Poly(vinylidene fluoride) (PVDF)/ poly(ethylene–butylacrylate–glycidyl methacrylate) (PTW) blends were directly prepared by melt blending and the interaction and properties of PVDF/PTW blends were explored systematically. The crystallization behavior, thermal stability, dynamic mechanical property, and morphological features of PVDF/PTW blends with different ratios have been studied by XRD, attenuated total reflection Fourier transform infrared spectroscopy, differential scanning calorimeter analysis (DSC), thermal gravimetric analysis (TGA), dynamic mechanical analysis, and polarized optical microscopy (POM). The results showed that the crystalline structure of neat PVDF was dominantly α-phase crystalline and the incorporation of PTW had no effect on the crystalline structure of PVDF in the PVDF/PTW blends. And T_g of PVDF in PVDF/PTW blends shifted to higher temperature compared with that of neat PVDF, indicating the weak interaction between PVDF and PTW, which was corresponding to DSC and TGA results. An increase in the coarseness and ring-band spacing observed from POM further substantiated the weak interaction between PVDF and PTW. This work provided a way for preparing improved properties of PVDF/PTW blends for the coating material. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43908.

Commercial brominated poly(isobutylene-co-isoprene) (BIIR) rubber has been directly used for the initiation of atom transfer radical polymerization (ATRP) by utilizing the allylic bromine atoms on the macromolecular chains of BIIR. The graft copolymerization of methyl methacrylate (MMA) from the backbone of BIIR which was used as a macroinitiator was carried out in xylene at 85 °C with CuBr/N,N,N′,N″,N″-pentamethyldiethylenetriamine as a catalytic complex. The polymerization conditions were optimized by adjusting the catalyst and monomer concentration to reach a higher monomer conversion and meanwhile suppress macroscopic gelation during the polymerization process. This copolymerization followed a first-order kinetic behavior with respect to the monomer concentration, and the number-average molecular weight of the grafted poly(methyl methacrylate) (PMMA) increased with reaction time. The resultant BIIR-graft-PMMA copolymers showed phase separation morphology as characterized by atomic force microscopy, and the presence of PMMA phase increased the polarity of the BIIR copolymers. This study demonstrated the feasibility of using commercial BIIR polymer directly as a macromolecular initiator for ATRP reactions, which opens more possibilities for BIIR modifications for wider applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43408.

Octadecylamine modified graphene oxide/styrene-butadiene rubber (GO-ODA/SBR) composites are prepared by a novel and environmental-friendly method called “Improved melt compounding”. A GO-ODA/ethanol paste mixture is prepared firstly, and then blended with SBR by melt compounding. GO-ODA sheets are uniformly dispersed in SBR as confirmed by scanning electron microscope, transmission electron microscopy, and X-ray diffraction. The interfacial interaction between GO-ODA and SBR is weaker than that between GO and SBR, which is proved by equilibrium swelling test and dynamic mechanical analysis. GO-ODA/SBR show more pronounced “Payne effect” than GO/SBR composites, indicating enhanced filler networks resulted from the modification of GO with ODA. GO-ODA/SBR composite has higher tensile strength and elongation at break than SBR and GO/SBR composite. The tensile strength and elongation at break for the composite with 5 parts GO-ODA per hundred parts of rubber increase by 208% and 172% versus neat SBR, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42907.

Miscible polychloroprene/polyvinyl chloride (CR/PVC) blends with nitrile butadiene rubber (NBR) as a compatibilizer were prepared. The effect of NBR on the compatibility between CR and PVC was mainly analyzed by studying the thermal behavior and the phase structure of CR/PVC blends. An obvious decrement in the T_g of PVC phase successfully provided an explanation for the compatibilization of NBR. Due to the improved compatibility between CR and PVC, the size of PVC particles in CR/PVC blends decreased a lot according to the scanning electronic microscopic images. The significant improvement of mechanical properties of CR/PVC blends was in good agreement with the better compatibility between CR and PVC phases. The softening effect of NBR on the nonlinear viscoelasticity of CR/PVC blends was also studied by RPA 2000. Temperature sweep test by RPA 2000, a less reported characterization method of T_g, was successfully applied to measure T_g of CR/PVC blends and study the compatibilization of NBR. The reason for better thermal stability and the thermal decomposition mechanism of CR/PVC blends were analyzed according to the results of TGA. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42448.

