Structure and properties of polypropylene-based nanocomposites: Effect of PP-g-MA to organoclay ratio

The structure-property relationships of polypropylene (PP)-based nanocomposites prepared by melt processing have been investigated with a main focus on the ratio of polypropylene grafted with maleic anhydride (PP-g-MA) to organoclay. The morphological observations by transmission electron microscopy and X-ray diffraction are presented in conjunction with the mechanical, rheological and thermal expansion properties of these nanocomposites. Detailed morphological studies and subsequent quantitative particle analyses for the dispersed clay phase reveal that the aspect ratio of clay particles decreases as the amount of clay increases, and it increases as the amount of PP-g-MA increases. The rheological properties suggest that the extent of a percolation network can be enhanced by increasing the number of organoclay particles at a fixed ratio of PP-g-MA to organoclay and by increasing the degree of exfoliation at fixed clay content. However, mechanical and thermal expansion behaviors do not improve correspondingly in all cases because of the reduction of matrix properties by PP-g-MA. The reduction of the modulus and the increase in the expansion of the polymer matrix caused by the presence of PP-g-MA are compared to the prediction of the Chow model. Clearly, the amount of PP-g-MA added along with its lower crystallinity are important factors affecting the mechanical and thermal expansion properties of PP-based nanocomposites.     

Morphology and properties of polypropylene nanocomposites based on a silanized organoclay

A silanized organoclay (s-M₂(HT)₂) was prepared by reaction of trimethoxyphenyl silane with an organoclay with a M₂(HT)₂ surfactant structure. Nanocomposites were formed from polypropylene (PP) and a blend of PP and maleic anhydride-grafted polypropylene (PP-g-MA) and the M₂(HT)₂ and s-M₂(HT)₂ organoclays by melt processing to explore the extent of exfoliation and the mechanical properties. Wide angle X-ray scattering (WAXS) and transmission electron microscopy (TEM) coupled with detailed particle analysis were used to determine the effect of the organoclay used and the PP-g-MA compatibilizer on exfoliation and mechanical, rheological, and thermal expansion properties. The PP/s-M₂(HT)₂ nanocomposites have higher particle densities than the PP/M₂(HT)₂ nanocomposites though the aspect ratio remains the same. Platelet dispersion is significantly improved by using PP-g-MA compatibilizer for both organoclays. The rheological properties and the relative modulus improve for the PP/s-M₂(HT)₂ nanocomposites but not to the same degree as either organoclay in a PP-g-MA compatibilized matrix. The thermal expansion properties, however, are not improved by using the s-M₂(HT)₂ organoclay. The s-M₂(HT)₂ organoclay is less prone to agglomeration during extrusion than the M₂(HT)₂ organoclay.     

Effect of the ratio of maleated polypropylene to organoclay on the structure and properties of TPO-based nanocomposites. Part I: Morphology and mechanical properties

The structure-property relationships of thermoplastic olefin (TPO)-based nanocomposites prepared by melt processing are reported with a main focus on the ratio of maleic anhydride-grafted polypropylene (PP-g-MA) to organoclay. The morphological observations by transmission electron microscopy, atomic force microscopy, and X-ray diffraction are presented in conjunction with the mechanical and rheological properties of these nanocomposites. Detailed quantitative analyses of the dispersed clay particles revealed that the aspect ratio of clay particles decreased as clay content increased but increased as the amount of PP-g-MA increased. Analysis of the elastomer phase revealed that the aspect ratio of the elastomer phase increased in both cases. The presence of clay causes the elastomer particles to become highly elongated in shape and retards the coalescence of the elastomer particles. The modulus and yield strength are enhanced by increasing the PP-g-MA/organoclay ratios. High levels of toughness of the TPO can be maintained when moderate levels of (organoclay) MMT and PP-g-MA are used. The rheological properties suggested that the addition of clay particles and PP-g-MA has a profound influence on the long time stress relaxation of the TPO nanocomposites. Based on these analyses, it is clear that it is important to optimize the ratio of PP-g-MA and organoclay to obtain the desired balance of mechanical properties and processing characteristics for TPO nanocomposites.     

