Kamizawa C
Japan,National Institute of Materials & Chemical
Research
The in
Á uence of temperature, pressure and reaction time
on the recovery of the constituent monomers (dimethyl
terephthalate and ethylene glycol) was investigated
and the proper conditions for the depolymerisation
of PETP with supercritical methanol established. The
maximum yield of dimethyl terephthalate was 94% and
that of ethylene glycol was 80%. Supercritical methanol
minimised secondary decomposition or side reactions of
the monomers. 8 refs.
JAPAN
Accession no.772137
Item 266
Macromolecules
33, No.6, 21st March 2000, p.1917-20
DISPERSION POLYMERIZATION OF 1-VINYL-2-
PYRROLIDONE IN SUPERCRITICAL CARBON
DIOXIDE
Carson T; Lizotte J; Desimone J M
North Carolina,State University
The low molec.wt. polymeric surfactant poly(1,1-
dihydroper
Á uorooctyl acrylate)(polyFOA) was used in
the dispersion polymerisation of 1-vinyl-2-pyrrolidone in
supercritical carbon dioxide. It was found that increasing
concentrations of polyFOA yielded a decrease in
polymer particle diameter, while increasing the monomer
concentration produced an increase in particle size. No
signi
À cant change was observed in the particle morphology
for polymerisations conducted at different pressures. 20
refs.
USA
Accession no.771863
Item 267
Macromolecules
33, No.5, 7th March 2000, p.1565-9
DISPERSION POLYMERISATION OF
ACRYLONITRILE IN SUPERCRITICAL
CARBON DIOXIDE
Shiho H; DeSimone J M
JSR Corp.; North Carolina,University
Details are given of the dispersion polymerisation
of acrylonitrile in carbon dioxide using a styrene-
dihydroperfluorooctyl acrylate block copolymer as a
stabiliser. The effects of the initial concentrations of
acrylonitrile and the stabiliser and the reaction pressure on
the resulting size of the colloidal particles are discussed.
31 refs.
JAPAN; USA
Accession no.771261
Item 268
Journal of Vinyl and Additive Technology
6, No.1, March 2000, p.39-48
CHALLENGE TO FORTYFOLD EXPANSION
OF BIODEGRADABLE POLYESTER FOAMS
BY USING CARBON DIOXIDE AS A BLOWING
References and Abstracts
© Copyright 2005 Rapra Technology Limited
89
AGENT
Park C B; Liu Y; Naguib H E
Toronto,University
A report is presented on the development of an approach for
making extruded, low-density, biodegradable polybutylene
succinate foams using supercritical carbon dioxide, as the
blowing agent. The aim of the approach was the promotion
of large volume expansion and production of a
À ne cell
structure by the prevention of cell coalescence, complete
dissolution of blowing agent in the melt, reduction of gas
diffusivity and optimisation of processing conditions in the
die. The effects of processing conditions on the volume
expansion ratio and cell population density and of the
amount of blowing agent on the volume expansion ratio
and die pressure are discussed. 35 refs.
CANADA
Accession no.769389
Item 269
Surface Coatings International
83, No.3, March 2000, p.106-10
SUPERCRITICAL FLUIDS - A POTENTIAL
REVOLUTION IN WOOD TREATMENT AND
COATING
Hay J N; Johns K
Surrey,University; Chemical & Polymer
The need to
À nd environmentally friendly alternatives for
wood coatings is discussed, with particular reference to the
use of supercritical
Á uids. European softwoods could have
their durability increased by increasing their hydrophobicity
and minimising their biodegradation. The waste disposal and
recycling of treated woods can be increased by the ef
À cient
use of more appropriate biocides, coupled with the ability
to remove these prior to disposal or recycling. The use of
supercritical carbon dioxide as a carrier for coating and
impregnation systems is examined. 35 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.768106
Item 270
Journal of Materials Chemistry
10, No.2, Feb.2000, p.207-34
POLYMER SYNTHESIS AND PROCESSING
USING SUPERCRITICAL CARBON DIOXIDE
Cooper A I
Liverpool,University
A review is presented on recent developments in polymer
synthesis and processing using liquid and supercritical
carbon dioxide. Polymer synthesis techniques discussed
include homogeneous polymerisation, precipitation
polymerisation, dispersion polymerisation, emulsion and
seeded polymerisation, synthesis of porous polymers,
bulk condensation polymerisation using carbon dioxide
as a plasticiser, and formation of polymer blends.
Polymer processing aspects covered include fractionation,
extraction and puri
À cation, impregnation and dyeing,
heterogeneous chemical modi
À cation, manufacture of
microcellular materials, particle formation, and coatings
and lithography. 271 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.766867
Item 271
Industrial and Engineering Chemistry Research
39, No.2, Feb.2000, p.245-9
CHEMICAL RECYCLING OF PHENOL RESIN
BY SUPERCRITICAL METHANOL
Ozaki J; Djaja S K I; Oya A
Gunma,University
The reaction of phenolic resin in supercritical methanol
was studied with variations in temp. from 300 to 420C
and in reaction times from 30 to 150 min. The conversion
increased rapidly above 350C to give 94% at maximum at
420C and the gas fraction also increased at the same time.
When a longer reaction time was used from the reaction at
400C, the conversion increased without giving additional
gas product. From the point of view of liquefaction, the
longer reaction at lower temp. would give better results.
A gas chromatographic study revealed that the liquid
product included phenol and its methylated derivatives.
The carbon content of the solid product was higher than
the initial phenol resin, showing that some carbonisation
took place during the reaction. 21 refs.
JAPAN
Accession no.766857
Item 272
Polymer News
25, No.2, Feb.2000, p.68-9
SUPERCRITICAL FLUID TECHNOLOGY IN
POLYMERISATION REACTIONS
Rudzinski W E; Aminabhavi T M
Southwest Texas,State University
An overview is presented of the current understanding of
supercritical
Á uid technology relating to Á uoropolymers.
Various polymerisations and copolymerisations carried
out in supercritical
Á uids are discussed. 3 refs.
USA
Accession no.766708
Item 273
Macromolecules
33, No.1, 11th Jan.2000, p.40-5
CRYSTALLISATION AND SOLID-STATE
POLYMERISATION OF POLYBISPHENOL
A CARBONATE FACILITATED BY
SUPERCRITICAL CARBON DIOXIDE
Gross S M; Roberts G W; Kiserow D J; DeSimone J M
North Carolina,University
References and Abstracts
90
© Copyright 2005 Rapra Technology Limited
Details are given of the solid-state polymerisation of
bisphenol A carbonate using supercritical carbon dioxide to
induce crystallinity in low molecular weight polycarbonate
beads. Crystallisation was studied as a function of
time, temperature, molecular weight and pressure. The
molecular weight and percent crystallinity of the polymer
were determined as a function of time and radial position
in the bead. 25 refs.
USA
Accession no.764719
Item 274
Polymer Engineering and Science
39, No.10, Oct.1999, p.2075-84
SUPERCRITICAL CARBON DIOXIDE
ASSISTED BLENDING OF POLYSTYRENE AND
POLY(METHYL METHACRYLATE)
Elkovitch M D; Tomasko D.L; Lee L J
Ohio State,University
Supercritical carbon dioxide addition has been used to
assist in the blending of polymethylmethacrylate and
polystyrene. Whether the melt viscosities of the two
polymers are equal, or varying with a viscosity ratio
of about 20, the results show a reduction in size of the
minor or dispersed phase. Addition of the carbon dioxide
lowers the melt viscosities, by being absorbed between
the polymer chains causing an increase in free volume,
resulting in a decrease in chain entanglement and thus
increased chain mobility. Single and twin screw extruders
were used in the studies. 29 refs.
USA
Accession no.760460
Item 275
Patent Number: EP 972626 A2 20000119
METHOD OF ADDING SUPERCRITICAL
CARBON DIOXIDE TO THERMOPLASTIC
RESIN AND FOAMED ARTICLES
Nishikawa S; Sugihara E; Takedachi M; Yorita K;
Inoue H; Shimada Y; Eriguchi M
Mitsui Chemicals Inc.
Carbon dioxide is charged from a lique
À ed carbon dioxide
cylinder into a predetermined amount deliverable pump
while allowing the carbon dioxide to remain in a lique
À ed
state. When the carbon dioxide is pressurised and delivered
by the pump, the delivery pressure of the carbon dioxide
is controlled at an optional pressure within a range from
a critical pressure (7.4 MPa) of carbon dioxide to 40 MPa
to deliver carbon dioxide without any
Á uctuation of the
amount of the delivery by setting up the pressure of a
pressure control valve. The carbon dioxide is heated to a
critical temperature (31C) of carbon dioxide or higher to
convert it into supercritical carbon dioxide, which is then
added to the thermoplastic resin in the forming machine.
JAPAN
Accession no.760435
Item 276
Macromolecules
32, No.22, 2nd Nov.1999, p.7610-6
EXPANSION OF POLYSTYRENE USING
SUPERCRITICAL CARBON DIOXIDE: EFFECTS
OF MOLECULAR WEIGHT, POLYDISPERSITY,
AND LOW MOLECULAR WEIGHT
COMPONENTS
Stafford C M; Russell T P; McCarthy T J
Massachusetts,University
Closed cell foams of broad MWD commercial PS
samples, prepared by expansion of supercritical carbon
dioxide-swollen specimens, exhibited cell diameters that
were 3 to 10 times larger than those of foams prepared
from PS samples with narrow MWDs. Cell diameters
for narrow MWD samples were independent of molec.
wt. from 147 to 1050K. Simulated polydisperse samples
prepared by blending narrow MWD samples ranging from
560 to 1050K and a polydisperse sample prepared by
radical polymerisation produced foams with cells of the
same size as in foams prepared from the narrow MWD
samples. These observations suggested that molec.wt. and
polydispersity were not important factors in determining
cell size and were not responsible for the disparity in cell
sizes described. This disparity was due to the presence
of a very low molec.wt. component in the commercial
samples. Extraction of this component reduced the cell
diameter of resulting foams to that of the narrow MWD
samples. Addition of a styrene oligomer to a narrow
MWD sample resulted in foams with larger cell diameters.
Varying the concentration of this oligomer allowed control
of cell size in foams. Classical nucleation theory could not
explain these observations, suggesting that an alternative
mechanism of cell formation was active. 21 refs.
USA
Accession no.759217
Item 277
Polymer Journal (Japan)
31, No.9, 1999, p.714-6
DECOMPOSITION OF POLYETHYLENE
2,6-NAPHTHALENE DICARBOXYLATE
TO CONSTITUENT MONOMERS USING
SUPERCRITICAL METHANOL
Sako T; Sugeta T; Otake K; Yoda S; Takebayashi Y;
Okajima I
Tsukuba,National Institute of Materials & Chemical
Research
The depolymerisation of polyethylene 2,6-naphthalene
dicarboxylate (PEN) to its constituent monomers and
oligomer using supercritical methanol without a catalyst
was investigated as a means of chemical recycling of
waste PEN. Attention focused on the analysis of the
decomposition products, which included both solids and
liquids. The amount of gases produced was negligible,
as the decomposition temperature was only 623 K. The
solid phase consisted of unreacted PEN, undissolved
References and Abstracts
© Copyright 2005 Rapra Technology Limited
91
monomer dimethyl 2,6-naphthalene dicarboxylate (DMN)
and oligomer. The oligomer was de
À ned as a product
which was hydrolysed with sodium hydroxide aqueous
solution to disodium 2,6-naphthalene dicarboxylate and
ethylene glycol. The liquid phase contained ethylene glycol
monomer, DMN monomer and oligomer. 5 refs.
JAPAN
Accession no.758005
Item 278
Industrial and Engineering Chemistry Research
38, No.10, Oct.1999, p.3655-62
POLYMER COATINGS BY RAPID EXPANSION
OF SUSPENSIONS IN SUPERCRITICAL
CARBON DIOXIDE
Jae-Jin Shim; Yates M Z; Johnston K P
Texas,University
Suspensions of poly(2-ethylhexyl acrylate) in supercritical
carbon dioxide formed by dispersion polymerisation with
a polydimethylsiloxane-based surfactant were sprayed
to form uniform
À lms. The viscosity reduction of the
dispersed phase caused by dissolved carbon dioxide was
crucial for atomisation to produce
À ne droplets and for
coalescence and levelling on the surface to form a uniform
À lm. Resuspension of the polymer after depressurisation
and repressurisation led to fairly large droplets in the
suspension which produced a
À lm nearly as uniform
as the original one. Inferior films were produced by
suspensions without surfactant. Unlike previous studies of
rapid expansion of homogeneous polymer solutions and
related techniques,
À lms were produced from concentrated
polymer mixtures without any organic solvent. 24 refs.
USA
Accession no.756190
Item 279
Industrial and Engineering Chemistry Research
38, No.10, Oct.1999, p.3622-7
SUPERCRITICAL FLUID SEPARATION FOR
SELECTIVE QUATERNARY AMMONIUM
SALT PROMOTED ESTERIFICATION OF
TEREPHTHALIC ACID
Brown J S; Lesutis H P; Lamb D R; Bush D;
Chandler K; West B L; Liotta C L; Eckert C A;
Schiraldi D; Hurley J S
Georgia,Institute of Technology; KoSa; Buckeye
Technologies
A study was conducted of the selective removal of a
desired reaction intermediate with a supercritical
Á uid in
a new synthesis route to PETP, avoiding ethylene glycol.
The esteri
À cation of terephthalic acid with ethylene oxide
in a supercritical
Á uid was successfully catalysed using
a series of quaternary ammonium salts to form mono(2-
hydroxyethyl terephthalate). This desired monoester was
removed from the non-volatile bed of terephthalic acid
and catalyst by continuous extraction with supercritical
Á uid before subsequent reaction to the diester could take
place. 11 refs.
USA
Accession no.756188
Item 280
Cellular Polymers
18, No.5, 1999, p.301-13
MEASUREMENT AND PREDICTION
OF BLOWING AGENT SOLUBILITY IN
POLYSTYRENE AT SUPERCRITICAL
CONDITIONS
Seong Uk Hong; Albouy A; Duda J L
Pennsylvania,State University
Partition coef
À cients of several blowing agents (HFCs
AND HCFCs) in PS at the infinitely dilute solvent
concentration region were measured using capillary
column inverse gas chromatography. The measured
partition coef
À cients were then used to calculate binary
interaction parameters in the perturbed soft chain
theory(PSCT). Using these values, solubility data of
blowing agents in the
À nite solvent concentration region
were predicted as a function of pressure in accordance
with the PSCT. The prediction results from the PSCT were
comparable with the experimental data in the literature.
In addition, the PSCT was found to be very sensitive to
the partition coef
À cient and, hence, the binary interaction
parameter. 21 refs.
USA
Accession no.755884
Item 281
Macromolecules
32, No.9, 4th May 1999, p.3167-9
SOLID STATE POLYMERISATION OF
POLYCARBONATES USING SUPERCRITICAL
CARBON DIOXIDE
Gross S M; Flowers D; Roberts G; Kiserow D J;
DeSimone J M
North Carolina,University; US,Army Research Of
À ce
Polycarbonate prepolymer was synthesised by step-growth
polymerisation of bisphenol A and diphenyl carbonate
using an aqueous solution of lithium hydroxide as the
initiator. The prepolymer formed beads when dripped
into room-temperature water.The beads were crystallised
by treatment with supercritical carbon dioxide. The
crystallisation of the low molecular weight (2500)
polycarbonate was studied as a function of time and
temperature. DSC gave melting point, Tg, enthalpy of
fusion and crystallinity. The crystallised prepolymer was
then polymerised in the solid state at 3C below the onset
of melting (160C) and samples removed after 2, 4, 6,
and 12 hours. Because the melting point increased with
polymerisation the process was repeated at 180C, 205C,
230C and 240C. It was repeated also with a 5000 molecular
weight prepolymer. The development of crystallinity,
References and Abstracts
92
© Copyright 2005 Rapra Technology Limited
molecular weight and melting point over 12h is shown.
12 refs.
USA
Accession no.754788
Item 282
Journal of Polymer Science: Polymer Physics Edition
37, No.19, 1st Oct.1999, p.2771-81
RHEOLOGY OF MOLTEN POLYSTYRENE
WITH DISSOLVED SUPERCRITICAL AND
NEAR-CRITICAL GASES
Kwag C; Manke C W; Gulari E
Wayne State,University
The viscosities of PS melts containing three different
dissolved gases, carbon dioxide and the refrigerants
R134a (1,1,1,2-tetrafluoroethane) and R152a (1,1-
difluoroethane) were investigated at pressures up to
20 MPa. These pressures reached near-critical and
supercritical conditions for the three gas components and
produced polymer-gas solutions containing up to 10 wt %
gas. The measurements were performed in a sealed high-
pressure capillary rheometer at 150 and 175C and at shear
rates ranging from 1 to 2000/s. Very large reductions in
melt viscosity were observed at high gas loading, 10 wt
% R152a at 150C reducing the Newtonian viscosity by
nearly three orders of magnitude relative to pure PS. The
viscosity data for all three PS-gas systems followed ideal
viscoelastic scaling, whereby the set of viscosity curves
for a polymer-gas system could be scaled to a master curve
of reduced viscosity versus reduced shear rate identical to
the viscosity curve for the pure polymer. The viscoelastic
scaling factors representing the effect of dissolved gas
content on rheological behaviour were found to follow
roughly the same variation with composition for all three
PS gas systems. 20 refs.
USA
Accession no.754124
Item 283
Antec ‘99. Volume II. Conference proceedings.
New York City, 2nd-6th May 1999, p.2433-5. 012
APPLICATIONS OF FTIR SPECTROSCOPY TO
CHARACTERISE POLYMERS PROCESSED
WITH SUPERCRITICAL CARBON DIOXIDE
Kazarian S G
London,Imperial College of Science,Technology &
Medicine
(SPE)
Supercritical CO2 can induce crystallisation of amorphous
polymers. Molecular level insight into the microstructures
of CO2-processed polymers is needed to form a basis
for utilisation and optimisation of supercritical fluid
processing of polymeric materials. FTIR spectroscopy is
applied to elucidate the morphology and microstructure
of polymers processed with supercritical CO2. FTIR
spectra of syndiotactic PS show an increased degree of
crystallinity after being subjected to scCO2. The various
crystalline forms induced by CO2 in syndiotactic PS
are characterised via FTIR spectra. FTIR spectroscopy
is also used to measure the kinetics of CO2-induced
crystallisation in these polymers. 19 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.749592
Item 284
Antec ‘99. Volume II. Conference proceedings.
New York City, 2nd-6th May 1999, p.2811-5. 012
MORPHOLOGY DEVELOPMENT IN CARBON
DIOXIDE ASSISTED POLYMER BLENDING IN
BATCH AND CONTINUOUS PROCESSES
Elkovitch M D; Lee L J; Tomasko D L
Ohio,State University
(SPE)
The compatibility of individual homopolymers is one of the
most important parameters in
Á uencing polymer blending.
Often blending involves components with vastly different
viscosities and interfacial tensions. Supercritical carbon
dioxide can be added to polymer melts as a processing
aid such that effective polymer blending will occur. A
blend system of a high viscosity PMMA and low viscosity
PS is analysed. Carbon dioxide has a higher af
À nity for
PMMA than for PS. Therefore, a greater plasticising effect
will occur for the PMMA than for the PS. The improved
results in polymer blending are shown. The morphology
development of the polymer blends is analysed in a
high-pressure batch mixer and the continuous extrusion
process. 13 refs.
USA
Accession no.749543
Item 285
Antec ‘99. Volume II. Conference proceedings.
New York City, 2nd-6th May 1999, p.2806-10. 012
EXTRUSION OF PE/PS BLENDS WITH
SUPERCRITICAL CO2 IN A TWIN-SCREW
EXTRUDER AND A TWIN/SINGLE TANDEM
SYSTEM
Lee M; Tzoganakis C; Park C B
Waterloo,University; Toronto,University
(SPE)
The effects of dissolved supercritical carbon dioxide on
the viscosity and morphological properties are investigated
for PE, PS and their blends in a twin-screw extruder and
a twin/single screw tandem system. The viscosities of the
polymer/CO2 and the blend/CO2 solutions wae measured
using a wedge die mounted on the twin-screw extruder.
The effect of CO2 on the morphology of PE/PS blends is
investigated using a twin/single screw tandem system. This
system allows for preferential dissolution of the CO2 into
the matrix and/or dispersed polymer phase. By introducing
devolatilisation to the tandem system, the morphological
References and Abstracts
© Copyright 2005 Rapra Technology Limited
93
behaviours of PE/PS blends are investigated on unfoamed
À laments. 22 refs.
CANADA
Accession no.749542
Item 286
British Plastics and Rubber
Oct.1999, p.14-8
WHERE NEXT FOR GAS INJECTION?
Coates P
Gas injection moulding provides improved surface
À nish, reduced costs, partly through material saving, and
improved dimensional stability. Original leading products
were TV housings, where gas injection was used to reduce
wall thicknesses and improve cosmetic appearance. Pentex
has presented a variation on the gas injection theme, “gas
in melt”, where carbon dioxide is added to the melt in
the injection barrel, passing into solution in the melt as a
supercritical
Á uid.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.749219
Item 287
Journal of Polymer Science: Polymer Physics Edition
37, No.15, 1st Aug.1999, p.1881-91
IN SITU DRAWING OF HIGH MOLECULAR
WEIGHT POLY(ETHYLENE TEREPHTHALATE)
IN SUBCRITICAL AND SUPERCRITICAL CO2
Hobbs T; Lesser A J
Massachusetts-Amherst,University
Amorphous melt-spun poly(ethylene terephthalate)
À bres were subjected to in situ drawing in the presence
of subcritical and supercritical carbon dioxide. The
mechanical properties and morphological properties were
studied in situ and following drawing treatment. Fibres
soaked in subcritical carbon dioxide could be drawn to
30 % higher draw ratios compared with
À bres which were
cold-drawn, and they had no measurable resistance to
deformation until strain hardening occurred. Fibres drawn
in supercritical carbon dioxide had a yield response, a
signi
À cant decrease in ductility and a signiÀ cant difference
in post-yield behaviour. The
À bres drawn in subcritical
carbon dioxide had slightly lower tensile properties than
cold-drawn samples, whilst those drawn under supercritical
conditions had much lower tensile properties, attributed to
the limited draw ratio. X-ray diffraction studies showed
that carbon dioxide treatment enhanced crystalline phase
development. 33 refs.
USA
Accession no.747616
Item 288
Journal of Materials Chemistry
9, No.7, July 1999, p.1403-7
DISPERSION POLYMERISATION OF METHYL
METHACRYLATE IN SUPERCRITICAL
CARBON DIOXIDE - EVALUATION OF
WELL DEFINED FLUORINATED AB BLOCK
COPOLYMERS AS SURFACTANTS
Hems W P; Yong T-M; van Nunen J L M; Cooper A I;
Holmes A B; Grif
À n D A
Melville Laboratory; ZENECA Agrochemicals
Application of the ‘screened anionic polymerisation’
method to the synthesis of well-defined AB block
copolymers derived from methyl methacrylate and
fluorinated methacrylate monomers has provided
a family of tuneable surfactants for the free radical
dispersion polymerisation of methyl methacrylate
in supercritical carbon dioxide. PMMA is obtained
with excellent conversion and high molecular weight.
Block copolymers having higher molecular weight and
higher
Á uorine contents are superior surfactants, and by
systematic evaluation of the parameters in the dispersion
polymerisation of methyl methacrylate, discrete polymer
particles can be obtained. 30 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.744478
Item 289
Journal of Polymer Science: Polymer Chemistry
Edition
37, No.14, 15th July 1999, p.2429-37
PREPARATION OF MICRON-SIZE
POLYSTYRENE PARTICLES IN
SUPERCRITICAL CARBON DIOXIDE
Shiho H; Desimone J M
JSR Corp.; North Carolina,Chapel Hill University
The dispersion polymerisation of styrene in supercritical
CO2 utilising poly(1,1-dihydroper
Á uorooctyl acrylate) (p-
FOA) as a polymeric stabiliser is investigated as well as
poly(1,1-dihydroper
Á uorooctyl methacrylate) (p-FOMA).
The resulting high yield of spherical and relatively uniform
PS particles with micron-size range (2.9-9.6 mu m) is
formed for 40 hrs at 370 bar using various amounts of p-
FOA and p-FOMA as a stabiliser with good stability until
the end of the reaction. The particle diameter is shown to be
dependent on the weight percent of added stabiliser. It has
been previously reported that p-FOA is not effective for the
dispersion polymerisation of styrene as a stabiliser. Here, it
is shown that p-FOA can indeed be an effective stabiliser
for the dispersion polymerisation of styrene in supercritical
CO2, but the pressure necessary to achieve good stability is
higher than pressure used previously. This study suggests
the possibility that
Á uorinated acrylic homopolymers are
effective for the dispersion polymerisation of various kinds
of monomers as a stabiliser. 30 refs.
JAPAN; USA
Accession no.743140
References and Abstracts
94
© Copyright 2005 Rapra Technology Limited
Item 290
Chemical Week
Suppl.161, No.30, 11th Aug.1999, p.s23
USING SUPERCRITICAL FLUIDS TO PROVIDE
USEFUL INFORMATION
Krukonis V
Phasex Corp.
The use of supercritical
Á uids to provide information on the
molecular weight, chemical composition and crystallinity
distribution in polyole
À ns, by the analysis of narrow
fractions, is discussed. Such data allows process kinetics,
reactor performance and catalyst activity to be determined
in more detail than ever before, it is claimed. Supercritical
Á uids exhibit a pressure-dependent dissolving power in
order to extract narrow fractions to a simultaneous level
of resolution and fraction amount that is not achievable
by other methods, and enables producers of polyole
À ns to
meet the increasing performance demands being placed on
them to develop applications-speci
À c polymers.
USA
Accession no.742794
Item 291
ACS Polymeric Materials Science & Engineering.
Volume 80.Conference proceedings.
Anaheim, Ca., Spring 1999, p.518-9
VINYL ACETATE DISPERSION
POLYMERIZATION IN SUPERCRITICAL
CARBON DIOXIDE
Rind
Á eisch F; Becker R; Hergeth W-D
Air Products Polymers GmbH & Co.KG; Wacker
Polymer Systems GmbH & Co.KG
(ACS,Div.of Polymeric Materials Science & Engng.)
The dispersion polymerisation of vinyl acetate in
supercritical carbon dioxide (SCCD), using a siloxane-
based comb-like graft copolymer stabiliser, was studied.
The solubility of polyvinyl acetate in vinyl acetate-
SCCD solutions of various compositions was studied by
observing the transparent-cloud transition of the mixtures
as the pressure was dropped at various
À xed temperatures.
3 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.741385
Item 292
Polymer Plastics Technology and Engineering
38, No.3, 1999, p.411-31
SEPARATION AND RECOVERY OF
NYLON FROM CARPET WASTE USING A
SUPERCRITICAL FLUID ANTISOLVENT
TECHNIQUE
Grif
À th A T; Park Y; Roberts C B
Auburn,University
The process involves selective dissolution of nylon
up to 2.31 wt.% from a model carpet with an 88 wt.%
liquid formic acid solution at 40C, recovery of nylon
powder with supercritical CO2 antisolvent precipitation
at pressures between 84 and 125 bar at 40C and recycling
of the solvent and antisolvent by
Á ashing into two phases.
Experiments carried out to study the effects of upstream
pressure, downstream pressure, nozzle diameter and nylon
solution concentration on the particle size and particle
size distribution of the nylon powder revealed that these
operating parameters had little in
Á uence on such properties,
indicating the controllability of the process. 19 refs.
USA
Accession no.741245
Item 293
Polymer Degradation and Stability
64, No.2, May 1999, p.289-92
DECOMPOSITION OF POLYCARBONATE IN
SUBCRITICAL AND SUPERCRITICAL WATER
Tagaya H; Katoh K; Kadokawa J; Chiba K
Yamagata,University
The decomposition reaction of polycarbonate in subcritical
and supercritical water was studied. The decomposition
products were phenol, bisphenol A, p-isopropenylphenol
and p-isopropylphenol at 230C-430C in water. The
reactions were accelerated when sodium carbonate was
added and the yields of identi
À ed products reached 67%,
even in the reaction at 300C for 24 h. 12 refs.