Dynamically vulcanized Nylon 1010/ethylene-vinyl acetate rubber (EVM)/SiO₂ nanocomposites were prepared. Maleic anhydride grafted ethylene-vinyl acetate copolymer (EVA-g-MA) and nano-silica (SiO₂) was used as a compatibilizer and a filler, and silane coupling agent (KH550, 3-triethoxysilylpropylamine) was used to improve the dispersion of SiO₂ in the nanocomposites. The nanocomposites were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), dynamic mechanical analysis (DMA), differential scanning calorimeter (DSC), and rheology analysis and mechanical properties test. SEM and AFM images showed that the compatibility between Nylon 1010 and EVM was improved by adding the compatibilizer. An increase in SiO₂ content and the addition of the compatibilizer led to an increase in the tensile strength of the nanocomposite. A nanocomposite based on Nylon 1010/EVM/DCP (30/70/0.8) with tensile strength of 16.3 MPa and elongation at break of 180% was obtained by the addition of 15 phr EVA-g-MA and 40 phr SiO₂. The non-isothermal crystallization processes of Nylon/EVM blend were investigated by DSC. It was observed that EVM rubber could act as heterogeneous nuclei for Nylon which was more effective in Nylon/EVM/DCP blend than in Nylon/EVM blend. POLYM. ENG. SCI., 55:581–588, 2015. © 2014 Society of Plastics Engineers

Fluoroelastomer (FKM)/reduced graphene oxide (rGO) composites are in situ prepared by solvent thermal reduction method in N,N-dimethylformamide (DMF) solution. The reduction of graphene oxide (GO) is characterized by X-Ray photoelectron (XPS), ultraviolet–visible (UV–vis), and Fourier transform infrared (FTIR) spectra. GO and rGO are both efficient fillers to improve the mechanical properties of FKM. The dispersibility of rGO is improved after solvent thermal reduction which is confirmed by scanning electron micrograph (SEM) and X-ray diffraction (XRD). The homogenous suspension of FKM/rGO composites in DMF can stay stable for more than a month. The dielectric permittivity of FKM/rGO (5 phr) is 26.4 at the frequency of 10⁻¹ Hz, higher than the pure FKM (8.1). The thermal conductivity of rGO/FKM composites increases. POLYM. COMPOS., 35:1779–1785, 2014. © 2013 Society of Plastics Engineers

The viscoelasticity and stress-softening behavior of chloroprene rubber (CR) filled with multiwalled carbon nanotubes (MWCNT) and carboxylated multiwalled carbon nanotubes (MWCNT-COOH) were studied using a Rubber Process Analyzer 2000 (RPA2000). In the strain sweep measurements, it is found that CR/MWCNT and CR/MWCNT-COOH compounds have different behavior on storage modulus (G′). With increasing strain, G′ of CR/MWCNT (100/8) compound decreases at strain less than 2°, while G′ of CR/MWCNT-COOH (100/8) compound stays at constant, indicating that MWCNT-COOH has stronger filler–filler network and filler–rubber interactions as compared to MWCNT in CR matrix. CR/MWCNT (MWCNT-COOH) vulcanizates have higher G′ but lower loss modulus (G″) than the corresponding uncured compounds. Repeated strain sweep scans were carried out to study the stress-softening behavior of CR compounds. A stress-softening effect of the filled CR compounds is observed and becomes more pronounced with increasing loading of MWCNT or MWCNT-COOH. The correlation between the Payne effect and stress-softening effect of CR/MWCNT (MWCNT-COOH) vulcanizates is also studied. It is found that the difference of the storage moduli at 0.1° and 10° strain amplitudes and the difference of storage moduli of first and second strain sweeps at 0.1° strain amplitude show a positive linear correlation. POLYM. COMPOS., 35:2194–2202, 2014. © 2014 Society of Plastics Engineers

Reactive processing is a useful method to improve the compatibility of immiscible polymer blends. Nylon 1010/Ethylene-vinyl acetate rubber (EVM) blends were prepared via melt blending at 240°C and tetrabutyl titanate (Ti(OBu)₄) was used as a catalyst. Ester–amide exchange reactions were proven to take place between Nylon and EVM during the shear processing. Melt flow index, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance spectra were used to study the reactions. It was demonstrated that tuning the shear rate could control the properties and reaction extent of Nylon 1010/EVM/Ti(OBu)₄ blends. The results revealed that the reactions were promoted by high shear rate. Tensile strength of the blends increased from 4.5 to 11.4 MPa when the shear rate increased from 20 to 80 rpm. Meanwhile, scanning electron microscopy was adopted to study the morphology of the reactive blends. It was found that the morphology of the blends was changed from sea-island structures to co-continuous structures while increasing the shear rate from 20 to 100 rpm. Dynamic mechanical analysis confirmed that high-shear processing was found to promote the compatibility of the blends. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40064.

The ester–amide exchange reaction between polyamide 6 (PA6) and ethylene-vinyl acetate rubber (EVM) with dibutyltin oxide (DBTO) as a catalyst took place during melt blending, leading to the formation of PA6-grafted EVM copolymer (EVM-g-PA6) and acetamide-terminated PA6. The exchange reaction extent, expressed by the percentage content of the acetate groups taking part in the exchange reaction, was 5.9 mol %, and the yield of EVM-g-PA6 copolymer was 6.8 wt % for PA6/EVM/DBTO (60/40/1) blend at 230°C for 60 min. The number-average molecular weight of PA6 branches in EVM-g-PA6 was ∼278 g/mol as evaluated from nuclear magnetic resonance spectra. The reaction kinetic parameters were calculated according to a second-order reversible reaction mechanism. The rate constant was dependent on the catalyst concentration, PA6/EVM ratio, and shearing conditions. In this article, the characterized ester–amide exchange reaction between PA6 and EVM will guide the fabrication of novel EVM-based graft copolymers and high-performance PA6/EVM thermoplastic elastomers for engineering applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40272.

