Morphology and properties of polypropylene/ethylene–octene copolymer/clay nanocomposites with double compatibilizers

The influence of nanoclay on the morphology and properties of the polypropylene (PP)/ethylene–octene block copolymer (EOC) blend with double compatibilizers of maleated PP (PP‐g‐MA) and maleated EOC (EOC‐g‐MA) was investigated and compared with the nanocomposites containing either PP‐g‐MA or EOC‐g‐MA as a compatibilizer. X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy were utilized for morphological characterization in conjunction with dynamic mechanical thermal analysis, mechanical testing, and rheological evaluation of these nanocomposites. The results suggested that in the nanocomposite including both compatibilizers of PP‐g‐MA and EOC‐g‐MA, clay was dispersed as a mixed structure of intercalation and exfoliation in both phases of the polymer blend. Comparing the mechanical properties of the studied nanocomposite with nanocomposites of PP/EOC/PP‐g‐MA/clay and PP/EOC/EOC‐g‐MA/clay also indicated that the nanocomposite containing mixed compatibilizers displayed higher tensile modulus, tensile strength, and complex viscosity because of the better dispersion of clay in both phases. The results also confirmed the increased structural stability and reduced dispersed phase size of PP/EOC/PP‐g‐MA/EOC‐g‐MA blend in the presence of clay that proposed the compatibilization role of clay in this nanocomposite. Copyright © 2014 John Wiley & Sons, Ltd.     

Formation and Detection of Clay Network Structure in Poly(propylene)/Layered Silicate Nanocomposites

Summary: The study of the structure and the rheological properties of poly(propylene) (PP)/montmorillonite (MMT)/maleinated PP (MAPP) composites strongly suggests that a silicate network may form under certain conditions. Network formation could not be proven unambiguously with the usual techniques, i.e., with TEM and by plotting the frequency dependence of viscoelastic properties. Cole‐Cole plots detect the network very sensitively. A certain number of silicate layers are needed to create a house‐of‐cards structure. A threshold concentration of MAPP exists in the investigated system, which depends on the silicate content.

Cole‐Cole representation of the viscoelastic properties of PP/OMMT/MAPP nanocomposites.     

Ultra‐high molecular weight styrenic block copolymer/TPU blends for automotive applications: Influence of various compatibilizers

Thermoplastic elastomers (TPEs) based on new generation ultrahigh molecular weight styrene‐ethylene‐butylene‐styrene (SEBS) and thermoplastic polyurethane (TPU) are developed and characterized especially for automotive applications. Influence of maleic anhydride grafted styrene‐ethylene‐butylene‐styrene (SEBS‐g‐MA) and maleic anhydride grafted ethylene propylene rubber (EPM‐g‐MA) as compatibilizers has been explored and compared on the blends of SEBS/TPU (60:40). The amount of compatibilizers was varied from 0 to 10 phr. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies revealed the dramatic changes from a nonuniform to finer and uniform dispersed phase morphology. This was reflected in various mechanical properties. SEBS‐g‐MA modified blends showed higher tensile strength. EPM‐g‐MA modified blends also displayed considerable improvement. Elongation at break (EB) was doubled for the entire compatibilized blends. Fourier‐transform infrared spectrometry (FTIR) confirmed the chemical changes in the blends brought about by the interactions between blend components and compatibilizers. Both SEBS‐g‐MA and EPM‐g‐MA had more or less similar effects in dynamic mechanical properties of the blends. Additionally, melt rheological studies have also been pursued through a rubber process analyzer (RPA) to get a better insight.     

Characterization and thermal degradation of polypropylene-montmorillonite nanocomposites

Polypropylene (PP)-montmorillonite nanocomposites have been prepared using isotactic PP homopolymers with different rheological properties, and a maleic anhydride grafted PP. Morphology and structure of the composites were investigated by using X-ray techniques (WAXD, SAXS) and transmission electron microscopy (TEM). The absence of pristine clusters of the clay and the presence of intercalated and exfoliated structures were shown for all the investigated samples. The nanocomposite prepared by using maleic anhydride grafted PP showed a widespread exfoliation. The thermal behaviour and degradation have been studied by means of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The incorporation of the montmorillonite improves the thermal stability in air atmosphere of all the investigated PPs, thanks to a physical barrier effect of the silicate layers.     