JAPAN
Accession no.737350
Item 294
Journal of Elastomers and Plastics
31, No.2, April 1999, p.162-79
CONVERSION OF TYRE WASTE USING
SUBCRITICAL AND SUPERCRITICAL WATER
OXIDATION
Park Y; Reaves J T; Curtis C W; Roberts C B
Auburn,University
The properties designed into tyres that make them strong
and chemically resistant also inhibit their ability to be
recycled easily. Conventional liquid solvents do not
sufficiently dissolve waste tyres and tyre production
material for convenient separation. Supercritical water
oxidation (SCWO) may provide an alternative solution to
this environmental problem. Partial SCWO can be used
as a means to partially break down rubber (polymeric)
waste materials into lower molecular weight components
that could be recovered as a chemical feedstock. The
feasibility of converting waste material from tyre
production into useful products is explored. Batch SCWO
studies illustrate the ability to ef
À ciently break down
the waste tyre production material into a range of lower
molecular weight organics for possible reuse depending
on reaction conditions. Furthermore, a semi-continuous
process is developed and preliminary results are presented.
Destruction ef
À ciencies of greater than 0.9 are obtained
References and Abstracts
© Copyright 2005 Rapra Technology Limited
95
in all runs regardless of reactor type. The results show
SCWO to be a promising remediation alternative to the
waste tyre problem. 32 refs.
USA
Accession no.732310
Item 295
Industrial and Engineering Chemistry Research
38, No.4, April 1999, p.1391-5
DECOMPOSITION OF PREPOLYMERS AND
MOULDING MATERIALS OF PHENOL RESIN IN
SUBCRITICAL AND SUPERCRITICAL WATER
UNDER AN ARGON ATMOSPHERE
Suzuki Y; Tagaya H; Asou T; Kadokawa J; Chiba K
Yamagata,University; Sumitomo Bakelite Co.Ltd.
Seven phenol resin prepolymers and moulding materials
were decomposed into their monomers by reactions at
523-703K under an argon atmosphere in subcritical and
supercritical water. The decomposition reactions were
accelerated by the addition of sodium carbonate. 28 refs.
JAPAN
Accession no.732130
Item 296
Polymer Preprints. Volume 40. Number 1. March 1999.
Conference proceedings.
Boston, Ma., March 1999, p.228-9. 012
METAL-POLYMER COMPOSITES IN
SUPERCRITICAL FLUID CARBON DIOXIDE
Rajagopalan P; McCarthy T J
Amherst,Massachusetts University
(ACS,Div.of Polymer Chemistry)
The synthesis of metal-polymer nanocomposites in
supercritical
Á uid (SCF) carbon dioxide has recently
been reported. Supercritical
Á uids have very attractive
properties enabling them to be viable reaction media, some
of these properties include gas-like diffusivity combined
with a liquid-like density and a tunable solvent strength.
Previously, an organo-platinum complex was dissolved in
SCF CO2 under a given set of conditions and then infused
within a polymer substrate (PTFE). Upon further reduction
of the organoplatinum complex, nanoscale platinum
particles were deposited through the entire polymer
substrate. The infusion of an additive (dissolved in SCF
CO2) into a SCF CO2 swollen polymer substrate has been
studied. The additive was iron acetylacetonate, (Fe(acac)3),
and LDPE was chosen as the polymer substrate. Fe(acac)3
has been reported to impart
Á ame retardant properties to
polymeric substrates, thus satisfying another objective
which is to observe thermal degradation properties of
metal/polymer composites. Fe(acac)3, in addition to
being a
Á ame retardant additive, is also a precursor to
iron oxide. Iron oxide, a dehydrogenation catalyst, can
promote char formation during thermal degradation of
polymers, thus enhancing their
À re retardant properties.
It is demonstrated that HDPE-Fe(acac)3 composites can
be formed in SCF CO2. Fe(acac)3 is deposited closer to
the surface of the LDPE plaques. In general, increasing
infusion temperature increases concentration of Fe(acac)3
deposited within LDPE. The thermal degradation of
LDPE-Fe(acac)3 composites in the 400-450 deg.C range
is slower in comparison to virgin LDPE. 13 refs.
USA
Accession no.730044
Item 297
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.260-1. 012
EFFECT OF ADDED HELIUM ON PARTICLE
SIZE AND PARTICLE SIZE DISTRIBUTION OF
DISPERSION POLYMERISATIONS OF METHYL
METHACRYLATE IN SUPERCRITICAL
CARBON DIOXIDE
Hsaio Y-L; DeSimone J M
North Carolina,University
(ACS,Div.of Polymeric Materials Science & Engng.)
The synthesis of spherical polymers particles with a range
of diameters has been an active area of research due to the
wide variety of applications for such materials. Practical use
of these particles includes standards for the determination
of pore size and the ef
À ciency of À lters, column packing
material for chromatographic separation, support materials
for biochemicals, toner, cosmetics, drug delivery vehicles,
etc. Control of particle size and uniformity has been a
major area of interest. It is particularly challenging to
prepare monodisperse polymer particles in the micron
size range. Dispersion polymerisation is one of the best
synthetic methods for the preparation of uniform particles
in the micron range. As a means to control particle size and
particle size distribution, a number of investigations has
focused on the in
Á uence of the reaction initiator, monomer
and stabiliser concentrations; reaction temperature, and
cosolvents. These studies concluded that the nucleation
period plays an important role in determining particle size
characteristics. One of the factors that strongly in
Á uence
the nucleation period is the solvency of the reaction
medium. There are numerous examples using cosolvents
to manipulate the particle size and particle size distribution
through changing the solvency of the reaction media. It is
demonstrated that it is possible to control the particle size
characteristics of the dispersion polymerisation of methyl
methacrylate in supercritical CO2 by varying the amount
of a gaseous cosolvent - helium. 31 refs.
USA
Accession no.724895
References and Abstracts
96
© Copyright 2005 Rapra Technology Limited
Item 298
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.256-7. 012
SYNTHESIS OF POLY(2,6-
DIMETHYLPHENYLENE OXIDE) IN CARBON
DIOXIDE
Kapellen K K; Mistele C D; DeSimone J M
North Carolina,University
(ACS,Div.of Polymeric Materials Science & Engng.)
The utilisation of CO2 as a medium for polymerisation
reactions has attracted signi
À cant interest. For example,
it has been successfully employed as a continuous
phase in homogeneous free radical polymerisations,
heterogeneous free radical polymerisations, as well as
cationic polymerisations and ring-opening methathesis
polymerisations. The advantages of carbon dioxide as a
reaction medium include the case with which the polymer
can be separated from the reaction medium and the powdery
form in which the polymer can be obtained. Furthermore, the
density and the viscosity of carbon dioxide can be tuned over
a large range due to the compressibility of CO2, particularly
in the supercritical phase. PPOs are mainly synthesised via
the oxidative coupling polymerisation of 2,6-di- and 2,3,6-
tri-substituted phenols. The most common of these processes
is performed using 2,6-dimethylphenol as monomer and
a catalyst system which includes a copper halide, an
amine and oxygen. Oxygen is usually passed through the
reaction solution during the course of the reaction. All of
the processes are solvent intensive as they are performed
in organic solvents like toluene, benzene, halogenated
hydrocarbons, dimethyl sulphoxide or in biphasic systems
and are precipitated into a nonsolvent such as methanol
to isolate the polymer. The use of carbon dioxide as the
reaction medium for the synthesis of PPOs would eliminate
the need for using organic solvents in the manufacture of
this commercially important polymer. 10 refs.
USA
Accession no.724893
Item 299
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.254-5. 012
CATIONIC POLYMERISATION OF OXETANES
IN LIQUID CARBON DIOXIDE
Kanameneni S; Desimone J M
North Carolina,University
(ACS,Div.of Polymeric Materials Science & Engng.)
Cationic ring opening polymerisations of cyclic ethers
are usually carried out in chlorinated organic solvents
such as methylene chloride (CH2Cl2). Increasing concern
regarding the dissemination of volatile organic compounds
prompted chemical industries to use environmentally
sound practices in the manufacture and processing of
products. Carbon dioxide (CO2) has low dielectric
constant, and low viscosity. It is a non-toxic, inexpensive
and environmentally sound reaction medium. Previously
it has been shown that supercritical carbon dioxide is an
excellent solvent to conduct free-radical chain reactions
and ring-opening metathesis reactions, etc. The cationic
polymerisation of vinyl and cyclic ethers in CO2 has
also recently been demonstrated, using boron tri
Á uoride-
tetrahydrofuran as the initiating system. The cationic
ring opening polymerisation of oxetanes in liquid carbon
dioxide as the solvent/dispersing medium are reported. The
goal is to use the bifunctional initiator p-DCC/AgSbF6
for the homopolymerisation of oxetane monomers such
as bis(ethoxymethyl)oxetane (BEMO) and ethoxymethyl
methyl oxetane (EMMO) in CO2 and to eventually make
triblock thermoplastic elastomers in CO2. The results of
the cationic polymerisation of oxetanes using a bifunctional
initiator in liquid CO2 are described. 12 refs.
USA
Accession no.724892
Item 300
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.248-9. 012
SYNTHESIS OF POLYESTERS IN
SUPERCRITICAL CARBON DIOXIDE
Burke A L C; Maier G; DeSimone J M
North Carolina,University
(ACS,Div.of Polymeric Materials Science & Engng.)
The melt phase polymerisation of many polyesters may
be accomplished by the condensation of a variety of
difunctional monomer units, releasing a small molecule
condensate as a by-product of either a transesteri
À cation
or a melt acidolysis reaction. Removal of this by-product
is an essential force in driving the polymerisation reaction.
The ef
À ciency of supercritical Á uid extraction methods to
solubilise condensation byproducts for subsequent removal
from the reaction is investigated. Polyesters suitable for
supercritical fluid extraction encompass a variety of
aliphatic and aromatic species, including polymers with
potential applications as powder coatings. The synthesis
of PETP using supercritical
Á uid extraction (SCFE) is
introduced. 9 refs.
USA
Accession no.724889
Item 301
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.246-7. 012
POLYMER MODIFICATION IN
SUPERCRITICAL CARBON DIOXIDE
Kerschner J L; Jurelle S H; Harris R
Unilever Research
(ACS,Div.of Polymeric Materials Science & Engng.)
With many polymers, the technique of compounding or
the infusion of modi
À ers into the polymer matrix requires
References and Abstracts
© Copyright 2005 Rapra Technology Limited
97
procedures involving mixing or kneading the modi
À er
with the polymer with the application or generation of
heat which is often detrimental to the stability of the
modi
À er itself or can even degrade the polymer. As an
alternative method, dissolution of a polymer in a solvent
followed by addition of the modi
À er can be successful,
but exhaustive removal of the solvent is often dif
À cult,
and the residual solvent present in the modi
À ed polymer
can affect the intended use of the polymer and can present
environmental and safety problems for the end product.
Supercritical
Á uids offer an inexpensive, non-toxic, non-
Á ammable alternative to typical organic solvents and
these
Á uids have the ability to swell and plasticise some
polymers, resulting in a signi
À cant reduction of the glass
transition temperature of the polymer. The adsorption of
chemically reactive modi
À ers/catalysts into the polymer
is described. Under modi
À cation conditions, the modiÀ ers
react with different polymer pendant groups adding new
chemical functionality to the polymeric material. For
example, in this process, long chain hydrophobic groups
could be added to hydrophilic polymers resulting in new
materials with distinctly different chemical and physical
properties. 6 refs.
USA
Accession no.724888
Item 302
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.2331-2. 012
HIGH-PRESSURE MISCIBILITY AND
EXTRACTION OF POLYMERIC COATINGS
AND HOT-MELT ADHESIVES WITH CARBON
DIOXIDE AND PENTANE MIXTURES
Kiran E; Malki K; Pohler H
Maine,University
(ACS,Div.of Polymeric Materials Science & Engng.)
More than 150 million tons of municipal solid waste is
generated each year in the USA; of this, paper and paper
board accounts for 40% and plastics account for 8% by
weight. A major source of waste is packaging materials
(about 32%) of which paper and paper board, and plastics
represent 18 and 3 %, respectively. The major plastic
components found in the municipal solid waste are
LDPE, HDPE, PS, PP and PETP. A variety of polymers
is also found in paper wastes as they are used as barrier
film coatings, hot-melt adhesives, pressure-sensitive
adhesives, laser printer and photocopier toner inks and
binders in paper coatings. These polymeric constituents
often represent dif
À culties in recycling of reclamation
of secondary
À bres from waste paper. The University of
Maine has been involved in applications of supercritical
Á uids in the polymers, pulp and paper and forest products
industries. Some recent activity has been focused on
extraction of polymeric constituents from mixed plastics
and/or from paper/polymer composites. For this purpose
it has generated a fundamental data base on the miscibility
of model polymers in selected fluid systems, and is
conducting extraction studies on both simulated and real
paper/plastic waste samples. The miscibility and extraction
of selected polymers using carbon dioxide and alkane
mixtures are described. 6 refs.
USA
Accession no.724880
Item 303
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.230. 012
FORMATION OF MICROCELLULAR
POLYMERIC MATERIALS VIA
POLYMERISATION IN CARBON DIOXIDE
Parks K; Sparacio D; Beckman E J
Pittsburgh,University
(ACS,Div.of Polymeric Materials Science & Engng.)
Microcellular materials have been produced via phase
separation in a liquid solution, via gas expansion in molten
polymers and via combinations of both approaches. Phase
separation can be accomplished via a temperature quench,
pressure quench or the addition of a non-solvent to a single
phase polymer-solvent mixture. Phase separation can also
be induced by an increase in molecular weight or crosslink
density, such as in the polymerisation of ion exchange
resin systems in solution. While the two gas expansion
techniques produce what is considered to be macrocellular
foam, it has been shown that when a polymer sample is
saturated with gas, then rapidly heated to a point above the
glass transition, a microcellular material is produced. The
formation of microcellular materials via generation of a
PU network in carbon dioxide, followed by solvent (CO2)
removal has been investigated. It has been shown that the
PU precursors, polyols and isocyanates, are miscible with
CO2 above certain threshold pressures. The polymerisation
of the precursors can be conducted under conditions where
the system is initially a single homogeneous phase. Here,
the reaction pressure, type of isocyanate reacted with a
particular polyol blend, ratio of diol to crosslinker in the
polyol blend, reaction temperature and foaming agent
are varied. Bulk densities, cell sizes and cell densities of
the resultant foams are measured. It is examined how the
mechanism for phase separation affects the pore size of
the foams. There is a variety of possible mechanisms for
introducing pores in a polymer/solvent mixture, several
of which are accessible to this system.
USA
Accession no.724879
References and Abstracts
98
© Copyright 2005 Rapra Technology Limited
Item 304
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.228-9. 012
POLYMER STABILISED EMULSIONS IN
SUPERCRITICAL CARBON DIOXIDE
O’Neill M L; Yates M Z; Johnston K P; Wilkinson S P;
DeSimone J M
Texas,University at Austin; Air Products & Chemicals
Corp.; North Carolina,University
(ACS,Div.of Polymeric Materials Science & Engng.)
Traditional supercritical fluid reaction and separation
processes require that the target species be soluble in the
SCI phase, yet few non-volatile species are soluble. SCF
technology could be expanded markedly with the use
of surfactants in heterogeneous processes, as reviewed
recently for hydrophilic dispersed phases. Recently, a key
breakthrough has been the dispersion of lipophilic phases
within CO2. Supercritical
Á uid (SCF) carbon dioxide (Tc=31
deg.C, Pc = 73.8 bar) is an attractive alternative to liquid and
SCF organic solvents because it is non-toxic, non
Á ammable,
inexpensive and environmentally benign compared
with organic solvents. However, because of its very low
dielectric constant, E, and polarisability per volume, alpha/v,
CO2 is a poor solvent for most non-volatile lipophilic or
hydrophilic solutes, i.e. water. Consequently, it may be
considered a third type of condensed phase. The appropriate
choice of surfactant affords an interesting opportunity to
disperse either lipophilic or hydrophilic phases into CO2
in the form of microemulsions, emulsions and latexes.
Recently dispersion polymerisation has been performed
successfully in SCF CO2 with surfactant stabilisers.
Poly(l,1-dihydroper
Á uorooctyl acrylate) poly(FOA) acts
as a stabiliser in the dispersion polymerisation of methyl
methacrylate. High molecular weight PMMA latex particles
are produced with diameters from 1.55 to 2.86 mm. Models
of emulsions and latexes in liquids are applied to SCF
emulsions to better understand stabilisation mechanisms for
polymer surfactants, in particular poly(FOA). 12 refs.
USA
Accession no.724878
Item 305
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.1835-. 012
PLASTICISATION OF POLYMER MELTS WITH
DENSE OR SUPERCRITICAL CO2
Kwag C; Gerhadt L J; Khan V; Gulari E; Manke C W
Wayne State,University
(ACS,Div.of Polymeric Materials Science & Engng.)
Supercritical gases (SCGs) are of great interest as plasticisers
for polymer processing applications such as composites, foams
and paints, where an environmentally benign supercritical gas
such as carbon dioxide can replace organic solvents or CFC
blowing agents, thereby reducing or eliminating the emissions
of VOCs or ozone-depleting components. Moreover, SCGs
have important performance advantages over conventional
organic solvents for applications where the viscosity of
a thermoplastic resin must be reduced for more ef
À cient
processing. Like organic solvents, SCGs act to reduce
viscosity by bulk dilution of the density of polymer chain
segments within the melt. However, SCUs can also contribute
signi
À cant free volume to the polymer melt, resulting in
signi
À cant reductions in melt viscosity beyond those that
can be achieved by chain dilution alone. The rheological
behaviour of high molecular weight polydimethylsiloxane
(PDMS) and PS melts plasticised with dissolved carbon
dioxide are examined. Viscosity curves for both systems
are measured with a pressurised capillary rheometer to
characterise the melt viscosity as a function of shear rate and
carbon dioxide content. An equation-of-state (EOS) model
for the density of polymer-CO2 solutions is combined with
a free-volume rheological theory to predict the composition-
dependent shift factors directly. 3 refs.
USA
Accession no.724855
Item 306
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.178-9. 012
SOLUBILITY OF POLYMERS AND
COPOLYMERS IN SUPERCRITICAL CO2: WHY
HIGH PRESSURES AND TEMPERATURES ARE
NEEDED
Rind
Á eisch F; DiNoia T; McHugh M A
Johns Hopkins University
(ACS,Div.of Polymeric Materials Science & Engng.)
Carbon dioxide has been touted as the solvent of choice
for many industrial applications because of its attractive
attributes, e.g., it is environmentally benign, non-hazardous,
and very inexpensive. CO2 has a modest critical temperature
and pressure and it is much more dense than most
supercritical
Á uids which suggests that at temperatures
slightly above room temperature it should be possible to
obtain liquid-like densities, and by implication, liquid-like
solvent characteristics. It has been shown that CO2 at or
near room temperature and at pressures typically below
600 bar can be used to solubilise a variety of polymeric
oils, such as many polydimethyl and polydiphenyl
silicones, per
Á uoroalkylpolyethers and chloro- and bromo-
tri
Á uoroethylene polymer. CO2 can also solubilise very low
molecular weight, slightly polar polymers, such as PS, with
molecular weights below 1,000. It has been demonstrated
that CO2 can dissolve polymers comprised of long-chain
side groups of
Á uorinated alkyl acrylates. High molecular
weight block copolymers have also been synthesised that are
CO2 soluble. However, most polymers do not dissolve in
CO2, regardless of temperature and pressure. Experimental
cloud-point data are presented for a number of polymers
and copolymers in CO2. The polymers of interest include
polyacrylates, polymethacrylates, PE, and fluorinated
copolymers. The cloud-point behaviour of these polymers in
References and Abstracts
© Copyright 2005 Rapra Technology Limited
99
CO2 are compared to similar behaviour in other supercritical
Á uids that exhibit certain physicochemical properties similar
to CO2. 16 refs.
USA
Accession no.724852
Item 307
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.433-4. 012
FREE RADICAL DISPERSION
POLYMERISATIONS IN LIQUID CARBON
DIOXIDE USING A REDOX INITIATOR
Dessipri E; Hsiao Y-L; Mathes A C J; Shaffer K A;
DeSimone J M
North Carolina,University
(ACS,Div.of Polymeric Materials Science & Engng.)
Supercritical carbon dioxide has proved to be an excellent
medium for the performance of free radical polymerisation
reactions because of obvious environmental and toxicity
advantages afforded by CO2 combined with its inertness
towards free radicals, low viscosity and the ability to obtain
high initiator ef
À ciencies. The use of carbon dioxide for
homogeneous polymerisations is rather limited because
of the insolubility of most common polymers in CO2. On
the other hand, dispersion polymerisation of a variety of
ole
À nic monomers can be carried out in carbon dioxide to
yield polymers in the form of free
Á owing powders made
of uniform spherical particles. When considering dispersion
polymerisations at lower temperatures, two issues are of prime
concern: the kinetics of polymerisation should allow for the
formation of high molecular weight materials at high yields
and within reasonable reaction times, and the stabilisers used
must be effective in liquid CO2. The successful polymerisation
of methyl methacrylate at 30 deg.C using a low temperature
initiator, 2,2’-azobis(4-methoxy-2,4-dimethyl valeronitrile),
and a PDMS macromonomer as stabiliser in liquid C02.
One system that can be used with organic solvents is the
combination of BPC N,N-dialkylanilines. The rate of BPO
decomposition is reported to increase by at least three orders
of magnitude in the presence of dialkylanilines. The use of this
initiating system for the dispersion polymerisation of methyl
methacrylate in carbon dioxide using various polymeric steric
stabilisers is described. 13 refs.
USA
Accession no.724785
Item 308
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.431-2. 012
ZINC CATALYSTS FOR THE
COPOLYMERISATION OF EPOXIDES AND
CARBON DIOXIDE TO POLYCARBONATES
Darensburg D J
Texas A & M University
(ACS,Div.of Polymeric Materials Science & Engng.)
Supercritical CO2 has been found to be a suitable substitute
for organic solvents in polymerisation reactions in which
CO2 is also a reactant. Furthermore, the use of CO2 (at
pressures greater than 700 psi) results in higher selectivity
for polycarbonate versus polyether formation. In addition,
the advantage of using supercritical carbon dioxide is that
it is as effective a solvent as inert organic solvents, such
as methylene chloride, for the copolymerisation, yet it is
environmentally benign. 7 refs.
USA
Accession no.724784
Item 309
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.430. 012
SUPERCRITICAL CO2 AS A MONOMER
AND SOLVENT: POLYCARBONATES FROM
CYCLOHEXENE OXIDE AND CARBON
DIOXIDE
Costello C A; Berluche E; Han S J; Sysyn D A;
Super M S; Beckman E J
Exxon Research & Engineering Co.;
Pittsburgh,University
(ACS,Div.of Polymeric Materials Science & Engng.)
Supercritical CO2 has received much attention in
extraction processes and in fractionation of polymers.
Recently, there has been much interest in replacing
organic polymerisation solvents with supercritical CO2
in various types of polymerisation processes due to the
low toxicity CO2 possesses. Success has been realised
in solution polymerisation, dispersion polymerisation
and inverse emulsion polymerisation. There is interest
in using supercritical CO2 as a monomer as well as a
polymerisation solvent, thus providing a route to polymers
using an inexpensive C1 feed. The concept of using
supercritical CO2 as a reactant and solvent has been
demonstrated in small molecule organic chemistry. The
application of CO2 as a monomer in polymerisation has
been reviewed. Most of the reactions reported are run
at subcritical conditions and employ organic solvents
in addition to CO2. Recent work on Ni(0)-catalysed
alternating cycloaddition copolymerisation of acyclic
diynes with CO2 also employs additional organic solvent.
The alternating copolymerisation of CO2 and epoxides
using zinc-based catalysts, which produces a polycarbonate
with some ether linkages, is investigated. Cyclic carbonate
is also produced in appreciable amounts. The development
of a CO2-soluble Zn catalyst for cyclohexene oxide/CO2
copolymerisation in the absence of any additional organic
solvents is reported, together with the pressure and
temperature dependence on the conversion and selectivity
of the reaction. 12 refs.
USA
Accession no.724783
References and Abstracts
100
© Copyright 2005 Rapra Technology Limited
Item 310
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.428-9. 012
SYNTHESIS OF TETRAFLUOROETHYLENE-
BASED, NON-AQUEOUS FLUOROPOLYMERS
IN SUPERCRITICAL CARBON DIOXIDE
Romack T J; DeSimone J M
North Carolina,University
(ACS,Div.of Polymeric Materials Science & Engng.)
Carbon dioxide is an excellent, environmentally
responsible alternative to CFCs in which to conduct non-
aqueous polymerisations of
Á uorooleÀ ns. Copolymers
of tetrafluoroethylene and perfluoro(propyl vinyl
ether), as well as copolymers of tetrafluoroethylene
and hexa
Á uoropropylene are synthesised in high yields
employing bis(per
Á uoro-2-propoxy propionyl) peroxide
as a free radical initiator in supercritical carbon dioxide.
For TFE/PPVE copolymers, molecular weights achieved
are high and FTIR analysis indicates the successful
elimination of deleterious end groups. Copolymers of HFP
with TFE show good incorporation and reasonable yields.
In light of the impending ban on CFCs, and the improved
physical attributes of these materials, the polymerisation
of
Á uorooleÀ ns in such an environmentally responsible
medium may well prove to be a viable alternative to
conventional solvents for the manufacture of non-aqueous
Á uoropolymers. 28 refs.
USA
Accession no.724782
Item 311
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.427. 012
SYNTHESIS OF POLYACRYLIC ACIDS IN
SUPER-CRITICAL CARBON DIOXIDE
Dada E; Lau W; Merritt R F; Paik Y H; Swift G
Rohm & Haas Co.
(ACS,Div.of Polymeric Materials Science & Engng.)
Polyacrylic acids are widely used in many applications
depending on their molecular weight. High molecular
weight polymers are usually prepared at low solids
because of viscosity limitations or as dispersions in organic
solvents; the former requires the use and transport of huge
volumes of water and the latter careful control of solvent
emissions. Low molecular weight polymers may also be
prepared in water or organic solvents and these have the
additional potential environmental issue of using high
organic initiator levels and/or chain transfer agents, such
as mercaptans, to control molecular weight. Should solid
polymer isolation be required, removal of solvent and/or
water is energy intensive which indirectly impacts the
environment, and solvent emissions need to be controlled.
There are quite obviously opportunities to develop
improved free-radical addition polymerisations for acrylic
acid which are free from these potential environmental
issues, with good molecular weight control over a
wide range, and with the ability to readily isolate solid
polymeric products. Preliminary investigations suggest
that polymerisations in super-critical carbon dioxide may
satisfy all these requirements. 5 refs.
USA
Accession no.724781
Item 312
ACS Polymeric Materials Science & Engineering.
Volume 74. Conference proceedings.
New Orleans, La., Spring 1996, p.404-5. 012
LIVING FREE RADICAL POLYMERISATIONS
IN SUPERCRITICAL CARBON DIOXIDE
Odell P G; Hamer G K
Xerox Corp.
(ACS,Div.of Polymeric Materials Science & Engng.)
Living free radical polymerisation, employing the concept
of reversible termination, using a nitroxide stable free
radical, such as TEMPO, has been studied. This system can
provide polymers of narrow polydispersity via controlled
stepwise growth. The molar mass of these polymers can
vary from low molecular weight oligomers through to
high molecular weight polymers. This approach has been
successfully applied not only to bulk homopolymerisation
and block copolymerisation, but also suspension
copolymerisation and aqueous polymerisations. Recent
efforts employing stable free radical polymerisation
(SFRP) techniques in supercritical carbon dioxide
are described. One valuable attribute of a ‘living’
polymerisation is the potential for forming well-de
À ned
block copolymers. Supercritical
Á uid technology provides
additional bene
À t to SFRP as block copolymers may be
obtained in the absence of conventional solvents and
without any additional puri
À cation beyond the extraction
of unreacted monomer of an earlier block. Furthermore, the
plasticisation of polymers by CO2(sc) may also enhance
the reactivity of the diffusion controlled process. Lastly,
the different kinetics of free radical processes in CO2 due
to its very low dielectric constant may provide insight or
advantage to the SFRP process. Concurrently, the study of
the repetitive homolytic cleavage of the nitroxide-polymer
chain end bond may offer a broader understanding of free
radical processes in supercritical carbon dioxide. 8 refs.
CANADA
Accession no.724768
Item 313
Patent Number: US 5766637 A 19980616
MICROENCAPSULATION PROCESS USING
SUPERCRITICAL FLUIDS
Shine A D; Gelb J
Delaware,University
The present invention comprises a method for
microencapsulating a core material comprising: (a)
mixing a core material with an encapsulating polymer,
References and Abstracts
© Copyright 2005 Rapra Technology Limited
101
(b) supplying a supercritical
Á uid capable of swelling
the polymer to the mixture under a temperature and a
pressure suf
À cient to maintain the Á uid in a supercritical
state, (c) allowing the supercritical
Á uid to penetrate and
liquefy the polymer while maintaining temperature and
pressure suf
À cient to maintain the Á uid in a supercritical
state, and (d) rapidly releasing the pressure to solidify the
polymer around the core material to form a microcapsule.