Poly(vinyl chloride) (PVC)/acrylonitrile–butadiene rubber (NBR) were mixed with multiwalled carbon nanotubes (MWCNTs) and silicon carbide (SiC) to prepare microwave-absorbing composites. The complex permittivity, direct-current (dc) conductivity, microwave-absorbing performance, morphology, and mechanical properties of the composites were studied. The real and imaginary parts of the permittivity of the composites increased with increasing MWCNT content. The premixing of the MWCNTs with PVC was more beneficial to the dispersion of MWCNTs; this led to a higher dc conductivity and permittivity and better microwave-absorbing performance than the premixing of MWCNTs with NBR for the PVC/NBR/MWCNT composites. The PVC/NBR/MWCNT composites had a minimum reflection loss (RL_min) of −49.5 dB at the optimum thickness of 1.96 mm. The efficient microwave absorption of the PVC/NBR/MWCNT composites was due to a high dielectric loss and moderate permittivity. The incorporation of SiC into the PVC/NBR/MWCNT composites increased the real and imaginary parts of permittivity of the composites. When the SiC content was 70 phr, RL_min decreased to −34.9 dB at a thickness of 3 mm. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

High performance thermoplastic elastomers based on ethylene-vinyl acetate rubber (EVM) and ternary polyamide copolymer (tPA) were prepared through a dynamic vulcanization process in the presence of dicumyl peroxide (DCP). The morphology, crystallization, and mechanical properties of the EVM/tPA blends were studied. A phase transition of EVM/tPA blend was observed at a weight ratio of 60/40. The presence of EVM increased the melting enthalpy at the high temperature of tPA, ascribing to the heterogeneous nucleating effect of EVM. The tensile strength of EVM/tPA (70/30) blends was increased up to 20.5 MPa as the DCP concentration increased to 3.5 phr, whereas the elongation at break of the blends kept decreasing as the DCP concentration increased. The addition of ethylene-acrylic acid copolymer (EAA) or maleic anhydride-grafted EVM (EVM-g-MAH) to the EVM/tPA blends both induced finer dispersion of the EVM particles in the tPA phase and improvement in the tensile strength and elongation at break of the blends, which were ascribed to the compatibilization of EAA or EVM-g-MAH. Finally, a high performance EVM/tPA (70/30) thermoplastic elastomer with Shore A hardness of 75, tensile strength of 24 MPa, elongation at break of 361%, and set at break of 20% was obtained by adding 5 wt % of EVM-g-MAH and 3.5 phr DCP. It has great potential in automotive and oil pipeline applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Nylon 1010 and acrylate rubber (ACM) were prepared by melt blending. The effects of blending time and catalyst on the properties of the blends were studied. It was found that ester-amide exchange reactions between the Nylon 1010 and ACM occurred during melt processing. Long blending time and Tetrabutyl titanate (Ti(OBu)₄) as a catalyst could promote the reactions, and grafted copolymer Nylon-g-ACM was in situ generated as a compatibilizer during processing procedure. The tensile strength of the blends increased from about 12.0–15.0 MPa when the blending time increased from 10 to 30 min. The presence of Ti(OBu)₄ led to the decrease in melt flow index (MFI), independent of the blending time (30 or 60 min). Glass transition temperature and heat of fusion of the blends increased after addition of the catalyst. Rheological behavior analysis provided evidence of formation of Nylon-g-ACM graft copolymer. Scanning electron microscopy (SEM) showed that the compatibility of the blends was improved by longer blending time and the addition of catalyst. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4587–4597, 2013

The effect of liquid isoprene rubber (LIR) on the dynamic mechanical properties of emulsion-polymerized styrene/butadiene rubber (ESBR) vulcanizates was investigated by temperature sweep using dynamic mechanical analysis. The introduction of LIR led to ESBR vulcanizates having higher loss factor (tan δ) in the temperature range − 30 to 0 °C, and lower tan δ in the range 60 to 80 °C. A small amount of LIR-403 (LIR with carboxyl groups) led to a significant change in tan δ: the addition of LIR-403 (3 phr) led to a 7.5% increase in tan δ from − 30 to 0 °C, and a 24.9% decrease in tan δ from 60 to 80 °C. It was found that the introduction of LIR increased the bound rubber content in the ESBR compound. Equilibrium swelling experiments showed that the crosslink density of the vulcanizates increased after the introduction of LIR-403 or LIR-50 (general purpose LIR). The change in tan δ from 60 to 80 °C was related to polymer–filler interactions. The characteristic constant of filler–ESBR matrix interaction (m) was calculated. At a given filler volume fraction, the increase in m in the presence of LIR could be well related to the decrease in tan δ from 60 to 80 °C. The influence of LIR on filler network in the ESBR compound was also investigated by strain and temperature sweeps using a rubber processing analyzer. Copyright © 2011 Society of Chemical Industry

