抄録
Viscosities of poly (butylene terephthalate) (PBT)/poly (Bisphenol A carbonate) (PC) and PBT/PC/di-n-octadecyl phosphate (DNOP) melt blends were measured at different temperatures by capillary rheometer. Melt viscosity indicate the Andrade's type of temperature dependence at temperature of 230 to 290°C. The changes of viscosity and activation energy with blend ratio could be explained well by the series model of PBT and PC components. The viscosity of 99/1 blend was as high as about two times that of PBT 100% sample. Activation energy for melt flow also increase by addition of small amount of PC. This was because a thermal degradation of PBT seems to be depressed by PC, which was bound to the PBT chain by transesterification and decrease the reactivity of the PBT end group. DNOP added to PBT/PC blends was bound to the end group of PBT chains and inhibited the transesterification between PBT and PC chains. DNOP lowered the molecular weight of PBT chain and causeed a drastic viscosity drop of PBT so as to give bubbles evolution during blending.