Extruder‐made TPO nanocomposites. II. Effect of maleated poly(propylene)/organoclay ratio on morphology and thermal expansion behavior

Coefficients of linear thermal expansion (CTE) for poly(propylene)/ poly(propylene)‐grafted‐maleic anhydride/montmorillonite ethylene‐co‐octene elastomer (PP/PP‐g‐MA/MMT/EOR) blend nanocomposites were determined as a function of MMT content and various PP‐g‐MA/organoclay masterbatch ratios. The nanocomposites were prepared in a twin‐screw extruder at a fixed 30 wt % elastomer, 0–7 wt % MMT content, and various PP‐g‐MA/organoclay ratio of 0, 0.5, 1.0, and 1.5. The organoclay dispersion facilitated by the maleated PP helps to reduce the size of the dispersed phase elastomer particles in the PP matrix. The elastomer particle size decreased significantly as the PP‐g‐MA/organoclay ratio and MMT content increased; the elastomer particles viewed // to flow direction (FD) are smaller and less deformed compared to those viewed // to transverse direction (TD). The elastomer particle shape based on the view along the three orthogonal directions of the injection molded sample is similar to a prolate ellipsoid. The CTE decreased significantly in the FD and TD, whereas a slight increase is observed in the normal direction in the presence of MMT and PP‐g‐MA. The Chow model based on a two population approach showed better fit to experimental CTE when the effect of MMT and elastomer are considered individually. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B Polym. Phys. 2013 , 51, 952–965     

Reactive melt blends of thermoplastic polyolefins,MAH‐g‐PP and nylon 6

Reactive melt blends of an ethylene‐propylene‐diene terpolymer (EPDM) based thermoplastic elastomer (TPE), maleic anhydride grafted polypropylene (MAH‐g‐PP), and nylon 6 were prepared in a single screw extruder and evaluated in terms of morphological, rheological, thermal, dynamic mechanical, and mechanical properties of the blends. It was found that MAH‐g‐PP‐co‐nylon 6 copolymers were in situ formed and acted as effective compatibilizers for polypropylene (PP) and nylon 6. Phase separation of PP and EPDM in TPE increased with the addition and increasing amount of MAH‐g‐PP and nylon 6, leading to decreased glass transition temperature (T_g) of TPE and increased crystalline melting temperature (T_m) of PP. Copyright © 2004 John Wiley & Sons, Ltd.     

The effects of reprocessing cycles on the structure and properties of isotactic polypropylene/cloisite 15A nanocomposites

The effects of reprocessing cycles on the structure and properties of isotactic polypropylene (PP)/Cloisite 15A (OMMT) (5 wt. %) nanocomposites was studied in presence of maleic anhydride-grafted-polypropylene (PP-g-MA) (20 wt. %) used as the compatibiliser to improve the clay dispersion in the polymer matrix. The various nanocomposite samples were prepared by direct melt intercalation in an internal mixer, and further they were subjected to 4 reprocessing cycles. For comparative purposes, the neat PP was also processed under the same conditions. The nanocomposite structure and the clay dispersion have been characterized by wide angle X-ray scattering (WAXS), transmission electron microscopy (TEM) and rheological measurements. Other characterization techniques such as Fourier transform infrared spectroscopy (FT-IR), tensile measurements, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) have also been used to evaluate the property changes induced by reprocessing. The study showed through XRD patterns that the repetitive reprocessing cycles modified the initial morphology of PP/OMMT nanocomposites by improving the formation of intercalated structure, especially after the fourth cycle. Further, the addition of PP-g-MA promoted the development of intercalated/exfoliated silicate layers in the PP matrix after the second cycle. These results are in agreement with TEM observations indicating an improved silicate dispersion in the polymer matrix with reprocessing cycles displaying a morphology with both intercalated/exfoliated structures. The initial storage modulus (G′) of the nanocomposites, which was highly improved in presence of PP-g-MA seems to be less affected by reprocessing cycles at very low frequencies exhibiting a quasi-plateau compared to pristine PP/OMMT and PP. In contrast, the complex viscosity was found to decrease for the whole samples indicating that the main effect of reprocessing was a decrease in the molecular weight. Moreover, the thermal and mechanical properties of the nanocomposites were significantly reduced after the first cycle; nevertheless they remained almost unchanged during recycling. No change in the chemical structure was observed in the FT-IR spectra for both the nanocomposites and neat PP samples after 4 cycles.     

