Highly enhanced the toughness and fatigue resistance of PC/ABS blends by constructing a double-comb compatibilizer

Abstract

PC/ABS (polycarbonate/acrylonitrile-butadiene-styrene) alloy has poor mechanical properties due to its poor compatibility and weak interfacial adhesion, which limits its application range. Therefore, it is necessary to compatibilize and modify the PC/ABS alloy to improve the compatibility and enhance the interfacial adhesion of the two phases. Reactive compatibilizers are frequently utilized to enhance the compatibility of incompatible polymer blends. However, traditional reactive compatibilizers often form graft copolymers with asymmetric molecular structure during melt blending, which frequently "migrate in" and "migrate out" under the influence of shear force, leading to a decrease in the compatibilization efficiency of compatibilizers. In this work, ethylene-maleic anhydride alternating copolymer (ZeMac) with more reactive sites was used as a reactive compatibilizer, and amino-terminated polystyrene (PS-NH₂) with good compatibility with ABS was synthesized via free radical polymerization. Combined with the difference of affinity between PC, ABS and ZeMac, and the difference of reactivity between PC, PS-NH₂ and ZeMac, a double-comb compatibilizer was constructed in-situ at the interface of the two phases by changing the blending sequence of raw materials in the melt blending process. Firstly, PC was blended with ZeMac, and then blended with ABS and PS-NH₂ to prepare (PC/ZeMac-1)/(ABS/PS-NH₂-1) alloy with excellent comprehensive properties. Compared with PC/ABS alloy, the notched impact strength of (PC/ZeMac-1)/(ABS/PS-NH₂-1) alloy increased from 62.0 kJ/m² to 90.2 kJ/m², increased by 45%. It can be seen from the microstructure of the cyclic tensile section that the debonding phenomenon of the PC/ABS alloy interface gradually weakened with the addition of ZeMac and PS-NH₂, which proved that the compatibility of PC and ABS phases was improved. This study provides a certain reference value for the design of high-efficiency compatibilizers and the preparation of high-performance composites.