Flame retardant polycarbonate (FRPC) with 0.2 wt % additives of potassium perfluorbutane sulfonate and polydimethylsiloxane was found to achieve V-0 rate at 1.6 mm thickness without significantly affecting the mechanical properties of PC. Condensed aromatic bonds with a small amount of SiO bonds were found in the UL-94 burning residues tested by FTIR spectra. A compact char layer with cavities inside was formed on the surface of the sample during the rapid decomposition of FRPC, and the concentration of Si was found to be much higher inside the surface of the char layer than that outside the surface analyzed by SEM-EDX, which was related to the synergistic effects of the two flame retardants of PPFBS and PDMS. A schematic diagram was designed to describe the mechanism of the FRPC. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Synergistic effects of two kinds of rare earth oxides (REOs), neodymium oxide (Nd₂O₃) or lanthanum oxide (La₂O₃) on the intumescent flame retardancy of thermoplastic polyolefin (TPO) made by polypropylene/poly (octylene-co-ethylene) blends were investigated systemically by various methods. The limiting oxygen index (LOI) of flame retardant TPO (FRTPO) filled by 30 wt% intumescent flame retardants (IFR) composed of ammonium polyphosphate (APP) and pentaerythritol (PER) has been increased from 30 to 32.5 and 33.5 when 0.5 wt% of IFR was substituted by La₂O₃ and Nd₂O₃, respectively. Cone calorimetry tests also reveal the existence of synergistic effects. Thermalgravimetric analyses (TGA) demonstrate that the presence of REOs promotes the esterification and carbonization process in low-temperature range while enhances the thermal stability of IFR and FRTPO in high-temperature range. X-ray diffraction (XRD) reveals that the interaction of Nd₂O₃ with IFR results in the formation of neodymium phosphate (NdP₅O₁₄) with high-thermal stability. Thermal scanning rheological tests show that the presence of REOs increases complex viscosity of FRTPO in the temperature range of 190∼300°C so as to suppress melt dripping but decreases the complex viscosity and increases the loss factors tan δ in temperature range of 300∼400°C to make the carbonaceous strucuture more flexible and viscous to resist stress, expand better and keep intact. Copyright © 2009 John Wiley & Sons, Ltd.

Ethylene-vinyl acetate rubber (EVM) vulcanizates cured by dicumyl peroxide (DCP) with excellent mechanical properties were obtained by adding superfluous magnesium hydroxides (MH)/methacrylic acid (MAA). Different factors such as the DCP content and MH content were investigated to reveal their effects on the properties of the MH/MAA-filled EVM vulcanizates. The formulation of DCP of 2 phr, MH of 60 phr, and MAA of 5 phr is recommended for the EVM vulcanizates with excellent mechanical properties. The stress relaxation and stress softening behavior of MH/MAA-filled EVM vulcanizates were studied. The stress relaxation and stress softening became faster and more obvious with increasing MH content. The hot air aging resistance of EVM vulcanizates filled with different fillers such as silica and high abrasion furnace were compared, and the MH/MAA-filled EVM vulcanizates had the best aging resistance at 40-phr filler content. The MH/MAA-filled EVM vulcanizates had excellent flame retardancy due to the high MH content. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Synergistic effects of the natural clays unexfoliated vermiculite (VMT), exfoliated vermiculate (EVMT), and montmorillonite (MMT) on the intumescent flame retardance of polypropylene were investigated systematically with the usual fire testing methods. The limiting oxygen index (LOI) of flame-retardant polypropylene (FRPP) filled with 30 wt % intumescent flame retardants (IFRs) composed of ammonium polyphosphate and pentaerythritol were increased from 30 to 33 vol % for VMT and MMT and to 36 vol % for EVMT when 1 wt % IFR was substituted for clay. The synergistic effectivities calculated on the basis of increases in the LOI values were 1.4 for VMT, 1.3 for MMT, and 1.6 for EVMT. Cone calorimetry also revealed the existence of a synergistic effect. EVMT had the best performance for lowering the peak values of the heat release rate and smoke production rate. The thermogravimetric analysis results show that EVMT had the best performance for increasing the char residue of FRPP higher than 650°C compared with VMT and MMT. The high content of iron and the small particle size of EVMT may have been responsible for its high synergistic effect at a low filling level. No remarkable variations of the diffraction peaks were observed in the X-ray diffraction patterns of the original clay and the clay in FRPP. All of the formulations, with or without clay, exhibited small variations in the mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Ethylene–vinyl acetate rubber (EVM) vulcanizates with excellent mechanical properties were obtained with magnesium hydroxides (MH) and methacrylic acid (MAA). MAA significantly improved the mechanical properties of the MH-filled EVM vulcanizates. The tensile strength, Shore A hardness, and tensile set modulus of the EVM vulcanizates significantly increased with increasing MAA content. The tensile strength of the MH-filled EVM vulcanizates increased from 12.3 to 18.5 MPa after the addition of 2.5 phr MAA when the MH content was fixed at 60 phr. The gross crosslink density and ionic crosslink density increased with increasing MAA content. The glass-transition temperature and tan δ slightly decreased with increasing MAA content. Morphological study showed that MAA obviously improved the dispersion of the MH particles in the EVM matrix. The thermal stability of the EVM vulcanizates was obviously enhanced after the addition of MAA. Fourier transform infrared analysis indicated that MAA reacted with MH to form magnesium methacrylates, and there was a polymerization of MAA during the curing process in the existence of peroxide. An ionic crosslink bond was thought to be formed on the surface of the MH aggregates; this resulted in a possible structure where MH aggregates were considered as crosslink points. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