Structural and mechanical behavior of polypropylene/ maleated styrene‐(ethylene‐co‐butylene)‐styrene/sisal fiber composites prepared by injection molding

Hybrid composites consisting of isotactic poly(propylene) (PP), sisal fiber (SF), and maleic anhydride grafted styrene‐(ethylene‐co‐butylene)‐styrene copolymer (MA‐SEBS) were prepared by melt compounding, followed by injection molding. The melt‐compounding torque behavior, thermal properties, morphology, crystal structure, and mechanical behavior of the PP/MA‐SEBS/SF composites were systematically investigated. The torque test, thermogravimetric analysis, differential scanning calorimetric, and scanning electron microscopic results all indicated that MA‐SEBS was an effective compatibilizer for the PP/SF composites, and there was a synergism between MA‐SEBS and PP/SF in the thermal stability of the PP/MA‐SEBS/SF composites. Wide‐angle X‐ray diffraction analysis indicated that the α form and β form of the PP crystals coexisted in the PP/MA‐SEBS/SF composites. With the incorporation of MA‐SEBS, the relative amount of β‐form PP crystals decreased significantly. Mechanical tests showed that the tensile strength and impact toughness of the PP/SF composites were generally improved by the incorporation of MA‐SEBS. The instrumented drop‐weight dart‐impact test was also used to examine the impact‐fracture behavior of these composites. The results revealed that the maximum impact force (F_max), impact‐fracture energy (E_T), total impact duration (t_r), crack‐initiation time (t_init), and crack‐propagation time (t_prop) of the composites all tended to increase with an increasing MA‐SEBS content. From these results, the incorporation of MA‐SEBS into PP/SF composites can retard both the crack initiation and propagation phases of the impact‐fracture process. These prolonged the crack initiation and propagation time and increased the energy consumption during impact fracture, thereby leading to toughening of PP/MA‐SEBS/SF composites. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1214–1222, 2002     

Synthesis and Characterization of PE-g-MA／MgAI-LDH Exfoliation Nanocomposite via Solution Intercalation

An organo‐modified MgAl‐layered double hydroxide (OMgAl‐LDH) was successfully exfoliated in the xylene solution of polyethylene‐grafted‐maleic anhydride (PE‐g‐MA) under re‐fluxing condition. A PE‐g‐MA/MgAl‐LDH exfoliation nanocomposite was formed after the precipitation of PE‐g‐MA from the dispersion system. The structure and thermal property of the PE‐g‐MA/MgAl‐LDH exfoliation nanocomposite were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetry analysis (TGA). The disappearance of d₀₀₁ XRD peak of OMgAl‐LDH at 20 = 3.2° suggests that the MgAl hydroxide sheets are exfoliated in the nanocomposite. The TEM image shows that the MgAl hydroxide sheets of less than 70 nm in length or width are exfoliated and dispersed disorderly in PE‐g‐MA matrix. TGA profiles indicate that the PE‐g‐MA/MgAl‐LDH nanocomposite with 5 wt% OMgAl‐LDH loading shows a faster charring process in temperature range from 210 to 390 °C and a greater thermal stability beyond 390 °C than PE‐g‐MA does. The decomposition temperature of the nanocomposite is 25 °C higher than that of PE‐g‐MA as measured at 50% weight loss. The PE‐g‐MA/MgAl‐LDH nanocomposite is promising for application of flame‐retardant polymeric materials.     

Impact‐modified polypropylene/vermiculite nanocomposites

Impact‐modified polypropylene (PP)/vermiculite (VMT) nanocomposites toughened with maleated styrene–ethylene butylene–styrene (SEBS‐g‐MA) were compounded in a twin‐screw extruder and injection‐molded. VMT was treated with maleic anhydride, which acted both as a compatibilizer for the polymeric matrices and as a swelling agent for VMT in the nanocomposites. The effects of the impact modifier on the morphology and the impact, static, and dynamic mechanical properties of the PP/VMT nanocomposites were investigated. Transmission electron microscopy revealed that an exfoliated VMT silicate layer structure was formed in ternary (PP–SEBS‐g‐MA)/VMT nanocomposites. Tensile tests showed that the styrene–ethylene butylene–styrene additions improved the tensile ductility of the (PP–SEBS‐g‐MA)/VMT ternary nanocomposites at the expense of their tensile stiffness and strength. Moreover, Izod impact measurements indicated that the SEBS‐g‐MA addition led to a significant improvement in the impact strength of the nanocomposites. The SEBS‐g‐MA elastomer was found to be very effective at converting brittle PP/VMT organoclay composites into tough nanocomposites. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2332–2341, 2003     

