| Abstract: | Glass-transition temperatures and phase separation have been studied in amorphous bisphenol-A polycarbonate plasticized with pentaerythritol tetranonanoate (PETN), trimellitic acid, tridecyloctyl ester (TMDO), and tritolyl phosphate. (TTP). Phase separations occur with partially compatible plasticizers like PETN or TMDO. With PETN, for compositions situated in the miscibility gap, the system is composed of a pure plasticizer phase and of a plasticized polymeric phase characterized by a transition temperature of 110°C. In the case of TMDO and additional phase separation occurs below 55°C and two plasticized polycarbonate phases are observed. In compositions falling in the region where the could point curve crosses the glass-transition diagram the phase separation may be delayed by quick cooling. TTP is completely compatible with polycarbonate and the variation of the glass-transition temperature follows a Gordon and Taylor equation. |
