文摘
Miscibility or compatibilization via transreactions in blends of one of two copolyesters, poly(butylene adipate-co-butylene terephthalate) [P(BA-co-BT)] or poly(butylene succinate-co-butylene terephthalate) [P(BS-co-BT)], with poly(hydroxy ether of bisphenol A) (phenoxy) were investigated. The P(BA-co-BT)/phenoxy blend exhibited a homogeneous phase and a composition-dependent glass transition temperature (Tg) without any heat annealing. The copolymer鈥損olymer interaction parameter (蠂12) for the P(BA-co-BT)/phenoxy blend was calculated from the melting-point-depression method to be 鈭?.12. However, variation in the composition and structure of the copolyesters easily causes phase separation in copolyester/phenoxy blends. The P(BS-co-BT)/phenoxy blend had a phase morphology that could be homogenized only following annealing at high temperatures. As-blended P(BS-co-BT)/phenoxy (50/50 composition) exhibited immiscible phases with two distinct Tgs, but the initially phase-separated blends finally merged to form a homogeneous phase with a single Tg upon heating and annealing for 60 min at 280 掳C. Chemical exchange reactions upon heat annealing of the P(BS-co-BT)/phenoxy blend caused phase homogenization.