Acrylonitrile–butadiene–styrene toughened nylon 6: The influences of compatibilizer on morphology and impact properties

Polymer alloys have been used as an alternative to obtain polymeric materials with unique physical properties. Generally, the polymer mixture is incompatible, which makes it necessary to use a compatibilizer to improve the interfacial adhesion. Nylon 6 (PA6) is an attractive polymer to use in engineering applications, but it has processing instability and relatively low notched impact strength. In this study, the acrylonitrile–butadiene–styrene (ABS) triblock copolymer was used as an impact modifier for PA6. Poly(methyl methacrylate‐co‐maleic anyhydride) (MMA‐MA) and poly(methyl methacrylate‐co‐glycidyl methacrylate) (MMA‐GMA) were used as compatibilizers for this blend. The morphology and impact strength of the blends were evaluated as a function of blend composition and the presence of compatibilizers. The blends compatibilized with maleated copolymer exhibited an impact strength up to 800 J/m and a morphology with ABS domains more efi8ciently dispersed. Moderate amounts of MA functionality in the compatibilizer (～5%) and small amounts of compatibilizer in the blend (～5%) appear sufficient to improve the impact properties and ABS dispersion. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 842–847, 2003     

Influence of epoxy resin on the properties of maleic anhydride functionalized acrylonitrile–butadiene–styrene copolymer toughened polyamide 6 blends

Maleic anhydride functionalized acrylonitrile–butadiene–styrene copolymer (ABS‐g‐MA) was used as an impact modifier of polyamide 6 (PA6). Epoxy resin was introduced into PA6/ABS‐g‐MA blends to further improve their properties. Notched Izod impact tests showed that the impact strength of PA6/ABS‐g‐MA could be improved from 253 to 800 J/m with the addition of epoxy resin when the ABS‐g‐MA content was set at 25 wt %. Differential scanning calorimetry results showed that the addition of epoxy resin made the crystallization temperature and melting temperature shift to lower temperatures; this indicated the decrease in the PA6 crystallization ability. Dynamic mechanical analysis testing showed that the addition of epoxy resin induced the glass‐transition temperature of PA6 and the styrene‐co‐acrylonitrile copolymer phase to shift to higher temperatures due to the chemical reactions between PA6, ABS‐g‐MA, and epoxy resin. The scanning electron microscopy results indicated that the ABS‐g‐MA copolymer dispersed into the PA6 matrix uniformly and that the phase morphology of the PA6/ABS‐g‐MA blends did not change with the addition of the epoxy resin. Transmission electron microscopy showed that the epoxy resin did not change the deformation mechanisms of the PA6/ABS‐g‐MA blends. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Structure–properties relationship in toughening of poly(butylene terephthalate) with core–shell modifier

The performance of acrylonitrile–butadiene–styrene (ABS) core–shell modifier with different grafting degree, acrylonitrile (AN) content, and core–shell ratio in toughening of poly(butylene terephthalate) (PBT) matrix was investigated. Results show PBT/ABS blends fracture in ductile mode when the grafting degree is high, and with the decrease of grafting degree PBT/ABS blends fracture in a brittle way. The surface of rubber particles cannot be covered perfectly for ABS with low grafting degree and agglomeration will take place; on the other hand, the entanglement density between SAN and PBT matrix decreases because of the low grafting degree, inducing poor interfacial adhesion. The compatibility between PBT and ABS results from the strong interaction between PBT and SAN copolymer and the interaction is influenced by AN content. Results show ABS cannot disperse in PBT matrix uniformly when AN content is zero and PBT/ABS fractures in a brittle way. With the addition of AN in ABS, PBT/ABS blends fracture in ductile mode. The core–shell ratio of ABS copolymers has important effect on PBT/ABS blends. When the core–shell ratio is higher than 60/40 or lower than 50/50, agglomeration or cocontinuous structure occurs and PBT/ABS blends display lower impact strength. © 2006 Wiley Periodicals, Inc. J Appl PolymSci 102: 5363–5371, 2006     

Recycling of ABS and ABS/PC blends

The aim of this work within the framework of mechanical recycling of polymers is upgrading recycled engineering plastics by means of a blending technique. Four different plastics from dismantled Volvo cars have been investigated. They are poly(acrylonitrile‐butadiene‐styrene) (ABS) and ABS‐polycarbonate (ABS/PC) as major components and poly(methyl methacrylate) (PMMA) and polyamide (PA) as minor components. Blending recycled ABS and PC/ABS (70/30) with a small amount of methyl methacrylate‐butadiene‐styrene core‐shell impact modifiers gives the mixture better impact properties than any of its individual components. Some 10% of PMMA from tail light housings can follow the PC/ABS blends made. The property profile will rather be improved. However, PA is an incompatible component that should be sorted out from the mixture. Antioxidants and metal deactivators do not help the recyclates show better mechanical properties. Two toughness measurements, Charpy impact strength and J‐integral method, show complimentary results for such blends. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 510–515, 1999     