The toughness of three different elastomer-toughened nylon 1010 blends was investigated via standard notched Izod impact test and single edge notched three-point bending test. The toughness of nylon 1010 blends varies much with different elastomer types and components. All three kinds of nylon/elastomer/maleated-elastomer blends showed high impact strength (over 50 kJ m⁻²) as long as at appropriate blending ratios. With increasing maleated elastomer content, brittle-ductile transition was observed for all three kinds of elastomer-toughened nylon 1010 blends. The number average dispersed particle size (d_n) of ethylene-1-octene copolymers or ethylene-vinyl acetate copolymers toughened nylon 1010 blends significantly decreased from over 1 to 0.1 μm with increasing corresponding maleated elastomer content. Investigation on the fracture toughness showed the dissipative energy density gradually increased with decreasing d_n, while the limited specific fracture energy increased with increasing d_n when d_n was below 1 μm and then sharply decreased with further increasing d_n. The energy consumed in the outer plastic zone was the main part of the whole energy dissipated during the fracture process. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Poly(2,6-dimethyl-1,4-phenylene oxide)/polyamide 6 (PPO/PA6 30/70) blends were impact modified by addition of three kinds of maleated polystyrene-based copolymers, i.e., maleated styrene-ethylene-butylene-styrene copolymer (SEBS-g-MA), maleated methyl methacrylate-butadiene-styrene copolymer (MBS-g-MA), and maleated acrylonitrile-butadiene-styrene copolymer (ABS-g-MA). The mechanical properties, morphology and rheological behavior of the impact modified PPO/PA6 blends were investigated. The selective location of the maleated copolymers in one phase or at interface accounted for the different toughening effects of the maleated copolymer, which is closely related to their molecular structure and composition. SEBS-g-MA was uniformly dispersed in PPO phase and greatly toughened PPO/PA6 blends even at low temperature. MBS-g-MA particles were mainly dispersed in the PA6 phase and around the PPO phase, resulting in a significant enhancement of the notched Izod impact strength of PPO/PA6 blends from 45 J/m to 281 J/m at the MBS-g-MA content of 20 phr. In comparison, the ABS-g-MA was mainly dispersed in PA6 phase without much influencing the original mechanical properties of the PPO/PA6 blend. The different molecule structure and selective location of the maleated copolymers in the blends were reflected by the change of rheological behavior as well. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Styrene–maleic anhydride copolymer (SMA) with higher MA content (21.8 wt %) than reported SMA (mostly 8 wt %) was used as a compatibilizer for poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)/polyamide 6 (PA6) blends by in situ formed PA-g-SMA during melt processing. The tensile strength and flexural strength of PPO/PA blends were greatly increased by the addition of SMA. The morphology of PPO/PA/SMA (30/70/variable) was investigated by scanning electron microscopy, and the addition of SMA led to a significant decrease in the particle size of the dispersed PPO phase. Melting and crystallization of PPO/PA/SMA blends were studied by differential scanning calorimetry, and the results showed that the addition of SMA could improve the compatibility between PPO and PA. The in situ reaction between PA and SMA was confirmed by Fourier transform infrared analysis. SMA was an effective compatibilizer for PPO/PA blends, and its compatibilization mechanism was discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Poly(butylene succinate-co-adipate) (PBSA) and two types of SiO₂ (hydrophilic or hydrophobic) were used to modify poly(L-lactic acid) (PLLA). The mechanical properties, rheological and thermal behavior, phase morphology, and thermal stability of PLLA/PBSA/SiO₂ composites were investigated. The impact strength, flexural strength, and modulus of PLLA/PBSA blends increased after the addition of hydrophobic SiO₂ without decreasing the elongation at break, and the elongation at break monotonically decreased with increasing hydrophilic SiO₂ content. The melt elasticity and viscosity of the PLLA/PBSA blend increased with the addition of SiO₂. The hydrophilic SiO₂ was encapsulated by the dispersed PBSA phase in the composites, which led to the formation of a core–shell structure, whereas the hydrophobic SiO₂ was more uniformly dispersed and mainly located in the PLLA matrix, which was desirable for the optimum reinforcement of the PLLA/PBSA blend. The thermogravimetric analysis results show that the addition of the two types of SiO₂ increased the initial decomposition temperature and activation energy and consequently retarded the thermal degradation of PLLA/PBSA. The retardation of degradation was prominent with the addition of hydrophobic SiO₂. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The mechanical properties, flame retardancy, hot-air ageing, and hot-oil ageing resistance of ethylene-vinyl acetate rubber (EVM)/hydrogenated nitrile-butadiene rubber (HNBR)/magnesium hydroxide (MH) composites were studied. With increasing HNBR fraction, elongation at break and tear strength of the EVM/HNBR/MH composites increased, whereas the limited oxygen index and Shore A hardness decreased slightly. Hot-air ageing resistance and hot-oil ageing resistance of the composites became better with increasing HNBR fraction. Thermal gravimetric analysis results demonstrated that the presence of MH and low HNBR fraction could improve the thermal stability of the composites. Differential scanning calorimeter revealed that the glass transition temperature (T_g) of the composites shifted toward low temperatures with increasing HNBR fraction, which was also confirmed by dynamic mechanical thermal analysis. Atomic force microscope images showed MH has a small particle size and good dispersion in the composites with high HNBR fraction. The flame retardancy, extremely good hot-oil ageing, and hot-air ageing resistance combined with good mechanical properties performance in a wide temperature range (−30°C to 150°C) make the EVM/HNBR/MH composites ideal for cables application. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The maleated poly(ethylene 1-octene) (POE-g-MAH)-toughened and glass fiber (GF)-reinforced nylon 1010 was prepared by melting extrusion. A good trade-off between stiffness and toughness was obtained by the combination of POE-g-MAH and GF. The essential work of fracture (EWF) model was used to characterize the fracture behavior of nylon/POE-g-MAH/GF composites. With increasing GF content, the energy consumed in outer plastic zone gradually decreased, and the work consumed in inner fracture process zone reached the maximum value at the GF content of 10 wt %. Morphology investigations showed that POE-g-MAH was uniformly dispersed in nylon/POE-g-MAH (80/20) blend, and the nylon around POE-g-MAH particles suffered a great plastic deformation in the impact test. For nylon/POE-g-MAH/GF composites, large plastic deformation occurred in the matrix around GF rather than around rubber particles. Dynamic mechanical analysis showed that GF significantly increased the storage and loss moduli and decreased value of tan δ, but had little effect on its position. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The thermal stability of nylon 1010/polyhedral oligomeric silsesquioxane (POSS) composites prepared by melt blending was investigated with thermogravimetric analysis. The octavinyl POSS (vPOSS) and epoxycyclohexyl POSS (ePOSS) were used, and it was found that nylon/vPOSS composites have higher integral procedure decomposition temperature and char yield at 800°C than nylon/ePOSS composites. The Doyle–Ozawa (model-free) and Friedman (model-fitting) methods were used to characterize the nonisothermal decomposition kinetics of nylon 1010 and its composites. The activation energy (E_a), reaction order (n), and the natural logarithm of frequency factor of nylon 1010 were 267 kJ/mol, 1.0, and 47 min⁻¹, respectively, in nitrogen. After the addition of POSS, the E_a of nylon 1010 considerably increased, whereas n had less change. The E_a steadily increased with increasing conversion and with increasing heating rate. The lifetime of nylon 1010 and its composites decreased with increasing temperature. At a given temperature, POSS significantly prolonged the lifetime of nylon 1010. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Octavinyl POSS (vPOSS) and epoxycyclohexyl POSS (ePOSS) were separately incorporated into the poly(lactic acid)/poly(butylene succinate-co-adipate) (PLA/PBSA) blend by melt mixing. Field emission scanning electron microscopy and X-ray diffraction analysis revealed that vPOSS existed as crystalline aggregates, whereas ePOSS was more uniformly dispersed in the composites. The storage modulus and complex viscosity slightly decreased after the addition of vPOSS, but significantly increased after the addition of ePOSS, indicating the higher melt elasicity and broader processing window of the PLA/PBSA after the addition of ePOSS. The chloroform solutions of PLA/PBSA/ePOSS composites were turbid in appearance, and the extracted POSS showed absorbant peaks assigned to the vibration of OH and CO groups in the Fourier transform infrared spectroscopy analysis, indicating the reactions between ePOSS and the PLA/PBSA. Polarized optical microscopy analysis revealed that the two types of POSS could act as nucleating agents for PLA, and enhance its crystallization ability. Thermal gravimetric analysis showed that the addition of the two types of POSS increased the decomposition temperature and activation energy, consequently retarding the thermal degradation of PLA/PBSA. The retardation of degradation is more significant with the addition of ePOSS, for the reactions reduced the end groups of PLA/PBSA as well as the molecular chain mobility. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci 2009

