Received: 2 April 2009,

Revised: 23 June 2009,

Accepted: 29 June 2009,

Published online in Wiley Online Library: 3 August 2009

New (PP/EPR)/nano-CaCO

3

based formulations

in the perspective of polymer recycling. Effect
of nanoparticles properties and
compatibilizers

Nizar Mnif

a , b

*, Vale´rie Massardier

a

, Tasnim Kallel

b

and Boubaker Elleuch

b

Phase structure of composite polypropylene (PP)/ethylene–propylene–rubber (EPR)/coated nano-CaCO

3

composites,

used in the manufacture of bumpers, with and without compatibilizers has been investigated using scanning electron
microscopy (SEM), dynamic mechanical analysis (DMA) mechanical tests, and differential scanning calorimetry (DSC).
Blends of various compositions were prepared using a corotating twin-screw extruder. The experimental results
indicated that the dispersion of nanoparticles in (PP/EPR) depends on their surface (stearic acid and fatty acid
coatings). In both cases, the final morphology is the core–shell structure in which EPR acts as the shell part
encapsulating coated nano-CaCO

3

. In this case, EPR-g-MAH copolymer does not improve the interface between

(PP/EPR) and nanoparticles but PEP propylene ethylene copolymer should be preferentially localized at the interface
of PP and (EPR/nano-CaCO

3

) phases generating an improved adherence, which will ensure a better cohesion of the

whole material. According to the nature of the compatibilizers and surface treatment, it is believed that the synergistic
effect of both the EPR elastomer and CaCO

3

nanoparticles should account for the balanced performance of the ternary

composites. Copyright

ß 2009 John Wiley & Sons, Ltd.

Keywords: polypropylene; EPR; calcium carbonate; compatibilization; recycling

INTRODUCTION

With an annual production of more than 250,000 tons in Europe,
polypropylene is one of the most widely used polymers.
Polypropylene is used in automobiles, household appliances,
etc. In order to overcome its high flammability, tendency to
brittleness at temperatures below its glass transition tempera-
ture, and low stiffness, polypropylene can be modified by fillers
(CaCO

3

, alumina, silica, etc.) and elastomers such as ethylene

propylene rubber (EPR) and ethylene propylene diene monomer
(EPDM). However, EPR particles decrease tensile properties of PP
such as yield strength and Young’s modulus. So, to compensate
the effect of EPR content, the addition of rigid fillers such as
calcium carbonate (CaCO

3

) is recommended.

[1]

Nanofillers, such

as nanosilica for example, can be used as compatibilizer instead
of copolymers.

[2]

This prospective study aims at studying new

(PP/EPR) based formulations containing nano-CaCO

3

fillers in the

perspective of processing more complex blends when recycling.
Indeed, as polymer sorting often produces complex mixtures (a
polymer in major proportions and others in minor proportions)
for being economy efficient, it may be interesting to substitute
conventional fillers by their homologous nanosized ones in order
to facilitate the recycling of complex blends using nano-CaCO

3

based compatibilization.

[3]

Postconsumer recycled polypropylene containing elastomers

(EPR, EPDM, EOC, etc.) and fillers (CaCO

3

, silica, etc.) from

automobile bumpers represent considerable amount of waste. To
recover high volumes of polymer materials with economic
efficiency, one solution is to recover polymers with lower degrees

of purity. In this perspective, complex formulations as well as
associated parts can be recovered with simplified sorting.

Usually, to counterbalance or to take advantage of some

mixtures, it is necessary to find the chemical formulation that will
upgrade mechanical properties. To this end, compatibilizers, such
as copolymers (PEP: copolymer of ethylene and propylene, EP-g-
MAH: copolymer of ethylene and propylene grafted maleic
anhydride, etc.)

[3]

and more recently nanofillers,

[2]

are often used.

Considering this strategy of recycling, (PP/EPR) formulations
could be mixed with nano-CaCO

3

instead of micron size CaCO

3

that is often used as a filler for polymer composites.

