PBT blends with rigid polymer and elastomer inclusions: the effect of component type and reactivity on mechanical behaviour

The present study shows the potential of the poly(butylene terephthalate) (PBT) matrix to form ternary blends with well‐balanced properties, analogous to Polyamide 6 (PA6) systems with a very fine (<100 nm) separately dispersed rigid polymer (poly(styrene‐co‐maleic anhydride)) and elastomer (maleated ethylene‐propylene elastomer). The use in PBT blends of maleated components analogous to those in the PA6 systems was much less effective, due to the presence of larger particles. Enhancement of all properties, including toughness, was found in the case of a blend containing at least one component with epoxide groups, such as rigid styrene‐glycidyl methacrylate copolymer or elastomeric poly[(ethylene)‐co‐(methyl acrylate)‐co‐(glycidyl methacrylate)]. In this case, the reactive compatibilization of the epoxy‐group‐containing component caused refinement of particle size of the other component due to enhanced viscosity. As a result, more advantageous micromechanical behaviour of this ternary in comparison with the binary system occurs. The PBT matrix offers a similar potential to PA6 in synergistic influencing of both well‐dispersed phases. This work supports the universality of rigid polymer‐elastomer combination for the enhancement of the properties of pseudoductile polymers. Copyright © 2004 Society of Chemical Industry     

Polyamide nanocomposites with improved toughness

Polymer nanocomposites containing several percent of exfoliated layered silicates are materials with a unique weight/performance ratio. The only parameter that is not enhanced, but even decreased, is toughness. This work focused on the toughness enhancement of these advanced systems with polyamide matrix prepared via melt‐mixing (i.e., by a conventional method of polymer processing having an advantage of easy simultaneous addition of other components). Analogously to ternary polyamide blends with improved mechanical behavior, containing finely and separately dispersed elastomer and rigid polymer, elastomer particles with an average size of 60 nm were incorporated in the nanocomposite. The very low particle size was achieved by in situ reactive compatibilization by using suitably functionalized elastomers. The simultaneously increasing viscosity of the system enhanced exfoliation of the silicate. Melt exfoliated nanocomposites containing 3 wt % of clay and 5 wt % of elastomer particles exhibit increased toughness without significant loss of other properties. Elastomer particles increase toughness by both acting as stress concentrators (by initiating energy absorbing microdeformations) and influencing the clay‐induced matrix crystalline structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 288–293, 2005     

Preparation of thermoplastic elastomer nanocomposites based on polyamide‐6/polyepichlorohydrin‐co‐ethylene oxide

This work is aimed at determining the effect of nanoclay and polyepichlorohydrin‐co‐ethylene oxide (ECO) content on the microstructure and mechanical properties of PA6/ECO thermoplastic elastomers (TPEs). TPE nanocomposites were prepared in a laboratory mixer using polyamide 6 (PA6), ECO, and an organoclay by a two‐step melt mixing process. First, the PA6 was melt blended with Cloisite 30B and then mixed by ECO rubber. X‐ray diffraction results and transmission electron microscopy image showed that the nanoclay platelets were nearly exfoliated in both the phases. The SEM photomicrograph of PA6 with ECO showed that the elastomer particles are dispersed throughout the polyamide matrix and the size of rubber particles is less than 3 μm. Introduction of organoclay in the PA6 matrix increased the size of dispersed rubber particles in comparison with the unfilled but otherwise similar blends. The nanoscale dimension of the dispersed clay results in an improvement of the tensile modulus of the nanocomposites. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers     

Microstructural characteristics of glass bead‐ and wollastonite‐filled isotactic‐polypropylene composites modified with thermoplastic elastomers

