Melt processing and characterization of polypropylene/pristine montmorillonite nanocomposite: Influence of compatibilizer and hyperbranched polymer

In the present investigation, nanocomposites of polypropylene (PP)‐montmorillonite (MMT) clay were prepared by a single‐step compounding method to study the influence of hyperbranched polyester (HBPE) on rheological and mechanical properties of PP composites in the presence of a compatibilizer. In service of this objective, polyvinylchloride‐grafted‐maleic anhydride (PP‐g‐MA) was used as a compatibilizer for hydrophobic PP and hydrophilic clay. Rheological property in terms of melt viscosity was examined by a Brabender torque rheometer. The composite's morphology was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), whereas the dispersion state of nanoparticles in the PP matrix was studied by X‐ray diffraction (XRD). The thermal behavior of nanocomposites was examined by differential scanning calorimetry (DSC). The analysis of results confirmed that the interactions among both additives significantly influenced the morphology, rheology, and thermomechanical properties of the nanocomposites. J. VINYL ADDIT. TECHNOL., 22:72–79, 2016. © 2014 Society of Plastics Engineers     

The effect of clay type and of clay–masterbatch product in the preparation of polypropylene/clay nanocomposites

Clay containing polypropylene (PP) nanocomposites were prepared by direct melt mixing in a twin screw extruder using different types of organo‐modified montmorillonite (Cloisite 15 and Cloisite 20) and two masterbatch products, one based on pre‐exfoliated clays (Nanofil SE 3000) and another one based on clay–polyolefin resin (Nanomax‐PP). Maleic anhydride‐grafted polypropylene (PP‐g‐MA) was used as a coupling agent to improve the dispersability of organo‐modified clays. The effect of clay type and clay–masterbatch product on the clay exfoliation and nanocomposite properties was investigated. The effect of PP‐g‐MA concentration was also considered. Composite morphologies were characterized by X‐ray diffraction (XRD), field emission gun scanning electron microscopy (FEG‐SEM), and transmission electron microscopy (TEM). The degree of dispersion of organo‐modified clay increased with the PP‐g‐MA content. The thermal and mechanical properties were not affected by organo‐modified clay type, although the masterbatch products did have a significant influence on thermal and mechanical properties of nanocomposites. Intercalation/exfoliation was not achieved in the Nanofil SE 3000 composite. This masterbatch product has intercalants, whose initial decomposition temperature is lower than the processing temperature (T ～ 180°C), indicating that their stability decreased during the process. The Nanomax‐PP composite showed higher thermal and flexural properties than pure PP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Exfoliation targeted toughness enhancement in polypropylene‐blend‐ montmorillonite nanocomposites

BACKGROUND: Both exfoliated and toughened polypropylene‐blend‐montmorillonite (PP/MMT) nanocomposites were prepared by melt extrusion in a twin‐screw extruder. Special attention was paid to the enhancement of clay exfoliation and toughness properties of PP by the introduction of a rubber in the form of compatibilizer toughener: ethylene propylene diene‐based rubber grafted with maleic anhydride (EPDM‐g‐MA). RESULTS: The resultant nanocomposites were characterized using X‐ray diffraction, atomic force microscopy, scanning electron microscopy, thermogravimetric analysis, dynamic mechanical analysis and Izod impact testing methods. It was found that the desired exfoliated nanocomposite structure could be achieved for all compatibilizer to organoclay ratios as well as clay loadings. Moreover, a mechanism involving a decreased size of rubber domains surrounded with nanolayers as well as exfoliation of the nanolayers in the PP matrix was found to be responsible for a dramatic increase in impact resistance of the nanocomposites. CONCLUSION: Improved thermal and dynamic mechanical properties of the resultant nanocomposites promise to open the way for highly toughened super PPs via nanocomposite assemblies even with very low degrees of loading. Copyright © 2008 Society of Chemical Industry     

Solid‐state graft polymerization of styrene in spherical polypropylene particles in the presence of montmorillonite

