Modification of acrylonitrile‐butadiene‐styrene terpolymer by graft copolymerization with maleic anhydride in the melt. II. Properties and phase behavior

The graft copolymerization of maleic anhydride (MAH) onto acrylonitrile‐butadiene‐styrene terpolymer (ABS) using dicumyl peroxide and benzoyl peroxide as the binary initiator and styrene as the comonomer in the molten state was described. The properties and phase morphologies of the modified products (ABS‐g‐MAH) were studied. The results indicate that the melt flow index (MFI) of ABS‐g‐MAH increases with the increase of MAH content, the initiator concentration, and the screw speed, whereas the MFI decreases with the increase of temperature. The impact strength and the percentage elongation of ABS‐g‐MAH both decreased and the tensile strength of ABS‐g‐MAH increased slightly as the grafting degree increased. The phase inversion behavior of the modified product was observed by transmission electron microscopy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2834–2839, 2004     

Preparation and properties of PC/SAN alloy modified with styrene‐ethylene‐butylene‐styrene block copolymer

A polycarbonate (PC)/ poly (styrene‐co‐acrylonitrile) (SAN) alloy modified with styrene‐ethylene‐butylene‐styrene (SEBS) block copolymer was prepared and the influence of SEBS content, PC content, and types of modifier on Izod notched impact strength, tensile strength, flexural strength, and Vicat softening temperature was studied. The results showed that the addition of SEBS could obviously increase the Izod notched impact strength and the elongation at break and decrease the tensile and flexural strength and Vicat softening temperature. PC/SAN alloy modified with SEBS had better mechanical properties than the PC/SAN alloy modified with ABS. DSC analysis and SEM photographs revealed that the SEBS was not only distributed in the SAN phase but also distributed in PC phase in a PC/SAN/SEBS alloy while the ABS was mainly distributed in SAN phase in a PC/SAN/ABS alloy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Compatibilization of polypropylene/Poly(acrylonitrile‐butadiene‐styrene) blends by polypropylene‐graft‐cardanol

The polypropylene‐graft‐cardanol (PP‐g‐cardanol) was prepared by reactive extrusion with polypropylene (PP) and natural renewable cardanol which could increase the interfacial energy of PP and inhibit the degradation of PP during the process of reactive extrusion and usage. In this article, PP‐g‐cardanol and polypropylene‐graft‐maleic anhydride (PP‐g‐MAH) were used as compatibilizers of the polypropylene (PP)/poly(acrylonitrile‐butadiene‐styrene) (ABS) blends. PP/ABS (70/30, wt %) blends with PP‐g‐cardanol and PP‐g‐MAH were prepared by a corotating twin‐screw extruder. From the results of morphological studies, the droplet size of ABS was minimized to 1.93 and 2.01 μm when the content of PP‐g‐cardanol and PP‐g‐MAH up to 5 and 7 phr, respectively. The results of mechanical testing showed that the tensile strength, impact strength and flexural strength of PP/ABS (70/30) blends increase with the increasing of PP‐g‐cardanol content up to 5 phr. The complex viscosity of PP/ABS (70/30) blends with 5 phr PP‐g‐cardanol showed the highest value. Moreover, the change of impact strength and tensile strength of PP/ABS (70/30) blends were investigated by accelerated degradation testing. After 4 accelerated degradation cycles, the impact strength of the PP/ABS (70/30) blends with 5 phr PP‐g‐cardanol decrease less than 6%, but PP/ABS (70/30) blends with 5 phr PP‐g‐MAH and without compatibilizer decrease as much as 12% and 32%, respectively. The tensile strength of PP/ABS (70/30) blends has a similar tendency to that of impact strength. The above results indicated that PP‐g‐cardanol could be used as an impact modifier and a good compatibilizer, which also exhibited better stability performance during accelerated degradation testing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41315.     