Microstructural characteristics of isotactic‐polypropylene/glass bead (iPP/GB) and iPP/wollastonite (iPP/W) composites modified with thermoplastic elastomers, poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) copolymer (SEBS) and corresponding block copolymer grafted with maleic anhydride (SEBS‐g‐MA), were investigated. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and dynamic mechanical analyses (DMA) showed that the iPP/SEBS and iPP/SEBS‐g‐MA blends were partially compatible two‐phase systems. Well‐dispersed spherical GB and acicular W particles without evidence of interfacial adhesion were observed in the iPP/GB and iPP/W binary composites respectively. Contrary to the blends, melt flow rates of the iPP/GB and PP/W composites decreased more with SEBS‐g‐MA than with SEBS because of enhanced interfacial adhesion with SEBS‐g‐MA elastomer. The SEM analyses showed that the ternary composites containing SEBS exhibited separate dispersion of the rigid filler and elastomer particles (i.e., separate microstructure). However, SEBS‐g‐MA elastomer not only encapsulated the spherical GB and acicular W particles completely with strong interfacial adhesion (i.e., core‐shell microstructure) but also dispersed separately throughout iPP matrix. In accordance with the SEM observations, the DSC and DMA revealed quantitatively that the rigid filler and SEBS particles in iPP matrix acted individually, whereas the rigid filler particles in the ternary composites containing SEBS‐g‐MA acted like elastomer particles because of the thick elastomer interlayer around the filler particles. The Fourier transform infrared analyses revealed an esterification reaction inducing the strong interfacial adhesion between the SEBS‐g‐MA phase and the filler particles. POLYM. COMPOS., 31:1265–1284, 2010. © 2009 Society of Plastics Engineers     

Compatibilization and elastomer toughening of polyamide‐6 (PA6)/poly(phenylene ether) (PPE) blends

In the elastomer‐modified (polyamide‐6/poly(phenylene ether) (PA6/PPE) = 50/50 blends, poly(styrene‐co‐maleic anhydride) (SMA) was demonstrated to be an efficient reactive compatibilizer. The G1651 elastomer was shown to be an effective impact modifier to result in superior toughness and heat‐deflection temperature (HDT) than is the 1901X elastomer for the SMA‐compatibilized blends because G1651 particles exclusively reside within the dispersed PPE phase but 1901X particles tend to distribute in the PA6 matrix and/or along the interface. The apparent average diameter of the dispersed PPE phase is insignificantly dependent on the elastomer content in the G1651‐modified blend, whereas it increases with increase of the elastomer content in the 1901X‐modified blend. Moreover, there exists a critical elastomer content, 15 phr, for the ductile–brittle transition of the G1651‐modified SMA‐modified PA6/PPE blends. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 23–32, 1999     

Melt rheological properties of polypropylene–polyamide6 blends compatibilized with maleic anhydride‐grafted polypropylene

The melt rheological properties of binary uncompatibilized polypropylene–polyamide6 (PP–PA6) blends and ternary blends compatibilized with maleic anhydride‐grafted PP (PP–PP‐g‐MAH–PA6) were studied using a capillary rheometer. The experimental shear viscosities of blends were compared with those calculated from Utracki's relation. The deviation value δ between these two series of data was obtained. In binary PP–PA6 blends, when the compatibility between PP and PA6 was poor, the deformation recovery of dispersed PA6 particles played the dominant role during the capillary flow, the experimental values were smaller than those calculated, and δ was negative. The higher the dispersed phase content, the more deformed the droplets were and the lower the apparent shear viscosity. Also, the absolute value of δ increased with the dispersed phase composition. In ternary PP–PP‐g‐MAH–PA6 systems, when the compatibility between PP and PA6 was enhanced by PP‐g‐MAH, the elongation and break‐up of the dispersed particles played the dominant role, and the experimental values were higher than calculated. It was observed that the higher the dispersion of the PA6 phase, the higher the δ values of the ternary blends and the larger the positive deviation. Unlike uncompatibilized blends, under high shear stress with higher dispersed phase content, the PP‐g‐PA6 copolymer in compatibilized blends was pulled out from the interface and formed independent micelles in the matrix, which resulted in reduced total apparent shear viscosity. The δ value decreased with increasing shear stress. Copyright © 2006 Society of Chemical Industry     

Effect of elastomer type and functionality on the behavior of toughened polyamide nanocomposites

The only shortcoming of PA6‐based nanocomposites is low toughness, which is the same as that of the matrix. This work is focused on optimization of toughening these nanocomposites by introduction of small amounts of finely dispersed elastomers. A comparison of reactively compatibilized and analogous nonreactive elastomer‐containing nanocomposites indicates the best‐balanced mechanical behavior for polar nonreactive elastomers such as NBR and E‐MA. This is explained by a significant compatibilizing effect of clay. Besides the elastomer particle size and its properties, the clay localization and its degree of ordering in the interfacial region also significantly influenced mechanical properties of the system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1571–1576, 2006     

Blends of polyamide 6 and epichlorohydrin elastomers. I. Graft copolymerization in the melt blending