In this work, cetyltrimethyl ammonium bromide and methacryloyloxyethyhrimethyl ammonium chloride were used to prepare organophilic montmorillonite (O‐MMT). Then, polypropylene (PP)–clay nanocomposites were prepared by the in situ grafting polymerization of styrene (St)‐containing O‐MMT onto PP with tert‐butyl perbenzoate as an initiator in the solid state. Fourier transform infrared spectroscopy, gel permeation chromatography, transmission electron microscopy, and X‐ray diffraction were applied to study the structure of the layered silicate and modified PP. The surfaces of the composites and, thus, the distribution of the clay in the PP matrix were characterized by scanning electron microscopy. The rheology and mechanical properties were studied and are discussed. According to the characterization results, OMMT and St were already grafted onto the PP main chain. Also, the intercalated structure of montmorillonite could be stabilized, and a stable exfoliated structure could be attained. Namely, intercalated PP/OMMT nanocomposites were obtained. The rheological results clearly show that these PP/OMMT nanocomposites had long‐chain‐branched structures. The peroxide modification of PP had minor effects on the tensile and bending strengths of the modified PP; however, this modification resulted in a significant reduction in the impact strength. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Combination of double‐modified clay and polypropylene‐graft‐maleic anhydride for the simultaneously improved thermal and mechanical properties of polypropylene

Double‐modified montmorillonite (MMT) was first prepared by covalent modification of MMT with 3‐aminopropyltriethoxysilane and then intercalation modification by tributyl tetradecyl phosphonium ions. The obtained double‐modified MMT was melt compounded with polypropylene (PP) to obtain nanocomposites. The dispersion of the double‐modified MMT in PP was found to be greatly improved by the addition of PP‐graft‐maleic anhydride (PP‐g‐MA) as a “compatibilizer,” whose anhydride groups can react with the amino groups on the surface of the double‐modified MMT platelets and thus improve the dispersion of MMT in PP. Fourier transform infrared, X‐ray diffraction, transmission electron microscopy, thermogravimetric analysis, scanning electron microscopy, and tensile test were used to characterize the structure of the double‐modified MMT, morphology, and the thermal and mechanical properties of the nanocomposites. The results show that PP‐g‐MA promotes the formation of exfoliated/intercalated morphology and obviously increases the thermal properties, tensile strength, and Young's modulus of the PP/double‐modified MMT nanocomposites. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Enhancing antibacterial properties of polypropylene/Cu‐loaded montmorillonite nanocomposite filaments through sheath–core morphology

Polypropylene (PP) loaded with copper‐exchanged montmorillonite (Cu‐MMT) nanocomposite filaments and films with excellent antimicrobial activity have been reported for the first time. A sheath–core morphology filament in which only the sheath contains Cu‐MMT was prepared for maximizing bioactivity. Sodium MMT clay was modified to acid‐activated MMT and further to Cu‐MMT via an ion exchange process. The exchange operation was confirmed using wide‐angle X‐ray diffraction and energy‐dispersive X‐ray spectroscopy (EDX) which suggested increased interlayer spacing and confirmed the loading of copper in Cu‐MMT. Further, Cu‐MMT was melt‐mixed in PP in the form of PP/Cu‐MMT nanocomposite filament, film and sheath–core morphology PP/Cu‐MMT nanocomposite filament. The surface morphology and elemental composition of the nanocomposites were studied using scanning electron microscopy coupled with EDX. Transmission electron micrographs were obtained to understand the dispersion characteristics of Cu‐MMT phase in PP. X‐ray diffraction analysis of nanocomposites suggested increased crystallinity at lower loading due to heterogeneous nucleating action of MMT. The PP nanocomposite filaments and films were tested for antimicrobial activity against Gram‐negative bacterium Escherichia coli, which is the main pathogenic bacterium found abundantly in water, and were found to exhibit excellent antimicrobial activity. © 2018 Society of Chemical Industry     

Effect of montmorillonoite modification and maleic anhydride‐grafted polypropylene on the microstructure and mechanical properties of polypropylene/montmorillonoite nanocomposites