Blends of recycled polycarbonate and acrylonitrile–butadiene–styrene: comparing the effect of reactive compatibilizers on mechanical and morphological properties

Blends of recycled polycarbonate (PC) and acrylonitrile–butadiene–styrene (ABS) were prepared and some mechanical and morphological properties were investigated. To compatibilize these blends, ABS‐g‐(maleic anhydride) (ABS‐g‐MA) and (ethylene–vinyl acetate)‐g‐(maleic anhydride) (EVA‐g‐MA) with similar degree of grafting of 1.5% were used. To compare the effect of the type of compatibilizer on mechanical properties, blends were prepared using 3, 5 and 10 phr of each compatibilizer. A co‐rotating twin‐screw extruder was used for blending. The results showed that ABS‐g‐MA had no significant effect on the tensile strength of the blends while EVA‐g‐MA decreased the tensile strength, the maximum decrease being about 9.6% when using 10 phr of this compatibilizer. The results of notched Charpy impact strength tests showed that EVA‐g‐MA increased the impact strength of blends more than ABS‐g‐MA. The maximum value of this increase occurred when using 5 phr of each compatibilizer, it being about 54% for ABS‐g‐MA and 165% for EVA‐g‐MA. Scanning electron microscopy micrographs showed that the particle size of the dispersed phase was decreased in the continuous phase of PC by using the compatibilizers. Moreover, a blend without compatibilizer showed brittle behaviour while the blends containing compatibilizer showed ductile behaviour in fracture. © 2013 Society of Chemical Industry     

Influence of high density polyethylene‐g‐maleic anhydride on compatibility and properties of poly(butylene terephthalate)/high density polyethylene blends

Poly(butylene terephthalate)/high density polyethylene (PBT/HDPE) blends and PBT/HDPE‐grafted maleic anhydride (PBT/HDPE‐g‐MAH) blends were prepared by the reactive extrusion approach, and the effect of blend compositions on the morphologies and properties of PBT/HDPE blends and PBT/HDPE‐g‐MAH blends was studied in detail. The results showed that flexural strength, tensile strength, and notched impact strength of PBT/HDPE blends decreased with the addition of HDPE, and flexural strength and tensile strength of PBT/HDPE‐g‐MAH blends decreased, while the notched impact strength of PBT/HDPE‐g‐MAH increased with the addition of HDPE‐g‐MAH. Compared with PBT/HDPE blends, the dimension of the dispersed phase particles in PBT/HDPE‐g‐MAH blends was decreased and the interfacial adhesion was increased. On the other hand, the effects of HDPE and HDPE‐g‐MAH contents on the crystalline and the rheological properties of the blends were also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 6081–6087, 2006     

Isotactic polypropylene toughened with poly(acrylonitrile–butadiene–styrene): Compatibilizing role of maleic anhydride grafted polypropylene

The β‐nucleating activity and toughening effect of acrylonitrile–butadiene–styrene (ABS) graft copolymer on isotactic polypropylene (iPP) and the compatibilizing role of maleic anhydride grafted polypropylene (PP‐g‐MAH) on the iPP/ABS blends were investigated. The results show that ABS can induce the formation of β‐crystal in iPP, and its β‐nucleating efficiency depends on its concentration and dispersibility. The relative content of β‐crystal form is up to 36.19% with the addition of 2% ABS. The tensile and impact properties of the iPP were dramatically enhanced by introducing ABS. The incorporation of PP‐g‐MAH into the iPP/ABS blends inhibits the formation of β‐crystal. The crystallization peaks of the blends shift toward higher temperature, due to the heterogeneous nucleation effect of PP‐g‐MAH on iPP. The toughness of iPP/ABS blends improved due to favorable interfacial interaction resulting from the compatibilization of PP‐g‐MAH is significantly better than the β‐crystal toughening effect induced by ABS. POLYM. ENG. SCI., 59:E317–E326, 2019. © 2019 Society of Plastics Engineers     

Morphological and mechanical properties of PP/ABS blends compatibilized with PP‐g‐acrylic acid

Polypropylene (PP) and acrylonitrile–butadiene–styrene (ABS) blends were prepared by a melt extrusion process. PP‐g‐acrylic acid was used as a compatibilizer. Blends with various compositions of PP, compatibilizer, and ABS were prepared and studied for morphological and mechanical properties. PP‐rich ternary blends showed good morphological and mechanical properties. The use of 5 wt % PP‐g‐acrylic acid as a compatibilizer resulted in a fine and homogeneous dispersion of the ABS phase in the PP phase. The experimental data of the tensile modulus showed good agreement in PP‐rich compositions with that generated from Kerner's model with perfect adhesion. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1731–1741, 2001     