Extrusion foaming behavior of a polypropylene/nanoclay microcellular foam

With maleic anhydride grafted polypropylene (PP‐g‐MAH) as a compatibilizer, composites of block‐copolymerized polypropylene (B‐PP)/nanoclay were prepared. The effects of the PP‐g‐MAH and nanoclay content on the crystallization and rheological properties of B‐PP were investigated. The microcellular foaming behavior of the B‐PP/nanoclay composite material was studied with a single‐screw extruder foaming system with supercritical (SC) carbon dioxide (CO₂) as the foaming agent. The experimental results show that the addition of nanoclay and PP‐g‐MAH decreased the melt strength and complex viscosity of B‐PP. When 3 wt % SC CO₂ was injected as the foaming agent for the extrusion foaming process, the introduction of nanoclay and PP‐g‐MAH significantly increased the expansion ratio of the obtained foamed samples as compared with that of the pure B‐PP matrix, lowered the die pressure, and increased the cell population density of the foamed samples to some extent. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44094.     

Dynamic mechanical properties and morphology of polypropylene/maleated polypropylene blends

The dynamic mechanical properties of both homopolypropylene (PPVC)/Maleated Poly-propylene (PP-g-MA) and ethylene-propylene block copolymer (PPSC)/Maleated Poly-propylene (PP-g-MA) blends have been studied by using a dynamic mechanical thermal analyzer (PL-DMTA MKII) over a wide temperature range, covering a frequency zone from 0.3 to 30 Hz. With increasing content of PP-g-MA, α relaxation of both blends gradually shift to a lower temperature and the apparent activation energy ΔE_α increases. In PPVC/PP-g-MA blends, β relaxation shifts to a higher temperature as the content of PP-g-MA increases from 0 to 20 wt % and then change unobviously for further varying content of PP-g-MA from 20 to 35 wt %. On the contrary, in the PPSC/PP-g-MA blends β₁ relaxation, the apparent activation energy ΔE_β1 and β₂ relaxation are almost unchanged with blend composition, while ΔE_β2 increases with an increase of PP-g-MA content. In the composition range studied, storage modulus É value for PPSC/PP-g-MA blends decreases progressively between β₂ and α relaxation with increasing temperature, but in the region the increment for PPVC/PP-g-MA blends is independent of temperature. The flexural properties of PPVC/PP-g-MA blend show more obvious improvement on PP than one of PPSC/PP-g-MA blends. Scanning electron micrographs of fracture surfaces of the blends clearly demonstrate two-phase morphology, viz. the discrete particles homogeneously disperse in the continous phase, the main difference in the morphology between both blends is that the interaction between the particles and the continuous phase is stronger for for PPVC/PP-g-MA than for PPSC/PP-g-MA blend. By the correlation of the morphology with dynamic and mechanical properties of the blends, the variation of the relaxation behavior and mechanical properties with the componenet structure, blend composition, vibration frequency, and as well as the features observed in these variation are reasonably interpreted. © 1996 John Wiley & Sons, Inc.     

Polypropylene–clay micro/nanocomposites as fused deposition modeling filament: effect of polypropylene-g-maleic anhydride and organo-nanoclay as chemical and physical compatibilizers

Amongst various polymers used as fused deposition modeling filaments, polypropylene is one which undergoes rigorous shrinkage during printing. This is a drawback for 3D-printer process and related applications, and to overcome this hurdle, mostly, mineral fillers are utilized; however, this additive reduces mechanical properties. To enhance mechanical and shrinkage properties, unmodified clay sheets extracted from bentonite mineral were used as a reinforcing agent, polypropylene grafted maleic anhydride (PP-g-MA) and nanoclay were used as compatibilizers. The compounding was carried out by a twin-screw extruder rather than a single-screw extruder to procure filaments. Afterwards, with fused deposition modeling, dumb-bells and disks were produced for testing. Scanning electron microscopy was employed to examine the morphological feature and dispersion of nanoclay and montmorillonite in the composites. X-ray diffraction was also used to study the dispersion of the nanoclays. The composite disks and dumb-bells were fabricated with a 3D printer to evaluate their rheological properties. Our results showed that the complex viscosity decreased drastically due to aligning the polymer chains along the clay sheets. Mechanical property measurements revealed that the tensile modulus was improved by 60% compared to that of the PP.

