Análise da processabilidade de blendas PBT/ABS compatibilizadas in situ com copolímeros acrílicos

Abstract

Poly(butylene terephthalate)/acrylonitrile-butadiene-styrene (PBT/ABS) blends show high toughness at room temperature, low ductile-brittle transition temperature and stable morphology when compatibilized. The flowability of PBT/ABS blends compatibilized in situ with methyl metacrylate- glicydil metacrylate-etyl acrylate (MGE) copolymer changes drastically with the kinds of ABS, PBT used and with the level of interfacial adhesion. In this work, a high rubber content ABS was mixed with PMMA and SAN copolymer. These blends were introduced in PBT/ABS/MGE system to study the processability. The addition of ABS/SAN or ABS/PMMA in the PBT/ABS/MGE blends didn t show high decreased of the torque in the blends with rubber content of 12 and 16 wt%. PBT 315/ABS/MGE and PBT 325/ABS/MGE blends showed inversion of viscosity concerning pure ABS under permanent shear condition. The mechanical properties of PBT/(ABS/SAN or PMMA)/MGE showed that the Young modulus and yield stress are not affected by the change of PBT matrix molecular weight. The kind of PBT matrix used changes strongly the blends behavior under impact, altering the values of ductile-brittle transition temperature and impact resistance. PBT 315 and ABS showed almost the same flow length. The compositions with ABS/PMMA added showed a higher flow length tendency in PBT 315 and PBT 325 blends. Blends with PBT 195 showed better flowability. However, these blends didn t become tough systems. The better mechanical properties/moldability relationship to PBT 315 and PBT 325 blends was observed for ABS/SAN or ABS/PMMA added with a rubber content of 30 %wt.