Properties of acrylonitrile–butadiene–styrene/polycarbonate blends with styrene–butadiene–styrene block copolymer

The importance of alloys and blends has increased gradually in the polymer industry so that the plastics industry has moved toward complex systems. The main reasons for making polymer blends are the strengthening and the economic aspects of the resultant product. In this study, I attempted to improve compatibility in a polymer blend composed of two normally incompatible constituents, namely, acrylonitrile–butadiene–styrene (ABS) and polycarbonate (PC), through the addition of a compatibilizer. The compatibilizing agent, styrene–butadiene–styrene block copolymer (SBS), was added to the polymer blend in ratios of 1, 5, and 10% with a twin‐screw extruder. The morphology and the compatibility of the mixtures were examined by scanning electron microscopy and differential scanning calorimetry. Further, all three blends of ABS/PC/SBS were subjected to examination to obtain their yield and tensile strengths, elasticity modulus, percentage elongation, Izod impact strength, hardness, heat deflection temperature, Vicat softening point, and melt flow index. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2521–2527, 2004     

Mechanical properties and fracture behavior of blends of acrylonitrile–butadiene–styrene copolymer and crystalline engineering plastics

The aim of this investigation was to evaluate the possibility of mechanically recycling blends of ABS with minor amounts of semicrystalline engineering plastics, such as polyamide, poly(ethylene terephthalate), and poly(butylene terephthalate). Compatibilizers and a core–shell impact modifier were incorporated into the blends in order to improve the mechanical properties. The toughness values, measured by the J‐integral method, and the Charpy impact strength did not always exhibit consistent results, due to the significant difference in deformation rate and in fracture mechanism. The formation of co‐continuous structures in the blends were noted and discussed. The fibrillation in the fracture surface contributed to the toughness as measured by the J‐integral method. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2435–2448, 2002     

Mechanical,thermal, and morphological behavior of the polyamide 6/acrylonitrile–butadiene–styrene blends irradiated with gamma rays

Polymeric materials with improved properties can be obtained through polymer blends. As a polymer mixture is generally immiscible and incompatible, it is necessary to use compatibilizers to improve the interfacial adhesion. Polyamide 6 (PA‐6) is an attractive polymer to engineering applications; however, it reveals processing instability and relatively low‐notched impact strength. This behavior can be modified by blending with acrylonitrile–butadiene–styrene (ABS) copolymer. In this study, blends of PA‐6 with ABS were prepared using gamma irradiation, and the effects of ABS and ionizing radiation on the properties of PA‐6/ABS blends were investigated by differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) techniques. The data showed that the presence of ABS (30 wt%) in the blend decreased the tensile strength and elongation at break with respect to pure PA‐6. The decrease in the mechanical property was observed at doses 30 and 50 kGy. ABS showed strong effect on the crystallization of PA‐6 in the PA‐6/ABS binary blends. All irradiated blends are thermally more stable than those non‐irradiated. Chemical changes can be clearly seen in FTIR spectra through two bands assigned for N? H and OH? groups. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers     

Melt processing,mechanical, and fatigue crack propagation properties of reactively compatibilized blends of polyamide 6 and acrylonitrile–butadiene–styrene copolymer

Within a IUPAC study, melt processing, mechanical, and fatigue crack growth properties of blends of polyamide 6 (PA 6) and poly(acrylonitrile–butadiene–styrene) (ABS) were investigated. We focused on the influence of reactive compatibilization on blend properties using a styrene–acrylonitrile–maleic anhydride random terpolymer (SANMA). Two series of PA 6/ABS blends with 30 wt % PA 6 and 70 wt % PA 6, respectively, were prepared with varying amounts of SANMA. Our experiments revealed that the morphology of the matrix (PA 6 or ABS) strongly affects the blend properties. The viscosity of PA 6/ABS blends monotonically increases with SANMA concentration because of the formation of high‐molecular weight graft copolymers. The extrudate swell of the blends was much larger than that of neat PA 6 and ABS and decreased with increasing SANMA concentrations at a constant extrusion pressure. This observation can be explained by the effect of the capillary number. The fracture resistance of these blends, including specific work to break and impact strength, is lower than that of PA 6 or ABS alone, but increases with SANMA concentration. This effect is most strongly pronounced for blends with 70 wt % PA 6. Fatigue crack growth experiments showed that the addition of 1–2 wt % SANMA enhances the resistance against crack propagation for ABS‐based blends. The correlation between blend composition, morphology and processing/end‐use properties of reactively compatibilized PA 6/ABS blends is discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