With the purpose of improving the mechanical properties of the polyamides, the possibility of combining polyamides with elastomers has been used. The low compatibility of the resulting blends leads to deficient mechanical properties, and therefore, it is necessary to add the compatibilizer to the mixture or to produce the compatibilizer during the melting mixture. Usually, at least one of the components must contain a reactive functional groups. In the present work, blends of polyamide 6 (PA 6) and epichlorohydrin elastomers, polyepichlorohydrin (PEPI), and the equimolar copolymer poly(epichlorohydrin‐co‐ethylene oxide), ECO, with different compositions were prepared by mechanical mixture using a Banbury‐type mixer. The blends were characterized by rheological measurements, the Molau test, elemental analysis, Infrared Spectroscopy by Diffuse Reflectance, Transmission Electron Microscopy, and X‐ray Diffractometry. The blends of PA 6 with PEPI and ECO are heterogeneous, showing a morphology of elastomer particles dispersed in the polyamide matrix. The results of rheological measurements and the Molau test indicate a graft copolymerization in the interface between the polyamide and the elastomer, PA 6‐g‐elastomer, whose concentration decreases with the elastomer content. It was found that the grafting of PEPI and PA 6 changed the diffraction pattern of PA 6. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1827–1833, 1999     

Co-continuous and encapsulated three phase morphologies in uncompatibilized and reactively compatibilized polyamide 6/polypropylene/polystyrene ternary blends using two reactive precursors

Phase morphology development in ternary uncompatibilized and reactively compatibilized blends based on polyamide 6 (PA6), polypropylene (PP) and polystyrene (PS) has been investigated. Reactive compatibilization of the blends has been performed using two reactive precursors; maleic anhydride grafted polypropylene (PP-g-MA) and styrene maleic anhydride copolymer (SMA) for PA6/PP and PA6/PS pairs, respectively. For comparison purposes, uncompatibilized and reactively compatibilized PA6/PP and PA6/PS binary blends, were first investigated. All the blends were melt-blended using a co-rotating twin-screw extruder. The phase morphology investigated using scanning electron microscope (SEM) and selective solvent extraction tests revealed that PA6/PP/PS blends having a weight percent composition of 70/15/15 is constituted from polyamide 6 matrix in which are dispersed composite droplets of PP core encapsulated by PS phase. Whereas, a co-continuous three-phase morphology was formed in the blends having a composition of 40/30/30. This morphology has been significantly affected by the reactive compatibilization. In the compatibilized PA6/(PP/PP–MA)/(PS/SMA) blends, PA6 phase was no more continuous but gets finely dispersed in the PS continuous phase. The DSC measurements confirmed the dispersed character of the PA6 phase. Indeed, in the compatibilized PA6/(PP/PP–MA)/(PS/SMA) blends where the PA6 particle size was smaller than 1 μm, the bulk crystallization temperature of PA6 (188 °C) was completely suppressed and a new crystallization peak emerges at a lower temperature of 93 °C as a result of homogeneous nucleation of PA6.     

Toughening of polyamide‐6 with little loss in modulus by block copolymer containing poly(styrene‐alt‐maleic acid) segment

Toughening of polyamide‐6 (PA6) by elastomers without sacrificing the modulus of blends has always been a challenge. In this study, PA6 was modified by poly(styrene‐alt‐maleic acid)‐block‐polystyrene‐block‐poly(n‐butyl acrylate)‐block‐polystyrene tetrablock copolymer (BCP) elastomer. The introduced acid groups in BCP resulted in the size of BCP inclusions down to nanometers in polyamide matrix. 10 wt % of BCP‐modified PA6 blends achieved five times increase in notched impact strength with almost no loss in modulus. Microscopic observations suggested the cavitation of elastomer particles and shear yielding of PA6 matrix to be the major toughening mechanism. This research provides a strategy to toughen polyamides by block copolymers at very low rubber content. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44849.     

Study on morphology and viscoelastic properties of PP/PET/SEBS ternary blend and their fibers