The produced blends are called hybrid composites. The

mechanical properties of hybrid composites are dictated not only
by their composition but also by their phase morphology.

(wileyonlinelibrary.com) DOI: 10.1002/pat.1520

Research Article

* Correspondence to: N. Mnif, Laboratoire des Mate´riaux Macromole´culaires,

Inge´nierie des Mate´riaux Polyme`res, IMP, UMR CNRS 5627, Universite´ de Lyon,
INSA de Lyon, Baˆt Jules Verne, 20 Av. A. Einstein, 69621 Villeurbanne Cedex,
France.
E-mail: [e-mail]

a N. Mnif, V. Massardier

Universite de Lyon, Lyon, F-69003, France; INSA de Lyon, IMP/LMM
Laboratoire des Mate´riaux Macromole´culaires, Villeurbanne, F-69621, France;
CNRS, UMR 5223. Inge´nierie des Mate´riaux Polyme`res, Villeurbanne, F-69621,
France

b N. Mnif, T. Kallel, B. Elleuch

Laboratoire Eau/Energie/Environnement, Ecole Nationale des Inge´nieurs de
Sfax (ENIS), Rte Soukra 3038 —Sfax—Tunisie

Polym. Adv. Technol. 2010, 21 896–903

Copyright

ß 2009 John Wiley & Sons, Ltd.

896

According to the literature, two kinds of phase morphologies are
normally found: either the rubber and rigid particles are
dispersed separately in the polypropylene matrix, or the rigid
particles are encapsulated by rubber particles.

[2]

Earlier works

showed that the most important factor that can determine phase
morphology is the surface treatment of the rigid particles. Most of
the previous studies have focused on the relationship between
phase morphology and mechanical properties of PP–rubber–filler
systems.

[3–7]

Adhesive forces acting among the particles depend

on the free energy surface of the filler.

[8]

The coating of CaCO

3

with stearic acid leads to a significant decrease in surface
tension,

[9–14]

which results in decreased interactions and hope-

fully to limited aggregation.

The phase structure of ternary phase composites is influenced by

the melt rheology of the system, compounding techniques, and the
surface characteristics and mutual wettability of the fillers and
polymer components. In PP/EPDM/calcium carbonate composites,
the surface treatment of filler was found to result in a separate
dispersion of phases (EPDM and CaCO

3

), whereas encapsulation

occurred when untreated calcium carbonate was used.

[15,16]

To

promote the adhesion between the polymer and filler particles, the
functionalization of polymer phases was carried out. In PP/EPR/filler
systems, it was shown that incorporating PP functionalized with
maleic anhydride resulted in separate dispersions of elastomer and
filler. Using maleated EPR and nonfunctionalized PP gave a filler
encapsulation structure.

[17,18]

In the present work, the properties of (PP/EPR)/nano-CaCO

3

ternary composites, with and without compatibilizers (EPR-g-
MAH and PEP), are investigated. The research is focused on the
synergistic toughening effect of compatibilizer and nano-CaCO

3

alongside the influence of particles’ surface treatment. The
rheological and mechanical analyses of the components and
the ternary blends of (PP/EPR)/nano-CaCO

3

as well as the effect of

the compatibilizers were studied.

EXPERIMENTAL

Materials

(PP/EPR) (78/22) (PP108MF97), supplied by Sabic, is a blend of an
isotactic polypropylene matrix (78 wt%) and an EPR dispersed
phase (random copolymer containing 50% of ethylene) (22 wt%);
specific gravity, 0.905 g/cm

3

; melt flow index (MFI), 10 g/10 min

under 2.16 kg at 230

8C.

EPR-g-MAH was supplied by Exxon Mobil (Exxelor VA 1801;

M

n

¼ 80.000 g/mol; ethylene content, 69.6 wt%; propylene con-

tent, 29.8 wt%; and MAH content, 0.6 wt%).

Vistamaxx 6200 (PEP), a copolymer of ethylene and propylene

(%propylene

> 80 wt%), is the result of a specially controlled

metallocene

polymerization

process

(density

¼ 0.861 g/m

3

;

MFI

¼ 20 g/10 min (2308C/2.16 Kg)).