This method requires neither that the polymer nor core
materials to be soluble in the supercritical
Á uid and can be
used to rapidly and ef
À ciently microencapsulate a variety
of materials for a variety of applications.
USA
Accession no.723418
Item 314
Journal of Polymer Science : Polymer Physics Edition
37, No.6, March 1999, p.553-60
HDPE FRACTIONATION WITH
SUPERCRITICAL PROPANE
Britto L J D; Soares J B P; Penlidis A; Krukonis V
Waterloo,University; Phasex Corp.
Supercritical propane was used to fractionate HDPE by
molecular weight and short chain branching. The use
of this solvent to obtain fractions of uniform molecular
weight or chemical composition without generating
hazardous solvent waste is discussed. 20 refs.
CANADA; USA
Accession no.723319
Item 315
Journal of the Textile Institute - Part 1: Fibre Science
and Textile Technology
89, No.4, 1998, p.657-68
DYEING OF POLYOLEFIN FIBRES IN
SUPERCRITICAL CARBON DIOXIDE. II. THE
INFLUENCE OF DYE STRUCTURE ON THE
DYEING OF FABRICS AND ON FASTNESS
PROPERTIES
Bach E; Cleve E; Schollmeyer E
Deutsches Textilforschungszentrum Nord-West eV
Dyeing of gel-spun PE
À bres of low and high draw ratio,
PP
À bres, and PETP À bres was carried out in supercritical
carbon dioxide at 280 bar and in water under optimum
dyeing conditions at 120 C. The in
Á uence of the chemical
structure of different disperse azo and anthraquinone dyes
on the dye uptake and also on the washing-, sublimation-,
and light-fastness of the
À bres was presented. 23 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.721406
Item 316
Journal of the Textile Institute - Part 1: Fibre Science
and Textile Technology
89, No.4, 1998, p.647-56
DYEING OF POLYOLEFIN FIBRES IN
SUPERCRITICAL CARBON DIOXIDE. I.
THERMOMECHANICAL PROPERTIES OF
POLYOLEFIN FIBRES AFTER TREATMENT
IN CARBON DIOXIDE UNDER DYEING
CONDITIONS
Bach E; Cleve E; Schollmeyer E
Deutsches Textilforschungszentrum Nord-West eV
Viscoelastic properties of gel-spun PE and PP
À bres after
treatment in supercritical carbon dioxide at 280 bar were
examined to determine the optimum conditions for dyeing
without causing
À bre damage. Melting, shrinkage and
thermomechanical properties of PE and PP
À bres after
treatment in carbon dioxide was presented. 18 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.721405
Item 317
ACS Polymeric Materials Science & Engineering,
Spring Meeting 1998. Volume 78. Conference
proceedings.
Dallas, Tx., Spring 1998, p.155. 012
DECOMPOSITION OF MODEL COMPOUNDS
AND PREPOLYMERS OF PHENOL RESIN
WASTE WITH SUPERCRITICAL WATER
Tagaya H; Suzuki Y; Karasu M; Kadokawa J; Chiba K
Yamagata,University
(ACS,Div.of Polymeric Materials Science & Engng.)
Phenol resin is known to be a thermosetting thermally
stable resin. It has been found that model compounds of
phenol resin wastes such as p- and o-bis(hydroxyphenyl)
methanes are decomposed into phenol and cresol easily by
reaction with supercritical water. However, condensation
reaction giving trimer is also con
À rmed. By the addition of
small amounts of NaCl, product yield increases, however
basic compounds are more effective additives than NaCl.
The chemical participation of water is suggested from the
structure of reaction intermediates which are obtained by
the reaction at mild conditions. Prepolymers of phenol
resin are also decomposed into their monomers even by the
reaction at below critical temperature of water. Addition
of basic compounds are also effective and yields of
monomers are greater than 90% in the case of prepolymers
of p-isopropylphenol resin. This abstract includes all the
information contained in the original article.
JAPAN
Accession no.719085
References and Abstracts
102
© Copyright 2005 Rapra Technology Limited
Item 318
ACS Polymeric Materials Science & Engineering,
Spring Meeting 1998. Volume 78. Conference
proceedings.
Dallas, Tx., Spring 1998, p.155. 012
CHEMICAL RECYCLING OF PLASTIC
MOULDING MATERIALS IN SUB-CRITICAL
AND SUPERCRITICAL WATER
Katoh K; Suzuki Y; Tagaya H; Karasu M; Kadokawa J;
Chiba K
Yamagata,University
(ACS,Div.of Polymeric Materials Science & Engng.)
In Japan, more than 80% of plastic wastes are land
À lled
and incinerated. Chemical recycling is essential to protect
the environment issue and proceed effective use of carbon
resources. To establish chemical recycling processes
of polymer waste, moulding material (phenol resin and
polycarbonate) decomposition in supercritical water
(SCW) and in sub-SCW is studied. Phenol resin moulding
materials are decomposed into phenol and cresol mainly
in SCW. Polycarbonate moulding materials decompose in
sub-SCW at around 300 deg.C; decomposition reaction
with additive gives high yields. This abstract includes all
the information contained in the original article.
JAPAN
Accession no.719083
Item 319
Polymer Engineering and Science
38, No.12, Dec.1998, p.2055-62
COMPRESSIVE BEHAVIOUR OF
MICROCELLULAR POLYSTYRENE FOAMS
PROCESSED IN SUPERCRITICAL CARBON
DIOXIDE
Arora K A; Lesser A J; McCarthy T J
Massachusetts,University
Microcellular PS foams were prepared using supercritical
carbon dioxide as the foaming agent. The cellular structures
from this process are shown to have a signi
À cant effect
on the corresponding mechanical properties of the foams.
Compression tests were performed on highly expanded
foams having oriented, anisotropic cells. For these
materials an anisotropic foam model can be used to predict
the effect of cell size and shape on the compressive yield
stress. Beyond yield, the foams deformed heterogeneously
under a constant stress. Microstructural investigations of
the heterogeneous deformation indicate that the dominant
mechanisms are progressive microcellular collapse
followed by foam densification. The phenomenon is
compared to the development of a stable neck commonly
observed in polymers subjected to uniaxial tension,
and a model that describes the densi
À cation process is
formulated from simple energy balance considerations.
Yield stress and collapse stress data are shown for various
foam densities and cell dimensions. 25 refs.
USA
Accession no.718722
Item 320
Macromolecular Symposia
Vol.135, Dec.1998, p.205-14
CONVERSION OF POLYMERS AND BIOMASS
TO CHEMICAL INTERMEDIATES WITH
SUPERCRITICAL WATER
Arai K
Tohoku,University
Results are reported of recent studies on the conversion
of polymers and biomass to chemical intermediates and
monomers by using subcritical and supercritical water
as the reaction solvent. The reactions of cellulose in
supercritical water are shown to be rapid and to proceed to
100% conversion with no char formation, these reactions
showing a signi
À cant increase in hydrolysis products and
lower pyrolysis products when compared with reactions in
subcritical water. There is also a jump in the reaction rate
of cellulose at the critical temp. of water. If the methods
used for cellulose are applied to synthetic polymers, such
as PETP or polyamide, high liquid yields can be achieved
although the reactions require about 10 min for complete
conversion. The reason for this is the heterogeneous
nature of the reaction system. For PE, higher yields of
short-chain hydrocarbons, higher alkene/alkane ratios
and higher conversions are obtained in supercritical water
than those obtained by pyrolysis. 18 refs. (IUPAC, 38th
Microsymposium on Recycling of Polymers, Prague,
July 1997)
JAPAN
Accession no.715499
Item 321
Patent Number: US 5780565 A 19980714
SUPERATMOSPHERIC REACTION
Clough R S; Senger C L; Gozum J E
Minnesota Mining & Mfg.Co.
A polymerisation process is carried out in a
Á uid held
under superatmospheric conditions such that the
Á uid is
a liquid or a supercritical
Á uid, such as carbon dioxide, a
hydro
Á uorocarbon, perÁ uorocarbon or mixture thereof.
The polymers obtained are insoluble in a reaction mixture,
which was homogeneous before the polymer began to
form. A dispersing agent in the polymerising system
allows a kinetically stable dispersion of the polymer to
be formed therein.
USA
Accession no.705587
Item 322
Supercritical Fluid Technology. Conference
proceedings.
Birmingham, 15th-17th Sept.1997, paper 10. 91141T
DESIGN OF INDUSTRIAL PLANT SPRAY
COATING
Mandel F S
Ferro Corp.
References and Abstracts
© Copyright 2005 Rapra Technology Limited
103
(Royal Society of Chemistry,Process Technology
Group; SCI Separation Science & Technology Group;
SCI Process Engineering Group; Environmental
Technology Best Practice Programme)
The employment of supercritical
Á uids as a mixing aid for
the manufacture of powder coatings and other products
characterised by highly loaded polymer systems is being
commercialised. Beneficial properties and enhanced
product performance has been attained via the production
of highly loaded polymer systems using supercritical
carbon dioxide, an environmentally friendly solvent. The
product bene
À ts include enhanced electrostatic properties,
high levels of porosity, strong colour adherence, excellent
molecular weight control and the formation of particles via
atomisation. The manufacturing techniques for the mixing
of polymer formulations via Supercritical Fluid assisted
manufacturing have been reviewed. Issues concerning
scale up from laboratory to pilot plant to commercial
facility have been addressed. This abstract includes all the
information contained in the original article.
USA
Accession no.704083
Item 323
Supercritical Fluid Technology. Conference
proceedings.
Birmingham, 15th-17th Sept.1997, paper 9. 91141T
POLYMER SYNTHESIS IN LIQUID/
SUPERCRITICAL CARBON DIOXIDE
Cooper A I
Cambridge,University
(Royal Society of Chemistry,Process Technology
Group; SCI Separation Science & Technology Group;
SCI Process Engineering Group; Environmental
Technology Best Practice Programme)
The use of carbon dioxide as an inert solvent has emerged
recently as an important development in polymer
chemistry. The past few years have seen major advances in
the synthesis of a variety of
Á uorinated and non-Á uorinated
polymeric materials in carbon dioxide. Synthetic studies
that de
À ne the scope of this approach have been reviewed,
including homogeneous polymerisation, dispersion
polymerisation and precipitation polymerisation in scC02.
Particular attention has been given to the equipment
requirements for these reactions and the potential for
industrial implementation of these techniques. Abstract
only. 10 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.704082
Item 324
Supercritical Fluid Technology. Conference
proceedings.
Birmingham, 15th-17th Sept.1997, paper 5. 91141T
PARTICLE FORMATION BY SUPERCRITICAL
FLUID TECHNOLOGIES
York P
Bradford,University
(Royal Society of Chemistry,Process Technology
Group; SCI Separation Science & Technology Group;
SCI Process Engineering Group; Environmental
Technology Best Practice Programme)
While the
À rst observations of the use of supercritical
Á uids (SCF) to precipitate particles were made over a
century ago, it is only relatively recently that researchers
have adapted these approaches to address the limitations
of currently used particle formation and processing
operations. Throughout the particle formation and powder
handling industries, conventional solvent crystallisation
and precipitation methods are widespread, although
dif
À culties frequently arise. These range from problems
with
À ltering and harvesting À ne particles, environmental
issues when milling to obtain desired particle size, to
quality and regulatory concerns, such as product being out
of speci
À cation for levels of retained solvent, and batch to
batch variation which can cause downstream inef
À ciency
and even product malfunction. An alternative procedure
with direct formation of particles of specified and
controlled physicochemical criteria, such as size and shape,
and enhanced handling properties is needed by industry.
This is especially so for the pharmaceutical industry where
the bioperformance of drug substances is often determined,
inter alia, by particle properties. A recent development
has been to cointroduce into a particle formation vessel
the solution of material of interest and an SCF via a
coaxial nozzle whereby the SCF acts simultaneously as an
antisolvent and also as a mechanical dispersing agent to
rapidly produce dry particles. This process, called SEDS
(solution enhanced dispersion by supercritical
Á uids),
has been shown to produce solvent free
À ne particles for
a range of materials including pharmaceuticals, proteins
and polymers. Extended abstract only.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.704081
Item 325
Supercritical Fluid Technology. Conference
proceedings.
Birmingham, 15th-17th Sept.1997, paper 3. 91141T
CHEMISTRY IN SUPERCRITICAL FLUIDS
Poliakoff M; Howdel S M
Nottingham,University
(Royal Society of Chemistry,Process Technology
Group; SCI Separation Science & Technology Group;
SCI Process Engineering Group; Environmental
Technology Best Practice Programme)
Supercritical fluids are highly compressed gases
characterised by a curious combination of gas- and
liquid-like properties which have fascinated scientists
for generations. Currently, the combined pressures of
environmental legislation and commercial competition
References and Abstracts
104
© Copyright 2005 Rapra Technology Limited
are forcing many chemical companies to re-evaluate the
possibility of replacing existing chemical technology
by supercritical fluids. These fluids, and particularly
supercritical CO2, scCO2, are becoming increasingly
attractive as solvents for environmentally more acceptable
chemical processes. High-pressure reactions, however,
are more capital intensive than conventional low pressure
processes. Therefore, supercritical
Á uids will only gain
widespread acceptance in those areas where the
Á uids give
real chemical advantages as well as environmental bene
À ts.
A number of examples illustrate some of these advantages.
The examples range from promising laboratory reactions
to processes which have already been commercialised or
will be soon. Extended abstract only. 8 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.704080
Item 326
Supercritical Fluid Technology. Conference
proceedings.
Birmingham, 15th-17th Sept.1997, paper 2. 91141T
PREPARATIVE CHROMATOGRAPHY: LIQUID
OR SUPERCRITICAL ELUENTS
Nicoud R-M
NOVASEP
(Royal Society of Chemistry,Process Technology
Group; SCI Separation Science & Technology Group;
SCI Process Engineering Group; Environmental
Technology Best Practice Programme)
Chromatography processes are being developed as
production techniques with gas and mainly liquid
eluents. These techniques are more and more used in
the pharmaceutical industry, because of their
Á exibility
and their ability to solve dif
À cult problems at reasonable
costs. First industrial chromatographic processes using
supercritical
Á uids are announced. In order to transform
a concept (the use of supercritical
Á uids) into a technique,
different technological aspects have to be carefully
addressed: the column, the devices performing the solute/
eluent separation, the eluent loop, the co-solvent module.
Whatever the physical state of the eluent, modelling is a
key tool allowing the rapid development and optimisation
of chromatographic processes. Good prediction models
allow optimisation of classical elution systems, but also the
design of new processes for which intuition is of limited
help simulated moving bed or extrography. The chemical
engineering tools allowing modelling of PSFC are similar
to those allowing to model LC: mass balances, knowledge
of adsorption isotherms, mass transfer coef
À cients. The
main differences are due to the dependence of the
Á uid
viscosity and of the adsorption isotherms with respect
to the pressure and thus to the position in the column.
These properties make supercritical
Á uids ‘adjustable’
solvents and most processes are based on these solvent
power variations. A new and innovative process based
on the association of columns to allow a continuous
chromatography process and to take advantage of the
variation of the solvent properties of supercritical
Á uids
is proposed. Extended abstract only.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.704079
Item 327
Supercritical Fluid Technology. Conference
proceedings.
Birmingham, 15th-17th Sept.1997, paper 1. 91141T
POLYMER FRACTIONATION
Clifford A A
Express Separations Ltd.
(Royal Society of Chemistry,Process Technology
Group; SCI Separation Science & Technology Group;
SCI Process Engineering Group; Environmental
Technology Best Practice Programme)
Fractionation of polymers using supercritical
Á uids is well
established. In fact fractionation in supercritical
Á uids
has been a feature of polymer production from the 1940s
and subsequent fractionation using a compressed gas was
patented then. Time is a factor in these extractions which
has previously been neglected. Modelling involves time
and this leads to the idea of using a density gradient during
extraction. An example of the use of a density gradient for
the production of narrow fractions of polymers, i.e. those
with low polydispersity, is given. However, by choosing an
appropriate density programme, any distribution of molar
mass in a polymer can, in principle, be produced. Narrow
fractions of polymers are used as analytical standards
for calibration in size-exclusion or gel permeation
chromatography. A wide range of polymer samples are
produced, typically with polydispersities of 1.05, for this
purpose. For example, polymers can be fractionated by
extracting them with a liquid using a solvent gradient:
initial extraction being a ‘poor’ solvent, which extracts
the lowest molar masses, to which a ‘better’ solvent is
added in higher and higher proportions to extract fractions
of progressively higher molar mass. For some polymers
of lower molar mass, this and other methods are not
successful because of their high solubility and the polymer
fractions are made by preparing directly polymers of low
polydispersity. However, the fractions made in this way
have higher polydispersity than is desirable and at the same
time these samples are more expensive. A possible solution
is to extend the solubility range downwards by using
supercritical
Á uid extraction. Extended abstract only.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.704078
Item 328
Macromolecules
31, No.19, 22nd Sept.1998, p.6481-5
PULSED-LASER POLYMERISATION OF
METHYL METHACRYLATE IN LIQUID AND
References and Abstracts
© Copyright 2005 Rapra Technology Limited
105
SUPERCRITICAL CARBON DIOXIDE
Quadir M A; DeSimone J M; van Herk A M; German A L
North Carolina,University; Eindhoven,University of
Technology
The free-radical propagation rate coef
À cients for methyl
methacrylate in liquid and supercritical carbon dioxide
were determined using pulsed-laser polymerisation. The
effect of carbon dioxide solvency on the propagation rate
coef
À cient was examined. Results are compared with
the bulk activation parameters for the propagation rate
coef
À cient of methyl methacrylate as set by IUPAC. 33
refs.
EUROPEAN COMMUNITY; EUROPEAN UNION;
NETHERLANDS; USA; WESTERN EUROPE
Accession no.699447
Item 329
Chemical Engineering
105, No.11, Oct.1998, p.32/41
German; English
SUPERCRITICAL FLUIDS STAY SOLVENT
Chin K; Crabb C; Ondrey G; Kamiya T
The use of supercritical
Á uids as environmentally-friendly
alternatives to chlorinated solvents is discussed. These
Á uids have already been used in coffee decaffeination
and spice-extraction processes, but have yet to capitalise
on the demand for environmentally-friendly alternatives
in other segments of the chemical processes industries.
Supercritical carbon dioxide applications for polymer
processing are described. These include modi
À cation of
aqueous processes to accommodate supercritical carbon
dioxide, which eliminates the energy-intensive drying that
is required when water is used, emulsion polymerisation
using supercritical carbon dioxide, and use of supercritical
carbon dioxide instead of water to dye polymer
À bres.
USA
Accession no.699045
Item 330
Patent Number: US 5739223 A 19980414
METHOD OF MAKING FLUOROPOLYMERS
DeSimone J M
North Carolina,Chapel Hill University
A process for making a
Á uoropolymer is disclosed. The
process comprises solubilising a
Á uoromonomer in solvent
comprising a carbon dioxide
Á uid, and then polymerising
the fluoromonomer to produce the fluoropolymer.
A preferred solvent for carrying out the process is
supercritical carbon dioxide; preferred
Á uoromonomer for
carrying out the process are
Á uoroacrylate monomers such
as 1,1-dihydroper
Á uorooctyl acrylate. The polymerisation
step is preferably carried out in the presence of an initiator
such as azobisisobutyronitrile.
USA
Accession no.697872
Item 331
Macromolecules
31, No. 16, 11th Aug. 1998, p.5407-14
THERMOPLASTIC VULCANISATES
FROM ISOTACTIC POLYPROPYLENE
AND ETHYLENE-PROPYLENE-DIENE
TERPOLYMER IN SUPERCRITICAL PROPANE.
SYNTHESIS AND MORPHOLOGY
Han S J; Lohse D J; Radosz M; Sperling L H
Exxon Research & Engineering Co.; Louisiana,State
University; Lehigh University
New thermoplastic vulcanisates were synthesised from
isotactic PP and EPDM in a supercritical propane solution.
The ternary solution of PP and EPDM in supercritical
propane exhibited less solubility than the corresponding
binary solutions of PP or EPDM separately in propane.
Higher pressure is the supercritical polymer solution
enhanced the mutual solubility of the two polymers.
EPDM was crosslinked with tert-butyl peroxide while
in supercritical solution. On lowering the pressure
while remaining above the melting temperature of the
polymers, the supercritical thermoplastic vulcanisate gel
phase separated in a manner consistent with spinodal
decomposition. On isobaric cooling of the supercritical
thermoplastic vulcanisate gel, the PP crystallised, freezing
the morphology. The crosslinking of EPDM in the
homogeneous supercritical propane solutions was found
to be nearly complete. The
À nal thermoplastic vulcanisates
were phase separated, exhibiting two melting transitions.
The morphology of the thermoplastic vulcanisates was a
microporous, apparently closed cell polymeric foam. Phase
contrast optical microscopy showed micro-heterogeneous
EPDM domains dispersed in the PP matrix for the
thermoplastic vulcanisates. The phase domain sizes were
much smaller, by a factor of 5 to 10, than those of the
corresponding melt blends. Phase diagrams are shown
for solutions and both optical and SEM micrographs for
solids. 25 refs.
USA
Accession no.696669
Item 332
Patent Number: EP 854165 A1 19980722
METHOD OF AND APPARATUS FOR
DECOMPOSING WASTE
Nagase Y; Fukuzato R
Kobe Steel Ltd.
Chemical plant waste, which contains target compounds
having one or more hydrolysable bonds, e.g. ether, ester,
amide or isocyanate bonds, is continuously supplied in a
molten state or liquid state to a reactor, supercritical water
or high pressure/high temperature water is continuously
supplied to the reactor, the water is brought into contact
with the waste to decompose the target compounds and
the decomposed target compounds are recovered as raw
material compounds or derivatives thereof for the target
compounds. The target compounds were previously
References and Abstracts
106
© Copyright 2005 Rapra Technology Limited
incinerated or discarded.
JAPAN
Accession no.694962
Item 333
Polymer Engineering and Science
38, No.7, July 1998, p.1112-20
EXTRUSION OF PE/PS BLENDS WITH
SUPERCRITICAL CARBON DIOXIDE
Minhee Lee; Tzoganakis C; Park C B
Waterloo,University; Toronto,University
The effects of dissolved supercritical carbon dioxide on the
viscosity and morphological properties were investigated
for PE/PS blends in a twin-screw extruder. The viscosities
of the blend/carbon dioxide solutions were measured at
various carbon dioxide concentrations using a wedge
die mounted on the extruder. The effect of processing
parameters on the size of the dispersed PS phase and cell
structure were investigated at various extrusion conditions
and carbon dioxide concentrations. 47 refs.
CANADA
Accession no.694905
Item 334
Japan Chemical Week
39, No.1990, 3rd Sept.1998, p.2
EPDM CAN BE RECYCLED WITH
SUPERCRITICAL WATER
It is brie
Á y reported that Nishikawa Rubber has À nished
a basic study on chemical recycling technology for
vulcanised EPDM. The technology enables the cracking of
used EPDM into a compound with a molecular weight of
1,000-5,000 in supercritical water with sodium hydroxide
under a high temperature and pressure.
NISHIKAWA RUBBER CO.
JAPAN
Accession no.691538
Item 335
Industrial and Engineering Chemistry Research
37, No.8, Aug.1998, p.3067-79
SOLUBILITY OF HOMOPOLYMERS AND
COPOLYMERS IN CARBON DIOXIDE
O’Neill M L; Cao Q; Fang M; Johnston K P; Wilkinson
S P; Smith C D; Kerschner J L; Jureller S H
Texas,University; Air Products & Chemicals Inc.;
Unilever Research
The cloud points of various amorphous polyether,
polyacrylate and polysiloxane homopolymers and some
commercially-available block copolymers were measured
in carbon dioxide at temps. from 25 to 65C and pressures
of about 1000 to 6000 psia. The solubility parameters
of the amorphous polymers, almost without exception,
increased with a decrease in the cohesive energy density
(or the surface tension of the polymer). With this decrease
in surface tension, the polymer cohesive energy density
became closer to that of carbon dioxide. Solubility was
thus governed primarily by polymer-polymer interactions,
while polymer-carbon dioxide interactions played a
secondary role. The solubility was strongly dependent
on molec.wt. for the less carbon dioxide-philic polymers.
The solubilities of high molec.wt. poly
Á uoroalkoxyphosp
hazenes in carbon dioxide were comparable with those of
poly(1,1-dihydroper
Á uorooctylacrylate). 56 refs.
USA
Accession no.691497
Item 336
Revista de Plasticos Modernos
73, No.488, Feb.1997, p.141-8
Spanish
LATEST TECHNOLOGICAL DEVELOPMENTS
IN THE PRODUCTION OF POLYETHYLENE
Vargas L
Repsol SA
Developments in metallocene catalysts and suspension
and gas phase polymerisation processes for PE production
are reviewed, and the advantages of bimodal PE resins are
examined. Statistics show world production capacities for
PE in 1995 with forecasts for 2000, and West European PE
consumption by application in 1993. 29 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN;
WESTERN EUROPE; WESTERN EUROPE-GENERAL; WORLD
Accession no.691292
Item 337
Journal of Applied Polymer Science
69, No.5, 1st Aug.1998, p.911-9
SUPERCRITICAL FLUID DYEING OF PMMA
FILMS WITH AZO-DYES
West B L; Kazarian S G; Vincent M F; Brantley N H;
Eckert C A
Georgia,Institute of Technology
In-situ UV-vis spectroscopy was used to study diffusion
of two azo dyes in a carbon dioxide-swollen matrix of
PMMA. The diffusivity of both dyes can be tuned simply
by changing the system pressure. The partitioning of the
dyes between the polymer phase and the
Á uid phase was
measured. 40 refs.
USA
Accession no.689709
Item 338
Macromolecules
31, No.14, 14th July 1998, p.4614-20
PREPARATION AND CHARACTERISATION OF
MICROCELLULAR POLYSTYRENE FOAMS
PROCESSED IN SUPERCRITICAL CARBON
DIOXIDE
References and Abstracts
© Copyright 2005 Rapra Technology Limited
107
Arora K A; Lesser A J; McCarthy T J
Massachusetts,University
Rapid decompression of supercritical carbon dioxide-
saturated PS at suf
À ciently high temperatures (above the
depressed Tg) yields expanded microcellular foams. The
resulting foam structures can be controlled by manipulating
processing conditions. Experiments varying the foaming
temperature while holding other variables constant show that
higher temperatures produce larger cells and reduce densities.
Structures range from isotropic cells in samples retaining
their initial geometry to highly expanded foams recovered
in the shape of the foaming vessel and having oriented
anisotropic cells and limited density reduction. Higher
saturation pressures lead to higher nucleation densities and
hence smaller cells. Decreasing the rate of depressurisation
permits a longer period of cell growth and therefore larger
cell sizes. Foams having a bimodal distribution of cell
sizes can be created by reducing the pressure in two stages.
Relevance to the production of foamed blends is suggested.
SEM micrographs show the size and shape of cells. 18 refs.
USA
Accession no.689680
Item 339
Antec ‘98. Volume II. Conference proceedings.
Atlanta, Ga., 26th-30th April 1998, p.1407-10. 012
VISCOSITY REDUCTION OF POLYMERS BY
THE ADDITION OF SUPERCRITICAL CARBON
DIOXIDE IN POLYMER PROCESSING
Elkovitch M D; Lee L J; Tomasko D L
Ohio,State University
(SPE)
The viscosity of a polymer often dictates the manner
in which a polymer is processed, as well as the end use
capabilities, mechanical strength and cost. As the viscosity
of polymers is increased so is the energy required to
process them. Plasticising agents are often added to high
viscosity materials to aid in processing. Supercritical
carbon dioxide, scCO2, can be added to polymer melts to
lower their viscosity. ScO2 is injected into the barrel of a
Haake single-screw extruder with a 0.75 inch screw and
L/D = 25 that is processing PS. This technique results in a
substantial drop in polymer melt viscosity as is measured
by a slit die rheometer attached to the single-screw
extruder. 9 refs.
USA
Accession no.688621
Item 340
Antec ‘98. Volume II. Conference proceedings.