The morphology development of polypropylene (PP)/polyethylene terephthalate (PET)/styrene‐ethylene‐butylene‐styrene (SEBS) ternary blends and their fibers were studied by means of scanning electron microscopy (SEM) in conjunction with the melt linear viscoelastic measurements. The morphology of the blends was also predicted by using Harkin's spreading coefficient approach. The samples varying in composition with PP as the major phase and PET and SEBS as the minor phases were considered. Although SEM of the binary blends showed matrix‐dispersed type morphology, the ternary blend samples exhibited a morphological feature in which the dispersed phase formed aggregates consisting of both PET and SEBS particles distributed in the PP matrix. The SEM of the blend samples containing 30 and 40 wt % of total dispersed phase showed an agglomerated structure formed between the aggregates. The SEM of the PP/PET binary fiber blends showed long well‐oriented microfibrils of PET whereas in the ternary blends, the microfibrils were found to have lower aspect ratio with a fraction of the SEBS stuck on the microfibril fracture surfaces. These results were attributed to a core‐shell type morphology in which the PET and SEBS formed the core‐shells distributed in the matrix. The melt viscoelastic behavior of the ternary blends containing less than 30 wt % of the total dispersed phase was found to be similar to the matrix and binary blend samples whereas the samples containing 30 and 40 wt % of dispersed phases exhibited a pronounced viscosity upturn and nonterminal storage modulus in low frequency range. These results were found to be in good agreement with the morphological results. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synergetic toughness and morphology of poly(propylene)/nylon 11/maleated ethylene‐propylene diene copolymer blends

Polypropylene (PP)/nylon 11/maleated ethylene‐propylene‐diene rubber (EPDM‐g‐MAH) ternary polymer blends were prepared via melt blending in a corotating twin‐screw extruder. The effect of nylon 11 and EPDM‐g‐MAH on the phase morphology and mechanical properties was investigated. Scanning electron microscopy observation revealed that there was apparent phase separation for PP/EPDM‐g‐MAH binary blends at the level of 10 wt % maleated elastomer. For the PP/nylon 11/EPDM‐g‐MAH ternary blends, the dispersed phase morphology of the maleated elastomer was hardly affected by the addition of nylon 11, whereas the reduced dispersed phase domains of nylon 11 were observed with the increasing maleated elastomer loading. Furthermore, a core‐shell structure, in which nylon 11 as a rigid core was surrounded by a soft EPDM‐g‐MAH shell, was formed in the case of 10 wt % nylon 11 and higher EPDM‐g‐MAH concentration. In general, the results of mechanical property measurement showed that the ternary blends exhibited inferior tensile strength in comparison with the PP matrix, but superior toughness. Especially low‐temperature impact strength was obtained. The toughening mechanism was discussed with reference to the phase morphology. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Ternary reactive blends of nylon‐6 matrix with dispersed rigid brittle polymer and elastomer

Except by elastomers, the toughness of nylon‐6 (N‐6) can be improved by the addition of rigid poly(styrene‐co‐maleic anhydride) (SMA). In this case, strength and stiffness are also enhanced. Combination of SMA with maleated ethylene‐propylene rubber or styrene‐ethene/butene‐styrene with a total content below 15% gives a ternary blend having a toughness level close to elastomer toughening, whereas the strength and stiffness reached at least the Nylon‐6 values. An explanation is a synergistic combination of both elastomer and rigid polymer toughening mechanisms. An opposite effect on mechanical behavior was found with high contents of both additives. Except for worsened strength and stiffness, in some cases, a higher elastomer content even did not enhance the toughness. This effect can be explained by too fine phase structure found, causing the matrix ligament dimension to be below its minimum critical value. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1404–1411, 1999     

Polystyrene and polyester polyurethane elastomer blends compatibilized by SMA

Blends of polystyrene (PS) with polyester polyurethane elastomer (PU‐es) were compatibilized by addition of poly(styrene‐co‐maleic anhydride) (SMA) containing 7 wt % of maleic anhydride. Binary nonreactive (PS/PU‐es) blends, binary reactive (SMA/PU‐es) blends, and ternary reactive blends (PS/SMA/PU‐es) were prepared with 10 and 20 wt % of PU‐es. The maleic anhydride content in the ternary reactive blends was varied through addition of different SMA amounts from 0.5 to 5 wt %. Polyurethane in the blends was crosslinked by using dicumyl peroxide or sulfur to improve its mechanical properties. The experimental processing conditions, such as temperature and rotor speed in an internal mixer, were analyzed before blend preparation by processing the individual polymers, PS and SMA, and the PS/PU‐es nonreactive blend (90/10), to prevent the degradation of the polymer during melt mixing and to assure macroscopic homogeneity. The torque behavior during the mixture indicated a grafting copolymerization, which was responsible for the significant drop of the PU‐es domain size in the glassy matrix, as observed by scanning electronic microscopy (SEM). The miscibility of the glassy matrix, which was shown to be dependent on the composition and the phase behavior of ternary blends, became very complex as the SMA concentration increased, as concluded from dynamical–mechanical analysis. Blends containing 20 wt % of PU‐es presented an increase up to a factor of 2 in the deflection at break in relation to PS. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2297–2304, 2004     