     

The Effect of Spray-Freeze Drying of Montmorillonite on the Morphology,Dispersion, and Crystallization in Polypropylene Nanocomposites

The spray-freeze drying (SFD) technique was applied to sonicated aqueous suspensions of spray-dried montmorillonite clay (MMT) to produce highly porous agglomerates (SFD-MMT). Both MMT (used as a reference) and SFD-MMT were subsequently incorporated in polypropylene (PP) via melt compounding to produce 2 wt % nanocomposites with and without maleic anhydride grafted polypropylene (PP-g-MA). Polypropylene nanocomposites containing SFD-MMT exhibited thinner silicate flake layers compared to large agglomerates in PP/MMT nanocomposites. SFD-MMT particles became even more finer in the presence of PP-g-MA (i.e., in PP/PP-g-MA /SFD-MMT) where it hindered PP crystallization instead of serving as nucleation sites for the PP crystallization during rapid cooling. SFD-MMT improved the thermal stability of PP/PP-g-MA by 30°C compared to only 5–8°C for MMT/nanocomposites. MMT acts as a heterogeneous nucleating agent in the nucleation-controlled PP nanocomposites, but the hindrance effect was observed for the PP/PP-g-MA with SFD-MMT. PP/PP-g-MA/SFD-MMT exhibited twice the edge surface energy as compared to PP/PP-g-MA/MMT. The incorporation of both types of MMT raised the tensile moduli of PP and PP/PP-g-MA, with no improvement in their tensile strength and a decrease in the elongation at break. The PP/PP-g-MA/SFD-MMT showed brittle failure. POLYM. ENG. SCI., 60:168–179, 2020. © 2019 Society of Plastics Engineers     

Effect of compatibilizer concentration on dynamic rheological behavior and morphology of thermoplastic starch/polypropylene blends

The reactive compatibilization of blends consisting polypropylene (PP) and thermoplastic starch (TPS) (70/30) with different portions of PP-grafted maleic anhydride (PP-g-MA) is carried out by melt mixing. The esterification reaction between the starch hydroxyl and the PP-g-MA groups proved by the FTIR leads to a compatibility improvement. The dynamic rheological properties, morphology, elongation at break, and the impact strength of the blends were studied. The SEM images show that increasing the compatibilizer concentration reduces the dispersed TPS droplet size. The generalized Zener model states that an elastic interface is established (minimum α value) and enables us to predict the dynamic rheological properties of our blends in a longer frequency range to where the current experimental limitation exists. The modified Cross model is implemented to confirm better adhesion between phases when 20 wt % PP-g-MA is used (minimum a_c value). The increase in the dynamic viscoelastic moduli at concentrations up to 20 wt % and the observed plateau at the elongation at break point at this concentration confirmed that this concentration is the optimum for the maximum stress transfer. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48742.     

Comparing the compatibility of various functionalized polypropylenes with thermoplastic polyurethane (TPU)

Three functionalized polypropylenes (PP), a maleated PP (PP-g-MA), primary amine functionalized PP (PP-g-NH₂), and secondary amine functionalized PP (PP-g-NHR), were melt blended with a thermoplastic polyurethane (TPU) at different compositions. Compatibility of each functionalized PP with TPU was compared by investigating the binary blends using rheological (mixer torques, dynamic shear rheometry), thermal (dynamic mechanical analysis), mechanical (tensile test), and morphological (scanning electron microscopy with image analysis, particle size analysis) measurements. Compatibility of the three functionalized PP's with TPU is ranked in a decreasing order as follows: PP-g-NHR≥PP-g-NH₂?PP-g-MA, which is attributed to higher reactivity of amine (primary and secondary) with urethane linkages. Accordingly, the TPU blends with the two types of amine functionalized PP's exhibited much better synergy, as reflected by much improved mechanical properties including higher tensile strength and ultimate elongation, and finer and more stable morphologies.     

