THERMAL AND MECHANICAL-PROPERTIES OF INJECTION-MOLDED BLENDS OF A LIQUID-CRYSTALLINE POLYMER AND POLY(BUTYLENE TEREPHTHALATE)

The microstructure and the thermal and mechanical properties of inject ion molded samples of different blends of Vectra (LCP) and poly(butyle ne terephthalate) (PBT) have been studied. Differential scanning calor imetry and hot-stage polarized light microscopy showed that the crysta llization of PBT was unaffected by the presence of LCP. X-ray diffract ion showed that the PBT component was always unoriented in the injecti on molded samples. Blends with less than 28 vol% LCP exhibited the sam e stiffness and the same coefficient of linear thermal expansion as PB T. Blends containing more than 38 vol% LCP contained an oriented LCP p hase and had a stiffness in accordance with the upper-bound composite equation. The coefficients of linear ther-mal expansion for these blen ds were close to that of pure LCP.