Development of Phase Morphology for Extruded and Moulded PBT/ABS Blends
Elias Hage Jr., Edson N. Ito, José A. Covas, Luiz A. Pessan
UNIVERSIDADE FEDERAL DE SÃO CARLOS
BRAZIL

Keywords: Morphology, Polymer Blends, PBT/ABS

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The morphological evolution of PBT/ABS blends during compounding in a twin screw extruder and moulding by injection process was investigated. The development of phase morphology for those blends was observed by transmission electron microscopy and the photomicrographs were analyzed by image analysis. Samples were collected from the melt mixing at specific barrel locations, from the pelletized extruded blends and from the moulded specimens. Acrylic copolymers were used as compatibilizer for PBT/ABS blends. Methyl methacrylate-co-glycidyl methacrylate (MMA-GMA) copolymer is a in situ reactive compatibilizer which reacts chemically with PBT molecules through epoxy groups from GMA component and is miscible with SAN matrix phase from ABS. It was observed that this modification in the system at the melt state affects significantly the evolution of phase morphology during melt blending and subsequent injection moulding. Addition of MMA-GMA to PBT/ABS blends improves significantly the ABS domains in the PBT matrix phase. That behaviour may be observed for samples obtained along the extruder as well as for samples observed after injection moulding. Mechanical properties such as tensile modulus, yield tensile strength and notched impact strength were measured for moulded samples to observe any correlation between the final phase morphology and its mechanical behaviour.