Changes in Properties of PET/PC Blend by Catalyst and Time

Abstract The effects of the catalyst and residence time on poly(ethylene terephthalate)/polycarbonate blends (PET/PC) were studied. The Tg increased, while the Tm decreased with catalyst content and residence time as a consequence of exchange reactions during the processing. The extent of these reactions also influenced the crystal size of PET. Additionally, impact and tension properties were influenced by the level of transesterification reactions. The best value of impact was 89,7 ± 0,9 J · m for the PET/PC blend which contained 75 × 10−3 wt% of catalyst and 10 min of residence time, which represents a fourfold increase over the neat PET. Concerning elastic modulus, the best value was 60% higher than plain PET due to a higher amount of PC chains inserted in the PET. The melt flow index showed that the presence of PC enhanced the thermal stability of PET due to the formation of PET/PC copolymers. Keywords: cobalt III acetylacetonateflow propertymechanical propertiesPET/PC reactive blendingphase behavior The authors thank Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação Coordenação do Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Universidade Federal do Rio de Janeiro (UFRJ) for supporting this investigation. Notes Nd: Not defined.