Calcium carbonate (CaCO

3

) was supplied by Solvay

1

. Proper-

ties are described in Table 1.

Preparation of blends

Blends with and without compatibilizer and nano-CaCO

3

were

premixed as pellets to the required proportions prior to
processing in a corotating twin-screw extruder (Clextral BC 21:
D

¼ 25 mm, L/D ¼ 36). The screw and the temperature profiles

used in this study are given in Fig. 1. The rotational speed of twin-
screw extruder is between 180 and 200 rpm (Fig. 1). Table 2
illustrates the composition of the blends.

Table 1. The characteristics of nanoparticles

Particle diameter

Surface coating

Specific surface (BET)

Socal 322V

30–50 nm

Stearic acid (3.5 wt%)
coating content

¼ 33 g/kg

coating ratio

¼ 1.1 mg/m

2

25 m

2

/g

Winnofil-SPM

100 nm

Stearic acid (2.5 wt%)
coating content

¼ 27 g/kg

coating ratio

¼ 1.5 mg/m

2

20 m

2

/g

Table 2. Composition of the blends

Blends

(PP/EPR) (wt%)

PEP (wt%)

EPR-g-MAH (wt%)

Nano-CaCO

3

(wt%)

Socal322V

WinnofilSPM

(PP/EPR)

(78/22)

0

0

0

0

(PP/EPR)/W

(74.5)/20.5

0

0

0

5

(PP/EPR)/W/EPR-g-MAH

(71)/20

0

4

0

5

(PP/EPR)/W/PEP

(71)/20

4

0

0

5

(PP/EPR)/S

(74.5)/20.5

0

5

0

(PP/EPR)/S/EPR-g-MAH

(71)/20

0

4

5

0

(PP/EPR)/W/PEP

(71)/20

4

0

5

0

Figure 1. Twin-screw extruder. Screw and temperature profile.

Polym. Adv. Technol. 2010, 21 896–903

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ß 2009 John Wiley & Sons, Ltd.

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(PP/EPR)/NANO-CACO

3

BASED FORMULATIONS IN THE PERSPECTIVE OF POLYMER RECYCLING

897

A vertical injection-molding machine (Battenfeld Unilog B2;

350 Plus) was used for preparing the specimens for mechanical
tests. Conditions are: speed of injection: 15 mm/sec, pressure
limits: 50 bars, temperature: 220

8C, and time: 15 sec.

Morphologies

Morphologies were studied with a Hitachi S800 scanning electron
microscope at an accelerating voltage of 30 kV realized in the
Technological center of the Microstructures (CT

m) of Lyon

(France). The specimens were injection molded in a Battenfeld
Unilog B2 and fractured in liquid nitrogen and covered with gold
before being examined. All SEM micrographs are secondary
electron images. These images were treated using some special
software (image treatment, ImageTool; http://ddsdx.uthscsa.edu/
dig/itdesc.html) in order to estimate the diameter of particles.
The analyses as well as the calculation of the diameters of the
particles were carried out on 30 nodules dispersed on a surface of
120

mm

2

.

Thermal analysis

The thermal analyses were performed under argon using a
Mettler-Toledo SA differential scanning calorimeter (DSC).
Standard aluminum pans were used. Samples (10–20 mg) were
weighted directly in the pan and an empty pan was used as
reference. Temperature calibration was performed using indium.
Heating was carried out from room temperature to 200

8C and

samples were then held at 200

8C for 5 min before cooling to

1008C. Cooling and heating rates were both set to 10 K/min.

Dynamic mechanical analysis

The complex modulus (G

), its storage (G

0

), loss parts (G

00

), and the

mechanical loss factor (tand

¼ G

00

/G

0

), were analyzed as a function

of temperature (T) with dynamic mechanical analysis (DMA)
using a Rheometrics Model RDA700. DMA spectra were taken in a
tension mode at 1 Hz frequency in a broad temperature range
T

¼ 80 to 1708C (heating rate 28C/min).

