MOLECULAR-STRUCTURE EFFECT OF THERMOTROPIC LIQUID-CRYSTALLINE POLYMERS ON INTERFACIAL ADHESION WITH POLYCARBONATE

Abstract

The effect of molecular structure of thermotropic liquid crystalline polymers (TLCP) on the interfacial adhesion with polycarbonate (PC) was investigated by varying the flexible spacer length in the main chain of the TLCP. The interfacial adhesion was estimated by two methods: (1) the debonding stress from the melt-contacted TLCP/PC plates was measured by a modified pin-pull test; (2) the mechanical response of the melt-mixed blend was analyzed by the composite theory. Both methods indicated that the interfacial adhesion of the TLCPs with flexible spacer was improved over that of a rigid TLCP (i.e., Vectra A950), and that it was further enhanced by an increase in the length of a flexible unit.