Morphology and mechanical properties of polyamide‐6/K resin blends

Mechanical properties and morphological studies of compatibilized blends of polyamide‐6 (PA‐6)/K resin grafted with maleic anhydride (K‐g‐MAH) and PA‐6/K resin/K‐g‐MAH were investigated as functions of K resin/K‐g‐MAH and dispersed phase K resin concentrations, and all the blends were prepared using twin screw extruder followed by injection molding. Scanning electron microscopy (SEM) were used to assess the fracture surface morphology and the dispersion of the K resin in PA‐6 continuous phase, the results showing extensive deformation in presence of K‐g‐MAH, whereas, uncompatibilized PA‐6/K resin blends show dislodging of K resin domains from the PA‐6 matrix. Dynamic mechanical thermal analysis (DMTA) test reveals the partially miscibility of PA‐6 with K‐g‐MAH, and differential scanning calorimetry (DSC) results further identified that the introduction of K‐g‐MAH greatly improved the miscibility between PA‐6 and K resin. The mechanical properties of PA‐6/K resin blends and K‐g‐MAH were studied through bending, tensile, and impact properties. The Izod notch impact strength of PA‐6/K‐g‐MAH blends increase with the addition of K‐g‐MAH, when the K‐g‐MAH content adds up to 20 wt %, the impact strength is as more than 6.2 times as pure PA‐6, and accompanied with small decrease in the tensile and bending strength less than 12.9% and 17.5%, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Morphology and mechanical properties of ABS blends prepared from emulsion‐polymerized PB‐g‐SAN impact modifier with AIBN as initiator

A series of PB‐g‐SAN impact modifiers (polybutadiene particles grafted by styrene and acrylonitrile) are synthesized by seed emulsion copolymerization initiated by oil‐soluble initiator, azobisiobutyronitrile (AIBN). The ABS blends are obtained by mixing SAN resin with PB‐g‐SAN impact modifiers. The mechanical behavior and the phase morphology of ABS blends are investigated. The graft degree (GD) and grafting efficiency (GE) are investigated, and the high GD shows that AIBN has a fine initiating ability in emulsion grafting of PB‐g‐SAN impact modifiers. The morphology of the rubber particles is observed by the transmission electron microscopy (TEM). The TEM photograph shows that the PB‐g‐SAN impact modifier initiated by AIBN is more likely to form subinclusion inside the rubber particles. The dynamic mechanical analysis on ABS blends shows that the subinclusion inside the rubber phase strongly influences the T_g, maximum tan δ, and the storage modulus of the rubber phase. The mechanical test indicates that the ABS blends, which have the small and uniform subinclusions dispersed in the rubber particles, have the maximum impact strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Blends of poly(2,6‐dimethyl‐1,4‐phenylene oxide)/polyamide 6 toughened by maleated polystyrene‐based copolymers: Mechanical properties,morphology, and rheology

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     

Studies on morphology and thermomechanical performance of ABS/PC/organoclay hybrids

In the present research, poly(acrylonitrile‐butadiene‐styrene)/polycarbonate (ABS/PC) blends were prepared in a twin screw extruder. An attempt to reinforce and promote compatibility of the above systems was made by the incorporation of organically modified montmorillonite (OMMT, Cloisite 30B), as well as by the addition of compatibilizer (ABS grafted with maleic anhydride, ABS‐g‐MAH), and the effect of those treatments on the morphology, thermal transitions, rheological, and mechanical properties of the above blends was evaluated. The addition of compatibilizer in ABS/PC blends does not significantly affect the glass transition temperature (T_g) of SAN and PC phases, whereas the incorporation of Cloisite 30B decreases slightly the T_g values of SAN and, more significantly, that of PC in compatibilized and uncompatibilized blends. The T_g of PB phase remains almost unaffected in all the examined systems. The obtained results suggest partial dissolution of the polymeric components of the blend and, therefore, a modified Fox equation was used to assess the amount of PC dissolved in the SAN phase of ABS and vice versa.Reinforcing with OMMT enhances the miscibility of ABS and PC phases in ABS/PC blends and gives the best performance in terms of tensile strength, modulus of elasticity, and storage modulus, especially in 50/50 (w/w) ABS/PC blends. The addition of ABS‐g‐MAH compatibilizer, despite the improvement of intercalation process in organoclay/ABS/PC nanocomposites, did not seem to have any substantial effect on the mechanical properties of the examined blends. POLYM. COMPOS., 35:1395–1407, 2014. © 2013 Society of Plastics Engineers     

Effect of the compatibilizers on flame-retardant polycarbonate (PC)/acrylonitrile–butadiene–styrene (ABS) alloy