The thermal degradation behavior of styrene-butadiene-styrene triblock copolymer (SBS) and SBS/multiwalled carbon nanotubes (MWCNTs) composites prepared by solution processing and melt mixing, respectively, was investigated using nonisothermal thermogravimetric analysis (TGA). The kinetic parameters of the activation energy (E_a) for degradation, preexponential factor A, and the reaction order (n) were evaluated by the Flynn-Wall-Ozawa, Kissinger, and Coats-Redfern methods, respectively. E_a increased and n decreased after the incorporation of 3 wt % of MWCNTs into the SBS. The E_a of SBS/MWCNTs composite prepared by melt mixing was higher than that by solution processing, which was attributed to the good dispersion of MWCNTs in SBS and the interactions between MWCNTs and SBS. The gases evolved during thermal degradation at a nitrogen atmosphere were studied by Fourier transform infrared spectroscopy (FTIR) coupled with the TGA. Aliphatic and aromatic CH peaks appeared simultaneously in FTIR spectra, indicating the thermal degradation of SBS proceeds by a random chain scission process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The nylon 1010/ethylene-vinyl acetate rubber (EVM)/maleated ethylene-vinyl acetate copolymers (EVA-g-MAH) ternary blends were prepared. The effect of EVM/EVA-g-MAH ratio on the toughness of blends was examined. A super tough nylon 1010 blends were obtained by the incorporation of both EVM and EVA-g-MAH. Impact essential work of fracture (EWF) model was used to characterize the fracture behavior of the blends. The nylon/EVM/EVA-g-MAH (80/15/5) blend had the highest total fracture energy at a given ligament length (5 mm) and the highest dissipative energy density among all the studied blends. Scanning electron microscopy images showed the EVM and EVA-g-MAH existed as spherical particles in nylon 1010 matrix and their size decreased gradually with increasing EVA-g-MAH content. Large plastic deformation was observed on the impact fracture surface of the nylon/EVM/EVA-g-MAH (80/15/5) blend and related to its high impact strength. Then with increasing EVA-g-MAH proportion, the matrix shear yielding of nylon/EVM/EVA-g-MAH blends became less obvious. EVM and EVA-g-MAH greatly increased the apparent viscosity of nylon 1010, especially at low shear rates. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 877–887, 2009