Morphological,thermal, and mechanical properties of polypropylene/polycarbonate blend

This work deals with the effect of compatibilizer on the morphological, thermal, rheological, and mechanical properties of polypropylene/polycarbonate (PP/ PC) blends. The blends, containing between 0 to 30 vol % of polycarbonate and a compatibilizer, were prepared by means of a twin-screw extruder. The compatibilizer was produced by grafting glycidyl methacrylate (GMA) onto polypropylene in the molten state. Blend morphologies were controlled by adding PP-g-GMA as compatibilizer during melt processing, thus changing dispersion and interfacial adhesion of the polycarbonate phase. With PP-g-GMA, volume fractions increased from 2.5 to 20, and much finer dispersions of discrete polycarbonate phase with average domain sizes decreased from 35 to 3 μm were obtained. The WAXD spectra showed that the crystal structure of neat PP was different from that in blends. The DSC results suggested that the degree of crystallization of PP in blends decreased as PC content and compatibilizer increased. The mechanical properties significantly changed after addition of PP-g-GMA. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1857–1863, 1997     

Mechanical and morphological properties of elastomer-modified polypropylene/polyamide-6 blends

Polypropylene/polyamide-6 (70:30) blends, containing dispersed discrete polyamide-6 microphases as matrix reinforcement, represent attractive materials for engineering applications. In order to enhance impact resistance, ethene/propene (EPM) was incorporated as a second separately dispersed microphase using reactive blending technology. Blend morphologies were controlled by adding maleic-anhydride-grafted-polypropylene (PP-g-MA) as compatibilizer during melt processing, thus enhancing dispersion and interfacial adhesion of the polyamide-6 phase. With PP-g-MA volume fractions increasing from 2.5 to 10 vol %, much finer dispersions of discrete polyamide-6 with average domain sizes decreasing from 8 to 0.8 μm were obtained. When polyamide-6 and ethene/propene (EPM)-rubber are dispersed simultaneously in the polypropylene matrix, impact resistance was improved. The influence of PP-g-MA volume fraction and blend morphologies on mechanical properties such as Young's modulus, yield stress, notched Charpy impact resistance was investigated. The ternary polypropylene/polyamide-6/EPM blend properties were compared with those of binary polypropylene blends containing the equivalent volume fraction of EPM. © 1995 John Wiley & Sons, Inc.     

Compatibilization effectiveness of maleated polypropylene compared to organoclay in PBT/PP blends

The compatibilization efficiency of a conventional compatibilizer (PP-grafted maleic anhydride) is compared with an organoclay of hydrophilic modifier (Cloisite 30B) in poly(butylene terephthalate)/polypropylene (PBT/PP) immiscible polymer blend. Moreover, the effect of PP-grafted maleic anhydride (PP-g-MA) on localization of Cloisite 30B organoclays is investigated, in this research. Accordingly, PBT/PP blends containing PP-g-MA, organoclay and PP-g-MA/organoclay are prepared by melt mixing method. According to morphological analysis, organoclays are more efficient than PP-g-MA in dispersion and distribution of droplets in PBT/PP blend. Additionally, the size of dispersed-droplets in PBT/PP/organoclay nanocomposite is lower than PBT/PP/PP-g-MA/organoclay sample. From X-ray diffractometry (XRD) and transmission electron microscopy illustrations, it is shown that organoclays represent the higher level of intercalation structure in PBT/PP/organoclay compared to PBT/PP/PP-g-MA/organoclay nanocomposite. PBT/PP/Organoclay nanocomposite indicates higher viscosity and elasticity in comparison with PBT/PP/PP-g-MA/organoclay, as well. The present subject can be explained by the role of PP-g-MA in transferring some parts of organoclays from PBT matrix into PP droplets which hinders the break-up of dispersed-droplets. According to non-linear viscoelastic properties, PBT/PP/organoclay sample shows stronger stress overshoots than PBT/PP/PP-g-MA/organoclay in start-up of shear flow. Modified De Kee-Turcotte model is studied to investigate the yield stress and viscoelastic behavior of different samples. PBT/PP/Organoclay nanocomposite shows higher yield stress compared to PBT/PP blend filled by PP-g-MA/organoclay system.     

Rheologically determined phase behavior and miscibility of reactively compatibilized poly(ethylene terephthalate)/polypropylene blends

Rheology, phase behavior and morphology of poly(ethylene terephthalate)/polypropylene (PET/PP) blends compatibilized with maleic-anhydrate-grafted-PP (PP-g-MA) and n-butyl-acrylate-glycidyl-methacrylate-ethylene (EBGMA) were studied. According to infrared spectroscopy results, whereas PP-g-MA was merely capable of reacting with hydroxyl groups of PET, epoxy groups of EBGMA could react with both the hydroxyl and carboxyl end groups of PET. The enhanced compatibilizing effect of EBGMA on PET/PP systems over PP-g-MA was also revealed by scanning electron microscopy and mechanical experiments. From frequency and temperature sweep rheological experiments, the dynamic characteristics of the compatibilized blends found to be improved in comparison with those of the uncompatibilized system. Such enhancement was interpreted as a result of the higher miscibility of the compatibilized blends which was further supported by Cole–Cole plot analyses.     