Polycarbonate (PC) blended with acrylonitrile–butadiene–styrene (ABS) has the maximum notched Izod impact strength, which is 58 kg cm cm^-1 for PC/ABS1 and 66 kg cm cm^-1 for PC/ABS2, at a ratio of 80/20 in this study. We selected the ratio of 80/20 to prepare flame-retardant PC/ABS alloys. The compatibility of flame-retardant PC/ABS alloy was examined by differential scanning calorimetry (DSC). The flame-retardant PC/ABS alloy had two values of the glass transition temperature (T_g), indicating that the alloy was not compatible. Three kinds of compatibilizers, methacrylate–butadiene–styrene (MBS), ethylene–vinyl acetate (EVA), and styrene–maleic anhydride (SMA) were used to improve the phenomenon. DSC measurement revealed that after compatibilization the alloy had only one value of T_g, meaning that the alloy became more compatible. Samples were frozen in liquid nitrogen to look at their morphology. We found that the domain sizes were reduced and the surface boundaries were closed and blurred, a feature that could promote the mechanical properties of the alloy. In this study, we also compared the effects of mechanical properties on differential compatibilizers for the flame-retardant PC/ABS alloy. Cycoloy 2800 is a commercial-grade flame-retardant product and was chosen to compare it with our prepared alloys in this study. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 795-805, 1997     

Structure and properties of heat‐resistant ABS resins innovated by NSM random copolymer

N‐phenylmaleimide(NPMI)‐styrene(St)‐maleic anhydride (MAH) copolymer was synthesized in xylene solution by one‐step free radical copolymerization, using di‐tert‐butyl diperoxyterephthalate as initiator. The resulting heat‐resistant NPMI‐St‐MAH (NSM) copolymer was characterized by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography, differential scanning calorimetry, elemental analysis, and nuclear magnetic resonance spectroscopy (¹H‐NMR and ¹³C‐NMR). The results show that NPMI‐St‐MAH exhibits a random sequence distribution with a NPMI: St: MAH weight ratio of 47:51:2. The glass transition temperature (T_g) is about 190.0°C. Blends of acrylonitrile‐butadiene‐styrene (ABS) with various contents of NSM were prepared using a twin‐screw extruder, and the effects of NSM content on the thermal and mechanical properties of ABS blends were investigated. It was found that the Vicat softening point, tensile strength, flexural strength, flexural modulus, and Rockwell hardness of the ABS/NSM blends were all significantly enhanced with increasing NSM content, whereas the impact strength shows the opposite trend. The impact fracture surface morphology was characterized by scanning electron microscope. It was revealed that cavitation and cavity coalescence resulted in the toughening of the material, which well accounts for the decrease of impact strength with increasing NSM content. In addition, the rheological properties of the blends were examined using a capillary rheometer. The blends present excellent processing property and are suitable for injection molding, although a pseudoplastic behavior was observed in all cases. POLYM. COMPOS., 34:920–928, 2013. © 2013 Society of Plastics Engineers     

Effect of poly(ethylene‐co‐vinyl acetate) additive on mechanical properties of maleic anhydride‐grafted acrylonitrile butadiene styrene for coating applications

The Izod impact strength of maleic anhydride‐grafted acrylonitrile butadiene styrene (MA‐g‐ABS) copolymer has been improved by the use of rubbery poly(ethylene‐co‐vinyl acetate) (EVA). The MA‐g‐ABS is prepared by an internal mixer using dicumyl peroxide as free radical initiator, and the grafting degree was determined using back‐titration method. The amount of EVA is optimized by evaluating the Izod impact strength, tensile, and flexural properties of the samples. Addition of 6% EVA into MA‐g‐ABS system improved the Izod impact strength and tensile strength by 18% and 35%, respectively. The miscibility of EVA in ABS and MA‐g‐ABS matrices has been observed using differential scanning calorimetry and scanning electron microscopy techniques. The enhanced adhesion property exhibited by MA‐g‐ABS/EVA systems promises it as a good candidate for thermoplastic coating applications on aluminum substrates. J. VINYL ADDIT. TECHNOL., 25:287–295, 2019. © 2018 Society of Plastics Engineers     