Preparation and characterization of PP/clay nanocomposites based on modified polypropylene and clay

X‐ray diffraction and differential scanning calorimeter (DSC) methods have been used to investigate the crystallization behavior and crystalline structure of hexamethylenediamine (HMDA)‐modified maleic‐anhydride‐grafted polypropylene/clay (PP‐g‐MA/clay) nanocomposites. These nanocomposites have been prepared by using HMDA to graft the PP‐g‐MA (designated as PP‐g‐HMA) and then mixing the PP‐g‐HMA polymer in hot xylene solution, with the organically modified montmorillonite. Both X‐ray diffraction data and transmission electron microscopy images of PP‐g‐HMA/clay nanocomposites indicate that most of the swellable silicate layers are exfoliated and randomly dispersed into PP‐g‐HMA matrix. DSC isothermal results revealed that introducing 5 wt % of clay into the PP‐g‐HMA structure causes strongly heterogeneous nucleation, which induced a change of the crystal growth process from a three‐dimensional crystal growth to a two‐dimensional spherulitic growth. Mechanical properties of PP‐g‐HMA/clay nanocomposites performed by dynamic mechanical analysis show significant improvements in the storage modulus when compared to neat PP‐g‐HMA. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3242–3254, 2005     

Comparative analysis of nanocomposites based on polypropylene and different montmorillonites

Nanocomposites of polypropylene (PP) were prepared by melt mixing using maleic anhydride modified polypropylene (PPg) and different organophilic montmorillonites (OMMT). The selected organo-modified clays differ in their initial particle size, amount and type of surfactant and/or their cation-exchange capacity. All composites have 80, 15 and 5 wt% of PP, PPg and OMMT, respectively. The materials were characterized using TGA, XRD, SEM and rotational rheometry. Cloisite 15A, Cloisite 93A, Nanomer I44 and a bentonite modified with octadecylammonium (B18) display intercalation and exfoliation after mixing and annealing and produce nanocomposites with different degrees of ‘solid-like’ rheological behavior. The composites based in Cloisite 15A and Nanomer I44, which use the same intercalant, show very similar phase structure and rheological response, regardless of the origin and initial characteristics of the clays. These nanocomposites are the most affected by the thermal history during rheological characterization in the molten state. On the other hand, Cloisite 10A and Cloisite 30B display collapse of the silicate layers after compounding with no evidence of exfoliation.     

Preparation and characterization of polypropylene and waste tire powder modified by allylamine blends

Waste tire powder subjected to allylamine modification in the presence of ultraviolet (UV) radiation has been used to prepare polypropylene based thermoplastic vulcanizates with maleic anhydride polypropylene (MA‐PP) as compatibilizer. The effect of increasing the concentration of MA‐PP on performance characteristics like tensile strength, elongation and rheological properties have been investigated. X‐ray diffraction studies of the PP/waste tire powder blend indicate the disappearance of β crystalline peaks on addition of waste tire powder in the PP, whereas it is observed in the allylamine modified rubber powder loaded PP. Differential scanning calorimetry results further supported the above fact. The improvement in mechanical properties of the PP/allylamine modified rubber powder loaded thermoplastic vulcanizates has been explained in terms of βα transformation of PP crystals during straining of the samples and uniform dispersion of allylamine coated rubber powder in the PP matrix. The melt rheological properties of the thermoplastic vulcanizates loaded with modified rubber powder are higher than its counterpart due to the higher dispersion as a result of chemical interaction between the rubber powder surface with the MA‐PP. Copyright © 2008 John Wiley & Sons, Ltd.     