Mechanical tests

Tensile tests were carried out on a MTS 2/M tester at a speed of
500 mm/min (preliminary tests on lower speeds were carried out
to find the test conditions of rupture). The mechanical behavior
was investigated using injection-molded samples. Charpy impact
tests were carried out at 21

18C using a falling-weight impact

tester (type Otto Wolpert–Werke Ludwigshafen a. Rh.) in
accordance with the French standard method NF T 51–035.
The results supplied correspond to an average of 20 measure-
ments for each blend. Tests were performed according to ISO
527–2 1BA (75

5 2 mm) standard methods (Temperature:

21

18C). A pre-crack of 2 mm was introduced at the center of

one edge of the rectangular bars. A pre-crack consisted of a saw
slot and a sharp crack tip, which was created with a mechanical
saw making of translatory movements high/low.

RESULTS AND DISCUSSION

Morphological properties

It is known that the dispersion of fillers in the polymer matrix can
have a significant effect on the mechanical properties of the

composites. The dispersion of an inorganic filler in the thermo-
plastic is not an easy process. The problem is even more severe,
when using nanoparticles as fillers, because the nanoparticles have
a strong tendency to agglomerate. Consequently, the homo-
geneous dispersion of the nanoparticles in the thermoplastic
matrix is a difficult process and a good dispersion can be achieved
by the surface modification of the filler particles and appropriate
processing conditions.

[19]

The observation of cryo-fractured

samples of the (PP/EPR) by SEM (Fig. 2(a)) displays a nodular
morphology, where the EPR morphology phase is dispersed in the
form of spherical particles (0.2–0.5

mm). In order to determine

whether stearic acid and fatty acid coatings of CaCO

3

particles really

help their dispersion in the PP/EPR matrix, SEM (Fig. 2(b) and 2(c))
was used to observe the fracture surfaces of samples fractured in
liquid nitrogen. According to these micrographs, the dispersion of
Winnofil CaCO

3

particles appears to be quite uniform; the size of

aggregates is lower than 2

mm. However, for specimens filled with

5 wt% of Socal322V [(PP/EPR)/S], the particles present large
agglomerates in the range of 3–12

mm (Fig. 2(c)). Indeed, the

presence of stearic acid decreased the adhesion between (PP/EPR)
and the particles of CaCO

3

. There are still presence of aggregates;

dispersion obviously is more difficult for the particles treated with
stearic acid. The particle–particle interaction is larger due to the
higher surface free energy. These aggregates are detrimental for
the toughening properties of these composites.

[20]

The large

aggregates create large voids upon loading and consequent
debonding, and could act as precursors for cracks.

[21]

The morphology of ternary blends with compatibilizers (EPR-g-

MAH and PEP) and nano-CaCO

3

is displayed in Fig. 3. Wang et al.

[22]

shows that according to routes were used to prepare the

PP/EPDM/nano-CaCO

3

tercomponent

composites

three

morphologies are observed: First, nano-CaCO

3

was randomly

distributed in the PP matrix and EPDM particles if the
components are premixed simultaneously. Second, nano-CaCO

3

particles and EPDM particles were separately distributed in the PP
matrix (PP and nano-CaCO

3

were mixed and EPRM is incorpor-

ated again). Finally, nano-CaCO

3

particles and their agglomerates

were embedded in EPDM particles to form a sandbag structure
like a sandbag for boxing. So two compatibilizers were used: the
PEP to improve PP/EPR interface and EPR-g-MAH for PP/nano-
CaCO

3

interface. In the case of the (PP/EPR)/W/EPR-g-MAH and

(PP/EPR)/S/EPR-g-MAH, Fig. 3(a) and 3(b) show that an increase of
the size of EPR particles (0.4–2

mm) and in the agglomerates of

CaCO

3

fillers (1–5

mm) and a bad adhesion between PP/EPR and

nanoparticles.

