THERMAL-PROPERTIES OF THERMOTROPIC LIQUID-CRYSTALLINE POLYMER POLYCARBONATE BLENDS

The thermal properties of blends of liquid crystalline poly(biphenyl-4,4'-ylene sebacate) (TLCP) and polycarbonate (PC) were investigated by differential scanning calorimetry. The glass transition temperature of blends decreases as the concentration of TLCP increases up to ca. 40% by weight. The observation of a single glass transition temperature indicates that PC is miscible with TLCP in this concentration range. The crystallization rate of TLCP in TLCP/PC blends decreases with increasing PC content. In particular, the crystallization rate is remarkably lower for a TLCP/PC (90/10) blend. However, the transition temperatures of TLCP are almost invariant with blend composition except for TLCP/PC (90/10) blend. The upper critical solution temperature (UCST) behavior was observed in blends containing 20-50 wt% PC whereas the phase separation was not observed in the other compositions.