Two types of modified montmorillonite (MMT) were achieved using octadecylamine as the modifying agent by the methods of dry process and wet route. Polypropylene (PP)/MMT nanocomposites were prepared using the melt mixing technique and employing maleic anhydride‐grafted polypropylene (PP‐MA) as the compatibilizer. The modification of montmorillonite was characterized by fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), and scanning electron microscope (SEM). The effect of MMT modification and PP‐MA on the microstructure and properties of PP/MMT nanocomposites was investigated by SEM, differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and polarizing microscopy. The results show that organic montmorillonite modified by wet process (WOMMT) has a large d‐spacing increment; whereas montmorillonite modified by dry process (DOMMT) shows little d‐spacing increment. Furthermore, the mechanical properties of composites incorporating WOMMT are better than that containing DOMMT. As a third component, the addition of PP‐MA benefits the formation of exfoliated structure and the dispersion of MMT in PP matrix, and hence, enhances the physical properties of the nanocomposite. With the presence of PP‐MA, the highly dispersed MMT increases the number of spherulite crystals, enhances the melting enthalpy, improves the thermal stability, and induces the desired tiny crazes more effectively. MMT increases the storage modulus (E′) and glass‐transition temperature (T_g) of PP because of the stiffness of MMT layers, but PP‐MA decreases them owing to its high melt flow index, both of which were in favor of improving the physical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3952–3960, 2013     

Preparation and properties of polypropylene filled with organo‐montmorillonite nanocomposites

Organo‐Montmorillonite (Org‐MMT)/maleic anhydride grafted polypropylene (PP‐g‐MAH)/polypropylene nanocomposites have been prepared by melt blending with twin‐screw extruder. The mechanical properties of the nanocomposites and the dispersion of Org‐MMT intercalated by the macromolecular chain were investigated by transmission electron microscopy and mechanical tests. The crystal properties of the nanocomposites have been tested by a differential scanning calorimeter. The thermal properties of the nanocomposites were investigated by thermo gravimetric analysis. The results show that not only the impact property but also the tensile property and the bending modulus of the system have been increased evidently by the added Org‐MMT. The Org‐MMT has been dispersed in the matrix in the nanometer scale. With the addition of the Org‐MMT, the melting point and the crystalling point of the nanocomposites increased; the total velocity of crystallization of the nanocomposites also increased. Thermal stability of the nanocomposites is increased by the filled Org‐MMT. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2875–2880, 2006     

Effects of the nature and combinations of solvents in the intercalation of clay with block copolymers on the properties of polymer nanocomposites

Polystyrene (PS) nanocomposites were prepared by the free‐radical polymerization of styrene in the presence of organically modified montmorillonite (MMT) clays. MMT clay was modified with a low‐molecular‐weight and quarternized block copolymer of styrene and 4‐vinylpyridine [poly(styrene‐b‐4‐vinylpyridine) (SVP)] with 36.4 wt % PS and 63.6 wt % poly(4‐vinylpyridine) (P4VP). Special attention was paid to the modification, which was carried out in different compositions of a solvent mixture of tetrahydrofuran (THF) and water. The swelling behavior of the MMT clay was studied by an X‐ray diffraction technique. The diffraction peak shifted to lower 2θ angles for all of the modified clays, which indicated the intercalation of the quarternized SVP copolymer into the MMT layers in different degrees. Higher interlayer distances, which showed a high degree of block copolymer insertion, were obtained for solvent compositions with THF in water. The resultant nanocomposites were characterized by X‐ray diffraction, atomic force microscopy, scanning electron microscopy, thermogravimetric analysis, and dynamic mechanical analysis. The desired exfoliated nanocomposite structure was achieved when the MMT modification was conducted in 50 or 66 wt % THF, whereas the other modifications all resulted in intercalated structures. The resulting exfoliated nanocomposite was found to have better thermal stability and dynamic mechanical performance compared to the others, even with 2% clay loading. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Studies on morphology and mechanical properties of dispersing intercalated silane montmorillonite in polypropylene matrix

We used a plastograph‐mixer by the twin‐screw mixed method to obtain the standard shaped specimens of polymer‐clay nanocomposites (PCN) to prepare polypropylene (PP)/silane montmorillonite (MMT) nanocomposites pellets, grafting with two kinds of different surfactant—hard grafting agent maleic anhydride (MA) or soft grafting agent thermoplastic polyolefin elastomers (TPO). The chemical structure and polymer morphology of these as‐synthesized PCN specimens were characterized by a wide‐angle powder X‐ray diffraction (XRD) and a scanning electron microscopy (SEM). In addition, we prepared these experimental specimens in order to probe into their mechanical properties. The tests used were: layer distance of PCN, tensile, impact, shore‐hardness, wearing tests, and so on. In addition, we used XRD to make the characterization analysis, and compare it to scatter and layer‐distance. It was found that when the MA is increased into the MMT, the layer‐distance at 3 wt% increased from 2.11 nm to 3.54 nm; when increasing the TPO into the MMT, layer‐distance at 3 wt% increased to the 3.28 nm. For the mechanical property, it was found that these specimens grafted with the MA have the following results: in the tensile test, the MMT weight percentage of 1 wt% had the best result, increasing by 3.2%. In the shore hardness test, the MMT of 3 wt% strengthens by 5.41%. In addition, the mechanical property of the specimens that grafted to the TPO decreased almost immediately at 1 wt%, but increased at 3–5 wt% trends. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Preparation and characterization of polystyrene–clay nanocomposites by free‐radical polymerization

