Effect of ABS grafting degree and compatibilization on the properties of PBT/ABS blends

Abstract

Abstract Blends of PBT/ABS and PBT/ABS compatibilized with styrene‐acrylonitrile‐glycidyl methacrylate (SAG) copolymer were prepared by melt blending method. Grafting degree (GD) of ABS influences the morphology and mechanical properties of PBT/ABS blends. ABS can disperse in PBT matrix uniformly and PBT/ABS blends fracture in ductile mode when ABS grafting degree is more than 44.8%, otherwise, agglomeration takes place and PBT/ABS blends fracture in brittle way. On the other hand, the grafting degree of ABS has no obvious influence on the morphology of PBT/ABS blends and PBT/ABS blends fracture in ductile mode when SAG is incorporated since the compatibilization effect. However, PBT/SAG/ABS blends display much lower impact strength values comparing with PBT/ABS when the blends fracture in ductile way. Side reactions in PBT/SAG/ABS blends were analyzed and which were the main reason for the decrease of impact strength of PBT blends. Tensile tests show that the tensile strength and tensile modulus of PBT blends decrease with the increase of ABS grafting degree due to the higher effective volume. PBT/SAG/ABS blends display much higher tensile properties than PBT/ABS blends since the compatibilization effect. POLYM. COMPOS., 28:484–492, 2007. © 2007 Society of Plastics Engineers