Di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH) was used as a new plasticizer for poly(lactic acid) (PLA), and the effects of DINCH and tributyl citrate ester (TBC) on the morphology, mechanical and thermal properties, and durability of PLA were compared. DINCH has limited compatibility with PLA, leading to PLA/DINCH blends with phase separation in which DINCH forms spherical dispersed phase. TBC is compatible with PLA and evenly distributed in PLA. Plasticized PLA with 10 and 20 phr DINCH have a constant glass transition temperature (T_g) of 50°C and are stiff materials with high elongation at break and impact strength. TBC could significantly decrease the T_g and increase the crystallinity of PLA, and PLA/TBC (100/20) blend is a soft material with a T_g of 24°C. The durability of plasticized PLA was characterized by weight loss measurement under water immersion, mechanical properties, and thermal analysis. The results reveal that PLA/DINCH blends have better water resistance and aging resistance properties than PLA/TBC blends, which is attributed to the relatively high hydrophobicity of DINCH and high T_g of PLA/DINCH blends. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

Nylon 1010 blends with ethylene–vinyl acetate copolymer (EVA) and maleated ethylene–vinyl acetate (EVA-g-MAH) were prepared through melt blending. The vinyl acetate (VA) content and viscosity of EVA significantly affected the notched impact strength of nylon/EVA/EVA-g-MAH (80/15/5) blends. The nylon/EVA/EVA-g-MAH blends with high notched impact strength (over 60 kJ/m²) were obtained when the VA content in EVA ranged from 28 to 60 wt%. The effect of VA content on the notched impact strength of blends was related to the glass transition temperature for EVA with high VA content and crystallinity for EVA with low VA content. For nylon blends with EVA with the same VA content, low viscosity of EVA led to high notched impact strength. Fracture morphology of nylon/EVA/EVA-g-MAH (80/15/5) blends showed that blends with ductile fracture behavior usually had large matrix plastic deformation, which was the main energy dissipation mechanism. A relationship between the notched impact strength and the morphology of nylon/EVA/EVA-g-MAH (80/15/5) blends was well correlated by the interparticle distance model. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

Biodegradable polymer blends consisting of poly(L-lactic acid) (PLLA) and poly(butylene succinate) (PBS) were prepared in the presence of dicumyl peroxide (DCP). The effects of DCP content on the mechanical properties, thermal and rheological behavior, phase morphology as well as the toughening mechanism of the blends were investigated. The notched Izod impact strength of PLLA/PBS (80/20) blend significantly increased after the addition of 0.05–0.2 phr DCP, but the strength and modulus monotonically decreased with increasing DCP content. PBS acted as a nucleating agent at the environmental temperature below its melting temperature and accelerated the crystallization rate of PLLA but had little effect on its final degree of crystallinity. The degree of crystallinity of PBS and the cold crystallization ability of PLLA gradually reduced with increasing DCP content. The addition of DCP induced an increase in viscosity of the blends at low frequencies as well as finer dispersion of PBS particles and better interfacial adhesion between PLLA and PBS, indicating the in situ compatibilization occurred between the two components. The optical clarity of PLLA/PBS blends was significantly improved after the addition of DCP, which was in accordance with the crystallization behavior and phase structure of the blends. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers

