THE MORPHOLOGY AND MECHANICAL-PROPERTIES OF PHENOXY LIQUID-CRYSTALLINE POLYMER BLENDS AND THE EFFECT OF TRANSESTERIFICATION

Morphological, theological, and mechanical properties of poly(hydroxy ether of bisphenol A) (phenoxy) and a Vectra liquid crystalline copoly ester (LCP) blends were investigated. Scanning electron micrographs of fracture surfaces of injection-molded samples show that the LCP forms an elongated fibrous dispersion in the phenoxy matrix. As the mixing time increases, the tensile strength and modulus increase while the el ongation at break remains almost constant. These improvements are attr ibuted to the formation of LCP-grafted phenoxy by the interchange reac tion between phenoxy and LCP. The interchange reaction was identified by DSC, a rheometer, and a FTIR spectrometer. The graft copolymer give s better adhesion between the two phases and thus improves mechanical properties of the blends. (C) 1995 John Wiley and Sons, Inc.