Atlanta, Ga., 26th-30th April 1998, p.1418-20. 012
SUPERCRITICAL FLUIDS AS POLYMER
PROCESSING AIDS
Khan V; Kwag C; Manke C W; Gulari E
Wayne State,University
(SPE)
The behaviour of molten thermoplastic polymers
containing dissolved supercritical gases are pertinent
to such processing operations as the manufacture of
thermoplastic composites and polymer foams. Knowledge
of supercritical gas solubility in polymer melts and the
effects of these dissolved gases and supercritical
Á uids
on the physical properties of the melts are important for
these processes. Measured viscosity ratios of PS melts with
dissolved carbon dioxide and 1,1-di
Á uoroethane relative
to the viscosity of pure PS at temperatures above the glass
transition temperature of PS are reported. A modi
À ed free-
volume theory is combined with thermodynamic models
to predict the measured viscosity ratios. 4 refs.
USA
Accession no.687566
Item 341
Antec ‘98. Volume II. Conference proceedings.
Atlanta, Ga., 26th-30th April 1998, p.1415-7. 012
IN SITU SPECTROSCOPY OF CO2-INDUCED
PLASTICISATION OF GLASSY POLYMERS
Kazarian S G; Brantley N H; Eckert C A
Georgia,Institute of Technology
(SPE)
In situ spectroscopy is used to study the plasticisation of
glassy polymers by high-pressure and supercritical CO2.
The methodology for in situ spectroscopic analysis of the
interactions between CO2 and polymers is described. The
changes in IR spectra of CO2 incorporated into various
polymers indicate a speci
À c interaction between CO2 and
polymer functional groups. Increased polymer segmental
mobility is also observed, indicative of the plasticisation
phenomenon. Implications of these discovered molecular
interactions are discussed. 25 refs.
USA
Accession no.687565
Item 342
Antec ‘98. Volume II. Conference proceedings.
Atlanta, Ga., 26th-30th April 1998, p.2538-41. 012
SUPERCRITICAL FLUID ASSISTED POLYMER
BLENDING
Elkovitch M D; Lee L J; Tomasko D L
Ohio,State University
(SPE)
The melt viscosity of individual homopolymers is one
of the most important parameters in
Á uencing polymer
blending. Often blending involves components with
vastly different viscosities. Supercritical carbon dioxide
can be added to polymer melts in order to lower their
viscosities, such that effective polymer blending will
occur. A blend system of a high viscosity PMMA and
low viscosity PS (viscosity ratio ca 20) is analysed.
Carbon dioxide has a higher af
À nity for PMMA than for
PS. Therefore the viscosity of the PMMA is selectively
lowered by the carbon dioxide such that it becomes closer
References and Abstracts
108
© Copyright 2005 Rapra Technology Limited
to that of PS. An improvement in polymer blending
results. 10 refs.
USA
Accession no.687407
Item 343
European Chemical News
69, No.1815, 1st-7th June 1998, p.25
TAKEDA/KOBE RECYCLING UNIT RECOVERS
TDA
It is brie
Á y reported that Takeda Chemical Industries
has started up a recycling unit using supercritical water
technology to recover toluene diamine during manufacture
of toluene diisocyanate at its Kashima plant in Japan.
The technology has been jointly developed by Takeda
and Kobe Steel. The recycling unit has a TDA recovery
rate of 80%.
TAKEDA CHEMICAL INDUSTRIES LTD.; KOBE
STEEL LTD.
JAPAN
Accession no.680580
Item 344
Polymers Paint Colour Journal
188, No.4400, Jan.1998, p.14-7
SUPERCRITICAL FLUID TECHNOLOGIES
- NEW OPPORTUNITIES FOR COATING AND
IMPREGNATING PLASTICS AND ELASTOMERS
Hay J N; Johns K
Surrey,University; Chemical & Polymer
It is explained that, usually, large quantities of undesirable
solvents are released during the application of coatings.
This article looks at a new development which involves
replacing the solvent (in part or completely) by carbon
dioxide under supercritical conditions. Full details of the
work are provided. 30 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.677252
Item 345
Journal of Polymer Science : Polymer Physics Edition
36, No.4, March 1998, p.617-27
ISOTACTIC POLYPROPYLENE FOAMS
CRYSTALLIZED FROM COMPRESSED
PROPANE SOLUTIONS
Whaley P D; Kulkarni S; Ehrlich P; Stein R S;
Winter H H; Conner W C; Beaucage G
Massachusetts,University; Cincinnati,University
Crystallisation of isotactic PP from homogeneous solution
in supercritical propane yielded open-cell foams of high
surface area. Their morphology usually consisted of
microspheres with a dense core and a porous periphery of
radiating
À brils. Pore radii covering the mesopore range (2-
50nm), making their largest contribution at 10-20 nm, were
calculated from nitrogen adsorption isotherms. Surface areas
of the correct order of magnitude were obtained by assuming
that gas adsorption took place on the surfaces of lamellar
crystals. Crystallisation of isotactic PP from n-butane and
n-heptane generated foams of lower mesoporosity and
smaller surface area. These more ‘liquid-like’ solvents did
not allow for formation of an open network of mesopores or
they promoted its collapse upon their removal. 22 refs.
USA
Accession no.672015
Item 346
Fibres and Textiles in Eastern Europe
5, No.3, 1997, p.70-3
WATER-FREE DYEING OF HIGH-
PERFORMANCE FIBROUS MATERIAL WITH
SUPERCRITICAL CARBON DIOXIDE AS
DYEING BATH (SFD)
Knittel D; Schollmeyer E
Deutsches Textilforschungszentrum Nord-West eV
The results of water-free dyeing of high-performance
À bres (aramids, polyarylketones, polyarylsulphides) are
described. The new dyeing process is based on the use of
supercritical carbon dioxide as a dyeing medium and on the
use of disperse dyestuffs. Selective laboratory screening
experiments are presented. Dyestuff uptake depends on
structure of the polymers and has to be optimised. High
washing fastnesses are obtainable. 17 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.668597
Item 347
Plastics Engineering
53, No.12, Dec.1997, p.37-40
CARBON DIOXIDE AS A CONTINUOUS PHASE
FOR POLYMER SYNTHESIS
Canelas D A; Burke A L C; DeSimone J M
North Carolina,University
The use is investigated of supercritical carbon dioxide
in polymer synthesis with reference to the advantages
it affords beyond the simple elimination of the use of
organic solvents or water. Advantages in the properties
and processing of materials are examined, which can be
realised through the use of this medium, which are reported
to be principally as a result of the lack of chain transfer
and high plasticisation propensity. 82 refs.
USA
Accession no.667077
Item 348
Patent Number: EP 818292 A2 19980114
PROCESS FOR PREPARING EXPANDED
PRODUCT OF THERMOPLASTIC RESIN
References and Abstracts
© Copyright 2005 Rapra Technology Limited
109
Nishikawa S; Yorita K; Ichikawa K; Inoue H; Eriguchi
M; Sueda T; Amemiya H
Mitsui Toatsu Chemicals Inc.
Supercritical carbon dioxide and/or nitrogen is added,
as a blowing agent, to a thermoplastic resin and melted
therein. The resulting molten resin composition is cooled
under a pressure not less than a critical pressure of the
blowing agent and discharged from a die to lower the
pressure to a level not more than the critical pressure and
the expanded product is cooled to a level not more than
the Tg or crystallisation temperature of the resin to control
the cell diameter of the expanded product. The process
uses a shear rate adjusting section, which generates a
shear rate in a speci
À ed range and has a sectional area
(A), and a
Á ow velocity distribution adjusting section,
which lowers the shear rate and has a sectional area (B),
B/A being in the range of 1.3 to 20. The foams obtained
have excellent surface appearance, high strength and cells
of a
À ne average cell diameter and a uniform average cell
density.
JAPAN
Accession no.664244
Item 349
Journal of the National Institute of Materials and
Chemical Research
5, No.4, 1997, p.175-183
Japanese
APPLICATION OF SUPERCRITICAL FLUIDS
TO EARTH ENVIRONMENT PROTECTION
TECHNOLOGY
Sako T; Sugeta T
Three kinds of promising innovative environmental
applications using supercritical
Á uids to solve problems
of energy, resources and global environment are shown:
the complete decomposition of hazardous compounds
with supercritical water, the recycling of waste plastics
with supercritical methanol or supercritical water, and
chemical reaction in supercritical carbon dioxide which
is free from toxic organic solvents. Supercritical methanol
depolymerised waste condensation polymers such as
PETP and PEN into constituent monomers easily. The
supercritical water decomposed composite plastics such as
FRP into the glass
À bre and fuel oil with high efÀ ciency.
12 refs.
JAPAN
Accession no.662847
Item 350
Journal of Materials Chemistry
7, No.10, Oct.1997, p.1965-6
FIRST EXAMPLE OF A CONDUCTING
POLYMER SYNTHESISED IN SUPERCRITICAL
FLUIDS
Kerton F M; Lawless G A; Armes S P
Sussex,University
Polypyrrole was synthesised via thermal decarboxylation
of a precursor monomer, pyrrole-2-carboxylic acid,
using ferric salts in both supercritical carbon dioxide and
supercritical
Á uoroform. Pressed pellet conductivities were
determined, and SEM revealed an unusual non-spherical
morphology. 10 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.657616
Item 351
Patent Number: EP 798314 A1 19971001
DEVOLATILISATION
Krupinski S; McQueen J T
Nova Chemicals (International) SA
A polymer melt may be devolatilised to less than 500,
preferably less than 150 ppm, of residual volatile material
by injecting into the melt an amount of a supercritical
Á uid
greater than the amount of residual volatile material in the
melt, typically not more than about 10 wt.%, and passing
the melt through a
Á ash chamber devolatiliser at a speciÀ ed
pressure and a temp. of from 200 to 350C.
SWITZERLAND; WESTERN EUROPE
Accession no.656382
Item 352
Macromolecules
30, No.4, 24th Feb.1997, p.745-56
DISPERSION POLYMERISATION OF METHYL
METHACRYLATE IN SUPERCRITICAL
CARBON DIOXIDE
Lepilleur C; Beckman E J
Pittsburgh,University
A series of graft copolymers, poly(methyl methacrylate-
co-hydroxyethyl methacrylate)-g-poly(per
Á uoropropylene
oxide), was synthesised for application as stabilisers
in dispersion polymerisation of methyl methacrylate in
supercritical carbon dioxide. The backbone, poly(methyl
methacrylate-co-hydroxyethyl methacrylate), is effectively
insoluble in carbon dioxide and the grafted chains,
poly(per
Á uoropropylene oxide), are completely miscible
in carbon dioxide at moderate pressures. The effect of
molecular architecture on polymerisation rate and PMMA
particle size was evaluated by varying the molecular
weight of the anchor group (backbone of the copolymer),
molecular weight of the carbon dioxide-soluble graft
chain, and graft chain density. The ef
À ciency of the graft
copolymers as dispersants was demonstrated as micron-
size polymer beads of molecular weight greater than
100000 were produced. The results showed that a careful
balance between anchor group size (backbone length) and
amount of soluble component (either graft chain length
or graft chain density) is necessary, but not suf
À cient to
achieve adequate stabilisation and that the distribution
of the soluble component along the anchor group was
also important. Furthermore, the backbone molecular
References and Abstracts
110
© Copyright 2005 Rapra Technology Limited
weight was shown as the key component for stabilisation,
provided that enough carbon dioxide-philic component has
been included to ensure solubility. 38 refs.
USA
Accession no.651555
Item 353
Advances in Polymer Science
No.133, 1997, p.103-40
POLYMERIZATIONS IN LIQUID AND
SUPERCRITICAL CARBON DIOXIDE
Canelas D A; DeSimone J M
North Carolina,University
A review is presented of the literature on the use of carbon
dioxide as an inert solvent for the synthesis and processing
of polymers. Homogeneous solution polymerisations are
discussed with emphasis on free radical chain growth and
cationic chain growth in the synthesis of
Á uoropolymers.
Heterogeneous polymerisations are then considered, with
reference to free radical precipitation polymerisations,
dispersion and emulsion polymerisations, heterogeneous
cationic polymerisations, metal-catalysed polymerisations,
step growth polymerisations and hybrid systems. 148
refs.
USA
Accession no.651346
Item 354
Journal of Polymer Science : Polymer Chemistry
Edition
35, No.10, 30th July 1997, p.2009-13
DISPERSION POLYMERIZATION OF METHYL
METHACRYLATE IN SUPERCRITICAL
CARBON DIOXIDE: INFLUENCE OF HELIUM
CONCENTRATION ON PARTICLE SIZE AND
PARTICLE SIZE DISTRIBUTION
Yu-Ling Hsiao; Desimone J M
North Carolina,University
Dispersion polymerisations of MMA using poly(1,1-
dihydroperfluorooctyl acrylate) as a steric stabiliser
in supercritical carbon dioxide were carried out in
the presence of helium. Particle size and particle size
distribution were found to be dependent on the amount
of inert helium present. Particle sizes ranging from 1.64
to 2.66 micrometres were obtained with various amounts
of helium. Solvatochromic investigations using 9-
(alpha-per
Á uoroheptyl-beta,beta-dicyanovinyl)julolidine
indicated that the solvent strength of carbon dioxide
decreased with increasing helium concentration. This
effect was confirmed by calculations of Hildebrand
solubility parameters. Dispersion polymerisation results
indicated that PMMA particle size could be attenuated
by the amount of helium present in supercritical carbon
dioxide. 34 refs.
USA
Accession no.648202
Item 355
Informations Chimie
No.375, Feb.1996, p.83-94
French
REVOLUTION OF METALLOCENES AND NEW
POLYMERISATION PROCESSES
Gauthier X V
Developments in metallocene polymerisation catalysts
for polyole
À n synthesis are examined, and commercial
developments by a number of companies are reviewed.
Some new polymerisation processes, including supercritical
suspension, high temperature and supercondensing mode
gas phase polymerisation, are also described. 6 refs.
WORLD
Accession no.643008
Item 356
Macromolecules
30, No.9, 5th May 1997, p.2792-4
FORMATION OF CELLULOSE ACETATE
FIBERS BY THE RAPID EXPANSION OF
SUPERCRITICAL METHANOL SOLUTIONS
Aniedobe N E; Thies M C
Clemson,University
The rapid expansion of secondary cellulose acetate
from supercritical methanol solutions was investigated.
Particular attention was paid to determining whether or not
continuous
À bres could be made and the extent to which
degradation of cellulose acetate occurred because of the
elevated processing temps. 7 refs.
USA
Accession no.638826
Item 357
Antec 97. Volume II. Conference proceedings.
Toronto, 27th April-2nd May 1997, p.1991-5. 012
ON-LINE MEASUREMENT OF PS/CO2
SOLUTION VISCOSITIES
Lee M; Park C B; Tzoganakis C
Waterloo,University; Toronto,University
(SPE)
The reduction of viscosity via gas dissolution in a polymer
is well explained in terms of the dilution and the free
volume increase. The viscosity of polymer/supercritical
Á uid (SCF) solutions has been studied by theoretical
prediction or off-line measurement to date. A technology
for the on-line measurement of melt viscosity of PS/SCF
solutions is presented using a linear capillary tube die
mounted on a single-screw extruder. Carbon dioxide
is injected into the extrusion barrel and the content of
CO2 is varied in the range of 0 to 4% by weight using a
positive displacement pump. Single-phase polymer/SCF
solutions are made using a microcellular extrusion system
and formation of two-phase mixture is prevented by
maintaining a high pressure in the capillary tube die. By
References and Abstracts
© Copyright 2005 Rapra Technology Limited
111
measuring the pressure drops through the die, the viscosity
of PS/CO2 solutions is determined. The solubility of CO2
is estimated by monitoring the pressure drops and the
absolute pressure in the die. The effect of pressure on the
viscosity of a PS/CO2 solution is also discussed. 27 refs.
CANADA
Accession no.638327
Item 358
Patent Number: US 5559198 A 19960924
PROCESS FOR PREPARING POLYVINYL
TRIFLUOROACETATE AND POLYVINYL
TRIFLUOROACETATE/VINYL ESTER
COPOLYMERS IN SUPERCRITICAL CO2
Eian G L; Elsbernd C L S
Minnesota Mining & Mfg.Co.
Polyvinyl tri
Á uoroacetate (PVTFA) is obtained in relatively
high yield under mild conditions by using carbon dioxide
under supercritical conditions, as a solvent. Synthesis of
syndiotactic PVTFA on a commercial scale without the
use of environmentally-harmful solvents is made possible
by the process, which provides a convenient route to
syndiotactic PVAL.
USA
Accession no.635518
Item 359
Journal of Applied Polymer Science
64, No.7, 16th May 1997, p.1309-17
HIGHLY REFLECTIVE POLYIMIDE FILMS
CREATED BY SUPERCRITICAL FLUID
INFUSION OF A SILVER ADDITIVE
Boggess R K; Taylor L T; Stoakley D M; St.Clair A K
US,NASA,Langley Research Center;
Radford,University
Supercritical
Á uid infusion of a silver-containing additive
into a fully cured polyimide was achieved with moderately
high-density carbon dioxide at 110C. The nature of the
silver and its distribution within the
À lm and on the À lm
surface were established via microscopy and surface
analysis techniques. 25 refs.
USA
Accession no.635399
Item 360
Patent Number: US 5550211 A 19960827
METHOD FOR REMOVING RESIDUAL
ADDITIVES FROM ELASTOMERIC ARTICLES
DeCrosta M A; Jagnandan I
Schering Corp.
The articles are cleaned by contacting them with at least one
supercritical
Á uid under conditions and for a time sufÀ cient
to remove the phthalates and/or polynuclear aromatic
hydrocarbons contained therein. Articles having reduced
phthalate contents can be used as gaskets, valves, seats,
Á aps
or plugs in metered dose delivery devices, such as aerosols
for demanding medicinal and pharmaceutical uses.
USA
Accession no.633883
Item 361
Journal of Polymer Science : Polymer Physics Edition
35, No.3, Feb.1997, p.523-34
RHEOLOGY OF POLYDIMETHYLSILOXAN
E(PDMS) SWOLLEN WITH SUPERCRITICAL
CARBON DIOXIDE
Gerhardt L J; Manke C W; Gulari E
Wayne State,University
Viscosity curves were measured for PDMS melts swollen with
dissolved carbon dioxide at 50 and 80C for shear rates ranging
from 40 to 2300/s, and for carbon dioxide contents ranging
from 0 to 21 wt %. The measurements were performed with
a capillary extrusion rheometer modi
À ed for sealed, high-
pressure operation to prevent degassing of the melt during
extrusion. The concentration-dependent viscosity curves for
these systems were self-similar in shape, exhibiting low-shear
rate Newtonian plateau regions followed by shear-thinning
power-law regions. Considerable reduction of viscosity was
observed as the carbon dioxide content increased. Classical
viscoelastic scaling methods, employing a composition-
dependent shift factor to scale both viscosity and shear rate,
were used to reduce the viscosity data to a master curve at each
temp. The dependence of the shift factors on polymer chain
density and free volume were investigated by comparing
the shift factors for PDMS-carbon dioxide systems with
those obtained by iso-free volume dilutions of high molec.
wt. PDMS. This comparison suggested that the free volume
added to PDMS upon swelling with dissolved carbon dioxide
was the predominant mechanism for viscosity reduction in
those systems. 19 refs.
USA
Accession no.625151
Item 362
Polymer Recycling
2, No.2, 1996, p.77-82
CHEMICALS OF COMMERCE FROM
RECYCLED SCRAP TYRES
Dhawan J C; Huddleston H T
South Alabama,University
Tyre disposal problems are highlighted. The application
of supercritical
Á uid (SCF) technology to produce liquid
hydrocarbons is discussed. The SCF-liquid can be blended
with crude oil for upgrading in an existing re
À nery scenario or
it could be fractionated to produce a variety of low molecular
weight aromatic hydrocarbons, The SCF-tyre oil process
is safe to operate since the pressure energy at supercritical
conditions is contained in the liquid. The process would only
require ‘off the shelf’ processing equipment. 16 refs.
USA
Accession no.622309
References and Abstracts
112
© Copyright 2005 Rapra Technology Limited
Item 363
R’95 - Recovery, Recycling, Re-Integration. Volume
IV: Chemical Processes, Biological Processes, Hospital
Waste. Conference proceedings.
Geneva, 1st-3rd Sept. 1995, p.IV.14-21. 8(13)
DEGRADATION OF POLYMERS AND
ADDITIVES IN SUB- AND SUPERCRITICAL
WATER
Hirth T; Bunte G; Eisenreich N; Krause H; Schweppe R
Fraunhofer-Institut fuer Chemische Technologie
Edited by: Barrage A; Edelmann X
(EMPA; Swiss Federal Laboratories for Mat.Testing &
Res.)
Polymers include problematic substances, e.g.
À re retardants,
which, for ecological reasons, cannot be passed on to the
environment but have to be disposed of by the correct
disposal process. These substances are usually disposed of
by incineration. However, as the waste materials contain
halogen and nitrogen compounds, their disposal poses
considerable problems. Thus, in the elimination of chlorine-
containing organic waste materials, the formation of
hydrogen chloride, chlorine and dioxins must be reckoned
with, whereas nitrous oxides may also be produced on the
destruction of waste materials containing nitrogen. The
removal of compounds containing chlorine is discussed, and
new possible conversion processes are presented: pressure
hydrolysis in subcritical and supercritical water and the
supercritical water oxidation. These processes are used for
the degradation of monomers, polymers and additives. When
alkaline hydrolysis of halogenated polymers is carried out in
the supercritical range, e.g. at 500 deg.C , over 98 % of the
organically bonded chlorine in the aqueous phase is found. In
this process the principal polymer chain is also decomposed.
Under supercritical water conditions it is also possible to
oxidise additives from plastics like
À re retardants. First results
have shown that compounds like tetrabromophthalic acid
anhydride break down in supercritical water to form carbon
dioxide, water and bromide. 6 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.615222
Item 364
R’95 - Recovery, Recycling, Re-Integration. Volume
IV: Chemical Processes, Biological Processes, Hospital
Waste. Conference proceedings.
Geneva, 1st-3rd Sept. 1995, p.IV.3-8. 8(13)
EXTRACTION OF BROMINATED FLAME
RETARDANTS FROM POLYMER COMPOSITES
WITH SUPERCRITICAL CARBON DIOXIDE
Bunte G; Hardle T; Mariothe E; Michelfelder B
Fraunhofer-Institut fuer Chemische Technologie
Edited by: Barrage A; Edelmann X
(EMPA; Swiss Federal Laboratories for Mat.Testing & Res.)
In the
À eld of polymer recycling and/or disposal of e.g.
polymer composites of mass consumer products, new
techniques are highly required. One promising way to
separate halogenated
Á ame retardants out of polymer
composites seems to be the extraction by supercritical
Á uids like C02. The main objective is to À nd suitable
conditions for high extraction ef
À ciencies. For model
mixtures involving the
Á ame retardants TBBA, TBPA
and HBCD, the extraction ef
À ciency from the inert matrix
MgSO4 was examined in relation to extraction pressure,
temperature and time. The data form the basis for realistic
tests on ABS composites with different
Á ame retardants.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.615221
Item 365
Antec ‘96. Volume II. Conference proceedings.
Indianapolis, 5th-10th May 1996, p.2326-30. 012
IMPACT OF SUPERCRITICAL FLUIDS ON THE
MORPHOLOGY OF POLYETHERETHERKETONE
Kander R G; Lee J R
Virginia,Polytechnic Institute & State University
(SPE)
The application of supercritical
Á uid (SCF) technology
to high-performance polymers is becoming increasingly
important as such polymers become more prevalent
in industry. The response of fabricated parts to SCF
environments can be critical to performance. This study
examines the effects of absorption of SCFs on the
crystallisation behaviour of polyaryletheretherketone
(PEEK). Special attention is given to the ability to induce
different levels of crystallinity by exposing PEEK to
chlorodi
Á uoromethane at various supercritical conditions.
29 refs.
USA
Accession no.606522
Item 366
Polymer
37, No.15, 1996, p.3405-10
EFFECT OF STRUCTURE ON GAS SOLUBILITY
AND GAS INDUCED DILATION IN A SERIES OF
POLY(URETHANE) ELASTOMERS
Briscoe B J; Kelly C T
London,Imperial College of Science,Technology &
Medicine
The interaction of high pressure subcritical and supercritical
carbon dioxide with a series of PU elastomers of differing
hard segment content was studied by means of dilation
and dynamic mechanical studies in a high pressure cell.
Pressures were up to 23 MPa. The data indicates that, for
this particular series of ester-based polyurethanes, the
extent of sorption and dilation are directly related to the
structural properties of each polymer including the extent
and characteristics of the soft phase component. DSC data
are given for each PU. 18 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.606324
References and Abstracts
© Copyright 2005 Rapra Technology Limited
113
Item 367
Patent Number: US 5462973 A 19951031
SEPARATION OF POLYETHYLENE
TEREPHTHALATE AND POLYVINYL
CHLORIDE USING SUPERCRITICAL CARBON
DIOXIDE
Serad G A; Thornburg T S
Hoechst Celanese Corp.
A method for separating co-mingled polymeric materials,
in particular PETP and PVC is described. The process
involves selectively dissolving a super
À cial Á uid into
one of the materials at the appropriate temperature and
pressure. Upon rapid reduction of the system pressure,
the selected material foams providing a change in density.
Under ambient conditions, the polymeric materials
having a large density difference can be separated by
means of aqueous separation and
Á otation. The preferred
supercritical
Á uid for the process is carbon dioxide, and
PVC is the material into which the supercritical
Á uid is
preferentially dissolved.
USA
Accession no.594423
Item 368
Japan Chemical Week
37, No.1874, 9th May 1996, p.6
USED PET RESIN DECOMPOSED INTO
CHEMICAL MATERIALS
The process is brie
Á y described in which researchers at
the National Institute of Materials & Chemical Research
have completely decomposed PETP using supercritical
Á uid. The process mixes used pulverised PETP which is
mixed with methanol in a ratio close to 1:10 by weight,
and in which the resultant product is put for 30 minutes
under the speci
À ed condition of 80-90 atmospheres and
a temperature of 300 degrees C. to produce dimethyl
terephthalate and ethylene glycol. The development hopes
to help with legislation in which producers of PETP bottles
are required to recycle them.
JAPAN,NATIONAL INSTITUTE OF MATERIALS & CHEMICAL
RESEARCH
JAPAN
Accession no.590180
Item 369
Chemical Engineering
103, No.4, April 1996, p.48
SUPERCRITICAL FLUIDS MOVE INTO
PLASTICS PROCESSING
Parkinson G
Supercritical
Á uids may soon be used to make plastics,
according to recent research. The article brie
Á y describes
the environmental and cost advantages, together with
possible disadvantages of using supercritical
Á uids in
the processing of plastics. Brief details of a process for
producing PETP, which offers advantages over current
commercial methods are given.
AMERICAN CHEMICAL SOCIETY; NORTH
CAROLINA,UNIVERSITY
USA
Accession no.587423
Item 370
Journal of Microencapsulation
13, No.2, March-April 1996, p.131-9
PRODUCTION OF DRUG LOADED
MICROPARTICLES BY THE USE OF
SUPERCRITICAL GASES WITH THE AEROSOL
SOLVENT EXTRACTION SYSTEM(ASES)
PROCESS
Bleich J; Mueller B W
Kiel,Christian-Albrecht-University
The ASES process using supercritical gas was used
for encapsulation of model drugs such as hyoscine
butylbromide, indomethacin, piroxicam and thymopentin.
As a carrier, the polymer poly-L-lactide was used. The
resulting microparticles were investigated with regard
to particle formation, morphology, particle size, size
distribution and drug loading. With decreasing polarity of
the incorporated drug, an increasing extraction occurred
which lowered the drug loading of the microparticles. The
extraction capacity of the gas phase depended on temp.
and pressure, which determined density and polarity of
the gas, The results obtained showed that the production
conditions had to be optimised for each drug/polymer
combination. Totally non-polar drugs were completely
extracted together with the organic solvent, but polar
drugs and especially peptides and proteins were easy to
incorporate with the ASES process. 24 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.586391
Item 371
Materials World
4, No.1, Jan.1996, p.6
GREEN SOLVENT FOR ACRYLIC PLASTICS
Research scientists at the University of Surrey are
investigating whether acrylic plastics can be made using
totally clean supercritical carbon dioxide in place of toxic
solvents. The article supplies brief details of the bene
À ts
of using supercritical carbon dioxide, which is cheaper,
easily recycled and leaves no toxic residue.
SURREY,UNIVERSITY; EPSRC
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.583032
References and Abstracts
114
© Copyright 2005 Rapra Technology Limited
Item 372
Patent Number: WO 9518834 A1 19950713
SUPERCRITICAL FLUID EXTRACTION
INVOLVING HYDROFLUOROALKANES
Blackwell J A; Chen D T; Alband T D; Perman C A
Minnesota Mining & Mfg.Co.