The polymerizable cationic surfactant, vinylbenzyldimethylethanolammouium chloride (VBDEAC), was synthesized to functionalize montmorillonite (MMT) clay and used to prepare exfoliated polystyrene–clay nanocomposites. The organophilic MMT was prepared by Na⁺ exchanged montmorillonite and ammonium cations of the VBDEAC in an aqueous medium. Polystyrene–clay nanocomposites were prepared by free‐radical polymerization of the styrene containing intercalated organophilic MMT. Dispersion of the intercalated montmorillonite in the polystyrene matrix determined by X‐ray diffraction reveals that the basal spacing is higher than 17.6 nm. These nanocomposites were characterized by differential scanning calorimetry (DSC), transmission electron micrograph (TEM), thermal gravimetric analysis (TGA), and mechanical properties. The exfoliated nanocomposites have higher thermal stability and better mechanical properties than the pure polystyrene. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1370–1377, 2002     

Morphology and mechanical properties of polypropylene/organoclay nanocomposites

Polypropylene (PP) nanocomposites were prepared by melt intercalation in an intermeshing corotating twin‐screw extruder. The effect of molecular weight of PP‐MA (maleic anhydride‐ modified polypropylene) on clay dispersion and mechanical properties of nanocomposites was investigated. After injection molding, the tensile properties and impact strength were measured. The best overall mechanical properties were found for composites containing PP‐MA having the highest molecular weight. The basal spacing of clay in the composites was measured by X‐ray diffraction (XRD). Nanoscale morphology of the samples was observed by transmission electron microscopy (TEM). The crystallization kinetics was measured by differential scanning calorimetry (DSC) and optical microscopy at a fixed crystallization temperature. Increasing the clay content in PP‐ MA330k/clay, a well‐dispersed two‐component system, caused the impact strength to decrease while the crystallization kinetics and the spherulite size remained almost the same. On the other hand, PP/PP‐MA330k/clay, an intercalated three‐component system containing some dispersed clay as well as the clay tactoids, showed a much smaller size of spherulites and a slight increase in impact strength with increasing the clay content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1562–1570, 2002     

Synthesis and characterization of poly(propylene)/montmorillonite nanocomposites by simultaneous grafting‐intercalation

A novel process for the preparation of poly(propylene)/montmorillonite (PP/MMT) nanocomposites was developed via simultaneous solution grafting‐intercalation in the presence of a reactive ammonium cation that can be grafted onto poly(propylene). Partially introducing this reactive cation into long alkyl ammonium modified MMT interlayers can transfer a conventional microcomposite into intercalated/exfoliated nanocomposites, which was evidenced by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The PP chains were tethered onto the clay surface through the bridge of the reactive ammonium cations, which can be characterized by FTIR. The bridged chemical bonding also results in a good interface adhesion between PP and MMT, as confirmed by SEM investigation. The enhanced thermal properties of PP/MMT nanocomposites were characterized by thermogravimetric analysis. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1018–1023, 2004     

Polypropylene/organically modified Sabah montmorillonite nanocomposites: Surface modification and nanocomposites characterization