Figure 3(c) and 3(d) reveal the influence of PEP copolymer on

the dispersion of nano-CaCO

3

in the (PP/EPR) matrix. The

morphological properties reveal: a reduction in the size of the EPR
dispersed phase (0.1–0.5

mm) and an improvement of PP and

(EPR/nano-CaCO

3

) interface. Indeed, EPR and nano-CaCO

3

form a

core–shell structure in which elastomer may act as a shell part
encapsulating nanoparticules as suggested by Wang et al.

[22]

.

Dynamic mechanical properties

Dynamic mechanical properties of PP/EPR blends were studied
over a wide range of temperature (from

808C to 1608C) and the

results are reported in Table 3. As expected, three different
relaxations occur; the variation of the modulus and the tan d is
represented in Figs 4 and 5. The first corresponds to the
amorphous EPR component relaxation and is called b

EPR

(

468C).

The second (b

PP

(3

8C)) corresponds to the glass transition of

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Copyright

ß 2009 John Wiley & Sons, Ltd.

Polym. Adv. Technol. 2010, 21 896–903

N. MNIF ET AL.

898

isotactic PP (iPP).

[23]

The last one, that is the a

PP

relaxation (78

8C)

is attributed to movements in the iPP crystalline regions.

[23]

The

rheological properties of (PP/EPR) show that a combination of
relaxation processes between those typical mechanisms from its
components, PP and EPR, is exhibited. Consequently, four
different relaxations are shown, two of them correspond to
the amorphous EPR component (at the lowest temperature and
labeled g

EPR

and b

EPR

) and the two others, namely b

PP

and a

PP

, are

stem from the semicrystalline PP homopolymer.

[24,25]

For (PP/EPR)/W and (PP/EPR)/S blends, Table 3 and Figs 4 and 5

show the displacement of the relaxation b

EPR

and a

PP

toward the

low temperatures (

DT ¼ 2–48C and 88C, respectively). The result is

attributed to a supplementary thermomechanical treatment for the
introduction of nano-CaCO

3

that generates a variation of the chain

length because without nanoparticles the dynamic mechanical
properties of (PP/EPR) blends are unchanged even after extrusion.
On the other hand, the presence of EPR-g-MAH copolymer does not
change the relaxation peaks b

EPR

and b

PP

but the displacement of

a

PP

toward higher temperatures shows that the presence of the

copolymer decreases the mobility of polymer chains.

In the case of (PP/EPR)/W/PEP and (PP/EPR)/S/PEP, Table 3 and

Figs 4 and 5 display a second peak of relaxation respectively at

Figure 2. Morphologies of the blends (a) (PP/EPR), (b) (PP/EPR)/W, and (c) (PP/EPR)/S.

Polym. Adv. Technol. 2010, 21 896–903

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(PP/EPR)/NANO-CACO

3

BASED FORMULATIONS IN THE PERSPECTIVE OF POLYMER RECYCLING

899

38 and 368C in the presence of PEP copolymer. Tsagaropoulos
and Eisenberg

[26,27]

studying a wide range of polymers, including

poly(dimethylsiloxane), filled with silica nanoparticles, observe in
dynamic mechanical measurements a second peak in tan d, 50–
100

8C above the glass transition, which is attributed to the glass

transition of an interfacial polymer layer with restricted mobility.
Their results are interpreted in terms of a model where there are
three types of polymer: a strongly bound, immobile layer
immediately surrounding the particle, which does not participate
in the glass transition; a second, loosely bound interfacial layer

which is responsible for the second glass transition; and quasi-
bulk polymer unaffected by the particle.

Thermal properties

The mechanical properties of the composites can be significantly
changed if the crystallization characteristics of PP have been
altered. Table 4 summarizes the differential scanning calorimetry
(DSC) results for unmodified (PP/EPR) matrix and its ternary
blends with either calcium carbonate or compatibilizers. The DSC

Figure 3. Morphologies of the blends (a) (PP/EPR)/W/EPR-g-MAH, (b) (PP/EPR)/S/EPR-g-MAH, (c) (PP/EPR)/W/PEP, and (d) (PP/EPR)/S/PEP.