A composition containing
À rst and second components
is contacted with a supercritical
Á uid comprising 1,1,1,2-
tetra
Á uoroethane or 1,1,1,2,3,3,3-heptaÁ uoropropane or a
mixture thereof, in the supercritical state under conditions
and for a time suf
À cient to remove the À rst component
from the composition.
USA
Accession no.582627
Item 373
2nd Annual Recycling Conference: Putting Plastics
Recycling Technology to Use. Retec proceedings.
Akron, Oh., 2nd-3rd Nov.1995, p.9-16 8(13)
INNOVATIVE APPROACH TO IMPROVE THE
QUALITY OF RECYCLED PLASTIC
Agrawal R; Lancaster T; Papinsick J
Liquid Carbonic Inc.
(SPE,Recycling Div.; SPE,Akron Section)
A novel technique is presented for removal of impurities from
plastic using supercritical carbon dioxide in a twin-screw
extruder. A 34 mm counterrotating, intermeshing twin-screw
extruder was used. The source of plastic used was from kerbside
collections consisting of detergent, fabric softener and milk
bottles. The impurities contained in these bottles were aromatic
hydrocarbons and fragrance type compounds like d-limonene.
Control experiments were run by doping virgin plastic with
naphthalene and then processing with supercritical carbon
dioxide. It is shown that this process can remove contaminants
within the plastic to 95% or greater ef
À ciencies.
USA
Accession no.579418
Item 374
Journal of Applied Polymer Science
59, No.4, 24th Jan.1996, p.707-17
INTERACTION OF SUPERCRITICAL CARBON
DIOXIDE WITH POLYMERS. II. AMORPHOUS
POLYMERS
Shieh Y T; Su J H; Manivannan G; Lee P H C;
Sawan S P; Spall W D
Lowell,University; Los Alamos National Laboratory
Eleven different polymers of amorphous type were subjected
to supercritical carbon dioxide treatment under a wide range of
pressures and temps. The effects of the treatment on appearance,
weight change, and thermal and mechanical properties were
followed systematically. In addition, the effects of treatment
conditions and dimension of the samples of weight changes
were also monitored. It was found that amorphous polymers
could absorb carbon dioxide to a greater extent than crystalline
polymers and, in turn, the phenomenon of plasticisation was
also very high. In addition to morphology, the polarity of the
polymer was also crucial in determining the solubility in carbon
dioxide. Comparison was also made with the behaviour of
crystalline polymers. 12 refs. (Pt.I, ibid, p.695-705)
USA
Accession no.576754
Item 375
Journal of Applied Polymer Science
59, No.4, 24th Jan.1996, p.695-705
INTERACTION OF SUPERCRITICAL CARBON
DIOXIDE WITH POLYMERS. I. CRYSTALLINE
POLYMERS
Shieh Y T; Su J H; Manivannan G; Lee P H C;
Sawan S P; Spall W D
Lowell,University; Los Alamos National Laboratory
The interaction of supercritical carbon dioxide with nine
different crystalline polymers (four types of substituted and
unsubstituted PE), PP, nylon 66, PETP, polyoxymethylene
and PVDF) was studied systematically over a wide range
of pressures and temps. Critical factors such as changes
in appearance and weight, temp., pressure and time of the
supercritical
Á uid treatment and dimension of samples were
observed. The effect of supercritical carbon dioxide on the
thermal properties of treated polymers was investigated
through TGA analysis. Changes in the mechanical
properties, such as yield strength, ultimate elongation and
elastic modulus, of the crystalline polymers studied were
also observed. The possible implications of the observed
changes for certain applications are discussed. 23 refs.
USA
Accession no.576753
Item 376
Polyole
À ns IX. Conference Proceedings.
Houston, Tx., 25th Feb-1st March,1995, p.31-47. 42C1
THIRD-GENERATION POLYOLEFIN
TECHNOLOGIES AND THEIR CAPABILITIES
Sinclair K B
SRI International
(SPE,South Texas Section; SPE,Thermoplastic
Materials & Foams Div.)
Three developments in polyole
À n technology are discussed,
together with their advantages over current commercial
polyole
À n processes. The developments are supercritical
slurry processes for PE and PP, high-temperature PP
processes and supercondensing gas-phase processes. These
developments in process operating techniques, combined
with recent developments in catalysis, promise to provide
great improvements in productivity and product range
capability. 5 refs.
NESTE OY; HOECHST; MITSUBISHI PETROCHEMICAL;
NOVACOR; DOW; UNION CARBIDE; EXXON; BASF
USA
Accession no.576276
References and Abstracts
© Copyright 2005 Rapra Technology Limited
115
Item 377
Macromolecules
28, No.24, 20th Nov.1995, p.8429-31
SYNTHESIS OF TETRAFLUOROETHYLENE-
BASED, NONAQUEOUS FLUOROPOLYMERS IN
SUPERCRITICAL CARBON DIOXIDE
Romack T J; DeSimone J M; Treat T A
North Carolina,University; du Pont de Nemours E.I.,&
Co.Inc.
Copolymers of tetra
Á uoroethylene with perÁ uoro(propyl
vinyl ether), as well as copolymers of tetra
Á uoroethylene
with hexa
Á uoropropylene, were synthesised in high yields
employing bis(perfluoro-2-propoxypropionyl) peroxide
as a free radical initiator in supercritical carbon dioxide.
Yield, copolymer composition and melting point data are
shown in addition to SEM micrographs of morphology. For
tetra
Á uoroethylene-perÁ uoro(propyl vinyl ether) copolymers,
molecular weights were high and FTIR indicated the
successful elimination of deleterious end groups. 28 refs.
USA
Accession no.576006
Item 378
Polymer
36, No.25, 1995, p.4817-26
MISCIBILITY, DENSITY AND VISCOSITY
OF POLYDIMETHYLSILOXANE(PDMS) IN
SUPERCRITICAL CARBON DIOXIDE
Xiong Y; Kiran E
Maine,University
Phase boundaries, densities and viscosities of solutions of
PDMS in supercritical carbon dioxide were determined. It
was shown that the densities and phase behaviour could be
well described with the Sanchez-Lacombe model. It was
shown that the molec.wt. and MWDs had a signi
À cant
effect on the observed demixing pressures. Viscosities of
these solutions showed the usual behaviour in that temp.
dependence followed Arrhenius-type behaviour with
Á ow
activation energies of about 8 kJ/mol. Pressure dependence
was also exponential, with the apparent volume of
activation being in the range 30 to 60 cc/mol. The effects
of temp. and pressure were uni
À ed with density and the
viscosity data were best correlated with Doolittle-type free
volume based relationships. 28 refs.
USA
Accession no.572198
Item 379
Polymer Journal (Japan)
27, No.9, 1995, p.951-8
CONTROLLED SYNTHESIS OF ISOTACTIC
AND SYMMETRICAL PMMA DIRECTED
TOWARD UNIFORM POLYMERS WITH HIGH
CRYSTALLINITY
Ute K; Yamasaki Y; Naito M; Miyatake N; Hatada K
Osaka,University
The synthesis and fractionation by supercritical
Á uid
chromatography of an isotactic and symmetrical PMMA
are described. Characterisation was undertaken by proton
NMR. Single crystals were grown from a solution and
the crystal structure was determined by X-ray analysis.
26 refs.
JAPAN
Accession no.565762
Item 380
Patent Number: US 5412027 A 19950502
PREPARATION OF HOMOGENEOUS
POLYMERS USING SUPERCRITICAL FLUID
SOLUTIONS
Shine A D; Smith S D; Noda I
Procter & Gamble Co.; Delaware,University
Homogeneous polymer blends are prepared from otherwise
thermodynamically immiscible polymers, especially block
copolymers. Thus, polymers, such as PS/PMMA block
copolymer or PS/poly(1,2-butadiene) block copolymer,
are dissolved under pressure in supercritical
Á uid solvents,
such as chlorodi
Á uoromethane and n-butane, respectively,
and expanded through a
À ne nozzle. As the SCF solvent
evaporates, the polymer deposits as a homogeneous
material.
USA
Accession no.564962
Item 381
Emerging Technologies in Plastics Recycling.
Symposium proceedings.
Philadelphia, Pa., 3rd-5th June 1991, p.172-85. 8(13)
SEPARATION OF THERMOPLASTICS BY
DENSITY USING NEAR-CRITICAL AND
SUPERCRITICAL CARBON DIOXIDE AND
SULPHUR HEXAFLUORIDE
Super M S; Enick R M; Beckman E J
Pittsburgh,University
Edited by: Andrews G D; Subramanian P M
(ACS,Div.of Polymer Chemistry)
ACS Symposium Series 513
Near-critical and supercritical fluids composed of
carbon dioxide and/or sulphur hexa
Á uoride are used to
sort thermoplastic waste mixtures according to density.
For example, PVC can be readily removed from waste
PETP, and tinted or
À lled materials can be separated
from their clear and unfilled counterparts. Carbon
dioxide alone can be used to separate polyole
À ns, while
pure sulphur hexa
Á uoride can be used to separate the
non-olefin thermoplastics. Sulphur hexafluoride-rich
CO2/SF6 mixtures can be used to separate all of the
thermoplastics. The brief exposure of the thermoplastics
to the mild temperature, high-pressure environment does
not chemically alter them. The densities of the supercritical
or near-critical
Á uid mixtures are accurately correlated to
temperature, pressure and
Á uid composition using a cubic
References and Abstracts
116
© Copyright 2005 Rapra Technology Limited
equation of state. 15 refs.
USA
Accession no.564824
Item 382
Adhesives Age
38, No.10, Sept.1995, p.34-6
UNGLUING BY SUPERCRITICAL FLUIDS
Manivannan G; Sawan S P
Massachusetts,University
The ability to unglue assembled parts will take on more
importance as recycling issues continue to gain more
importance. The use of supercritical carbon dioxide
could
À nd a niche among various existing dismantling
technologies. Aspects covered include adhesives and
supercritical
Á uid treatment. 6 refs.
USA
Accession no.562909
Item 383
Cellular Polymers II. Conference proceedings.
Edinburgh, 23-25th March 1993, paper 5. 6124
GENERATION OF MICROCELLULAR
POLYMERS USING SUPERCRITICAL CO2
Goel S K; Beckman E J
Pittsburgh,University
(Rapra Technology Ltd.)
Supercritical CO2 is known to be a very good swelling
agent and plasticiser for PMMA, a consequence of
an interesting combination of liquid-like and gas-like
properties exhibited by supercritical fluids. Making
use of this behaviour, a constant temperature process
of generating microcellular polymers which employs
a sudden pressure drop to induce phase separation in a
solution of supercritical CO2 and PMMA is studied. The
method is different from commonly-used temperature
quench methods in that it makes use of the glass transition
depression due to the presence of diluent in the polymer
rather than heating the polymer to above its normal glass
transition temperature. 24 refs.
USA
Accession no.562718
Item 384
Polymer
36, No.16, 1995, p.3173-82
SEMICRYSTALLINE MICROFIBRILS AND
HOLLOW FIBRES BY PRECIPITATION WITH A
COMPRESSED FLUID ANTISOLVENT
Luna-Barcenas G; Kanakia S K; Sanchez I C; Johnston
K P
Austin,University of Texas
Precipitation with a compressed-
Á uid antisolvent was
studied theoretically and experimentally. Solutions of PAN
in DMF sprayed into supercritical
Á uid carbon dioxide
form hollow
À bres and highly oriented microÀ bril. In the
dilute region, micro
À brils are produced with diameters as
low as 100 nm due to the dipole forces, in contrast with
microspheres produced from solutions of PS in toluene.
For PAN micro
À brils, orientation increases with shear,
then goes through a maximum and eventually decreases at
higher
Á ow rates due to an expanding jet. The concentration
for the transition from micro
À brils to a single hollow À bre
is in agreement with the calculated transition concentration
(C) from the dilute to semidilute region. In the semidilute
region, the morphology changes from hollow
À bres to
highly oriented
À brils with an increase in Á ow rate. The
increase in turbulence enhances convective mass transport,
leading to more uniform nucleation throughout the cross-
section of the jet, favouring the highly oriented
À brils. The
enhanced transport of carbon dioxide into the jet lowers the
solvent quality, raising the above transition concentration
(C), which further favours
À bril formation. For both PAN-
DMF and PS-toluene solutions, the transition from highly
oriented micro
À brils to hollow À bres occurs at about 3C
(in a good solvent), suggesting some similarities in the
mass-transfer pathways in each system. 27 refs.
USA
Accession no.562479
Item 385
Polymer
36, No.16, 1995, p.3099-102
PLASTICISATION OF A POLYURETHANE BY
CARBON DIOXIDE AT HIGH PNEUMATIC
STRESSES
Briscoe B J; Kelly C T
London,Imperial College of Science,Technology &
Medicine
The interaction of high pressure, subcritical and
supercritical carbon dioxide with a polyesterurethane
elastomer (Diprane 54) was studied. A novel optical high
pressure cell was employed to examine the gas-polymer
interactions at a molecular level, using FTIR. Spectra
indicated that the hydrogen bonding between the polymer
chains was disrupted by the imbibed gas. The data were
then used in conjuction with temperature-dependent
spectral data and the modulus-temperature characteristics
of the polymer, to estimate the change in modulus of the
polymer as a function of gas pressure. The predicted
modulus of the PU was seen to fall as the gas pressure
was increased, indicating that the PU was plasticised by
the carbon dioxide. The plasticisation effect became the
less dominant process at pressures above 12 MPa. The
procedure provides a relatively convenient method for
quantifying plasticisation in PU systems in the presence
of high pneumatic stresses. Such data are valuable in
predicting the consequences of gas-induced rupture during
ambient gas decompression. 13 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN
EUROPE
Accession no.562469
References and Abstracts
© Copyright 2005 Rapra Technology Limited
117
Item 386
Advanced Materials Newsletter
17, No.16, 28th Aug.1995, p.6
SUPERCRITICAL FLUIDS CAN BENEFIT
POLYMER AND COMPOSITE PROCESSES
It is reported that researchers at the Center for Composite
Materials have been introducing high pressure CO2 to
act as a solvent, non-solvent or as a plasticiser. How the
supercritical
Á uids function depends on the Á uid density
and which polymer or composite is being processed. The
processing techniques could eventually prove useful in
composite work; brief details are noted.
US,CENTER FOR COMPOSITE MATERIALS
USA
Accession no.561374
Item 387
Macromolecules
28, No.8, 10th April 1995, p.3002-4
CATIONIC POLYMERISATION OF VINYL AND
CYCLIC ETHERS IN SUPERCRITICAL AND
LIQUID CARBON DIOXIDE
Clark M R; DeSimone J M
North Carolina,University
Vinyl ethers, particularly isobutyl vinyl ether, and
oxetanes, particularly bis(ethoxymethyl)oxetane, were
successfully polymerised cationically in carbon dioxide.
Yield, molecular weight and MWD data are given. The
processes became heterogeneous using hydrocarbon
vinyl ethers and oxetanes, but high molar mass and
high conversions could still be achieved. Homogeneous
cationic polymerisations were also possible with several
Á uorocarbon-based alkyl vinyl ethers and 3-methyl-3’-
((1,1-dihydrohepta
Á uorobutoxy)methyl)oxetane. Control
polymerisations were performed using cyclohexane and
Freon-113 as solvent. 18 refs.
USA
Accession no.550488
Item 388
Antec ‘94. Conference Proceedings.
San Francisco, Ca., 1st-5th May 1994, Vol.II, p.2105-9.
012
MODELLING OF THE TRANSPORT OF
CARBON DIOXIDE THROUGH POLYMERS
Bicerano J; Ralston A R K; Moll D J
Dow Chemical Co.; Wisconsin-Madison,University
(SPE)
The sorption of carbon dioxide in a wide variety of
polymers was modelled by the combination of a statistical
thermodynamic equation of state with simple empirical
quantitative structure-property relationships. Henry’s law
solubility coef
À cients in rough but reasonable agreement
with experimental values could be calculated in this
manner. Information could also be obtained on the effects
of polymer structure and morphology on the amount
of non-ideality of the mixing behaviour as quanti
À ed
by the magnitude of the interaction parameter of the
equation of state. Atomistic simulations were applied to
the sorption and diffusion of carbon dioxide in bisphenol
A polycarbonate. The heat of solution and diffusion
coef
À cient could be calculated with rough but reasonable
agreement with experimental results by using model
systems of suf
À cient size and averaging over many such
systems. 17 refs.
USA
Accession no.549411
Item 389
Macromolecules
28, No.5, 27th Feb.1995, p.1724-6
FREE-RADICAL TELOMERISATION
OF TETRAFLUOROETHYLENE IN
SUPERCRITICAL CARBON DIOXIDE
Romack T J; Combes J R; DeSimone J M
North Carolina,University; Kenan Laboratories
Telomerisation of tetrafluoroethylene was performed
in supercritical carbon dioxide using AIBN as initiator
and per
Á uorobutyl iodide as telogen. Thermally initiated
telomerisations were also performed. Safety advantages
of using carbon dioxide are emphasised. Data are shown
for yield, molecular weight (570-650) and polydispersity
index. 15 refs.
USA
Accession no.547164
Item 390
Macromolecules
28, No.4, 13th Feb.1995, p.912-5
PRECIPITATION POLYMERISATION OF
ACRYLIC ACID IN SUPERCRITICAL CARBON
DIOXIDE
Romack T J; Maury E E; DeSimone J M
North Carolina,University
Precipitation polymerisation was successful at pressures
from 125 to 345 bar using AIBN as initiator. Analyses
by GPC and SEM indicate that for the pressure range
studied there was no appreciable effect on molecular
weight, MWD, particle size or morphology. In addition,
effective molecular weight control was demonstrated for
precipitation polymerisation of acrylic acid in carbon
dioxide through use of ethyl mercaptan as a chain transfer
agent. 15 refs.
USA
Accession no.545142
References and Abstracts
118
© Copyright 2005 Rapra Technology Limited
Item 391
Plastics and Rubber Weekly
No.1576, 10th March 1995, p.1
PE OUTPUT RATE SET TO MULTIPLY
A new, third generation of polyolefin manufacturing
technology is promising to revolutionise production giving
undreamed of output rates limited more by downstream
handling than reactor capability. Newly patented advances
could mean three-fold boosts to gas phase reactors, while
developments in slurry and catalyst technology for PP
and PE manufacture also presage improvements in both
product and output. BP Chemicals recently announced its
High Productivity System and Exxon’s Supercondensing
Technology has just been patented. Exxon has managed to
lift the liquids content in the gas
Á ow to between 25 and
30%. Development of the Supercritical Slurry Processes
led by Neste centres upon using a propane diluent enabling
process temperatures to be raised.
USA
Accession no.544143
Item 392
Patent Number: WO 9413733 A1 19940623
French
METHOD FOR ELIMINATING POLLUTANTS
OF LOW MOLEC.WT. CONTAINED IN
ELASTOMER SEALS AND PLASTIC
MATERIALS
Tcherevatchenkoff A; Perre C
Etablissements Valois
The pollutants are extracted by immersing the part
in supercritical CO2 followed by a slow isothermal
decompression step in the CO2 down to atmospheric
pressure for between 30 min. and 16h at a temp. above
31C.
EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE;
WESTERN EUROPE
Accession no.533047
Item 393
Trends in Polymer Science
2, No.9, Sept.1994, p.301-7
SUPERCRITICAL FRACTIONATION OF
POLYMERS AND COPOLYMERS
McHugh M A; Krukonis V J; Pratt J A
Johns Hopkins University; Phasex Corp.
Supercritical
Á uid fractionation (SCF) is a relatively rapid
technique providing macrosized fractions that characterise
the molecular weight and chemical composition
distributions of the parent material, and which allow
product performance determination of narrow molecular
weight and chemical composition fractions. A review is
given of the techniques used for fractionating polymers
with supercritical
Á uids, particularly Á uid fractionation
operating schemes, selected SCF fractionations, SCF
solvent selection, and applications of SCF fractionation.
A thermodynamic basis is provided to aid in choosing an
appropriate SCF solvent for a given fractionation, and
several fractionation examples are given to reveal the
potential of this emerging technique. 24 refs
USA
Accession no.529942
Item 394
Polymer Engineering and Science
34, No.14, July 1994, p.1148-56
GENERATION OF MICROCELLULAR
POLYMERIC FOAMS USING SUPERCRITICAL
CARBON DIOXIDE. II. CELL GROWTH AND
SKIN FORMATION
Goel S K; Beckman E J
Pittsburgh,University
Microcellular polymeric foam structures were generated
using a pressure induced phase separation in concentrated
mixtures of supercritical carbon dioxide and PMMA. The
process typically generates a microcellular core structure
encased by a non-porous skin, the thickness of which
decreases with increasing saturation pressure. This trend
can be described by a model for skin formation that is
based on the diffusion rate of gas out of the sample.
Signi
À cant density reductions can be achieved by changing
the pressure and temperature conditions in the foaming
process. Variation of cell size by temperature and pressure
is described. 20 refs.
USA
Accession no.523554
Item 395
Polymer Engineering and Science
34, No.14, July 1994, p.1137-47
GENERATION OF MICROCELLULAR
POLYMERIC FOAMS USING SUPERCRITICAL
CARBON DIOXIDE. I. EFFECT OF PRESSURE
AND TEMPERATURE ON NUCLEATION
Goel S K; Beckman E J
Pittsburgh,University
A process for synthesising microcellular polymeric
foams has been studied that makes use of a pressure
quench at constant temperature to initiate nucleation in
a homogeneous liquid solution of supercritical carbon
dioxide in PMMA. The foams thus generated invariably
have a microcellular core surrounded by a relatively non-
porous skin, the characteristics of which can be manipulated
by changing the process conditions. 25 refs.
USA
Accession no.523553
Item 396
Patent Number: EP 595184 A1 19940504
RECYCLING CELLULOSE ESTERS FROM THE
WASTE FROM CIGARETTE MANUFACTURE
References and Abstracts
© Copyright 2005 Rapra Technology Limited
119
Schiraldi D A
Hoechst Celanese Corp.
A substantial portion of cellulose ester polymer is separated
from a waste stream, which includes tobacco, cellulose
ester polymer and paper. The polymer is contacted with
a sufficient volume of fluid to extract contaminants
therefrom. The
Á uid is under pressure and temperature
conditions such that the
Á uid is a supercritical or near
supercritical
Á uid.
USA
Accession no.519269
Item 397
Utech ‘94: Groundwork for Growth. Conference
proceedings.
Hague, 22nd-24th March 1994, paper 14, pp.3. 43C6
SOLVENT EMISSION REDUCTION
TECHNOLOGY FOR MOULD RELEASE OF
HIGH RESILIENCE MOULDED FOAM
Derderian E J; Blakemore D L
OSi Specialities Inc.
Edited by: Reed D; Lee C A
(Crain Communications Ltd.; Rapra Technology Ltd.)
OSi’s novel mould release technology (SERT or Solvent
Emissions Reduction Technology) uses supercritical
carbon dioxide to replace hydrocarbon solvents. Since
SERT uses by-product carbon dioxide which has already
been generated, no new carbon dioxide is created. The
critical point for carbon dioxide occurs at rather mild
conditions of temperature and pressure, 31C and 73.7 bar.
Above these conditions, carbon dioxide is a supercritical
Á uid with solvency properties similar to hydrocarbon
solvents. This paper discusses the principles of the SERT
Mould Release Technology and its performance features.
It also describes the commercially available blending/
metering and spray equipment for delivering SERT mould
release agents to the mould surface. 2 refs.
USA
Accession no.518942
Item 398
Industrial and Engineering Chemistry Research
33, No.6, June 1994, p.1476-85
EFFECT OF RESS DYNAMICS ON POLYMER
MORPHOLOGY
Lele A K; Shine A D
Delaware,University
Details are given of the relationship between polymer
morphology and the dynamics of the rapid expansion
of supercritical solutions (RESS) process. Data are
given for polycaprolactone, polylactic acid, PMMA,
polyethyl methacrylate, and a styrene-methyl methacrylate
copolymer. Experimentally observed morphologies were
correlated with RESS. 42 refs.
USA
Accession no.517649
Item 399
Angewandte Makromolekulare Chemie
Vol.218, May 1994, p.69-79
German
DYEING IN SUPERCRITICAL CARBON
DIOXIDE: DETERMINATION OF PARAMETERS
INFLUENCING THE STRUCTURAL
CHARACTERISTICS OF PETP FIBRES
Knittel D; Saus W; Hoger S; Schollmeyer E
Deutsches Textilforschungszentrum Nord-West ev
The effect of dyeing in supercritical carbon dioxide
Á uids
on characteristics of polymer structure was investigated
using PETP
À bres. The implications of À bre structure for
successful dyeing or impregnation of
À bres in supercritical
systems are discussed. 28 refs.
EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY;
WESTERN EUROPE
Accession no.517591
Item 400
Polymer Bulletin
32, No.5/6, May 1994, p.537-43
CARBOCATIONIC POLYMERISATIONS
IN SUPERCRITICAL CARBON DIOXIDE.
I. EXPLORATORY EXPERIMENTS WITH
ISOBUTYLENE
Pernecker T; Kennedy J P
Akron,University
The carbocationic polymerisation of isobutylene in
supercritical carbon dioxide was achieved. It was shown
that in carbon dioxide at 32.5C and about 120 bar, the 2-
chloro-2,4,4-trimethylpentane(TMPCl)/tin tetrachloride
and TMPCl/titanium tetrachloride initiating systems
led to about 30% isobutylene conversion and gave
polyisobutylenes with Mn about 2000 and Mw/Mn about
2.0. It was claimed that this was the highest temp. at
which isobutylene was ever polymerised to reasonably
high molec.wt. products. Polymerisations at 32.5C under
similar but conventional (non-living) conditions in the
absence of supercritical carbon dioxide would yield
only very low molec.wt. oligomers. The structure of the
polymers obtained in supercritical carbon dioxide was
virtually identical with those obtained at much lower
temps. in conventional liquid-phase systems, indicating
the presence of chain transfer to monomer in both systems.
In contrast to TMPCl initiated polymerisations, the 1,3-
bis(2-hydroxy-2-propyl)-5-tert-butylbenzene initiator in
conjunction with boron trichloride and tin tetrachloride
yielded only oligomers in supercritical carbon dioxide.
22 refs.
USA
Accession no.516307
References and Abstracts
120
© Copyright 2005 Rapra Technology Limited
Item 401
Patent Number: EP 590842 A2 19940406
PROCESS FOR PREPARING LOW MOLEC.WT.
POLYMERS
Dada E A; Lau W; Merritt R F; Paik Y H; Swift G
Rohm & Haas Co.
Polymerisation is conducted in supercritical carbon dioxide
at temps. of at least 200C and pressures above 3,500 psi.
The process may be continuous, semi-continuous or
batch. The polymers, which have molec.wts. below 5000
and polydispersity below 2.5, are useful as detergent
additives, scale inhibitors, dispersants and crystal growth
modi
À ers.
USA
Accession no.512984
Item 402
Recycle ‘93. Conference Proceedings.
Davos, 22nd-26th March 1993, paper 14/4. 8(13)
INCORPORATION OF RECYCLABILITY
THROUGH MOLECULAR DESIGN
Beckman E J
Pittsburgh,University
(Maack Business Services)
The use of molecular design in different ways to incorporate
recyclability into thermoplastic and thermoset materials is
reviewed. Design of a material whose molecular properties
allow easier separation from a mixed thermoplastic waste
stream or creation of a material which degrades chemically
in a predetermined way are both aspects of recyclability by
molecular design. Examples are discussed. All decisions
about molecular design must take into account the full
life cycle of the material so that improved recyclability
by molecular design does not result in a negative impact
of the polymer on the environment. 35 refs.
USA
Accession no.505789
Item 403
In Tune with the Newest Decorating Technologies.
Retec proceedings.
Nashville, Tn., 12th-13th Oct.1993, p.104-17. 8(11)34
SUPERCRITICAL FLUID SPRAY APPLICATION
OF LOW-POLLUTION COATINGS FOR
PLASTIC SUBSTRATES
Miller W P
Union Carbide Corp.
(SPE,Decorating Div.; SPE,Tennessee Valley Section)
The supercritical
Á uid spray coating process, use of which
can result in signi
À cant reductions of volatile organic
content(VOC) emissions, is described. Particular attention
is paid to supercritical carbon dioxide as a coating solvent,
reduction of the ‘greenhouse effect’, spray generation and
conditions, spray characteristics, transfer ef
À ciency, and
suitable polymeric coating systems. Comparative VOC,
coverage and cost data for conventional and supercritical
Á uid plastics coating formulations are presented. 9 refs.