Microstructures and mechanical properties of polypropylene/polyamide 6/polyethelene-octene elastomer blends

A series of polymer blends were designed and manufactured. They are composed of three phases: polypropylene (PP), polyamide-6 (PA6) and polyethylene-octene elastomer (POE) grafted with maleic anhydride. The weight fraction of PA6 was adjusted from 0 to 40% by increments of 10%, and the weight fraction of POE was systematically half that of PA6. The morphology, essentially made of PA6 particles dispersed in the PP matrix, was characterised by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In the extruded plates prepared with the blends, the shape of the dispersed PA6 particles showed an elongated ellipsoidal shape, whose aspect ratio increased somehow with alloying content. The POE modifier was observed both as a thin interlayer (less than 100 nm thickness) at the PP/PA6 interface, and as a few isolated particles. The elastic modulus and yield stress in tension are nearly constant for PP and blends. By contrast, the notched Izod impact strength increases very much with alloying content. This remarkable effect is interpreted in terms of POE interphase cavitation, enhanced plastic shear deformation and resistance of PA6 particles to crack propagation.     

The effect of interface characteristics on the morphology,rheology and thermal behavior of three‐component polymer alloys

Immiscible polymer blends are interesting multiphase host systems for fillers. Such systems exhibit, within a certain composition limits, either a separate dispersion of the two minor phases or a dispersion of encapsulated filler particles within the minor polymer phase. Both thermodynamic (e.g. interfacial tension) and kinetic (e.g. relative viscosity) considerations determine the morphology developed during the blending process. The effect of interfacial characteristics on the structure‐property relationships of ternary polymer alloys and blends comprising polypropylene (PP), ethylene‐vinyl alcohol copolymer (EVOH) and glass beads (GB), or fibers (GF), was investigated. The system studied was based on a binary PP/EVOH immiscible blend, representing a blend of a semi‐crystalline apolar polymer with a semicrystalline highly polar copolymer. Modification of the interfacial properties was obtained through using silane coupling agents for the EVOH/glass interface and compatibilization using a maleic anhydride grafted PP (MA‐g‐PP) for the PP/EVOH interface. The compatibilizer was added in a procedure aimed to preserves the encapsulated EVOH/glass structure. Blends were prepared by melt extrusion compounding and specimens by injection molding. The morphology was characterized using scanning electron microscopy (SEM) and high resolution SEM (HRSEM), the shear viscosity by capillary rheometry and the thermal behavior using differential scanning calorimetry (DSC). The system studied consisted of filler particles encapsulated by EVOH, with some of the minor EVOH component separately dispersed within the PP matrix. Modification of the interfaces resulted in unique morphologies. The aminosilane glass surface treatment enhanced the encapsulation in the ternary [PP/EVOH]GB blends, resulting in an encapsulated morphology with no separtely dispersed EVOH particles. The addition of a MA‐g‐PP compatibilizer preserves the encapsulated morphology in the ternary blends with some finely dispersed EVOH particles and enhanced PP/EVOH interphase interactions. The viscosity of the binary and ternary blends was closely related to the blend's morphology and the level of shear rate. The treated glass surfaces showed increased viscosity compared to the cleaned glass surfaces in both GB and GF containing ternary blends. Both EVOH and glass serve as nucleating agents for the PP matrix, affecting its crystallization process but not its crystalline structure. The aminosilane glass surface treatment completely inhibited the EVOH crystallization process in the ternary blend. In summary, the structure of the multicomponent blends studied has a significant effect on their behavior as depicted by the rheological and thermal behavior. The structure‐performance relationships in the three‐component blends can be controlled and varied.     