Properties and morphologies of PVC/nylon terpolymer blends

A new kind of blends of polyvinyl chloride (PVC)/nylon terpolymer was reported in this article. Two compatibilizers were used in this study: one is a terpolymer of ethylene–n‐butyl acrylate–monoxide (EnBACO); the other is terpolymer of EnBACO grafted with maleic anhydride (EnBACO‐g‐MAH). The observation of scanning electron microscope (SEM) reveals that the PVC/nylon terpolymer blends have a two‐phase structure; and the nylon terpolymer phase is the continuous phase, and PVC domains in the PVC/nylon terpolymer/EnBACO‐g‐MAH blends have fine dispersion over a broad range of the PVC/nylon terpolymer ratio. EnBACO‐g‐MAH is more compatible with the nylon terpolymer than EnBACO. EnBACO and EnBACO‐g‐MAH have different effects on the glass transition temperatures of the PVC phase and nylon terpolymer phase in the blends. The notched Izod impact strength, tensile strength, elongation at break, Vicat softening temperature (VST), and melt flow index (MFI) critically depend on PVC/nylon terpolymer ratio, the kinds and concentration of the compatibilizers. The PVC/nylon terpolymer/EnBACO‐g‐MAH blends display a good combination of high toughness, high flowability, and high VST under low load. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2823–2832, 2001     

Biodegradation of blends of polyethylene‐octene elastomer with starches by fungi

Five fungi including Aspergillus niger, Penicilium pinophilum, Chaetoomium globsum, Gliocladium virens and Aureobasium pullulans were used to investigate the biodegradation of starch‐based elastomers: polyethylene‐octene elastomer (POE)/starch and grafted POE‐g‐MAH/starch copolymer blends. The viability of the composite spore suspensions were measured before estimating the fungal growth on the surface of specimens. The weight loss, morphology and mechanical properties of the blended specimens were measured using scanning electron microscopy and a mechanical properties tester after 28 days of culturing. The spore suspension in the experiment showed good viability. Pure POE and POE‐g‐MAH did not allow significant fungal growth. Pure POE did not lose weight or have a change in tensile strength, but pure POE‐g‐MAH lost about 0.07% of its weight with a slight reduction in tensile strength during culture period. There was heavy growth on the surface of POE/starch and POE‐g‐MAH/starch blends after 28 days of culturing. The weight loss of POE/starch and POE‐g‐MAH/starch blends increased with increasing starch content. POE‐g‐MAH/starch blends tended to lose more weight than POE/starch blends. After biodegradation, the surface of POE/starch and POE‐g‐MAH/starch blends became rough with many holes and cracks, indicating that the films were eroded by the fungi. Tensile strength of POE/starch and POE‐g‐MAH/starch blends decreased after culturing because of microbial attack. On the contrary, elongation at break of POE‐g‐MAH/starch blends increased after biodegradation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114:3574–3584, 2009     

Mechanical performance of ternary in situ polycarbonate/poly(acrylonitrile‐butadiene‐styrene)/liquid crystalline polymer composites

Ternary in situ polycarbonate (PC)/poly(acrylonitrile‐butadiene‐styrene) (ABS)/liquid crystalline polymer(LCP) composites were prepared by injection molding. The LCP used was a versatile Vectra A950, and the matrix of composite specimens was PC/ABS 60/40 by weight. Maleic anhydride (MA) copolymer and solid epoxy resin (bisphenol type‐A) were used as compatibilizers for these composites. The tensile, dynamic mechanical, impact, morphology, and thermal properties of the composites were studied. Tensile tests showed that the tensile strength of the PC/ABS/LCP composite in the longitudinal direction increased markedly with increasing LCP content. However, it decreased slowly with increasing LCP content in the transverse direction. The modulus of this composite in the longitudinal direction appeared to increase considerably with increasing LCP content, whereas the incorporation of LCP into PC/ABS blends had little effect on the modulus in the transverse direction. The impact tests revealed that the Izod impact strength of the composites in both longitudinal and transverse direction decreased with increasing LCP content up to 15 wt %; thereafter it increased slowly with increasing LCP. Dynamic mechanical analyses (DMA) and thermogravimetric measurements showed that the heat resistance and heat stability of the composites tended to increase with increasing LCP content. Scanning electron microscopy observation and DMA measurement indicated that the additions of epoxy and MA copolymer to PC/ABS matrix appeared to enhance the compatibility between the PC and ABS, and between the matrix and LCP. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2274–2282, 1999     

Toughening of recycled poly(ethylene terephthalate)/glass fiber blends with ethylene–butyl acrylate–glycidyl methacrylate copolymer and maleic anhydride grafted polyethylene–octene rubber