USA
Accession no.503913
Item 404
Plastics World
52, No.1, Jan.1994, p.10
NOVEL GAS PROCESS MAKES UNIQUE FOAMS
Miller B
A new approach to producing thermoplastic foams has been
developed at Massachusetts Institute of Technology. These
microcellular foams (MCF) contain billions of micron-size
voids per cubic centimetre, a structure that is claimed to
retain unusually high levels in mechanical properties, even
at substantial density reductions. The MCF process involves
using supercritical liquid carbon dioxide, injected into the
extruder barrel, as the blowing agent. Applications are foreseen
in light-weighting all types of thermoplastic extrusions
including pro
À les, À lms and À bres. Commercialisation of
MCF is being handled by Axiomatics Corp.
MASSACHUSETTS INSTITUTE OF TECHNOLOGY;
AXIOMATICS CORP.
USA
Accession no.501618
Item 405
Macromolecules
26, No.19, 13th Sept.1993, p.5052-60
PHASE BEHAVIOUR OF
POLYMER-SUPERCRITICAL
CHLORODIFLUOROMETHANE SOLUTIONS
Haschets C W; Shine A D
Delaware,University
The phase behaviour of solutions of PMMA and
polycaprolactone in supercritical chlorodi
Á uoromethane
was studied using a high pressure variable-volume view
cell. The effect of polymer polydispersity and the critical
state of the solvent on the phase behaviour was examined,
and the ability of lattice
Á uid and hydrogen bond models to
describe the experimental data was investigated. 43 refs.
USA
Accession no.494354
Item 406
Resources, Conservation and Recycling
9, No.1/2, Aug.1993, p.75-88
DENSITY-BASED SEPARATION OF
THERMOPLASTICS FOUND IN THE POST-
CONSUMER WASTE STREAM
Super M S; Enick R M; Beckman E J
Pittsburgh,University
The use of near-critical CO2 and near-critical mixtures of
CO2 and SF6,
Á uids with highly adjustable densities, to
References and Abstracts
© Copyright 2005 Rapra Technology Limited
121
separate thermoplastics found in the post-consumer waste
stream from each other and contaminants was investigated.
Separation of thermoplastics mixtures, including HDPE/
LDPE/PP and PVC/PETP, was carried out in a lab-scale,
density-based separator. Separation ef
À ciency, factors
affecting separation purity and favourable operating
conditions and procedures were evaluated. The purity
of the separated homopolymers ranged from 100 to 77
wt.%. 14 refs.
USA
Accession no.490055
Item 407
Plastiques Modernes et Elastomeres
45, No.3, April 1993, p.58-60
French
SUPERCRITICAL CARBON DIOXIDE: A
SOLUTION TO EMISSIONS OF VOLATILE
ORGANIC COMPOUNDS
Moudden B
Unicarb System Europe
The Unicarb coating process developed by Union
Carbide and Nordson is described. Carbon dioxide in the
supercritical state is used in place of the usual diluents,
thereby considerably reducing solvent emissions. The
coatings, based on conventional resins, are applied by
spraying using electrostatic guns developed by Nordson.
UNION CARBIDE CHEMICALS & PLASTICS
CO.INC.; NORDSON CORP.
SWITZERLAND; USA; WESTERN EUROPE
Accession no.483667
Item 408
Polymer
33,No.23,1992,p.5032-9
MODELLING THE SWELLING OF
CROSSLINKED ELASTOMERS BY
SUPERCRITICAL FLUIDS
Goel S K; Beckman E J
Pittsburgh,University
The mean
À eld lattice-gas model of Kleintjens et al for the
free energy of mixing with an additional elastic term due
to Flory was used to model the swelling of crosslinked
silicones by supercritical carbon dioxide. Whereas
the model reproduces well the pressure trends in both
volume change and weight fraction of
Á uid absorbed for
the poly(dimethylsiloxane)-carbon dioxide system, the
absolute predictions of weight fraction carbon dioxide
absorbed are too high in the vicinity of critical pressure.
37 refs.
USA
Accession no.464484
Item 409
Journal of Applied Polymer Science
46,No.8,15th Nov.1992,p.1395-9
REMOVAL OF CARBON TETRACHLORIDE
FROM CHLORINATED POLYISOPRENE USING
CARBON DIOXIDE
Burgess A N;Jackson K
ICI CHEMICALS & POLYMERS LTD.
The use of supercritical carbon dioxide in the removal of
residual carbon tetrachloride from chlorinated polyisoprene
in a packed column was demonstrated. The effects of varying
temp. and pressure on the ef
À ciency of extraction were
examined. The data indicated that an optimum combination
of pressure and temp. existed and that quite small deviations
from these conditions could produce markedly poorer
extraction ef
À ciency and lead to the destruction of the
polymer particle morphology. 10 refs.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.461780
Item 410
Die Makromolekulare Chemie- Macromolecular
symposia
No.57,May 1992,p.305-10
CHEMICAL RECYCLING OF POLYURETHANES
AND SEPARATION OF THE COMPONENTS BY
SUPERCRITICAL AMMONIA
Lentz H;Mormann W
SIEGEN,UNIVERSITAT
Chemical recycling of a RIM PU elastomer and a
Á exible
foam based on MDI and a polyether polyol was performed
by ammonolytic cleavage of urethane and urea bonds
under supercritical conditions. Resulting products were
the polyols, the amines corresponding to the isocyanates
used, and unsubstituted urea. Under suitable conditions
the polyether polyol was completely separated from the
ammonolysis products which in turn could be further
separated and used for the manufacture of PU’s or for the
synthesis of diisocyanates. 10 refs. (IUPAC, Macromol.
Div., Int. Symp. on Recycling of Polymers. Science &
Technology. Marbella, Spain, 18th-20th Sept. 1991).
GERMANY
Accession no.455131
Item 411
Industrial and Engineering Chemistry Research
31,No.5,May 1992,p.1414-7
MICROCELLULAR MATERIALS VIA
POLYMERISATION IN SUPERCRITICAL
FLUIDS
Srinivasan G;Elliott J R
AKRON,UNIVERSITY
A process is demonstrated whereby microcellular polymer
foams can be obtained by polymerisation directly in a near-
critical diluent. Critical point drying can be effected in the
References and Abstracts
122
© Copyright 2005 Rapra Technology Limited
reactor vessel in a relatively ef
À cient manner. The key to
the process is the choice of diluent and matching it to the
polymer to be gelled and dried. Propane and Freon-22 were
studied as diluents with the polymer system of poly(methyl
methacrylate-co-ethylene glycol-dimethacrylate). Freon
22 proved to be the superior choice. Morphology and
density of the resulting materials were comparable to
microcellular foams prepared by a more conventional
carbon dioxide wash and dry approach. 14 refs.
USA
Accession no.454109
Item 412
Advanced Materials Newsletter
14,No.3,10th Feb.1992,p.4
LIGHTWEIGHT EPOXY FOAM
US,DEPT.OF ENERGY
US patent 5,066,684 has been assigned to the US
Department of Energy for a lightweight epoxy foam
material. It can have densities ranging from 35-150 mg/cc.
The foam’s cell diameters are less than 1 micron. The epoxy
resin is a multifunctional type mixed with a non-reactive
diluent. A crosslinked epoxy gel is formed, which is mixed
with a solvent, replacing the diluent. The solvent is then
replaced with liquid carbon dioxide. Vaporising the carbon
dioxide under supercritical conditions yields the foam.
This abstract includes all the information contained in the
original article.
USA
Accession no.443062
Item 413
Polymeric Materials Science and Engng.Vol.60.
Conference Proceedings.
Dallas,Tx.,Spring 1989,p.695-9. 012
LOW DENSITY FOAMS FROM MACROPOROUS
EPOXY GELS
LeMay J D
LAWRENCE LIVERMORE NATIONAL
LABORATORY
(ACS,Div.of Polymeric Materials Science & Engng.)
A technology for making low density, microcellular
epoxy foams is described. The foam precursor is a two
phase macroporous gel made by homopolymerising an
epoxy novolac oligomer in an inert diluent. Dry foam is
recovered from the gel with little shrinkage by exchanging
the diluent with lique
À ed carbon dioxide then processing
at supercritical conditions. Foams have been made
with densities ranging from 0.034 to 0.15 g/cc. SEM
micrographs reveal a highly porous rami
À ed morphology
that is self-similar over at least 1-2 orders of magni
À cation.
The structure contains open cells with diameters ranging
from 0.1 to several microns. The foams are characterised
by high BET surface areas. 8 refs.
USA
Accession no.439871
Item 414
Journal of Polymer Science : Polymer Physics Edition
29,No.8,July 1991,p.989-99
INTERACTION OF CARBON DIOXIDE GAS
WITH SILICONE ELASTOMER AT HIGH
AMBIENT PRESSURES
Briscoe B J;Zakaria S
London,Imperial College of Science,Technology &
Medicine
Interaction of high pressure carbon dioxide gas with a
silicone elastomer, nitrile rubber and PTFE was studied.
Sorption dilation was measured with piezoelectric
ultrasonic transducers under gas pressures up to ca.22
MPa at 42C. The gas mass sorption was determined by
a vibrating reed probe. For silicone elastomer systems,
the dilation isotherm mimicked the sorption isotherm. A
signi
À cant drop in the partial molar volume of the absorbed
gas was observed when the carbon dioxide gas became
supercritical. In the transition region the formation of
discrete small high density zones of carbon dioxide in the
rubber matrix was observed. Plasticisation effects of the
absorbed high pressure gas were indicated by changes in
the acoustic longitudinal modulus. Signi
À cant inÁ ation
of certain polymer specimens in the desorption cycle was
observed. 26 refs.
EUROPEAN COMMUNITY; UK; WESTERN EUROPE
Accession no.434957
Item 415
Die Makromolekulare Chemie- Macromolecular
symposia
No.42/43,March 1991,p.219-28
THERMAL AND RHEOLOGICAL PROPERTIES
OF ACRYLIC COPOLYMERS POSSESSING
CRYSTALLISABLE POLYESTER SIDE CHAINS
Scholsky K M;Orier E B;Bixler K J;Stackman R W
JOHNSON S.C.,& SON INC.
Ring-opening of epsilon-caprolactone onto styrene-acrylic
acid copolymers occurred readily at 220C. GPC and
extraction experiments utilising supercritical carbon dioxide
indicate that the caprolactone has grafted onto the polymer
backbone as polyester side chains. DSC of these comb-like
polymers showed that grafted side chains lowered Tg and
contributed to crystallinity. M.p. and heat of fusion increased
as a function of the amount of grafted polycaprolactone. The
extent of grafting had a pronounced effect on melt rheology
and crystallisation rate. 8 refs. (ACS,Div.Polym.Chem.,6th
Int.Symp.on Ring-opening and Cyclopolymerisation,
Boston,Mass.,22nd-27th April 1990).
USA
Accession no.424716
Item 416
Plastics Technology
37,No.3,March 1991,p.29/37
NOVEL LOW-VOC PAINT TECHNOLOGY
References and Abstracts
© Copyright 2005 Rapra Technology Limited
123
Schut J H
Detailed information is presented on paint spraying
equipment being developed by several companies for use
with Unicarb technology from Union Carbide Chemicals
& Plastics Co.Inc. The Unicarb technology is reported to
have been developed for thinning paint with supercritical
carbon dioxide. Union Carbide is also said to have licensed
À ve paint companies to produce coatings compatible with
the Unicarb process. Advantages and limitations of the
Unicarb process are discussed in some detail.
UNION CARBIDE CHEMICALS & PLASTICS CO.INC.
USA
Accession no.419191
References and Abstracts
124
© Copyright 2005 Rapra Technology Limited
Subject Index
© Copyright 2004 Rapra Technology Limited
125
Subject Index
A
ABS, 74 88 286 364 374
ABSORPTION, 1 22 39 56 61 193
200 212 233 374
ACRYLIC, 344
ACRYLIC ACID COPOLYMER,
121 415
ACRYLIC POLYMER, 28 147 211
246 278 301 354 371 407
ACRYLONITRILE-METHYL
ACRYLATE COPOLYMER,
6 94
ACTIVATION ENERGY, 17 51
110 197 238 328 378
ADDITION REACTION, 259
ADDITIVE, 8 10 24 115 116 165
166 192 200 211 212 214 220
237 262 270 280 296 318 329
334 346 355 359 363 364 383
ADHESIVE, 43 68 211 302
ADIPIC ACID, 37
ADSORPTION, 92 184 193
AEROSOL, 193 360 370
AIBN, 28 54 60 77 88 96 100 107
111 126 213 224
AIR, 71 104 219
AIRCRAFT, 133
ALBUMIN, 193
ALCOHOLYSIS, 138 171
ALKYD RESIN, 407
AMINOCAPROIC ACID, 174
AMMONIA, 52 209 402 410
AMMONOLYSIS, 52 410
AMORPHOUS, 127 183 300 335
336 365 374 386 388
AMPHIPHILIC, 150 223
ANALYSIS, 1 2 4 19 23 37 45 55
65 75 81 83 93 96 108 124 132
135 136 160 161 176 280 294
393 405
ANIONIC POLYMERISATION,
150 256
ANTISOLVENT, 292 384
APPLICATION, 15 25 36 39 40 42
62 64 70 79 82 99 106 115 118
133 144 166 169 180 187 192
193 195 203 210 211 219 225
237 243 260 278 324 336 344
349 360 362 370 375 393 407
AQUEOUS, 109 220 269
ARGON, 237 295
AROMATIC, 1 7 9 14 83 95 107
224 276 280 282 360 362 373
ARRHENIUS’S LAW, 17 110 378
ARTIFICIAL BONE, 210 286
ATOMIC FORCE MICROSCOPY,
77 112 180 183
ATTENUATED TOTAL
REFLECTION
SPECTROSCOPY, 132 341
AUTOCLAVE, 7 17 116 135 193
197 222 246 312
AUTOMOTIVE APPLICATION,
42 64 82 118 133 166 192 203
344 382 402 416
AZOBISISOBUTYRONITRILE,
28 54 60 77 88 96 100 107 111
126 213 224
B
BATCH POLYMERISATION, 49
155 168 401
BATCH REACTOR, 17 161 164
174 205
BENZENE, 110 125 205 238
BENZOIC ACID, 193 205
BENZOIN ETHYL ETHER, 92
BIMODAL, 89 122 135 336
BIOCIDE, 115 269
BIOCOMPATIBLE, 40 125
BIODETERIORATION, 12 39 76
125 193 210 268 269
BIOMATERIAL, 15 39 40 63 106
198
BIOMEDICAL APPLICATION,
15 193
BIOPOLYMER, 149 209
BIREFRINGENCE, 182 200 212
247
BISETHYLHEXYL PHTHALATE,
195
BISPHENOL A, 75 162 231
BISPHENOL A
POLYCARBONATE, 47 281
388
BLEND, 10 11 15 48 50 55 61 69
95 101 103 107 112 127 130
155 182 199 204 206 217 224
242 251 270 274 276 284 285
286 331 333 342 355 362 380
BLIND, 253
BLOCK COPOLYMER, 88 182
257 258 267 288 335 380
BLOW EXTRUSION, 228
BLOW MOULDING, 196 203 336
BLOWING AGENT, 19 24 39 69
83 118 127 166 186 192 196
204 228 232 237 260 262 268
275 280 338 348 357 383 395
402 404
BORNYL METHACRYLATE
COPOLYMER, 168
BOTTLE, 196 373 402
BUILDING APPLICATION, 260
BULK POLYMERISATION, 136
270
BUMPER, 166
BUSINESS MACHINE, 167
BUTADIENE-ACRYLONITRILE
COPOLYMER, 44 414
BUTADIENE-STYRENE
COPOLYMER, 205
BUTANE, 345 380
BUTANEDIOL, 35 248
BUTYL METHACRYLATE
COPOLYMER, 254
BUTYLENE COPOLYMER, 336
355
C
CABLE COVERING, 151
CABLE INSULATION, 143 153
336
CABLE TIE, 203
CALORIMETRY, 5 53 84 86 111
365
CAPACITY, 143 151 336 343 355
376
CAPROLACTAM, 174 175
CAPROLACTONE, 18
CAPROLACTONE COPOLYMER,
57 415
CAPSULE, 70 193
CAR, 166 192
CARBOCATIONIC
POLYMERISATION, 400
CARBON FIBRE-REINFORCED
PLASTIC, 260
CARBON MONOXIDE, 172 205
CARBON TETRACHLORIDE, 409
CATALASE, 210
CATALYSIS, 336 355 376
CATALYST, 5 18 20 44 125 128
177 279 298 336 349 353 355
369 391
CATALYTIC DEGRADATION, 109
CATHETER, 195
CATIONIC POLYMERISATION,
256 299 353 387 400
CAVITY PRESSURE, 192
CAVITY TRANSFER MIXER, 204
260
Subject Index
126
© Copyright 2004 Rapra Technology Limited
CELL COLLAPSE, 319
CELL DENSITY, 22 26 31 32 116
127 249 303 319 348
CELL GROWTH, 4 22 26 167 192
394
CELL MORPHOLOGY, 22 26 31 32
CELL SIZE, 26 31 32 95 97 116
144 166 167 196 229 232 249
276 303 319 338 348 383 388
394 404
CELL STRUCTURE, 4 22 26 29
31 32 116 144 196 229 268 333
338 413
CELLULOSE, 209 320 396 407
CELLULOSE ACETATE, 356
CELLULOSE ACETATE
BUTYRATE, 374 407
CEMENT KILN, 102
CFC, 218 347
CFC FREE, 377
CFC REPLACEMENT, 193 310
CHAIN TRANSFER, 9 122 135
347 400
CHAIN TRANSFER AGENT, 9
28 390
CHARACTERISATION, 5 16 19
20 34 35 53 55 59 61 83 84 92
93 95 103 124 125 183 233 258
289 327 393 411
CHEMICAL MODIFICATION, 43
44 63 83 84 95 109 162 171 197
248 259 270 279 301 350 364
402
CHEMICAL PLANT, 332
CHEMICAL RECYCLING, 38 102
171 172 189 197 248 271 277
334
CHEMICAL SENSOR, 216 225
CHEMICAL STRUCTURE, 2 3 5
15 35 45 51 52 57 59 77 92 106
119 125 128 157 163 177 190
213 239 240 256 258 267 295
315 336 341 349 355 359
CHEMICAL VAPOUR
DEPOSITION, 180
CHLORODIFLUOROMETHANE,
16 27 380 405
CHLOROFLUOROCARBON, 218
347
CHLOROFLUORO-
HYDROCARBON, 204 237 280
CHLOROFORM, 165
CHLOROTRIFLUOROETHYLENE
COPOLYMER, 148
CHLOROTRIFLUOROMETHANE,
240
CHLOROTRIMETHYLPENTANE,
400
CHROMATOGRAPHY, 1 3 5 16
17 18 20 27 34 35 36 37 51 52
73 76 84 85 86 100 110 111 119
124 125 128 135 136 146 157
161 171 174 190 195 205 232
234 238 239 248 250 256 261
267 271 273 295 311 314 326
327 379
CIGARETTE, 396
CLAMP FORCE, 42 166 167 192
CLAMPING UNIT, 178
CLAY, 4 22 32 33 53 69 78 116
CLEANING, 18 117 360
CLOSED CELL, 42 83 116 250
276 331
CLOUD POINT, 137 155 173 240
289 335 398 405
COALESCENCE, 217 268 278
COATED FABRIC, 243
COATING, 46 115 154 194 198
211 225 235 236 244 254 269
270 278 300 302 322 336 344
403 407 416
COCATALYST, 336 355 376
COINJECTION, 29 167
COLLOID, 157 267
COLLOIDAL STABILITY, 28 297
COMMERCIAL INFORMATION,
153 343 355 376 416
COMPACT DISC, 286
COMPATIBILITY, 182 212 284
COMPOSITE, 12 22 30 32 40 58
64 65 69 76 78 102 108 116 133
172 187 201 260 296 313 333
349 364 369 386 402
COMPOSITION, 11 22 30 36 62
78 98 103 127 137 202 217 277
291 372
COMPOUNDING, 12 217 251
COMPRESSION MOULDING,
19 65
COMPUTER SIMULATION, 40
114 388
CONCENTRATION
DEPENDENCE, 11 20 21 22
78 257
CONDENSATION
POLYMERISATION, 191 264
270 279
CONDUCTIVE FIBRE, 209
CONDUCTIVE POLYMER, 63
350
CONFOCAL LASER SCANNING
MICROSCOPY, 134
CONSTRAINED GEOMETRY
CATALYST, 336 355
CONTAMINANT, 373 396
CONTAMINATION, 250 406
CONTINUOUS, 89 117 127 222
274 332 356
CONTINUOUS
POLYMERISATION, 89 122
145 151 168 401
CONTINUOUS STIRRED TANK
REACTOR, 122
CONTROLLED-RELEASE, 99
106 193 258 386
CONVERSION, 7 11 111 197 222
271 320 400
COOLING, 96 166 192 204 237
348 391
COPOLYMER COMPOSITION,
20 60 67 91 148 377 388
CORE, 394 395
CORE-SHELL, 181
COSMETICS, 166
COSOLVENT, 43 68 70 88 128 193
COST, 42 64 144 167 192 203 204
209 253 259 260 286 339 371
376 403
COUNTER-ROTATING
EXTRUDER, 373
CRACKING, 163 261 336
CRITICAL POINT, 170 248 411
CRITICAL PRESSURE, 275 348
408
CRITICAL SOLUTION
TEMPERATURE, 155 405
CRITICAL TEMPERATURE, 175
275 320
CROSSLINK, 160 226 402
CROSSLINK DENSITY, 45 119
CROSSLINKED, 111 149 170 205
263 408
CROSSLINKING, 58 92 111 131
170 216 230
CRYSTALLINITY, 23 54 61 71 84
90 91 104 127 183 185 200 208
247 252 258 273 281 287 290
336 376 379 388 415
CRYSTALLISATION, 33 47 48 63
64 80 104 170 206 231 245 273
281 283 314 345 365 415
CURING, 216 269 407
CURING AGENT, 45 119 131 165
331
CYCLE TIME, 42 64 166 167 192
203
CYCLOHEXANONE OXIME, 175
CYCLOHEXENE OXIDE, 309
D
DEBROMINATION, 162
DECHLORINATION, 109
DECOMPOSITION, 38 96 160 162
Subject Index
© Copyright 2004 Rapra Technology Limited
127
172 174 175 204 259 293 332
349 368
DECOMPOSITION PRODUCT, 37
160 161 162 163 164 259 265
277
DECOMPRESSION, 117 385 392
407 414
DEGRADABLE, 12 125 210 268
DEGRADATION, 10 13 34 35 88
98 109 110 138 171 197 205
261 293 317 318 363 402
DEGRADATION PRODUCT, 17
138 197 271 293 320
DEGREE OF POLYMERISATION,
11 378 387 389 390 392 393
398 400 401
DEGREE OF SWELLING, 66 152
219
DEMIXING, 378 405
DEMOULDING, 166
DENSIFICATION, 319
DENSITY, 24 49 66 88 95 97 110
116 164 170 192 193 197 218
237 240 255 260 336 338 361
378 381 383 388 394 395 402
404 406 411 412
DEPOLYMERISATION, 17 34 35
73 88 171 197 205 248 265 277
349 402
DEPRESSURISED, 140 193 221
278 338
DESIGN, 41 64 90 97 178 192 215
322 357 376
DESORPTION, 1 14 61 117 184
388 414
DETERGENT, 373 401
DEVOLATILISATION, 242 351
DEVULCANISATION, 2 45 119
165
DIAMINOTOLUENE, 343
DICHLOROMETHANE, 5 106
DIE, 72 201 202 260 268 333 339
DIE DESIGN, 196
DIELECTRIC CONSTANT, 83 151
193 388
DIETHYL
PEROXYDICARBONATE, 89
122 135 222
DIETHYLHEXYL PHTHALATE,
195
DIFFERENTIAL THERMAL
ANALYSIS, 5 19 23 47 51 53
55 61 66 71 80 81 84 90 107
112 119 121 125 158 183 212
239 273 314 316 379 398
DIFFRACTION, 19 23 53 54 61 69
76 80
DIFFUSION, 14 51 75 88 90 92 99
172 174 175 204 259 293 332
349 368
DECOMPOSITION PRODUCT, 37
160 161 162 163 164 259 265
277
DECOMPRESSION, 117 385 392
407 414
DEGRADABLE, 12 125 210 268
DEGRADATION, 10 13 34 35 88
98 109 110 138 171 197 205
261 293 317 318 363 402
DEGRADATION PRODUCT, 17
138 197 271 293 320