Influence of the compatibilizer/nanoclay ratio on final properties of polypropylene matrix modified with montmorillonite-based organoclay

The use of nanoclays as additives for polymer matrices requires, in some cases (with non-polar matrices) the use of a compatibilizer agent which will act as a bridge or permanent buffer for nanoclay-matrix interaction. In this research, we have worked on the improvement of mechanical and thermal properties of polypropylene matrices by adding montmorillonite based nanoclays (MMT) which have been previously modified with an organic component (a quaternary ammonium salt modifier). In this particular case, we have worked on the optimization of the compatibilizer:nanoclay ratio. As a compatibilizer agent it has been used a propylene graft maleic anhydride copolymer (PP-g-MA) and the PP-g-MA:MMT ratio has varied from 0.25:1 to 4:1. Nanoclay dispersion and intercalation–exfoliation degree has been investigated by X-ray diffraction spectroscopy (XRD) and transmission electron microscopy (TEM). Also, mechanical and thermal properties for different PP-g-MA:MMT ratios have been determined. The results show optimum dispersion and intercalation–exfoliation levels for PP-g-MA:MMT ratios close to 3:1 and 4:1 and also we can observe a slight increase in mechanical and especially in thermal properties for similar ratios.     

Phase behaviors of poly(oxyethylene)-grafted polypropylene copolymers

A family of amphiphilic graft copolymers were prepared from a maleated polypropylene (PP-g-MA) and various crystalline poly(oxyethylene)-segmented amines of 1000 to 3000 molecular weight. Structurally, these copolymers consist of polypropylene (PP) backbone and several crystalline poly(oxyethylene) (POE) pendants in the structure. In the observation of their phase behaviors by using a differential scanning calorimeter (DSC), the interference between the POE segments and PP backbone was found. In a particular case (PP-g-MA/ED-2001), the heat of POE crystallization did not show off in the cooling curve of the DSC, but appeared during the consecutive heating process. Generally, heating and cooling patterns of the DSC analyses showed the shifts of melting and crystallizing temperatures, depending on the length and the termini of POE, from those of the starting materials— PP-g-MA and POE amines. The TGA and optical microscopy observation further supported the DSC analyses.     

An investigation on the mechanical and dynamic rheological properties of single and hybrid filler/polypropylene composites based on talc and calcium carbonate

Some results of experiments on the mechanical and rheological properties of mineral filled polypropylene were presented. Single filler and hybrid filler composites of talc and calcium carbonate (CaCO₃) were prepared in a co‐rotating twin‐screw extruder. The effect of filler type, filler content, and coupling agent on the mechanical and rheological properties of the polypropylene were studied. The coupling agent was maleic anhydride‐grafted polypropylene (PP‐g‐MA). It was found that the mechanical properties are affected by filler type, filler concentration, and the interaction between filler and matrix. The tensile strength of the composite is more affected by the talc while the impact strength is influenced mostly by CaCO₃ content. The elongation at break of PP/CaCO₃ composites was higher than that of PP/talc composites. The incorporation of coupling agent into PP/mineral filler composites increased the mechanical properties. Rheological properties indicated that the complex viscosity and storage modulus of talc filled samples were higher than those of calcium carbonate filled samples while the tan δ was lower. The rheological properties of hybrid‐filler filled sample were more affected by the talc than calcium carbonate. The PP‐g‐MA increased the complex viscosity and storage modulus of both single and hybrid composites. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers     

Effect of matrix features on polypropylene layered silicate nanocomposites

The aim of this study was to examine the effect of the polypropylene based resin on the properties of organoclay-PP nanocomposites prepared by melt compounding using a twin screw extruder.The characterization of the obtained materials was performed by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), melt flow rate (MFR) and mechanical tests.The study has shown the effect of the polymer matrix molecular weight on the possibility of producing by melt compounding nanocomposites based on PP homopolymers or heterophasic PP-PE copolymers and an organically modified montmorillonite, in presence of maleic anhydride-modified polypropylene (PP-g-MAH).An increase of mechanical properties was achieved both for homopolymers and heterophasic copolymers. However the reinforcing effect of clay dispersed in heterophasic copolymers was not as high as found for the homopolymers.     