The aim of this study was to improve the toughness of recycled poly(ethylene terephthalate) (PET)/glass fiber (GF) blends through the addition of ethylene–butyl acrylate–glycidyl methacrylate copolymer (EBAGMA) and maleic anhydride grafted polyethylene–octene (POE‐g‐MAH) individually. The morphology and mechanical properties of the ternary blend were also examined in this study. EBAGMA was more effective in toughening recycled PET/GF blends than POE‐g‐MAH; this resulted from its better compatibility with PET and stronger fiber/matrix bonding, as indicated by scanning electron microscopy images. The PET/GF/EBAGMA ternary blend had improved impact strength and well‐balanced mechanical properties at a loading of 8 wt % EBAGMA. The addition of POE‐g‐MAH weakened the fiber/matrix bonding due to more POE‐g‐MAH coated on the GF, which led to weakened impact strength, tensile strength, and flexural modulus. According to dynamic rheometer testing, the use of both EBAGMA and POE‐g‐MAH remarkably increased the melt storage modulus and dynamic viscosity. Differential scanning calorimetry analysis showed that the addition of EBAGMA lowered the crystallization rate of the PET/GF blend, whereas POE‐g‐MAH increased it. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effects of the polybutadiene/poly(styrene‐co‐acrylonitrile) ratio in a polybutadiene‐g‐poly(styrene‐co‐acrylonitrile) impact modifier on the morphology and mechanical behavior of acrylonitrile–butadiene–styrene blends

Polybutadiene‐g‐poly(styrene‐co‐acrylonitrile) (PB‐g‐SAN) impact modifiers with different polybutadiene (PB)/poly(styrene‐co‐acrylonitrile) (SAN) ratios ranging from 20.5/79.5 to 82.7/17.3 were synthesized by seeded emulsion polymerization. Acrylonitrile–butadiene–styrene (ABS) blends with a constant rubber concentration of 15 wt % were prepared by the blending of these PB‐g‐SAN copolymers and SAN resin. The influence of the PB/SAN ratio in the PB‐g‐SAN impact modifier on the mechanical behavior and phase morphology of ABS blends was investigated. The mechanical tests showed that the impact strength and yield strength of the ABS blends had their maximum values as the PB/SAN ratio in the PB‐g‐SAN copolymer increased. A dynamic mechanical analysis of the ABS blends showed that the glass‐transition temperature of the rubbery phase shifted to a lower temperature, the maximum loss peak height of the rubbery phase increased and then decreased, and the storage modulus of the ABS blends increased with an increase in the PB/SAN ratio in the PB‐g‐SAN impact modifier. The morphological results of the ABS blends showed that the dispersion of rubber particle in the matrix and its internal structure were influenced by the PB/SAN ratio in the PB‐g‐SAN impact modifiers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2165–2171, 2005     

Preparation and properties of dynamically cured PP/MAH‐g‐EVA/epoxy blends

A method concerning with the simultaneous reinforcing and toughening of polypropylene (PP) was reported. Dynamical cure of the epoxy resin with 2‐ethylene‐4‐methane‐imidazole (EMI‐2,4) was successfully applied in the PP/maleic anhydride‐grafted ethylene‐vinyl acetate copolymer (MAH‐g‐EVA), and the obtained blends named as dynamically cured PP/MAH‐g‐EVA/epoxy blends. The stiffness and toughness of the blends are in a good balance, and the smaller size of epoxy particle in the PP/MAH‐g‐EVA/epoxy blends shows that MAH‐g‐EVA was also used as a compatibilizer. The structure of the dynamically cured PP/MAH‐g‐EVA/epoxy blends is the embedding of the epoxy particles by the MAH‐g‐EVA. The cured epoxy particles as organic filler increases the stiffness of the PP/MAH‐g‐EVA blends, and the improvement in the toughness is attributed to the embedded structure. The tensile strength and flexural modulus of the blends increase with increasing the epoxy resin content, and the impact strength reaches a maximum of 258 J/m at the epoxy resin content of 10 wt %. DSC analysis shows that the epoxy particles in the dynamically cured PP/MAH‐g‐EVA/epoxy blends could have contained embedded MAH‐g‐EVA, decreasing the nucleating effect of the epoxy resin. Thermogravimetric results show the addition of epoxy resin could improve the thermal stability of PP, the dynamically cured PP/MAH‐g‐EVA/epoxy stability compared with the pure PP. Wide‐angle x‐ray diffraction analysis shows that the dynamical cure and compatibilization do not disturb the crystalline structure of PP in the blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009