Syndiotactic poly(propylene)/organoclay nanocomposite fibers: influence of the nano‐filler and the compatibilizer on the fiber properties

Melt spinning of nanocomposites prepared from syndiotactic poly(propylene) (sPP) and organolayered silicate (M‐ODA), containing bound octadecyl ammonium chains, was investigated. The influence of the nano‐filler reinforcement and the role of the addition of maleic anhydride grafted isotactic poly(propylene) (iPP‐g‐MA) as compatibilizer with respect to the fiber proportion was examined. The presence of nano‐filler, the drawing ratio, and the compatibilizer addition afforded increased tenacity of the fibers. Only in the presence of the compatibilizer high drawing ratio of the sPP nanocomposite fibers was achieved. Transmission electron microscopy (TEM) was applied to monitor morphology development during nanocomposite fiber spinning in the presence and the absence of the compatibilizer. Copyright © 2005 John Wiley & Sons, Ltd.     

Melt rheology of polypropylene containing small amounts of high molecular weight chain. I. Shear flow

Large enhancements of the melt strength of polypropylene (PP) were achieved by the introduction of high molecular weight polyethylene (PE) into PP. The viscoelastic properties of the high‐melt‐strength PP melts under shear flow were investigated. It was found that the rheological properties of the high‐melt‐strength PP were distinctly different from those of conventional PP. The elastic response at low frequencies was significantly enhanced in comparison with the conventional PP, implying a presence of a long relaxation time mode that was not revealed in conventional PP. In step‐shear measurements, the fast and slow relaxation processes that characterized the linear viscoelastic properties were observed also for nonlinear relaxation moduli. The dependence of the damping for the slow process of the high‐melt‐strength PP on shear strain was much weaker than that of the fast process. These rheological behaviors characterizing the long relaxation time mode were further enhanced with the increasing concentration of high molecular mass PE. The unusual shear rheological behaviors were discussed in view of the role of high molecular weight PE as a long relaxation time mode within PP. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2692–2704, 2001     

Preparation of poly(propylene)/clay layered nanocomposites by melt intercalation from pristine montmorillonite (MMT)

Poly(propylene)/clay nanocomposites were prepared by melt intercalation, using pristine montmorillonite (MMT), hexadecyl trimethyl ammonium bromide (C16), poly(propylene) (PP) and maleic acid (MA) modified PP (MAPP), The nanocomposites structure is demonstrated using X‐ray diffraction (XRD) and high resolution electronic microscopy (HREM). Our purpose is to provide a general concept for manufacturing polymer nanocomposites by melt intercalation starting from the pristine MMT. We found different kneaders (twin‐screw extruder or twin‐roll mill) have influence on the morphology of the PP/clay nanocomposites. Thermogravimetric analysis (TGA) shows that the thermal stability of PP/clay nanocomposites has been improved compared with that of pure PP. Copyright © 2003 John Wiley & Sons, Ltd.     

Polyamide 66/EPR‐g‐MA blends: mechanical modeling and kinetic analysis of thermal degradation

The present investigation deals with the mechanical, thermal, and morphological properties of binary nylon 66/maleic anhydride grafted ethylene propylene rubber (EPR‐g‐MA) blends at different dispersed phase (EPR‐g‐MA) concentrations. The effects of EPR‐g‐MA concentration and dispersed particle size on the mechanical properties of the blends were studied. Analysis of the tensile data in terms of various theoretical models revealed the variation of stress concentration effect with blend composition and the improvement of interfacial adhesion between dispersed rubber phase and nylon 66 matrix. The thermal degradation of the blends was analyzed by nonisothermal thermogravimetric analysis (TGA). It was found that the activation energy (E_a) and overall reaction order of thermal degradation decreased with increasing EPR‐g‐MA content. The scanning electron microscopic (SEM) analysis showed a significant decrease in dispersed particle size with increasing EPR‐g‐MA content, which was explained on the basis of the level of chemical interaction (in situ compatibilization) between nylon 66 and EPR‐g‐MA. The surface morphology of the nylon 66/EPR‐g‐MA blends was illustrated by the roughness of atomic force microscopy (AFM) images. Copyright © 2008 John Wiley & Sons, Ltd.     