Aniline-Modified Polypropylene as a Compatibilizer in Polypropylene Carbon Nanotube Composites

Maleic anhydride-grafted polypropylene (PP-g-MA) was reacted with aniline (NH₂C₆H₅) to produce PP-g-NHC₆H₅ and used as a compatibilizer in polypropylene/carbon nanotube composites. Infrared spectroscopy (FTIR) and nuclear magnetic resonance confirmed the reaction between PP-g-MA and aniline. PP-g-NHC₆H₅ resulted a better compatibilizer than PP-g-MA, producing good dispersion and homogeneous distribution of the carbon nanotubes with less agglomerates, as observed by SEM analysis. Improved dispersion and distribution is assumed to be due to the π–π interactions between the –C₆H₅ ring in the prepared compatibilizer and the hexagonal carbon structure in the nanotubes. In addition, a higher degree of crystallinity (12%) was promoted, since it was favored by π–π interactions. This achieved higher crystallinity promoted an increase in tensile modulus, with only slight changes in tensile strength but with an adverse effect on elongation at break.     

The effect of compatibilizers and organically modified nanoclay on the morphology and performance properties of poly(acrylonitrile–butadiene–styrene)/polypropylene blends

In this study, poly(acrylonitrile–butadiene–styrene)/polypropylene (ABS/PP) blends with various compositions were prepared by melt intercalation in a twin‐screw extruder. Modifications of the above blends were performed by using organically modified montmorillonite (OMMT, Cloisite 30B) reinforcement as well as two types of compatibilizers, namely polypropylene grafted with maleic anhydride (PP‐g‐MAH) and ABS grafted with maleic anhydride (ABS‐g‐MAH). Increasing the PP content in ABS matrix seems to increase the melt flow and thermal stability of their blends, whereas a deterioration of the tensile properties was recorded. On the other hand, the addition of ABS to PP promotes the formation of the β‐crystalline phase, which became maximum at 30 wt% ABS concentration, and increases the crystallization temperature (T_c) of PP. A tendency for increase of T_c was also recorded by incorporation of the above compatibilizers, whereas the glass transition temperature (T_g) of PP and SAN phase in ABS was reduced. Regarding the Young's modulus, the greatest improvement was observed in pure ABS/PP blends containing organically modified nanoclay. However, in reinforced pure PP, the use of compatibilizers is recommended in order to improve the elastic modulus. The addition of OMMT to noncompatibilized and compatibilized ABS/PP blends significantly improves their storage modulus. POLYM. ENG. SCI., 56:458–468, 2016. © 2016 Society of Plastics Engineers     

Effects of clay contents on the dynamic mechanical and rheological properties of polypropylene/MAH‐g‐POE/clay composites

A series of polypropylene/maleic anhydride grafted polypropylene octane elastomer (MAH‐g‐POE)/clay (PPMC) nanocomposites were prepared with a novel compatilizer MAH‐g‐POE and different contents of octadecyl amine modified montmorillonite, and the effects of clay contents on the dynamic mechanical and rheological properties of these PPMC composites were investigated. With clay content increasing, the characteristic X‐ray diffraction peak changed from one to two with intensity decreasing, indicating the decreasing concentration of the intercalated clay layers. The gradual decrease of crystallization temperature of PPMC composites with the increase of clay loading should be attributed to the preferred intercalation of MAH‐g‐POE molecules into clay interlayer during blending, which is also reflected by scanning electron microscopy observations. By evaluating the activation energy for the glass transition process of MAH‐g‐POE and polypropylene (PP) in the PPMC composites, it is found that clay intercalation could cause the restriction effect on the glass transition of both MAH‐g‐POE and PP, and this restriction effect appears stronger for PP and attained the highest degree at 5 wt % clay loading. The melt elasticity of PP could be improved apparently by the addition of MAH‐g‐POE, and 5 wt % clay loading is enough for further enhancing the elastic proportion of PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009