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Polym. Adv. Technol. 2010, 21 896–903

N. MNIF ET AL.

900

thermograms of (PP/EPR) show two peaks: a single-peak
characteristic of the melting of a-PP was observed at 167

8C

(T

mPP

) and a second peak associated with the crystallinity of PP at

126

8C (T

cPP

). The presence of compatibilizers and nano-CaCO

3

does not change the percentage of crystallinity of the PP. The loss

of nucleating efficiency of filler in the presence of EPR on the PP
matrix is attributed to its encapsulated structure as the filler
particles in this system were surrounded by the EPR phase.
According to Zuiderduin et al.

[21]

the melting enthalpy is lowered

when the particle content is increased. The CaCO

3

particles

(treated and untreated) do not act as a nucleating agent in
polypropylene since the crystallinity is not increased.

Tensile properties

The extensive analysis of the mechanical properties of ternary-
phase composites was carried out.

[5,28–31]

Most of the studies

have focused on the influence of the phase morphology. Ternary
composites containing encapsulated fillers have been reported
to have somewhat higher tensile impact strength but lower
modulus than those with a separation structure, because the
effect of the dispersed elastomer is extended by the filler.

[17]

However, composites having a separation structure yielded a
marked increase in the composite modulus.

[17]

Although some

Figure 4. Dynamic mechanical spectra of (PP/EPR), (PP/EPR)/W, (PP/EPR)/W/EPR-g-MAH, and (PP/EPR)/W/PEP blends.

Figure 5. Dynamic mechanical spectra of (PP/EPR), (PP/EPR)/S, (PP/EPR)/S/EPR-g-MAH, and (PP/EPR)/S/PEP blends.

Table 3. Rheological characteristics of the blends

Blends

b

EPR

(

8C)

b

PP

(

8C) a

PP

(

8C)

(PP/EPR)

46

3

78

(PP/EPR)/W

50

0

70

(PP/EPR)/W/EPR-g-MAH

50

0

86

(PP/EPR)/W/PEP

52 and 38

5

78

(PP/EPR)/S

48

0

70

(PP/EPR)/S/EPR-g-MAH

48

0

85

(PP/EPR)/S/PEP

52 and 36

4

72

Polym. Adv. Technol. 2010, 21 896–903

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(PP/EPR)/NANO-CACO

3

BASED FORMULATIONS IN THE PERSPECTIVE OF POLYMER RECYCLING

901

experimental data on the mechanical properties of such ternary
composites have been published in the literature, contradictory
results on the influence of the filler on the microstructure and
crystallization of the ternary composites were reported.

[5,28–31]

Some tensile properties of PP/EPR blends with and without

nano-CaCO

3

and compatibilizers are summarized in Table 5. The

decrease in the yield stress is due to the early debonding of the
filler particles from the polymer matrix. Debonded particles do
not contribute to the yield stress.

[21]

The particle size does not

seem to influence the tensile yield stress for these composites.
Although debonding becomes increasingly more difficult with
smaller particles

[32]

this is not seen in this particle size regime. The

addition of copolymer elastomer (4% of EPR-g-MAH and PEP) into
PP/CaCO

3

blends led to a decrease of tensile stress about 15–

20%. The bad dispersion and adhesion of the filler (particularly
Socal particles) as well as the brittleness of the (PP/EPR) matrix in
the presence of EPR-g-MAH copolymer cause a reduction in the
elongation at break.

Energy at break represents surface with the lower part of the

traction diagram s

¼ f (e) limited by the elongation at break. The

presence of fillers increases the energy at break about 100% by
widening of the maximum of the peak of the traction diagram
but the addition of copolymers (PEP and EPR-g-MAH) decreases
its value with reduction in yield stress and elongation at break.