Mechanical properties and structural characteristics of PP/PP‐g‐SBR nanocomposites prepared by dynamical photografting

Poly(propylene) (PP)/PP grafted styrene‐butadiene rubber (PP‐g‐SBR) nanocomposite was prepared by blending PP with PP‐g‐SBR using dynamical photografting. The crystal morphological structure, thermal behavior, and mechanical properties of PP/PP‐g‐SBR nanocomposites have been studied by photoacoustic Fourier transform infrared spectroscopy (PAS‐FT‐IR), wide‐angle X‐ray diffraction (WAXD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and mechanical measurements. The data obtained from the mechanical measurements show that the PP‐g‐SBR as a modifier can considerably improve the mechanical properties of PP/PP‐g‐SBR nanocomposites, especially for the notched Izod impact strength (NIIS). The NIIS of the nanocomposite containing 2 wt% PP‐g‐SBR measured at 20°C is about 2.6 times that of the control sample. The results obtained from PAS‐FTIR, WAXD, SEM, and DSC measurements revealed the enhanced mechanism of impact strength of PP/PP‐g‐SBR nanocomposites as follows: (i) the β‐type crystal of PP formed and its content increased with increasing the photografting degree of PP‐g‐SBR; (ii) the size of PP‐g‐SBR phase in the PP/PP‐g‐SBR nanocomposites obviously reduced and thus the corresponding number of PP‐g‐SBR phase increased with increasing the photografting degree of PP‐g‐SBR. All the earlier changes on the crystal morphological structures are favorable for increasing the compatibility and enhancing the toughness of PP at low temperature. Copyright © 2004 John Wiley & Sons, Ltd.     

Extruder‐made TPO nanocomposites. I. Effect of maleated polypropylene and organoclay ratio on the morphology and mechanical properties

PP/PP‐g‐MA/MMT/EOR blend nanocomposites were prepared in a twin‐screw extruder at fixed 30 wt % elastomer and 0 to 7 wt % MMT content. Elastomer particle size and shape in the presence of MMT were evaluated at various PP‐g‐MA/organoclay masterbatch ratios of 0, 0.5, 1.0, and 1.5. The organoclay dispersion facilitated by maleated polypropylene serves to reduce the size of the elastomer dispersed phase particles and facilitates toughening of these blend nanocomposites. The rheological data analysis using modified Carreau‐Yasuda model showed maximum yield stress in extruder‐made nanocomposites compared with nanocomposites of reactor‐made TPO. Increasing either MMT content or the PP‐g‐MA/organoclay ratio can drive the elastomer particle size below the critical particle size below which toughness is dramatically increased. The ductile‐brittle transition shift toward lower MMT content as the PP‐g‐MA/organoclay ratio is increased. The D‐B transition temperature also decreased with increased MMT content and masterbatch ratio. Elastomer particle sizes below ～1.0 μm did not lead to further decrease in the D‐B transition temperature. The tensile modulus, yield strength, and elongation at yield improved with increasing MMT content and masterbatch ratio while elongation at break was reduced. The modified Mori‐Tanaka model showed better fit to experimental modulus when the effect of MMT and elastomer are considered individually. Overall, extruder‐made nanocomposites showed balanced properties of PP/PP‐g‐MA/MMT/EOR blend nanocomposites compared with nanocomposites of reactor‐made TPO. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

Effects of functionalized multiwalled carbon nanotubes on the morphologies and mechanical properties of PP/EVA blend

The maleic anhydride‐grafted multiwalled carbon nanotubes (MWCNTs‐g‐MA) have been introduced into polypropylene/ethylene‐co‐vinyl acetate (PP/EVA) blend. To clearly describe the effects of MWCNTs‐g‐MA on the morphology and mechanical properties of PP/EVA blends, the selective distribution of MWCNTs‐g‐MA in the blends is realized through different sample preparation methods, namely, MWCNTs‐g‐MA disperse in EVA phase and MWCNTs‐g‐MA disperse in PP matrix. The results show that the distribution of MWCNTs‐g‐MA has an important effect on the final morphology of EVA and the crystallization structure of PP matrix. Compared with PP/EVA binary blend, distribution of MWCNTs‐g‐MA in PP matrix induces the aggregation of EVA phase at high EVA content and the decrease of spherulite diameters of PP matrix simultaneously. However, when MWCNTs‐g‐MA are dispersed in the EVA phase, they induce more homogeneous distribution of EVA, and the crystallization behavior of PP is slightly affected by MWCNTs‐g‐MA. The corresponding mechanical properties including impact strength and tensile strength are tested and analyzed in the work. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1481–1491, 2009