The aim of the work is to extract, purify, and organically modify montmorillonite (MMT) of Lahad Datu, Sabah bentonite. The octadecylamine treated Sabah MMT (S‐OMMT) (2–8 wt%) was then melt blended with polypropylene (PP) and maleated polypropylene (PPgMAH) (10 wt%) via single screw nanomixer extruder followed by injection molding into test samples to examine the mechanical, thermal, and morphological properties of PP/S‐OMMT nanocomposites. Unmodified Sabah MMT (S‐MMT) and commercial grade MMT (Nanomer 1.30P) filled PP nanocomposites were also characterized for comparison purpose. X‐ray diffraction results showed that the interlayer spacing of S‐MMT increased after organic modification as Fourier transform infra‐red and elemental analysis evidenced the presence of octadecylamine. PP/S‐OMMT nanocomposites showed a better dispersion and strength compared to PP/Nanomer 1.30P nanocomposites due to its smaller MMT platelet size. differential scanning calorimetry and Thermogravimetry analysis revealed that the thermal stability and crystallinity of neat PP improved with the addition of all types of MMT. Dynamic mechanical analyzer showed that PP nanocomposites have higher storage modulus (E′) values than the neat PP over the whole temperature range. The new PP/S‐OMMT nanocomposites showed a comparable performance with PP/Nanomer 1.30P nanocomposites exhibiting promising future applications of S‐MMT in polymer/MMT nanocomposites. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Morphology and properties of PVC/clay nanocomposites via in situ emulsion polymerization

PVC/Na⁺–montmorillonite (MMT) nanocomposites were prepared via a simple technique of emulsion polymerization at several different MMT clay concentrations. X‐ray diffraction and transmission electron microscopy studies revealed the formation of a mixture of intercalated and exfoliated nanostructure. Tensile testing results showed that the tensile modulus of the nanocomposites increased with the addition of clay, while the tensile strength decreased little. The notched impact strength of the nanocomposites was also improved. For systems containing clay in the range of 2.1 to 3.5 wt %, the impact strength was almost two times as large as that of pure PVC. However, those mechanical properties began to decrease with the continuously increasing amount of clay. The fracture surface of pure PVC and the nanocomposites was observed by scanning electron microscope. Thermal properties of the nanocomposites were found to increase as a result of clay incorporation. The glass transition temperatures of the PVC/clay nanocomposites were nearly identical to that of pure PVC. The Vicat softening points exhibited a progressively increasing trend with the clay content added. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 277–286, 2004     

Microstructure‐properties correlations in dynamically vulcanized nanocomposite thermoplastic elastomers based on PP/EPDM

Thermoplastic vulcanized (TPV) nanocomposites were prepared in a laboratory mixer using EPDM, polypropylene of different viscosities, maleic anhydride modified polypropylene, an organo‐clay, and a sulfur‐based curing system. Based on the obtained results from X‐ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), differential scanning calorimeter, and mechanical properties, the microstructure of the prepared nanocomposites was found to be sensitive to the viscosity difference between the two phases and the clay content. X‐ray diffraction and TEM images of the TPV nanocomposites showed that clay was nearly exfoliated and randomly distributed into the polypropylene phase. The SEM photomicrographs of the dynamically vulcanized thermoplastic elastomer samples showed that the rubber particles were dispersed through the polypropylene in form of aggregates and their size increased with the introduction of clay. The nanoscale dimensions of the dispersed clay resulted in a significant improvement of the tensile modulus of the TPV nanocomposite samples, from 20 to 90% depending on clay content and the viscosity ratio of PP/EPDM. In the PP nanocomposites, the clay layers act as nucleating agents, resulting in higher crystallization temperature and reduced degree of crystallinity. Moreover, the oxygen permeability in the TPV nanocomposites was found to be lower than in unfilled but otherwise similar materials. POLYM. ENG. SCI., 47:207–217, 2007. © 2007 Society of Plastics Engineers.     

Effect of oligomeric‐modified montmorillonite on morphology and properties of polycarbonate/montmorillonite nanocomposites

Low‐molecular‐weight copolymers of styrene and vinylbenzyl ammonium salts (oligomeric surfactant) were used to modify montmorillonite (MMT). The oligomeric‐modified MMT showed good thermal stability, which made it suitable to be used for preparing polycarbonate(PC)/MMT nanocomposites at high temperature. A different series of PC/MMT nanocomposites had been prepared by melt processing using a twin screw extruder. The effect of oligomeric surfactant structure and clay loading on the morphology, mechanical property, thermal stability, and color appearance of the nanocomposites were explored. The results of X‐ray diffraction and transmission electron microscopy analyses indicated that the PC/MMT nanocomposites had partially exfoliated structures. The PC/MMT nanocomposites were found to retain light colored, which was important for optical application. Compared to neat PC, the nanocomposites showed better properties of thermal stability and heat insulation. The mechanical properties of the nanocomposites are significantly enhanced by incorporating clay into the PC matrix. The tensile strength of nanocomposites with 2 wt% clay content was up to 55 MPa, which was much higher than that of the neat PC (37 MPa). The maximum tensile modulus value was 19% higher than that of neat PC. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers     