Impact properties

The impact strength for the different blends as a function of
composition is shown in Table 5. The mechanical properties of

hybrid composites are dictated not only by their composition, but
also by their phase morphology. According to the literature, two
kinds of phase morphologies are normally found. Either
the rubber particles and rigid particles are dispersed in the
polypropylene matrix separately, or the rigid particles are
encapsulated by rubber particles. Earlier work showed that
the most important factor that can determine phase morphology
is the surface treatment of the rigid particles. Most of the previous
studies have focused on the relationship between phase
morphology and mechanical properties in PP–rubber–filler
systems.

[1,5–8]

According to the morphological observations,

the bad adhesion and dispersion of fillers (particularly Socal
particles) in the (PP/EPR) matrix decrease the impact strength of
the blends. The addition of the copolymer EPR-g-MAH increases
impact strength; indeed, the presence of 4% of elastomer tends
to increase the impact properties of the blends. On the other
hand, a better adhesion between PP and EPR in the presence of
PEP copolymer considerably improves the impact properties
compared to the noncompatibilized (by 45% and 60%,
respectively, in the case of (PP/EPR)/W/PEP and (PP/EPR)/S/PEP).

CONCLUSION

The influence of surface treatment and compatibilizers on the
microstructure and mechanical properties of complex (PP/EPR)
composites containing calcium carbonate was investigated. A
study of the phase morphology by SEM, DMA, DSC, and
mechanical properties revealed that the dispersion of calcium

Table 4. Thermal properties of (PP/EPR) blends

Blends

T

c

(

8C)

T

c onset

(

8C)

T

mPP

(

8C)

Crystallinity (x

c

)

(PP/EPR)

126

134

169

48

(PP/EPR)/W

127

134

169

50

(PP/EPR)/W/EPR-g-MAH

127

133

170

51

(PP/EPR)/W/PEP

125

134

172

50

(PP/EPR)/S

126

135

170

50

(PP/EPR)/S/EPR-g-MAH

128

134

169

49

(PP/EPR)/S/PEP

125

136

172

49

Table 5. Mechanical properties of (PP/EPR) blends (21

18C)

Blends

Traction test

Charpy impact

Yield stress

(MPa)

Elongation at

break (%)

Energy at

break (J)

Impact strength

(kJ/m

2

)

(PP/EPR)

20.3

0.40

180

25

8.5

0.9

75

8

(PP/EPR)/W

19.4

0.35

175

20

16

0.8

60

10

(PP/EPR)/W/EPR-g-MAH

16.5

0.45

115

20

14.5

1.1

70

9

(PP/EPR)/W/PEP

17.5

0.40

182

25

13.9

1.3

88

7

(PP/EPR)/S

19.4

0.35

135

35

15.9

1.2

51

8

(PP/EPR)/S/EPR-g-MAH

17.8

0.45

130

40

15.5

1.1

73

10

(PP/EPR)/S/PEP

17.8

0.35

195

30

14.8

1.3

82

9

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Copyright

ß 2009 John Wiley & Sons, Ltd.

Polym. Adv. Technol. 2010, 21 896–903

N. MNIF ET AL.

902

carbonate on the (PP/EPR) matrix depends on surface treatment.
Indeed, calcium carbonate with fatty acids is dispersed better
than nano-CaCO

3

with stearic acid. Second, in ternary poly-

propylene/elastomer/calcium carbonate, the final structure is
determined by the dynamic equilibrium of encapsulation. Third,
the presence of the PEP copolymer considerably improves the
adherence at the interface between the PP and EPR phases and
consequently PP and (EPR/nano-CaCO

3

) interface. Finally, the

EPR-g-MAH copolymer does not present interaction with the (PP/
EPR) and nanoparticles but affects the mechanical properties of
the composites.

Acknowledgements

The authors gratefully acknowledge the Technological Center of
Microstructures (CTm) of University Claude Bernard-69622-Lyon
(France) for SEM observations.

REFERENCES

[1] J. Jancar, A. DiAnselmo, A. T. DiBenedetto, J. Kucera, Polymer 1993, 34,

1684.

[2] L. Elias, F. Fenouillot, J. C. Majeste, P. h. Cassagnau, Polymer 2007, 48,

6029.