The influence of the internal structure of core–shell particles on poly(vinyl chloride)/(methyl methacrylate–butadiene–styrene) blends

Methyl methacrylate–butadiene–styrene (MBS) core–shell particles were prepared by grafting styrene and methyl methacrylate onto polybutadiene seeds via emulsion polymerization. All the MBS particles were designed with the same chemical composition, similar grafting degree but different internal structures. The difference in internal structure was realized by controlling the ratio of ‘external grafting’ and ‘internal grafting’ of styrene. The work focused on the influence of the internal structure of MBS core–shell particles on the properties of poly(vinyl chloride)/MBS blends. From transmission electron microscopy, three different internal structures were observed: rare sub‐inclusions, a large number of small sub‐inclusions and large sub‐inclusions. The results of dynamic mechanical analysis illustrated that the different internal structures greatly affected the glass transition temperature T_g of the rubber phase and the storage modulus of the core–shell particles. The notched Izod impact test results showed that the MBS with large sub‐inclusions had the lowest brittle–ductile transition temperature, while the transparency test revealed that the presence of sub‐inclusions in the rubbery phase reduced the transparency of the blend. Copyright © 2012 Society of Chemical Industry     

Application of styrene‐acrylonitrile random copolymer–polyarylate block copolymer as reactive compatibilizer for polyamide and acrylonitrile‐butadiene‐styrene blends

Styrene‐acrylonitrile random copolymer (SAN) and polyarylate (PAr) block copolymer were applied as a reactive compatibilizer for polyamide‐6 (PA‐6)/acrylonitrile‐butadiene‐styrene (ABS) copolymer blends. The SAN–PAr block copolymer was found to be effective for compatibilization of PA‐6/ABS blends. With the addition of 3.0–5.0 wt % SAN–PAr block copolymer, the ABS‐rich phase could be reduced to a smaller size than 1.0 μm in the 70/30 and 50/50 PA‐6/ABS blends, although it was several microns in the uncompatibilized blends. As a result, for the blends compatibilized with 3–5 wt % block copolymer the impact energy absorption reached the super toughness region in the 70/30 and 50/50 PA‐6/ABS compositions. The compatibilization mechanism of PA‐6/ABS by the SAN–PAr block copolymer was investigated by tetrahydrofuran extraction of the SAN–PAr block copolymer/PA‐6 blends and the model reactions between the block copolymer and low molecular weight compounds. The results of these experiments indicated that the SAN–PAr block copolymer reacted with the PA‐6 during the melt mixing process via an in situ transreaction between the ester units in the PAr chain and the terminal amine in the PA‐6. As a result, SAN–PAr/PA‐6 block copolymers were generated during the melt mixing process. The SAN–PAr block copolymer was supposed to compatibilize the PA‐6 and ABS blend by anchoring the PAr/PA‐6 and SAN chains to the PA‐6 and ABS phases, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2300–2313, 2002     

Oxazoline‐containing compatibilizers for polyamide/SAN and polyamide/ABS blends

Polyamide (PA) and acrylonitrile/butadiene/styrene copolymer (ABS) may appear as a mixture in the recycled plastic stream. The incompatibility of these blends results in a blend with poor mechanical properties. The aim of this work is to partially convert the nitrile groups of the acrylonitrile/styrene copolymer (SAN) into oxazoline groups by reaction with aminoethanol (AE). Such modified SAN (SAN‐m) can react with the amine or carboxylic acid end groups of PA, and therefore used as compatibilizers for blends of PA with ABS. SAN‐m was found to reduce the SAN‐domain size in the PA/SAN‐blends. The initial acrylonitrile content of SAN‐m had a strong influence on the degree of conversion into oxazoline groups and on the compatibilizing effect. Mechanical properties of SAN‐m compatibilized PA/ABS blends were investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 449–455, 2002     

Compatibility and thermal properties of poly(acrylonitrile–butadiene–styrene) copolymer blends with poly(methyl methacrylate) and poly(styrene‐co‐acrylonitrile)