The toughening effect of ethylene-vinyl acetate rubbers (EVM) with maleated ethylene-vinyl acetate copolymers (EVA-g-MAH) on the nylon 1010 was investigated. The addition of 5 phr (per hundred nylon 1010) EVM increased the elongation at break of nylon 1010 to a great extent. The notched Izod impact strength of nylon/EVM blends increased with increasing EVM content. Scanning electron microscope showed that the EVM particle size was around 0.5 μm when the EVM content was 5 phr and increased with increasing EVM content. After the addition of EVA-g-MAH to nylon/EVM (100/20) blend, the average diameter of EVM particles decreased from more than 1 μm to 0.5–0.6 μm. EVA-g-MAH could improve the adhesion between nylon 1010 and EVM. A sharp brittle-ductile transition (BDT) was observed when the interparticle distance was about 0.2 μm, independent of the addition of EVA-g-MAH. The notched Izod impact strength of nylon/EVM blends at low temperatures was measured and the BDT shifted toward low temperatures with increasing EVM or EVA-g-MAH content. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 434–444, 2009

Poly(2,6-dimethyl-1,4-phenylene oxide)/polyamide 6 (PPO/PA6) blends were reactively compatibilized by maleic anhydride (MA) grafted PPO (PPO-g-MA) and reinforced by short glass fibers (SGF) via melt extrusion. An observation of the SGF-polymer interface by scanning electronic microscope (SEM) together with etching techniques indicated that the PPO-g-MA played a decisive role in the adhesion of polymers to SGF. The rheological behavior was investigated by capillary rheometer, and the addition of PPO-g-MA, and SGF could increase the viscosity of the PPO/PA6 blends. The analysis of fiber orientation and distribution in the PPO/PA6/SGF composites showed PPO-g-MA favored to the random dispersion of SGF. The statistic analysis of SGF length showed that PPO-g-MA was helpful to maintain the fiber length during melt-processing. For the composites at a given SGF content of 30 wt %, the addition of PPO-g-MA increased the tensile strength from 59.4 MPa to 97.1 MPa and increased SGF efficiency factor from 0.028 to 0.132. The experimental data were consistent with the theoretical predictions of the extension of Kelly-Tyson model for tensile strength. The fracture toughness of the composites was investigated by single edge notch three-point bending test. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2188–2197, 2009

The effects of fumed silica on the crystallization behavior and thermal properties of poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) were investigated. The PHBV/silica composites were prepared by a melt-blending method. The nonisothermal crystallization, melting process, and isothermal crystallization kinetics of PHBV and PHBV/silica composites were characterized with differential scanning calorimetry. The spherulite development and morphology were observed by polarized optical microscopy. In addition, the thermal degradation properties were determined via thermogravimetric analysis. The results indicated that the melting and crystallization kinetics of PHBV were greatly affected by fumed silica, and this was due to the effective nucleation function of silica, which enhanced the crystallization process. The thermal onset degradation temperature of PHBV increased with the addition of fumed silica. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Wollastonite reinforced polypropylene (PP/CaSiO₃) composites were prepared by melt extrusion. A silane coupling agent and a maleic anhydride grafted PP (PP-g-MA) were used to increase the interfacial adhesion between the filler and the matrix. The increased adhesion observed by scanning electron microscopy (SEM) resulted in improved mechanical properties. A model was applied to describe the relationship between the interfacial adhesion and tensile properties of PP/CaSiO₃ composites. There is stronger interfacial adhesion between silane-treated CaSiO₃ and polymer matrix containing PP-g-MA as a modifier. Results of dynamic mechanical thermal analysis (DMTA) showed that stronger interfacial adhesion led to higher storage modulus. The influence of CaSiO₃ particles on the crystallization of PP was studied by using differential scanning calorimetry (DSC). The introduction of CaSiO₃ particles does not affect the crystallization temperature and crystallinity of PP matrix significantly. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Polyamide 6 (PA6)/maleated ethylene–propylene–diene rubber (EPDM-g-MA)/organoclay (OMMT) composites were melt-compounded through two blending sequences. Glycidyl methacrylate (GMA) was used as a compatibilizer for the ternary composites. The composite prepared through via the premixing of PA6 with OMMT and then further melt blending with EPDM-g-MA exhibited higher impact strength than the composite prepared through the simultaneous blending of all the components. However, satisfactorily balanced mechanical properties could be achieved by the addition of GMA through a one-step blending sequence. The addition of GMA improved the compatibility between PA6 and EPDM-g-MA, and this was due to the reactions between PA6, EPDM-g-MA, and GMA, as proved by Fourier transform infrared analysis and solubility (Molau) testing. In addition, OMMT acted as a compatibilizer for PA6/EPDM-g-MA blends at low contents, but it weakened the interfacial interactions between PA6 and EPDM-g-MA at high contents. Both OMMT and GMA retarded the crystallization of PA6. The complex viscosity, storage modulus, and loss modulus of the composites were obviously affected by the addition of OMMT and GMA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008