[3] N. Mnif, V. Massardier, T. Kallel, B. Elleuch, Polym. Comp. 2008, DOI

10.1002

[4] S. M. Zebarjad, S. A. Sajjadi, M. Tahani, J. Mat. Proc. Tech. 2006, 175,

446.

[5] J. Jancar, A. T. J. Dibenedetto, J. Mater. Sci. 1994, 29, 4651.
[6] R. Premphet, P. Horanont, J. Appl. Polym. Sci. 2000, 76, 1929.

[7] D. Benderly, M. Siegmann, M. Narksis, Polym. Comp. 1996, 17, 86.
[8] S. E. Barbosa, J. Kenny, N. J. Capiti, Polym. Comp. 2000, 21, 377.
[9] J. Jancar, J. Mater. Sci. 1996, 31, 3983.

[10] B. Puka´nszky, E. Fekete, F. Tu¨do’’s, Makromol. Chem. Macromol. Symp.

1989, 28, 165.

[11] B. Puka´nszky, E. Fekete, Adv. Polym. Sci. 1999, 139, 109.
[12] E. Fekete, J. Mo´czo´, B. Puka´nszky, J. Colloid. Interf. Sci. 2004, 269, 143.
[13] J. Mo´czo´, E. Fekete, B. Puka´nszky, Prog. Colloid. Polym. Sci. 2004, 125,

134.

[14] H. Balard, E. Papirer, Prog. Org. Coat. 1993, 22, 1.
[15] B. Pukanszky, J. Kolarik, F. Lednicky, 1986, 553.
[16] J. Kolarik, F. Lednicky, Polym. Compos. 1986, 537.
[17] J. Kolarik, F. Lednicky, J. Jancar, B. Pukanszky, Polym. Commun. 1990,

31, 201.

[18] J. Kolarik, J. Jancar, Polymer 1992, 33, 4961.
[19] C. M. Chan, J. Wu, J. X. Li, Y. K. Cheung, Polymer 2002, 43, 2981.
[20] G. H. Michler, J. M. Tovmasjan, Plaste Kautschuk 1988, 35, 73.
[21] W. C. J. Zuiderduin, C. Westzaan, J. Hue´tink, R. J. Gaymans, Polymer

2003, 44, 261.

[22] X. Wang, J. Sun, R. Huang, J. Appl. Polym. Sci. 2006, 99, 2268.
[23] L. D’Orazio, R. Greco, C. Mancarella, E. Martuscelli, G. Ragosta, G.

Silvestre, Polym. Eng. Sci. 1982, 22, 536.

[24] N. Mnif, V. Massardier, M. Jaziri, J. Appl. Polym. Sci. 2007, 104,

3220.

[25] M. Jaziri, N. Mnif, V. Massardier, H. Perier-Camby, Polym. Eng. Sci. 2007,

47, 1009.

[26] G. Tsagaropoulos, A. Eisenberg, Macromolecules 1995, 28, 6067.
[27] G. Tsagaropoulos, A. Eisenberg, Macromolecules 1995, 28, 396.
[28] J. Jancar, A. T. Dibenedetto, J. Mater. Sci. 1995, 30, 1601.
[29] W. Y. Chiang, W. D. Yang, B. Pukanszky, Polym. Eng. Sci. 1992, 32,

641.

[30] J. Wang, J. F. Tung, M. Y. Ahmad Fuad, P. R. Hornsby, J. Appl. Polym. Sci.

1996, 60, 1425.

[31] K. Premphet, P. Horanont, J. Appl. Polym. Sci. 1999, 74, 3445.
[32] B. Pukanszky, Polypropylene: Structure, Blends and Composites, (Eds. J.

Karger-Kocsis), Chapter 1, Chapman & Hall, London, 1995,

Polym. Adv. Technol. 2010, 21 896–903

Copyright

ß 2009 John Wiley & Sons, Ltd.

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(PP/EPR)/NANO-CACO

3

BASED FORMULATIONS IN THE PERSPECTIVE OF POLYMER RECYCLING

903