Property enhancement in polypropylene ternary blend nanocomposites via a novel poly(ethylene oxide)‐grafted polystyrene‐block‐poly(ethylene/butylene)‐block‐polystyrene toughener–compatibilizer system

Synthesis and characterization of a novel toughener–compatibilizer for polypropylene (PP)–montmorillonite (MMT) nanocomposites were conducted to provide enhanced mechanical and thermal properties. Poly(ethylene oxide) (PEO) blocks were synthetically grafted onto maleic anhydride‐grafted polystyrene‐block‐poly(ethylene/butylene)‐block‐polystyrene (SEBS‐g‐MA). Special attention was paid to emphasize the effect of PEO‐grafted SEBS (SEBS‐g‐PEO) against SEBS‐g‐MA on morphology, static/dynamic mechanical properties and surface hydrophilicity of the resultant blends and nanocomposites. It was found that the silicate layers of neat MMT are well separated by PEO chains chemically bonded to nonpolar SEBS polymer without needing any organophilic modification of the clay as confirmed by X‐ray diffraction and transmission electron microscopy analyses. From scanning electron microscopy analyses, elastomeric domains interacting with MMT layers via PEO sites were found to be distributed in the PP matrix with higher number and smaller sizes than the corresponding blend. As a benefit of PEO grafting, SEBS‐g‐PEO‐containing nanocomposite exhibited not only higher toughness/impact strength but also increased creep recovery, as compared to corresponding SEBS‐g‐MA‐containing nanocomposite and neat PP. The damping parameter of the same nanocomposite was also found to be high in a broad range of temperatures as another advantage of the SEBS‐g‐PEO toughener–compatibilizer. The water contact angles of the blends and nanocomposites were found to be lower than that of neat hydrophobic PP which is desirable for finishing processes such as dyeing and coating. © 2018 Society of Chemical Industry     

Polypropylene nanocomposite film: A critical evaluation on the effect of nanoclay on the mechanical,thermal, and morphological behavior

Polypropylene (PP)/clay nanocomposites prepared by melt blending technique using different percentages of clay with and without maleic anhydride grafted PP (MA‐PP) were studied. The intercalated and exfoliated structure of nanocomposites was characterized by X‐Ray Diffraction (XRD) and transmission electron microscopy (TEM). Because of the typical intercalated and exfoliated structure, the tensile modulus of the nanocomposites were improved significantly as compared to virgin PP. The viscoelastic behavior of the nanocomposites was studied by dynamical mechanical analysis (DMA) and the results showed that with the addition of treated clay to PP there was substantial improvement in storage modulus increases. The thermal stability and crystallization of the PP nanocomposites as studied by differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) were also improved significantly compared to PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Mesua ferrea L. seed oil based highly branched polyester/epoxy blends and their nanocomposites

Mesua ferrea L. seed oil based highly branched polyester and epoxy resins blends were prepared by mechanical mixing at different weight ratios. The best performing blend was used as the matrix for the preparation of nanocomposites with different dose levels of organophilic montmorillonite (OMMT) nanoclay. The prepared nanocomposites were characterized by X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. Data resulting from the mechanical and thermal studies of the blends and nanocomposites indicated improvements in the tensile strength and thermal stability to appreciable extents for the nanocomposites with OMMT loading. The nanocomposites were characterized as well‐dispersed, partially exfoliated structures with good interfacial interactions. From the X‐ray diffraction analysis, the absence of d₀₀₁ reflections of the OMMT clay in the cured nanocomposites indicated the development of an exfoliated clay structure, which was confirmed by transmission electron microscopy. The homogeneous morphologies of the pure polyester/epoxy blend and clay hybrid systems were ascertained with scanning electron microscopy. The tensile strength of the 5 wt % clay‐filled blend nanocomposite system was increased by 2.4 times compared to that of the pure blend resin system. The results suggest that the prepared nanocomposites have the potential to be used as active thin films for different applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011