The effect of interface characteristics on the static and dynamic mechanical properties of three‐component polymer alloys

The effect of interfacial characteristics on the structure‐property relationships of ternary polymer alloys and blends comprising polypropylene (PP), ethylene‐vinyl alcohol copolymer (EVOH) and glass beads (GB) or fibers (GF) was investigated. The systems studied were based on a binary PP/EVOH immiscible blend, representing a blend of a semi‐crystalline apolar polymer with a semi‐crystalline highly polar copolymer. The ternary systems studied consisted of filler particles encapsulated by EVOH, with some of the minor EVOH component separately dispersed within the PP matrix. Modification of the interfacial properties was done using silane coupling agents for the EVOH/glass interface and compatibilization using a maleic anhydride grafted PP (MA‐g‐PP) for the PP/EVOH interface. Both glass fillers increased the dynamic modulus and decreased the damping of the neat polymers and of their binary blends, especially in the rubbery region. GF has a more profound effect on both the modulus and the damping. Glass surface treatments and compatibilization have only a marginal effect on the dynamic mechanical behavior of the ternary blends. Yet, compatibilization shifted the polymers' T_gS to higher temperatures. Both glass fillers increased the elastic modulus of the binary blends, where GF performed better than GB as a reinforcing agent. GF slightly increased the strength of the binary blends while, GB reduced it. Both fillers reduced the ductility of the binary blends. The blends' mechanical properties were related to the morphology and their components' crystallinity. The compatibilizer increases both stiffness and strength and reduces deformability.     

Beiträe zur künstlichen bewitterung von PVC

The concentration dependences of particle size of the dispersed phase on rheological properties of the components were investigated by scanning electron microscopy for blends of polypropylene and ethylene-propylene elastomers obtained by melt mixing. At very low concentrations the minority component is dispersed the more finely the lower its viscosity is. With increasing concentration of the dispersed phase the size of its particles in the given matrix increases the more quickly the lower the viscosity of the dispersed phase is. With increasing viscosity of the matrix the particle size of the minority phase decreases at all compositions of the blend. The results obtained were interpreted as a result of dynamic equilibrium between the break up and coalescence of particles in flow. At elastomer concentrations higher than 15% the differences between impact strength values of the blends are determined by the size of inclusions of the elastomeric modifier. Dispersions finer than the optimal one with respect to impact strength can be reached only with the polypropylene matrix possessing high viscosity.     

Characteristics of impact modified polystyrene/organoclay nanocomposites

The poor impact resistance of Polystyrene (PS) was enhanced by the addition of elastomeric material, SEBS‐g‐MA. To prevent the reduction in strength and stiffness, organoclay Cloisite® 25A was used as filler and introduced into the matrix by a corotating twin screw extruder. Throughout the study, the clay content was kept at 2 wt%, whereas the content of SEBS‐g‐MA was varied between 5 and 40 wt%. It was found that Cloisite® 25A displays well dispersion in the ternary nanocomposites and the degree of dispersion increases with the elastomer content. The elastomeric phase has a greater viscosity than pure PS. Thus, as expected, at low elastomer contents, it forms the dispersed phase in the matrix as droplets. Transmission electron microscopy results show that the clay layers reside at the interphase between PS and elastomer and also inside the elastomeric phase. Owing to the location of the clay particles, the average elastomer domain size in ternary nanocomposites are found to be greater than that in the relative binary blends of PS‐(SEBS‐g‐MA). Moreover, with the organoclay addition, phase inversion point shifts to lower elastomer contents. The mechanical test results showed that the nanocomposites containing 15 and 20 wt% SEBS‐g‐MA have the optimum average domain size that results in high‐impact strength values without deteriorating the tensile properties. POLYM. COMPOS., 31:1853–1861, 2010. © 2010 Society of Plastics Engineers.     

Effects of nanotalc inclusion on mechanical,microstructural, melt shear rheological,and crystallization behavior of polyamide 6‐based binary and ternary nanocomposites

The objective of the study is to investigate the effect of inclusion of nanotalc on the strength properties of polyamide 6 (PA6)‐based binary and ternary nanocomposites. Binary nanocomposites were prepared by melt compounding of PA6 with varying content of nanotalc (1, 2, and 4 wt%). Ternary nanocomposites were prepared by melt compounding of compatibilized blend of PA 6 and ethylene‐co‐butyl acrylate (EBA elastomer) with varying content of nanotalc (1, 2, and 4 wt%). Both the binary and ternary nanocomposites registered a very high improvement in the strength/stiffness‐related properties at lower filler loading of 1 wt%. Phase morphology of the composites studied by SEM, TEM, and XRD revealed the formation of extended brane‐like structures and delaminated talc layers in the binary nanocomposites. The modulus predicted by Halpin‐Tsai and Mooney equation suggests that the composites retained a very good aspect ratio after melt mixing. Orientation effects of nanotalc enhanced the melt flow behavior in the composites. POLYM. ENG. SCI., 50:1978–1993, 2010. © 2010 Society of Plastics Engineers