DEGREE OF POLYMERISATION,
11 378 387 389 390 392 393
398 400 401
DEGREE OF SWELLING, 66 152
219
DEMIXING, 378 405
DEMOULDING, 166
DENSIFICATION, 319
DENSITY, 24 49 66 88 95 97 110
116 164 170 192 193 197 218
237 240 255 260 336 338 361
378 381 383 388 394 395 402
404 406 411 412
DEPOLYMERISATION, 17 34 35
73 88 171 197 205 248 265 277
349 402
DEPRESSURISED, 140 193 221
278 338
DESIGN, 41 64 90 97 178 192 215
322 357 376
DESORPTION, 1 14 61 117 184
388 414
DETERGENT, 373 401
DEVOLATILISATION, 242 351
DEVULCANISATION, 2 45 119
165
DIAMINOTOLUENE, 343
DICHLOROMETHANE, 5 106
DIE, 72 201 202 260 268 333 339
DIE DESIGN, 196
DIELECTRIC CONSTANT, 83 151
193 388
DIETHYL
PEROXYDICARBONATE, 89
122 135 222
DIETHYLHEXYL PHTHALATE,
195
DIFFERENTIAL THERMAL
ANALYSIS, 5 19 23 47 51 53
55 61 66 71 80 81 84 90 107
112 119 121 125 158 183 212
239 273 314 316 379 398
DIFFRACTION, 19 23 53 54 61 69
76 80
DIFFUSION, 14 51 75 88 90 92 99
117 139 152 159 164 165 182
183 186 192 193 200 212 214
219 220 247 268 316 337 388
404 414
DIFFUSIVITY, 14 88 92 95 337
DIFLUOROETHANE, 141 282
DILATION, 66 90 414
DILUENT, 88 263 336 376 383
391 407 411 412
DIMENSIONAL STABILITY, 24
144 167 192 286 375
DIMETHYL ACRYLAMIDE
COPOLYMER, 96
DIMETHYL ETHER, 156
DIMETHYL FORMAMIDE, 54
DIMETHYL SILOXANE
COPOLYMER, 257
DIMETHYL TEREPHTHALATE,
17 34 35 171 197 248 265 368
DIMETHYLACRYLAMIDE
COPOLYMER, 96
DIPHENYL DISULFIDE, 119 165
DIPHENYL ETHER, 38
DISPERSE DYE, 176
DISPERSE PHASE, 242 333
DISPERSE RED 1, 214
DISPERSION, 12 43 49 68 131
187 193 199 217 321 324
DISPERSION
COPOLYMERISATION, 96
DISPERSION
POLYMERISATION, 7 28 59
67 86 88 96 111 147 157 181
223 233 246 255 266 267 270
278 288 289 291 297 307 323
352 353 354
DISSOLUTION, 44 164 242 268
292 348 380
DISSOLVING, 141 333
DIVINYL BENZENE, 131
DOMESTIC APPLIANCE, 166
DOOR HANDLE, 286
DOPING, 108 350 373
DRAWING, 71 104 208 252 287
315
DRUG DELIVERY, 106 193 258
386
DWELL TIME, 122
DYE, 176 179 200 212 214 220
227 247 315 337 346 399
DYEING, 23 176 200 209 212 270
315 316 329 337
E
ELASTIC MODULUS, 107 130
230 336 375
ELASTIC PROPERTIES, 141 142
316
ELASTOMER, 2 28 44 45 64 68 82
90 92 115 119 130 137 165 166
187 192 199 203 204 205 216
225 237 294 299 313 321 323
324 325 326 327 330 331 332
334 344 351 353 355 360 361
366 367 371 372 377 378 380
385 387 388 392 397 401
ELECTRICAL APPLICATION, 64
166 187
ELECTRICAL CONDUCTIVITY,
58 63 93 108 187 350
ELECTRICAL PROPERTIES, 63
108 187 193 350 388
ELECTROCHEMICAL
POLYMERISATION, 93
ELECTRON MICROGRAPH, 111
127 213
ELECTRON MICROSCOPY, 4 19
23 29 55 83 93 130 150 170 173
183 184 232 233 294 296
ELECTRONIC APPLICATION,
166 180 192 382
ELONGATION, 143 151 250 375
EMISSION, 344 407
EMISSION CONTROL, 347
EMULSION, 115 134 269 304
EMULSION POLYMERISATION,
49 88 134 150 155 270 329 353
ENCAPSULATION, 29 193 313
370
END GROUP, 28 84 138 213
ENERGY CONSERVATION, 181
259
ENERGY SAVING, 167
ENGINEERING APPLICATION,
42 88 166 192 204 221 260
ENVIRONMENT, 88 102 181 188
204 254 269 308 311 318 325
344 349 368 369 397 402 403
407
ENVIRONMENTALLY
FRIENDLY, 18 115 203 211 329
343 358 371
ENZYME, 18 99 209
EPDM, 331 334 355
EPOXY NOVOLAC RESIN, 413
EPOXY RESIN, 73 102 162 382
402 407 412
EPSILON CAPROLACTAM, 174
175
EPSILON-CAPROLACTONE, 18
EQUIPMENT, 25 222 397 416
ETHANOL, 70 80 187 190 220
ETHYL METHACRYLATE
COPOLYMER, 239
ETHYLBENZENE, 205
Subject Index
128
© Copyright 2004 Rapra Technology Limited
ETHYLENE, 5 393
ETHYLENE-BUTYLENE
COPOLYMER, 336 355
ETHYLENE COPOLYMER, 336
355
ETHYLENE GLYCOL, 34 60 79
138 171 197 265 349 368 411
ETHYLENE-HEXENE
COPOLYMER, 336 355
ETHYLENE-MALEIC
ANHYDRIDE COPOLYMER,
11
ETHYLENE-METHYL
ACRYLATE COPOLYMER,
199
ETHYLENE-OCTENE
COPOLYMER, 355
ETHYLENE OXIDE, 279
ETHYLENE-PROPYLENE
COPOLYMER, 26 355
ETHYLENE-PROPYLENE-
DIENE TERPOLYMER, 331
334 355
ETHYLENE-STYRENE
COPOLYMER, 355
ETHYLENE-VINYL ALCOHOL
COPOLYMER, 402
EXCLUSION
CHROMATOGRAPHY, 52 84
136 146 190 232 256 314 327
EXFOLIATION, 32
EXPANSION, 70 90 154 193 278
356
EXTRACTION, 1 56 80 121 193
227 241 270 279 300 344 364
370 372 409
EXTRUDER, 2 12 26 79 123 127
199 201 204 217 228 242 260
274 284 285 333 339 357
EXTRUSION, 2 12 26 69 72 103
105 113 114 123 127 142 143
196 199 201 202 203 204 217
218 228 237 242 245 250 251
260 262 268 274 284 285 333
336 339 404
EXTRUSION BLOW
MOULDING, 196
EXTRUSION BLOWING, 228
EXTRUSION COMPOUNDING,
217
EXTRUSION MIXING, 103 199
242 284 285
F
FABRIC, 179 209 227 243 315
FIBRE, 23 71 87 102 104 176 179
200 208 209 212 227 230 247
252 287 315 316 329 336 346
356 399 404
FIBRE-REINFORCED PLASTIC,
65 172 260
FIBRILLATION, 247
FILLER, 33 40 53 69 76 78 102
116 123 217
FILM, 14 44 46 79 143 151 180
183 194 219 220 254 278 336
337 344 404
FLAME PROOFING, 24 296 363
364
FLAME RETARDANCE, 24 296
363 364
FLAMMABILITY, 12 204
FLASHING, 292
FLEXURAL PROPERTIES, 12 65
143 199 237 336
FLOW, 114 116 192 262 348 378
FLOW RATE, 2 105 151
FLOW REACTOR, 161
FLUID, 88 136 193 321 337 344
FLUID BED, 193 336 376
FLUORINATED, 26 137 289
FLUORINATED ETHYLENE-
PROPYLENE COPOLYMER,
143 377
FLUOROACRYLATE POLYMER,
354
FLUOROELASTOMER, 137
FLUOROPOLYMER, 46 62 88 122
137 143 148 150 151 153 180
222 223 240 244 266 272 330
335 353 375 377 387
FOAM, 4 12 19 22 24 33 39 48 63
64 69 76 82 83 97 114 116 118
127 133 134 141 144 155 166
167 178 186 187 188 192 203
204 218 228 229 232 237 249
250 253 260 262 263 268 275
276 280 303 319 331 338 345
348 357 383 394 395 397 404
410 411 412 413
FOAMING, 22 41 95 127 142 204
338
FOAMING AGENT, 19 24 39 69
83 118 127 166 186 192 196
204 228 232 237 260 262 268
275 280 338 348 357
FOAMING TEMPERATURE, 127
FOURIER TRANSFORM
INFRARED SPECTROSCOPY,
2 10 23 34 35 55 92 98 125 150
160 175 180 213 214 219 248
283 294 339 377 385
FRACTIONATION, 119 234 270
290 314 327 362 379 393
FRACTURE MORPHOLOGY, 4 7
15 23 27 29 33 40 49 50 54 55
57 58 65 67 69 76 81 83 87 93
106 107 112 114 121 130 134
157 173 195 199 212 216 239
242 246 249 251 255 266 267
274 331 342 345 350 359
FREE RADICAL
COPOLYMERISATION, 96
168 377
FREE RADICAL
POLYMERISATION, 5 7 9 49
55 59 61 67 89 96 122 130 131
136 145 146 168 190 191 213
239 263 288 299 307 310 311
312 328 377 389 390
FREE VOLUME, 141 142 193 215
227 361 378
FREON, 411
FURNITURE, 166 407
G
GALACTOSIDASE, 210
GAS ABSORPTION, 22 385 408
GAS-ASSISTED, 166 192
GAS CHROMATOGRAPHY, 1 34
35 37 73 85 161 171 174 205
271 280
GAS DIFFUSION, 192 268 388
GAS INJECTION, 12 133 166 167
GAS INJECTION MOULDING,
166 192 286
GAS PERMEABILITY, 388 414
GAS-PHASE, 167 172 193 344 376
GAS PHASE POLYMERISATION,
67 336 355 391
GAS PRESSURE, 192 286
GAS SOLUBILITY, 169 335 366
388
GAS SORPTION, 366 385 388
GEL, 149 170 331 412 413
GEL PERMEATION
CHROMATOGRAPHY, 3 5 16
17 18 20 27 36 51 76 86 100
110 111 119 124 125 128 135
157 195 234 238 239 248 250
261 267 273 295 311 327 379
GEL SPINNING, 315 316
GLASS FIBRE-REINFORCED
PLASTIC, 64 102 260 349
GLASS TRANSITION
TEMPERATURE, 43 48 68 76
83 85 90 94 112 114 121 141
152 193 199 218 231 254 263
281 348 383 398 415
GLASSY, 206 214 341
GLYCIDYL METHACRYLATE,
111 168 173
Subject Index
© Copyright 2004 Rapra Technology Limited
129
GLYCOL COPOLYMER, 59
GLYCOLIDE COPOLYMER, 39
106 169 210 258
GRAVIMETRIC ANALYSIS, 7 14
53
H
HARDNESS, 25 151 203
HCFC, 204 237 280
HEAT DEGRADATION, 45 109
163 164 238 293 295 296 356
HEATING, 1 96 160 365
HELIUM, 297 354
HEPTAFLUOROPROPANE, 372
HEPTANE, 345
HETEROGENEOUS
POLYMERISATION, 49 193
HEXAFLUOROPROPYLENE
COPOLYMER, 46 91 240 377
HFA-134A, 141 282
HFC, 244 280 321
HIGH DENSITY
POLYETHYLENE, 33 88 204
237 260 261 314 336 355 373
376 381 393 406
HIGH PERFORMANCE LIQUID
CHROMATOGRAPHY, 59 161
171 174 295
HIGH PRESSURE, 132 155 158
172 182 208 248 252 259 332
334 366 405 414
HIGH TEMPERATURE, 151 172
203 248 259 332 334 376
HOMOGENEOUS, 122 222 270
321 345 353 380 395
HOT MELT ADHESIVE, 302
HOT WATER, 332
HOUSING, 203 286
HYDROCHLORO-
FLUOROCARBON, 204 237
280
HYDROFLUOROCARBON, 244
280 321
HYDROLYSIS, 124 162 174 259
320 363
HYDROLYTIC DEGRADATION,
37 161 162 259 293
HYDROPHILIC, 49 92 150 211
223 301
HYDROPHOBIC, 150 193 223 269
315
HYDROXYAPATITE, 40 210
HYDROXYBENZENE, 75 205 271
I
IMMISCIBLE, 15 127 242 380
IMPACT PROPERTIES, 12 31 32
131 199 224 336
IMPLANT, 40
IMPREGNATION, 48 55 61 108
112 132 193 206 214 219 220
224 245 269 270 344 399
IMPURITY, 360 373
INDOMETHACIN, 106 370
INFRARED SPECTRA, 3 10 23 61
80 92 107 126 132 138 171 191
213 283 294 341
INITIATOR, 10 16 21 27 28 40 49
54 55 60 61 86 87 88 89 92 96
100 107 111 120 122 126 131
135 145 157 207 213 222 224
230 239 256 299 307 310 330
INJECTION MOULD, 166 192
INJECTION MOULDED, 31 32
129
INJECTION MOULDING, 4 12
25 29 31 32 41 42 48 64 97 101
118 129 144 166 167 178 188
192 203 229 245 286 336
INJECTION MOULDING
MACHINE, 29 42 105 166 192
INJECTION PRESSURE, 42 166
167 192
INJECTION RATE, 70 260
INJECTION SPEED, 4 31 41 97
129 167
INSULATION, 83 143 153 260
INTEGRAL SKIN FOAM, 29 394
395
INTERACTION, 8 11 14 193 219
240 315 335 374 375 388
INTERCALATION, 33 53 78
ISOTACTIC, 10 36 331 336 345
355
ISOTHERM, 88 405 414
ISOTHERMAL, 316 392 393
K
KINETICS, 9 16 17 21 49 51 61
75 92 110 136 146 147 152 182
207 222 246 248 290 355
L
LACTIDE COPOLYMER, 39 106
169 210 258
LANGIVIN EQUATION, 17 61 66
72 85 92 98 101 110 134 152
193
LATICES, 139 155 211 233
LICENCE, 42 203 237
LINEAR LOW DENSITY
POLYETHYLENE, 88 170 183
185 237 336 355 376 393
LIQUID CARBON DIOXIDE, 43
49 68 176 223 264
LIQUID CHROMATOGRAPHY,
59 161 171 174 295 326
LIQUID CRYSTAL, 209
LITHOGRAPHY, 62 198 254 270
LIVING POLYMERISATION, 9 36
150 312
LOW DENSITY
POLYETHYLENE, 88 103 113
123 204 224 237 296 336 355
381 406
LOWER CRITICAL SOLUTION
TEMPERATURE, 155 405
M
MACHINERY, 12 29 42 79 105
127 144 166 178 188 192 201
217 228 260 274 285 332 333
339 357 373 406 416
MALEIC ANHYDRIDE
COPOLYMER, 10 98 116
MASS POLYMERISATION, 136
270
MASS SPECTRA, 1 37 174
MATERIAL REPLACEMENT, 82
88 181 204 269 310 329 344
402
MATRIX, 50 83 131 193 214 337
MEASUREMENT, 44 90 92 98 105
117 119 152 280 333 337 357
383
MECHANISM, 163 197 248 276
293 361
MEDICAL APPLICATION, 15 25
39 40 99 166 169 192 193 195
360 386
MEDIUM-DENSITY
POLYETHYLENE, 336
MELAMINE RESIN, 407
MELT, 10 33 79 140 141 237 268
282 351
MELT FLOW, 10 30 192
MELT FLOW INDEX, 167 222
MELT FLOW RATE, 98 143
MELT RHEOLOGY, 6 30 94 142
217
MELT STRENGTH, 204 228 260
MELT TEMPERATURE, 4 6 94 97
129 167 183 192 201 231 260
MELT VISCOSITY, 6 26 30 94 127
142 192 217 274 282 339 361
415
MELT VISCOSITY INDEX, 167
222
MELTING, 47 66 80 90 91 132 316
Subject Index
130
© Copyright 2004 Rapra Technology Limited
348
MELTING POINT, 116 151 158
281 377 379 393 398 415
MELTING TEMPERATURE, 23
66 91 248
MERCURY POROSIMETRY, 134
184
METALLOCENE, 170 336 355
METERING, 275 397
METHACRYLATE COPOLYMER,
59 62 67 136 168 223 254
METHACRYLIC ESTER
COPOLYMER, 59 62 67 136
168 223 254
METHANOL, 17 34 35 79 160 171
197 248 265 271 277 349 356
368
METHANOLYSIS, 171 197 248
METHYLBENZENE, 9 27 43 68
88 128 205
METHYL METHACRYLATE, 59
213
METHYL METHACRYLATE
COPOLYMER, 60 67 96 239
352 380 398 402 411
MICROCAPSULE, 70 193
MICROCELLULAR, 4 12 29 31 32
41 42 64 83 95 97 118 127 129
140 142 144 155 166 167 178
192 196 203 218 229 232 249
253 263 270 303 319 338 383
394 395 404 411 413
MICROEMULSION, 115 269 304
MICROENCAPSULATION, 313
370
MICROFIBRIL, 384
MICROLITHOGRAPHY, 62
MICROPARTICLE, 111 193 370
MICROPOROUS, 115 193
MICROSPHERE, 27 193 225 345
384
MICROSTRUCTURE, 19 65 97
107 128 129 156 177 221 250
283
MIRROR, 167 286
MISCIBILITY, 127 155 182 302
378
MIXER, 204 260 284
MIXING, 53 103 199 242 274 284
285 388 405
MODIFICATION, 41 84 263 270
301
MOLECULAR STRUCTURE, 2 3
5 15 35 45 51 52 57 59 77 92 96
106 119 125 126 128 157 163
177 190 213 239 240 256 258
267 290 295 315 336 341 349
355 359 379 388 400 402
MOLECULAR WEIGHT, 3 5 7 9
10 15 16 18 20 21 27 36 50 52
54 67 70 71 75 76 79 84 86 87
89 98 100 110 120 122 125 128
130 135 138 145 146 148 152
156 160 164 165 173 177 193
207 213 222 230 232 234 239
257 261 266 267 273 276 281
288 289 290 306 311 312 314
334 335 336 352 355 361 362
378 387 389 390 392 393 398
400 401 405
MOLECULAR WEIGHT
DISTRIBUTION, 27 89 110
120 122 128 135 139 146 238
250 257 276 314 328 336 355
376
MONOETHYLENE GLYCOL, 34
79 138 171 197 265 349
MONOMER, 17 38 61 89 92 111
136 213 349 350 369
MONOMER RECOVERY, 88 265
MONTMORILLONITE, 19 22 30
33 53 78
MORPHOLOGY, 4 7 15 23 27 29
33 40 49 50 54 55 57 58 65 67
69 76 78 81 83 87 93 103 106
107 111 112 114 121 127 130
134 140 154 155 157 170 173
177 183 184 185 195 199 212
213 216 217 239 242 246 249
251 255 266 267 274 283 285
287 331 333 342 345 350 359
370 374 377 384 390 398 411
413
MOULD, 166 192
MOULD RELEASE, 397
MOULD TEMPERATURE, 129
167
MOULDING, 19 65 167 203 237
295 318
MOULDING PRESSURE, 166 192
MULTI-COMPONENT, 155 166
182
MULTI-MATERIAL MOULDING,
166
MULTIPLE INJECTION
MOULDING, 166
N
NANOCOMPOSITE, 4 12 19 22 30
32 33 53 78 116 133 296
NANOPARTICLE, 4 30 33 46 49
198
NANOSTRUCTURE, 50 63
NAPHTHALENE, 88 315 373 405
NAPHTHALENEDICARBOXYLIC
ACID, 368
NATURAL RUBBER, 119
NBR, 44
NITRILE RUBBER, 44 414
NITROGEN, 32 51 75 155 166 167
184 192 203 229 237 348 363
NON-POLAR, 43 68
NON-POROUS, 394 395
NOZZLE, 41 166 292
NUCLEAR MAGNETIC
RESONANCE, 5 20 27 36 45
57 59 119 124 125 126 128 145
157 160 177 239 241 256 258
261 298 379
NUCLEATION, 4 19 26 49 167
192 196 221 246 276 338 383
395
NYLON, 10 32 55 88 161 166 167
208 264 292 320
NYLON-11, 186
NYLON-12,12, 55
NYLON-6, 4 10 11 61 174 175
NYLON-6-6, 12 37 65 203 208 252
375
O
OFFICE EQUIPMENT, 166 192
OIL RESISTANCE, 43 68 243
OPEN-CELLED, 345
OPTICAL MICROSCOPY, 61 65
97 152 183 212
OPTIMISATION, 38 67 92 111 370
376
ORTHOPAEDIC APPLICATION,
263
P
PACKAGING, 1 166 237 260 368
381 402
PARTICLE FORMATION, 147 246
270
PARTICLE SIZE, 28 76 88 103 106
111 121 154 157 193 213 223
246 255 257 266 267 292 297
331 354 370 390
PARTICLE SIZE DISTRIBUTION,
70 147 154 173 292 297 354
370
PATENT, 25 42 237 336 412
PENTANE, 302 405
PEROXIDE, 88 98 122 222 331
PHARMACEUTICAL
APPLICATION, 70 99 106 169
193 210 324 360 370
PHASE BEHAVIOUR, 8 49 96 155
156 182 199 240 244 337 393
Subject Index
© Copyright 2004 Rapra Technology Limited
131
405
PHASE SEPARATION, 50 63 134
241 249 331 394
PHASE STRUCTURE, 103 112
199
PHENOL, 75 205 271
PHENOLIC RESIN, 102 172 271
295 317 318 407
PHOTOLITHOGRAPHY, 62 254
PHOTOPOLYMERISATION, 40
PHOTORESIST, 62 198 254
PIPE, 237 336
PLASTICISATION, 6 26 66 81 85
90 91 117 142 158 166 193 206
208 212 215 220 284 305 341
347 374 385 395 414
PLASTICISER, 91 117 142 185
186 215 218 270 305 339 340
355 386
PLASTICISING, 121 178
PLASTICS WASTE, 74 172 402
POLAR, 43 68
POLARITY, 126 128 223 370 374
388
POLYACRYLAMIDE, 134
POLYACRYLATE, 8 88 136 211
266 278 335
POLYACRYLIC ACID, 55 61 193
311 390
POLYACRYLONITRILE, 54 87
120 126 267 384
POLYAMIDE, 10 32 55 88 161 166
167 208 229 264 292 320 375
POLYAMIDE-11, 186
POLYAMIDE-12,12, 55
POLYAMIDE-6, 4 10 11 61 174
175
POLYAMIDE-6,6, 12 37 65 252
375
POLYARAMIDE, 346
POLYARYL KETONE, 346
POLYARYLATE, 219
POLYARYLETHERKETONE, 260
POLYARYLSULFIDE, 346
POLYBISETHOXYMETHYLOXE
TANE, 387
POLYBUTADIENE, 92 137 140
POLYBUTYL ACRYLATE, 306
POLYBUTYL METHACRYLATE,
152
POLYBUTYLENE, 400
POLYBUTYLENE SUCCINATE,
268
POLYBUTYLENE
TEREPHTHALATE, 35 84 248
POLYCAPROAMIDE, 4 10 11 61
POLYCAPROLACTAM, 4 10 11
61
405
PHASE SEPARATION, 50 63 134
241 249 331 394
PHASE STRUCTURE, 103 112
199
PHENOL, 75 205 271
PHENOLIC RESIN, 102 172 271
295 317 318 407
PHOTOLITHOGRAPHY, 62 254
PHOTOPOLYMERISATION, 40
PHOTORESIST, 62 198 254
PIPE, 237 336
PLASTICISATION, 6 26 66 81 85
90 91 117 142 158 166 193 206
208 212 215 220 284 305 341
347 374 385 395 414
PLASTICISER, 91 117 142 185
186 215 218 270 305 339 340
355 386
PLASTICISING, 121 178
PLASTICS WASTE, 74 172 402
POLAR, 43 68
POLARITY, 126 128 223 370 374
388
POLYACRYLAMIDE, 134
POLYACRYLATE, 8 88 136 211
266 278 335
POLYACRYLIC ACID, 55 61 193
311 390
POLYACRYLONITRILE, 54 87
120 126 267 384
POLYAMIDE, 10 32 55 88 161 166
167 208 229 264 292 320 375
POLYAMIDE-11, 186
POLYAMIDE-12,12, 55
POLYAMIDE-6, 4 10 11 61 174
175
POLYAMIDE-6,6, 12 37 65 252
375
POLYARAMIDE, 346
POLYARYL KETONE, 346
POLYARYLATE, 219
POLYARYLETHERKETONE, 260
POLYARYLSULFIDE, 346
POLYBISETHOXYMETHYLOXE
TANE, 387
POLYBUTADIENE, 92 137 140
POLYBUTYL ACRYLATE, 306
POLYBUTYL METHACRYLATE,
152
POLYBUTYLENE, 400
POLYBUTYLENE SUCCINATE,
268
POLYBUTYLENE
TEREPHTHALATE, 35 84 248
POLYCAPROAMIDE, 4 10 11 61
POLYCAPROLACTAM, 4 10 11
61
POLYCAPROLACTONE, 18 193
207 256 398 405
POLYCARBONATE, 51 52 74 75
85 88 97 110 117 129 166 221
228 231 260 286 293 309 318
374 388 404
POLYCONDENSATION, 191 264
270 279
POLYCYANOACRYLATE, 382
POLYDIHYDROPERFLUOROOC
TYL ACRYLATE, 46 266 354
POLYDIMETHYLAMINOETHYL
METHACRYLATE, 67
POLYDIMETHYLPHENYLENE
OXIDE, 298
POLYDIMETHYLSILOXANE,
7 28 117 141 216 225 234 246
278 327 361 378 393 408
POLYDIMETHYLSILOXANE
METHACRYLATE, 60 111 147
POLYDISPERSITY, 5 16 18 20 122
135 232 276 327 394 401 405
POLYEPOXIDE, 73 102 162
POLYETHER KETONE, 38 73
POLYETHER URETHANE, 366
POLYETHER-ETHERKETONE,
38 80 83 228 237 365
POLYETHERIMIDE, 374
POLYETHYL ACRYLATE, 306
POLYETHYL HEXYL
ACRYLATE, 211 278 306
POLYETHYL METHACRYLATE,
398
POLYETHYLACRYLAMIDE, 150
POLYETHYLENE, 5 33 50 56 71
88 103 104 112 113 123 149
160 163 164 166 170 183 185
201 204 208 224 230 237 242
260 261 285 296 314 315 316
320 333 336 355 373 375 376
381 391 393 402 405 406
POLYETHYLENE GLYCOL, 70
POLYETHYLENE GLYCOL
METHACRYLATE, 60
POLYETHYLENE
NAPHTHALENE
DICARBOXYLATE, 277
POLYETHYLENE OXIDE, 53 158
POLYETHYLENE
TEREPHTHALATE, 23 34 79
138 171 176 197 200 208 209
220 221 227 247 250 265 279
287 300 315 320 349 368 369
374 375 381 399 402 406
POLYETHYLHEXYL
ACRYLATE, 211 278 306
POLYFLUOROETHYLENE, 26 88
151 310
POLYGLYCIDYL
METHACRYLATE, 111 181
POLYIMIDE, 359
POLYIMINOCARBONATE, 402
POLYISOBORNYL
METHACRYLATE, 60
POLYISOPRENE, 45 137 165 409
POLYKETONE, 80
POLYLACTIC ACID, 12 193 398
POLYLACTIDE, 16 27 57 76 99
210 370
POLYMER CRACKING, 334
POLYMERIC STABILISER, 7 28
60 67 147 213 289 354
POLYMERIC SURFACTANT, 49
88 96 266 278 352
POLYMERISATION CATALYST,
18 128 177 279 298 336 353
355
POLYMERISATION INITIATOR,
10 21 27 28 40 54 55 60 61 86
87 88 89 96 100 107 111 120
122 126 135 145 157 207 213
222 224 239 256 299 310 330
400
POLYMERISATION KINETICS, 9
16 21 49 51 75 136 146 147 207
222 246 355
POLYMERISATION
MECHANISM, 18 27 40 49 51
54 57 69 86 87 92 100 139 146
157 190 239 255 256 267 273
298 308 328 336
POLYMERISATION PRESSURE,
7 67 96 135 266 321 336 401
POLYMERISATION RATE, 9 21
75 122 177 222
POLYMERISATION REACTOR, 3
122 336 355 411
POLYMERISATION
TEMPERATURE, 7 96 122 135
224 336 400 401
POLYMERISATION TIME, 10 67
75 111 120 147 246
POLYMERISATION YIELD, 3 18
POLYMETHACRYLATE, 40 50 67
77 136 147 223 382
POLYMETHYL ACRYLATE, 8
306
POLYMETHYL
MERCAPTOACETAMIDE,
155
POLYMETHYL
METHACRYLATE, 21 28 36
58 59 65 70 78 85 86 88 90 106
112 117 127 132 139 141 147
152 155 157 159 181 199 213
214 217 233 246 251 255 274
Subject Index
132
© Copyright 2004 Rapra Technology Limited
284 288 297 304 307 328 337
341 342 352 354 374 379 383
394 395 398 405
POLYNORBORNENE, 128
POLYOLEFIN, 7 9 10 13 14 95
107 116 149 204 208 212 224
276 280 282 290 315 316 320
336 344 345 355 375 376 381
391 400
POLYOLEFIN ELASTOMER, 355
POLYORGANOSILOXANE, 7 28
58 88 115 117 216 225 226 234
246 278
POLYOXETANE, 299 387
POLYOXYETHYLENE, 53
POLYOXYMETHYLENE, 375
POLYPHENYLACETYLENE, 177
POLYPHENYLENE OXIDE, 117