The mechanical and heat‐resistant properties of acrylonitrile–butadiene–styrene (ABS) binary and ternary blends were investigated. The relationship of compatibility and properties was discussed. The results show that poly(methyl methacrylate) (PMMA) and styrene–maleic anhydride (SMA) can improve the thermal properties of conventional ABS. The Izod impact property of ABS/PMMA blends increases significantly with the addition of PMMA, whereas that of ABS/SMA blends decreases significantly with the addition of SMA. Blends mixed with high‐viscosity PMMA are characterized by higher heat‐distortion temperature (HDT), and their heat resistance is similar to that of blends mixed with SMA. For high‐viscosity PMMA, from 10 to 20%, it is clear that blends appear at the brittle–ductile transition, which is related to the compatibility of the two phases. TEM micrographs show low‐content and high‐viscosity PMMA in large, abnormally shaped forms in the matrix. Compatibility between PMMA and ABS is dependent on both the amount and the viscosity of PMMA. When the amount of high‐viscosity PMMA varied from 10 to 20 wt %, the morphology of the ABS binary blends varied from poor to satisfactory compatibility. As the viscosity of PMMA decreases, the critical amount of PMMA needed for the compatibility of the two phases also decreases. SMA, as a compatibilizer, improved the interfacial adhesiveness of ABS and PMMA, which results in PMMA having good dispersion in the matrix. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2652–2660, 2002     

Recycling of acrylonitrile–butadiene–styrene and high‐impact polystyrene from waste computer equipment

Acrylonitrile–butadiene–styrene (ABS) and high‐impact polystyrene (HIPS) are two of the plastics most frequently used as outer casings for computer equipment such as monitors, keyboards, and other similar components. We assessed the effects of the recycling and blending of ABS and HIPS on mechanical properties. We found that the effects of recycling on ABS and HIPS were similar, in that changes in glass‐transition temperatures, tensile strengths, and tensile moduli were negligible, but strains to failure and impact strengths were reduced considerably. Blending proportions of ABS and HIPS caused no more deterioration in properties than occurred as a result of the recycling process, and the presence of small proportions of one material in the other actually restored significant amounts of ductility, as seen by increases in the strains to failure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 572–578, 2002     

Polylactide toughening with epoxy‐functionalized grafted acrylonitrile–butadiene–styrene particles

Glycidyl methacrylate functionalized acrylonitrile–butadiene–styrene (ABS‐g‐GMA) particles were prepared and used to toughen polylactide (PLA). The characteristic absorption at 1728 cm^?1 of the Fourier transform infrared spectra indicated that glycidyl methacrylate (GMA) was grafted onto the polybutadiene phase of acrylonitrile–butadiene–styrene (ABS). Chemical reactions analysis indicated that compatibilization and crosslinking reactions took place simultaneously between the epoxy groups of ABS‐g‐GMA and the end carboxyl or hydroxyl groups of PLA and that the increase of GMA content improved the reaction degree. Scanning electron microscopy results showed that 1 wt % GMA was sufficient to satisfy the compatibilization and that ABS‐g‐GMA particles with 1 wt % GMA dispersed in PLA uniformly. A further increase of GMA content induced the agglomeration of ABS‐g‐GMA particles because of crosslinking reactions. Dynamic mechanical analysis testing showed that the miscibility between PLA and ABS improved with the introduction of GMA onto ABS particles because of compatibilization reactions. The storage modulus decreased for the PLA blends with increasing GMA content. The decrease in the storage modulus was due to the chemical reactions in the PLA/ABS‐g‐GMA blends, which improved the viscosity and decreased the crystallization of PLA. A notched impact strength of 540 J/m was achieved for the PLA/ABS‐g‐GMA blend with 1 wt % GMA, which was 27 times than the impact strength of pure PLA, and a further increase in the GMA content in the ABS‐g‐GMA particles was not beneficial to the toughness improvement. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Behavior of ionomers of sulfonated styrene–butadiene–styrene triblock copolymer in polymer blends with crystalline polyolefins and as compatibilizer

The blends of ionomers of sulfonated (styrene–butadiene–styrene) triblock copolymer with two polyolefins as well as the blends of polystyrene (PSt) with two polar, oil‐resistant elastomers, i.e., chlorohydrin rubber (CHR) and chlorosulfonated polyethylene (CSPE), using the ionomer as compatibilizer were studied. The blends of the ionomer with polypropylene or high density polyethylene showed synergistic effects with respect to tensile strength. With increasing PSt content, the blends change their behavior from thermoplastic elastomer to toughened plastics. The synergism is probably because of the thermoplastic interpenetrating polymer networks formed in the blend. The blends exhibited high resistance against diesel oil or toluene. When PSt was blended with CHR or CSPE using the ionomer as compatibilizer, only 2 or 3% ionomer was needed to enhance the mechanical properties of the blends. The effect is due to the ion–polar interaction of the ionomer with the polar polymer. The enhanced compatibility of the blends by the ionomer was demonstrated by DSC and Scanning electron micrograph. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1887–1894, 2006     