167 228 298 374
POLYPHENYLENE SULFIDE,
237 260
POLYPHENYLOXAZOLINE, 256
POLYPHENYLSULFONE, 228
POLYPHOSPHAZENE, 335
POLYPROPYLENE, 10 12 13 64
88 98 101 105 107 116 131 166
167 176 203 204 212 228 237
260 315 316 331 336 345 355
375 376 381 391 402 406
POLYPYRROLE, 58 93 108 187
350
POLYSILOXANE, 7 28 49 88 96
115 216 226 335
POLYSTYRENE, 7 9 14 19 26 29
30 41 58 61 69 72 85 88 90 95
103 107 108 114 127 130 131
141 142 146 155 166 167 181
182 190 199 202 204 217 224
232 233 237 238 242 251 260
274 276 280 282 283 284 285
289 312 319 333 336 338 340
342 355 357 374 384 402 404
POLYSULFONE, 374
POLYTETRAFLUORO-
ETHYLENE, 26 88 151 310 367
389
POLYTRIFLUOROCHLOROETH
YLENE, 58
POLYTRIMETHYLENE
TEREPHTHALATE, 17 33
POLYTRIMETHYLOLPROPANE
TRIMETHACRYLATE, 184
POLYURETHANE, 24 187 259
303 344 374 382 397 402 407
410
POLYURETHANE ELASTOMER,
385
POLYVINYL ACETATE, 8 291
POLYVINYL ALCOHOL, 358
POLYVINYL CHLORIDE, 88 100
117 195 237 367 374 381 402
404 406
POLYVINYL CYANIDE, 54 87 267
POLYVINYL ETHER, 387
POLYVINYL ISOBUTYL ETHER,
387
POLYVINYL PYRROLIDONE, 49
181 257 266
POLYVINYL
TRIFLUOROACETATE, 358
POLYVINYLBENZENE, 26 30
41 85 103 131 141 142 155 182
199 202 204 217 242 274
POLYVINYLIDENE FLUORIDE,
66 81 88 89 90 91 122 127 135
155 194 222 240 375
POLYVINYLPYRROLIDONE, 49
181 257 266
PORE SIZE, 77 134 170 263 345
PORE STRUCTURE, 149 319
POROSITY, 4 39 40 76 77 89 115
134 149 166 170 263 269 276
345 413
POROUS, 58 63 99 115 184 193
198 249 263 270
POWDER COATING, 115 269 300
322 407
PRECIPITATION, 88 193 292 324
384
PRECIPITATION
POLYMERISATION, 54 87 89
120 122 126 135 145 222 270
323 353 390
PRESSURE, 5 13 14 16 17 44 47
66 70 84 88 89 90 91 92 95 111
119 120 121 128 138 140 142
149 152 156 158 159 173 182
192 193 200 220 221 224 227
237 240 247 248 249 268 275
280 282 286 292 315 316 335
337 344 348 350 351 362 370
374 375 378 380 392 393 394
395 396 404 405 407 409
PRESSURE CONTROL, 159 166
167 192 275 286
PRESSURE DEPENDENCE, 22 31
129 137 201 202 252 316 337
385
PRESSURE DROP, 41 201 202
PRESSURE-SENSITIVE
ADHESIVE, 43 68
PRESSURISATION, 275 278
PROCESS CAPABILITY, 31 32 376
PROCESSABILITY, 6 26 62 79 94
203 347
PROCESSING, 2 4 19 31 39 47 48
62 79 97 99 104 112 115 116
127 143 165 178 182 195 198
200 201 208 209 218 223 270
271 320 329 333 353 356 373
376 395 403 407
PROOFED FABRIC, 243
PROPANE, 88 149 170 314 331
336 345 393 405 411
PROPYLENE COPOLYMER, 10
98 116 355
PROPYLENE-ETHYLENE
COPOLYMER, 26
PROTEIN, 99 193 370
PULSED LASER
POLYMERISATION, 136 328
PURIFICATION, 79 218 270 373
392 409
PYROLYSIS, 102 162 320
R
RADICAL POLYMERISATION, 5
7 9 49 55 59 61 67 89 122 130
131 145 146 190 191 222 223
257 263 276 299 328 353
RATE CONSTANT, 51 136 175
197
RATE OF POLYMERISATION, 9
21 75 122 177 222
REACTION CONDITIONS, 17 18
61 89 92 98 111 128 138 197
213 248 376
REACTION INJECTION
MOULDING, 204 410
REACTION MECHANISM, 17 18
35 84 92 197 248 293
REACTION PRESSURE, 111 173
248 376
REACTION RATE, 21 197 248
REACTION TEMPERATURE, 17
174 248 376
REACTION TIME, 111 138 174
248
REACTIVE EXTRUSION, 11 98
REACTOR, 3 89 122 197 376 391
RECIPROCATING SCREW, 178
RECLAIM, 109 294 302 318 363
364 381
RECLAIMING, 45 119 165 189
277 349 396 402 406
RECLAMATION, 189 277 402
RECYCLING, 12 18 38 52 56 73
74 79 88 102 109 160 161 171
172 189 195 197 226 248 250
259 271 277 292 294 302 318
320 332 334 343 349 362 363
364 368 371 373 381 402 410
REINFORCED PLASTIC, 30 31
Subject Index
© Copyright 2004 Rapra Technology Limited
133
40 64 65 69 76 78 102 172 187
260 333 349 369 386 402
RHEOLOGICAL PROPERTIES, 2
6 10 26 30 48 54 72 78 79 80 87
88 94 98 101 105 113 114 116
123 127 141 142 166 167 186
191 192 193 201 202 206 215
217 221 242 250 251 262 278
282 284 285 305 333 340 342
357 361
RIBONUCLEASE, 99 210
RING-OPENING
POLYMERISATION, 16 18 27
128 174 207 299 355 387 415
RUBBER, 2 28 44 45 68 82 90 92
115 119 130 137 165 166 187
192 199 203 205 216 225 237
294 313 321 323 324 325 326
327 330 331 332 334 344 351
353 355 360 361 366 367 371
372 377 378 380 385 387 388
392 397 401 408 409 410 414
S
SATURATED POLYESTER, 179
200 208 209 210 220 221 268
279 320 375
SCANNING ELECTRON
MICROSCOPY, 4 15 19 23 27
29 39 40 46 48 49 55 57 59 69
77 83 87 93 97 106 111 116 121
127 130 134 150 155 157 170
173 181 183 184 186 194 195
213 232 233 239 246 255 267
274 294 296 331 333 338 350
359 377 383 384 390 413
SCRAP TYRES, 2 294 362
SCREW DESIGN, 196
SCREW EXTRUDER, 26 123 204
217 242
SCREW PLASTICISATION, 166
SEEDED POLYMERISATION,
270
SEMI-CONTINUOUS
POLYMERISATION, 401
SEMICRYSTALLINE, 90 91 127
149 183 244 336 384
SEPARATION, 36 56 259 279 292
367 372 381 402 406
SEQUENTIAL INJECTION
MOULDING, 166
SHEAR FLOW, 105 202
SHEAR PROPERTIES, 105 215
361
SHEAR RATE, 6 72 105 127 141
142 282 305 348 361
SHOT SIZE, 4 97 129
SILICONE COPOLYMER, 291
SILICONE ELASTOMER, 130 216
408
SILICONE POLYMER, 7 28 88 96
115 216 226 335
SIMULATION, 8 17 197 276 388
SINGLE SCREW EXTRUDER, 26
204 242 339 357
SIZE EXCLUSION
CHROMATOGRAPHY, 52 84
136 146 190 232 256 314 327
SKIN FORMATION, 394 395
SKIN-CORE, 29
SKIN-INSERT MOULDING, 167
SLIT DIE, 72 201 202 339
SLIT-DIE RHEOMETER, 215
SLOT DIE, 72 201 202 339
SLURRY POLYMERISATION,
376 391
SMALL ANGLE NEUTRON
SCATTERING, 156 182
SOLID STATE
POLYMERISATION, 75 231
273 281
SOLUBILITY, 3 8 44 48 51 52 57
62 70 88 90 92 95 100 113 114
127 128 137 148 150 167 169
173 176 179 180 187 191 193
194 216 218 221 223 231 234
240 244 251 258 260 280 291
297 304 306 309 335 336 342
343 357 374 375 404 405 414
SOLUBILITY PARAMETER, 88
335 354 388
SOLUTION, 99 108 113 132 137
182 192 193 219 292 331 333
345 378 380 395 405
SOLUTION POLYMERISATION,
21 88 125 136 148 190 218 308
309 336 353 355
SOLVATION, 8 88 176 218
SOLVENT EMISSION, 403 407
SOLVENT EVAPORATION, 380
SOLVENT EXTRACTION, 56 193
370 409
SOLVENT-FREE, 214 236 407
SORPTION, 14 55 61 117 132 158
182 218 220 242 388 414
SPECTRA, 5 34 35 111
SPECTROSCOPY, 1 2 3 5 10 23 34
35 37 55 59 92 93 98 125 132
160 174 182 213 214 235 248
337 339 341
SPHERE, 27 193 225 345
SPINNING, 87 200 230 247
SPRAY COATING, 403 407
SPRAYING, 384 407 416
STABILISER, 7 28 60 67 86 111
147 157 213 239 255 257 267
288 289 291 297 304 307 354
STATIC MIXER, 204 260
STEP-GROWTH
POLYMERISATION, 353
STEREOREGULARITY, 126 355
STIRRED TANK REACTOR, 89
STIRRING, 122 135 222
STRUCTURAL FOAM, 203
STYRENE, 61 172 205
STYRENE ACRYLONITRILE
COPOLYMER, 88 249
STYRENE-BUTADIENE-
STYRENE BLOCK
COPOLYMER, 90
STYRENE COPOLYMER, 168
257 267 355 380 398 415
STYRENE-MALEIC
ANHYDRIDE TERPOLYMER,
228 260
SUBCRITICAL, 110 293
SUBCRITICAL FLUID, 38 162
174 175 385
SUBLIMATION, 88 315
SUGAR COPOLYMER, 223
SUPERCONDENSING MODE,
336 355 391
SUPERCRITICAL SOLUTION, 26
31 32 62 73 78 105 137 154 189
192 193 196 225 331 356 398
SUPERCRITICAL SOLVENT, 8
72 88 125 137 177 193 201 202
207 235 265 281 291 331 349
358 371 377
SURFACE ACTIVE AGENT, 15 49
57 88 96 106 150 173 193 211
236 288 304 321 352
SURFACE FINISH, 12 42 166 167
192 262 286
SURFACE PROPERTIES, 23 46 77
92 93 177 195 359 413
SURFACE TENSION, 180 335 395
SURFACE TREATMENT, 25 63 92
236 316 359 403
SURFACTANT, 15 49 57 88 96
106 150 173 193 211 236 266
278 288 304
SURFACTANT FREE, 135 148 222
SURGICAL APPLICATION, 210
263
SUSPENSION, 106 193 211 278
SUSPENSION
POLYMERISATION, 57 88 100
184 336 355
SWELLING, 2 10 45 66 90 91 92
107 119 130 132 140 147 149
152 170 186 193 200 214 219
249 296 313 337 361 395 408
Subject Index
134
© Copyright 2004 Rapra Technology Limited
414
SWELLING AGENT, 55 61 130
131 193 224
SYNDIOSPECIFIC
POLYMERISATION, 355
SYNDIOTACTIC, 36 283 336 355
358
SYNTHESIS, 7 9 10 36 49 60 67
68 75 93 96 107 122 126 141
147 148 155 168 175 182 184
191 198 211 219 222 246 263
264 266 270 272 278 279 300
350 353 354 358 369 383 395
400 401 411 415
T
TACTICITY, 126 355
TANDEM EXTRUDER, 242
TELEPHONE, 166
TELEVISION, 166 286
TEMPERATURE CONTROL, 159
167 204 260
TEMPERATURE DEPENDENCE,
6 17 22 26 104 110 129 137 201
238 252 291 316 328 378 405
TENSILE PROPERTIES, 31 32 65
69 78 97 107 129 130 131 143
151 185 208 224 230 252 287
TEREPHTHALIC ACID, 279
TERPOLYMERISATION, 168
TETRAFLUOROETHANE, 141
282 372
TETRAFLUOROETHYLENE
COPOLYMER, 46 124 148 377
TETRAFLUOROETHYLENE-
HEXAFLUOROPROPYLENE
COPOLYMER, 143 377
TETRAHYDROFURAN, 54 128
TEXTILE, 243 399
THERMAL DEGRADATION, 45
109 163 164 238 293 295 296
356
THERMAL INSULATION, 83
THERMAL POLYMERISATION,
190 389
THERMAL PROPERTIES, 19 66
71 81 86 90 91 94 121 127 131
142 169 182 192 193 248 316
345 374 375 380 383
THERMOGRAVIMETRIC
ANALYSIS, 53 117 125 158 375
THERMOPLASTIC
ELASTOMER, 64 82 192 203
204 237 299 331 355
THICKNESS, 44 46 62 79 133 194
394
TOLUENE, 9 27 43 68 88 128 205
TOLUENE DIAMINE, 343
TRANSITION PHENOMENA, 6
30 94 217 228
TRANSMISSION ELECTRON
MICROSCOPY, 4 15 19 23 29
54 55 69 76 83 93 106 107 116
130 150 155 170 173 181 183
184 232 233 251 274 294 296
359
TRIFLUOROCHLOROETHYLENE
COPOLYMER, 148
TRIFLUOROMETHANE, 350
TRIMETHYLOL PROPANE, 263
TUBING, 143 151
TUBULAR REACTION, 336
TURBIDIMETRY, 147 246 255
TWIN-SCREW EXTRUDER, 2 79
199 217 242 274 284 285 333
373
TWO-MATERIAL INJECTION
MOULDING, 29 166
TYRE, 2 294 362
U
ULTRA HIGH MOLECULAR
WEIGHT POLYETHYLENE,
50 71 104 208 230
ULTRADRAWN, 230
UNSATURATED POLYESTER,
138 172 407
UREA-FORMALDEHYDE
RESIN, 407
UV POLYMERISATION, 121
UV SPECTROSCOPY, 81 92 93
194 212 214 307 337
V
VAPOUR PHASE
POLYMERISATION, 336 355
VEHICLE INTERIOR, 42
VEHICLE MIRROR, 167 286
VEHICLE TRIM, 64
VIBRATIONAL
SPECTROSCOPY, 3 10 23 61
80 107 126 132 171 191 283
294
VINYL ACETATE COPOLYMER,
124 148 402
VINYL ESTER COPOLYMER,
358
VINYL PYRROLIDONE, 49
VINYL TRIFLUOROACETATE
COPOLYMER, 358
VINYLIDENE FLUORIDE
COPOLYMER, 46 81 91 148
240
VISCOELASTIC, 141 142 316
VISCOSITY, 2 6 26 48 54 72 78
79 84 87 88 98 101 105 113 114
123 141 142 166 167 186 191
192 193 201 202 206 215 221
242 250 251 262 278 282 284
285 305 333 340 342 357 378
VISCOSITY MODIFIER, 94 245
339
VISIBLE SPECTROSCOPY, 92 93
214 337
VOLATILE ORGANIC
COMPOUND, 263 269 347 397
403
VULCANISATE, 45 119 237 331
W
WALL THICKNESS, 166 167 192
237
WASHING MACHINE, 166
WASTE, 74 88 102 172 226 277
292 332 349 396 402 406
WATER, 13 37 38 88 108 132 134
160 161 162 163 164 166 171
175 189 205 211 223 226 259
264 293 315 320 332 336 349
WATER ABSORPTION, 121 151
WATER BLOWN, 24
WATER DEGRADABLE, 13
WATER SOLUBILITY, 181 343
WATER-ASSISTED INJECTION
MOULDING, 166
WEIGHT REDUCTION, 41 42 166
167 179 192 203 237 286 404
WELD LINE, 31 97 129 166
WIDE ANGLE X-RAY
SCATTERING, 47 71 183
WOOD, 115 269
X
X-RAY SCATTERING, 19 23 47
53 54 61 69 71 76 80 183 212
219
XYLYLENE POLYMER, 73
Y
YIELD, 20 37 67 148 163 164 171
174 175 197 213 317 320 350
377
Z
ZIEGLER-NATTA CATALYST,
336 355 376
Company Index
© Copyright 2005 Rapra Technology Limited
135
Company Index
A
ACHILLES CORP., 24
AIR PRODUCTS & CHEMICALS,
304 335
AIR PRODUCTS POLYMERS
GMBH & CO.KG, 291
AKRON,UNIVERSITY, 7 400 411
ALICANTE,UNIVERSITY, 195
ALUSUISSE COMPOSITES, 237
253
AMERICAN CHEMICAL
SOCIETY, 369
AMHERST,MASSACHUSETTS
UNIVERSITY, 71 232 296
ATOFINA CHEMICALS INC., 186
AUBURN,UNIVERSITY, 106 205
292 294
AUSTIN,UNIVERSITY OF
TEXAS, 384
AXIOMATICS CORP., 404
B
BARCELONA,INSTITUT DE
CIENCIA DE MATERIALS, 193
BASF, 376
BEIJING,INSTITUTE OF
CHEMISTRY, 95 107 224
BEIJING,STATE KEY
LABORATORY OF
ENGINEERING PLASTIC, 47
BEIJING,UNIVERSITY OF
TECHNOLOGY & BUSINESS,
14
BRADFORD,UNIVERSITY, 324
BROOKLYN,POLYTECHNIC
UNIVERSITY, 18
BRUNEL UNIVERSITY, 123 201
BUCKEYE TECHNOLOGIES, 279
C
CAMBRIDGE,UNIVERSITY, 323
CANADA,NATIONAL
RESEARCH COUNCIL, 21
CATALUNYA,UNIVERSITAT
POLITECNICA, 88
CAVENDISH LABORATORY, 134
CHANGCHUN,INSTITUTE OF
APPLIED CHEMISTRY, 34 35
80 138
CHEMICAL & POLYMER, 115
236 269 344
CHIBA,INSTITUTE OF
TECHNOLOGY, 37 248
CHINESE ACADEMY OF
SCIENCES, 17 61 130 131 171
CHINESE CULTURE
UNIVERSITY, 108
CINCINNATI,UNIVERSITY, 345
CLAUSTHAL,TECHNICAL
UNIVERSITY, 8
CLEMSON,UNIVERSITY, 356
CNRS, 190 256
CONNECTICUT,UNIVERSITY,
1 187
COPENHAGEN,UNIVERSITY,
152 219
CORNELL UNIVERSITY, 180
D
DELAWARE,UNIVERSITY, 313
380 398 405
DEMAG ERGOTECH GMBH, 42
DEUTSCHES
DEXTILFORSCHUNGS-
ZENTRUM NORD-WEST EV,
315 316 346 399
DOW, 376 388
DSM HIGH PERFORMANCE
FIBERS, 230
DSM RESEARCH, 84
DU PONT DE NEMOURS E.I.,&
CO.INC., 377
DUMAPLAST, 237
DUPONT CO., 151 153
DUPONT FLUOROPOLYMERS,
143
E
ECLIPSE BLIND SYSTEMS INC.,
237 253
EINDHOVEN,UNIVERSITY OF
TECHNOLOGY, 5 74 84 139
230 328
ENGEL NORTH AMERICA, 167
229
EPSRC, 371
ETABLISSEMENTS VALOIS, 392
EXPRESS SEPARATIONS LTD.,
327
EXXON, 376
EXXON RESEARCH &
ENGINEERING CO., 309 331
F
FARADAY PLASTICS, 188
FENG CHIA,UNIVERSITY, 212
FERRO CORP., 169 322
FRAUNHOFER-INSTITUT
FUER CHEMISCHE
TECHNOLOGIE, 56 246 363
364
FUKUI,UNIVERSITY, 36 176
FUKUOKA,UNIVERSITY, 70 173
G
GEORGIA,INSTITUTE OF
TECHNOLOGY, 58 92 214 279
337 341
GERMAN TEXTILE RESEARCH
INSTITUTE NORTH-WEST
EV, 209
GOTTINGEN,GEORG-AUGUST-
UNIVERSITAT, 8 9 136 168
GOTTINGEN,UNIVERSITY, 146
GUNMA,UNIVERSITY, 271
H
HANYANG,UNIVERSITY, 197
HARBIN,INSTITUTE OF
TECHNOLOGY, 37 248
HITACHI CABLE LTD., 160
HOECHST, 376
HOECHST CELANESE CORP.,
367 396
HUSKY INJECTION MOULDING
SYSTEMS LTD., 192
I
I-SHOU,UNIVERSITY, 221
ICI CHEMICALS & POLYMERS
LTD., 409
INDIAN INSTITUTE OF
SCIENCE, 110 238
INSTITUTO DE CIENCIA
Y TECNOLOGIA DE
POLIMEROS, 193
J
JAPAN,CHEMICAL
INNOVATION INSTITUTE,
158 159
JAPAN,NATIONAL INSTITUTE
Company Index
136
© Copyright 2005 Rapra Technology Limited
OF ADVANCED INDUSTRIAL
SCIENCE & TECHNOL, 160
162 172 175 177
JAPAN,NATIONAL INSTITUTE
OF MATERIALS &
CHEMICAL RESEARCH, 265
368
JAPAN,SOCIETY OF PLASTICS
RECYCLING, 102
JILIN,UNIVERSITY, 34 35 80 83
138
JOHN HOPKINS UNIVERSITY,
240 244 306 393
JOHNSON S.C.,& SON INC., 415
JSR CORP., 267 289
JYCO SEALING
TECHNOLOGIES, 82
K
KARLSRUHE,UNIVERSITY, 147
246
KAYSUN CORP., 32 129
KENAN LABORATORIES, 389
KIEL,CHRISTIAN-ALBRECHT-
UNIVERSITY, 258 370
KOBE SEIKO SHO KK, 259
KOBE STEEL LTD., 332 343
KOBE,UNIVERSITY, 28 54 157
KONOSHIMA CHEMICAL
CO.LTD., 173
KOREA,INSTITUTE OF
SCIENCE & TECHNOLOGY,
16 27 240
KOSA, 279
KUMAMOTO,INDUSTRIAL
RESEARCH INSTITUTE, 172
174
KUMAMOTO,UNIVERSITY, 174
KUMOH,NATIONAL
UNIVERSITY OF
TECHNOLOGY, 137
KYOTO,INSTITUTE OF
TECHNOLOGY, 45 70 119 200
247
KYOTO,MUNICIPAL TEXTILE
RESEARCH INSTITUTE, 200
KYOTO,UNIVERSITY, 45 113 116
119 165
L
LAUSANNE,ECOLE
POLYTECHNIQUE
FEDERALE, 250
LAWRENCE LIVERMORE
NATIONAL LABORATORY,
413
LEHIGH UNIVERSITY, 331
LIEGE,UNIVERSITY, 207
LIFESTYLE &
ENVIRONMENTAL
TECHNOLOGY
LABORATORIES, 161
LIQUID CARBONIC INC., 373
LIVERPOOL,UNIVERSITY, 63 77
134 184 198 263 270
LONDON,IMPERIAL COLLEGE
OF SCIENCE,TECHNOLOGY
& MEDICINE, 132 206 245
283 366 385 414
LOS ALAMOS NATIONAL
LABORATORY, 374 375
LOUISIANA,STATE
UNIVERSITY, 331
LOWELL,UNIVERSITY, 374 375
M
MADISON GROUP, 4
MAINE,UNIVERSITY, 302 378
MAR DEL
PLATA,UNIVERSIDAD
NACIONAL, 195
MARIBOR,UNIVERSITY, 227
MASSACHUSETTS,INSTITUTE
OF TECHNOLOGY, 180 404
MASSACHUSETTS,UNIVERSIT
Y, 26 33 65 78 104 149 170 182
183 185 208 252 276 319 338
345 382
MASSACHUSETTS-
AMHERST,UNIVERSITY, 287
MAX-PLANCK-INSTITUT FUER
KOHLENFORSCHUNG, 177
MAX-PLANCK-INSTITUT FUER
POLYMERFORSCHUNG, 257
MCP EQUIPMENT LTD., 188
MELVILLE LABORATORY, 288
MENDELEEV UNIVERSITY OF
CHEMICAL TECHNOLOGY, 3
MICELL TECHNOLOGIES, 46
51 243
MINNESOTA MINING & MFG.
CO., 321 358 372
MINNESOTA,UNIVERSITY, 137
MITSUBISHI GAS CHEMICAL
CO.INC., 70
MITSUBISHI PETROCHEMICAL,
376
MITSUI CHEMICALS INC., 275
MITSUI TOATSU CHEMICALS
INC., 348
MOSCOW,INSTITUTE OF
ORGANIC CHEMISTRY, 20
MOSCOW,INSTITUTE OF
ORGANOELEMENT
COMPOUNDS, 20
MOSCOW,LOMONOSOV
UNIVERSITY, 152
N
NESMEYANOV INSTITUTE
OF ORGANO-ELEMENT
COMPOUNDS, 219
NESTE OY, 376
NEW JERSEY,INSTITUTE OF
TECHNOLOGY, 194
NIIGATA,UNIVERSITY, 109
NIPPON TELEGRAPH &
TELEPHONE CORP., 161
NISHIKAWA RUBBER CO., 334
NITTO DENKO CORP., 43 68
NORDSON CORP., 407
NORTH CAROLINA,CHAPEL
HILL UNIVERSITY, 89 145
231 233 289 330
NORTH CAROLINA,STATE
UNIVERSITY, 51 62 75 79 89
122 127 135 142 145 154 155
156 179 181 186 215 222 231
233 254 266
NORTH
CAROLINA,UNIVERSITY, 53
62 122 142 150 154 155 181 223
241 264 267 273 281 297 298
299 300 304 307 310 328 347
353 354 369 377 387 389 390
NORTH TEXAS,UNIVERSITY,
19 22
NORTHEASTERN UNIVERSITY,
93
NOTTINGHAM,UNIVERSITY, 15
18 40 50 57 60 67 86 99 111 112
210 213 235 239 255 263 325
NOVA CHEMICALS
(INTERNATIONAL) SA, 351
NOVACOR, 376
NOVASEP, 326
O
OHIO,STATE UNIVERSITY, 30 48
59 69 114 133 199 217 251 274
284 339 342
OSAKA,UNIVERSITY, 379
OSI SPECIALITIES INC., 397
P
PACIFIC NORTHWEST
NATIONAL LABORATORY, 46
Company Index
© Copyright 2005 Rapra Technology Limited
137
PALERMO,UNIVERSITY, 10 49
96
PENNSYLVANIA,STATE
UNIVERSITY, 280
PHASEX CORP., 234 290 314 393
PITTSBURGH,UNIVERSITY, 303
309 352 381 383 394 395 402
406 408
POLYMER PROCESSING
INSTITUTE, 237
PROCTER & GAMBLE CO., 380
PUSAN,NATIONAL
UNIVERSITY, 176
R
RADFORD,UNIVERSITY, 359
RAPRA TECHNOLOGY LTD.,
188 204 228 237 260
REEDY INTERNATIONAL
CORP., 118 262
REPSOL SA, 336
ROHM & HAAS CO., 311 401
ROSKILDE,UNIVERSITY, 3 20
ROSTI MEDICAL PLASTICS, 25
RUSSIAN ACADEMY OF
SCIENCES, 3 40 152 191
S
SAN JUAN,NATIONAL
UNIVERSITY, 195
SCHERING CORP., 360
SEOUL,NATIONAL
UNIVERSITY, 16 27
SHANGHAI,DONGHUA
UNIVERSITY, 23 120 126
SHIZUOKA,UNIVERSITY, 160
162 172
SIEGEN,UNIVERSITAT, 52 410
SLOVAK ACADEMY OF
SCIENCES, 146
SMITH & NEPHEW, 57
SOUTH
ALABAMA,UNIVERSITY,
362
SOUTHWEST TEXAS,STATE
UNIVERSITY, 125 128 272
SRI INTERNATIONAL, 376
SULZER CHEMTECH AG, 42
SUMITOMO BAKELITE
CO.LTD., 295
SURREY,UNIVERSITY, 115 239
269 344 371
SUSSEX,UNIVERSITY, 67 350
T
TAIPEI,NATIONAL TAIWAN
UNIVERSITY, 108
TAIWAN,NATIONAL
UNIVERSITY OF SCIENCE &
TECHNOLOGY, 101 105
TAKEDA CHEMICAL
INDUSTRIES LTD., 259 343
TEXAS A & M UNIVERSITY, 308
TEXAS,UNIVERSITY, 100 211
255 278 335
TEXAS,UNIVERSITY AT
AUSTIN, 304
TIANJIN,UNIVERSITY, 13
TOHOKU ELECTRIC POWER
CO.INC., 163 261
TOHOKU,UNIVERSITY, 163 164
261 320
TOKYO,INSTITUTE OF
TECHNOLOGY, 200
TONGJI,UNIVERSITY, 87 126
TORINO,POLITECNICO, 220
TORONTO,UNIVERSITY, 124
148 237 242 268 285 333 357
TOYO TIRE & RUBBER
CO.LTD., 45 165
TOYOTA CENTRAL R & D
LABORATORIES INC., 116
TOYOTA TECHNOLOGICAL
INSTITUTE, 76 116
TREXEL, 42 64 82 144 166 167
178 192 196 203 229 237 253
TRIESTE,UNIVERSITY, 85
TSINGHUA,UNIVERSITY, 121
TSUKUBA,NATIONAL
INSTITUTE OF MATERIALS
& CHEMICAL RESEARCH,
277
U
UK,HEALTH AND SAFETY
LABORATORY, 86
UNICARB SYSTEM EUROPE,
407
UNILEVER RESEARCH, 301 335
UNION CARBIDE, 376
UNION CARBIDE CHEMICALS
& PLASTICS CO.INC., 407
416
UNION CARBIDE CORP., 403
UNIQEMA, 67 111 213
UNITIKA LTD., 76
US,ARMY, 231
US,ARMY RESEARCH OFFICE,
75 281
US,ARMY SOLDIER SYSTEMS
COMMAND, 71 104
US,ARMY,ABERDEEN
PROVING GROUND, 117
US,CENTER FOR COMPOSITE
MATERIALS, 386
US,DEPT.OF
AGRICULTURE,FOREST
PRODUCTS LABORATORY,
32
US,DEPT.OF ENERGY, 412
US,NASA,LANGLEY
RESEARCH CENTER, 359
US,RESEARCH &
TECHNOLOGY
DIRECTORATE, 117
V
VIRGINIA,COMMONWEALTH
UNIVERSITY, 66 81 90 91 137
140 156 169 216 225 240
VIRGINIA,POLYTECHNIC
INSTITUTE & STATE
UNIVERSITY, 6 94 365
W
WACKER POLYMER SYSTEMS
GMBH & CO.KG, 291
WARWICK,UNIVERSITY, 41
WASHINGTON,UNIVERSITY, 39
WATERLOO,UNIVERSITY, 2 11
44 72 98 103 202 242 285 314
333 357
WAYNE STATE,UNIVERSITY,
141 282 305 340 361
WISCONSIN-
MADISON,UNIVERSITY, 4 29
31 32 97 129 388
X
XEROX CORP., 312
Y
YAMAGATA,UNIVERSITY, 38 73
293 295 317 318
YAZAKI CORP., 226
YONSEI,UNIVERSITY, 249
Z
ZENECA AGROCHEMICALS,
288
ZHENGZHOU,UNIVERSITY, 55
61
Company Index
138
© Copyright 2005 Rapra Technology Limited
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