Augmenting the performance of acrylonitrile–butadiene–styrene plastics for low‐noise dynamic applications

The main objective of this study was to enhance the performance of acrylonitrile–butadiene–styrene (ABS) plastics for dynamic structural applications, including those of automobile relevance. First, ABS was modified by blending with maleic anhydride grafted styrene–ethylene–butadiene–styrene block copolymer (MA‐g‐SEBS) in various proportions. Squeaking noise characteristics were evaluated by measurement of the frictional behavior in an in‐house fabricated friction testing apparatus, and the results are explained on the basis of the change in surface energy upon modification. Detailed dynamic mechanical analyses (strain, frequency, and temperature sweep) revealed significant improvements in the damping characteristics of the modified ABS, especially that modified with 10 wt % MA‐g‐SEBS, without much sacrifice in its mechanical strength. The modulus values predicted with Kerner's model of the blends were well correlated with the morphological changes upon modification. © 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     

Toughening modification of PS with n‐BA/MMA/styrene core–shell structured copolymer from emulsifier‐free emulsion polymerization

Core–shell structured particles, which comprise the rubbery core and glassy layers, were prepared by emulsifier‐free emulsion polymerization of poly(n‐butyl acrylate/methyl methacrylate)/polystyrene [P(n‐BA/MMA)/PS]. The particle diameter was about 0.22 μm, and the rubbery core was uncrosslinked and lightly crosslinked, respectively. The smaller core–shell structured particle–toughened PS blends were investigated in detail. The dynamic mechanical behavior and observation by scanning electron microscopy of the modified blend system with core–shell structured particles indicated good compatibility between PS and the particles, which is the necessary qualification for an effective toughening modifier. Notched‐impact strength and related mechanical properties were measured for further evaluation of the toughening efficiency. The notched‐impact strength of the toughened PS blends with uncrosslinked particles reached almost sixfold higher than that of the untoughened PS when 15 phr of the core–shell structured particles was added. For the crosslinked particles the toughening effect for PS was not obvious. The toughening mechanism for these smaller particles also is discussed in this article. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1290–1297, 2003     

Toughening of PA6 nanocomposites by reactive acrylonitrile–butadiene–styrene core–shell rubber particles

The effect of addition of organoclay and the reactive ABS‐g‐MA core‐shell particles on the mechanical properties and morphology of blends of polyamide (PA6) were reported. The reactive rubber particles with core‐shell structure were selected as modifier instead of conventional reactive bulk rubber. The microstructure of the ternary nanocomposites was characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Impact strength and stress–strain behavior of blends were measured as a function of organoclay content and core/shell ratio of ABS‐g‐MA. The organoclay plates affected the interfacial adhesion between polyamide and the core‐shell particles because of a shielding effect of organclay on the interacting of amine end groups of PA6 with the MA groups of ABS‐g‐MA. The poor dispersion behavior of ternary nanocomposites was observed when the core/shell ratio is 80/20, and with an increase of organoclay content, the core/shell dispersed phase size increased. Blends based on the maleated elastomer with the core/shell ratio 60/40 gave a more beneficial balance of toughness versus stiffness. POLYM. COMPOS., 35:864–871, 2014. © 2013 Society of Plastics Engineers     

Study on the microphase structure and mechanical properties of the blends of acrylonitrile–butadiene–styrene and sodium sulphonated styrene–acrylonitrile ionomer

The tensile properties of the blends containing neat acrylonitrile–butadiene–styrene (ABS), styrene–acrylonitrile (SAN) and the sodium sulphonated SAN ionomer have been investigated as a function of ion content of the ionomer in the blend. The tensile toughness and strength of the blends showed maximum values at a certain ion content of the ionomer in the blend. This is attributed to the enhanced tensile properties of the SAN ionomer by introduction of ionic groups into SAN and the interfacial adhesion between the rubber and matrix phase in the blend. The interfacial adhesion was quantified by NMR solid echo experiments. The amount of interphase for the blend containing the SAN ionomer with low ion content (3·1mol%) was nearly the same as that of ABS, but it decreased with the ion content of the ionomer for the blend with ion content greater than 3·1mol%. Changing the ionomer content in the blends showed a positive deviation from the rule of mixtures in tensile properties of the blends containing the SAN ionomer with low ion content. This seems to result from the enhanced tensile properties of the SAN ionomer, interfacial adhesion between the rubber and matrix, and the stress concentration effect of the secondary particles. © 1998 SCI.