Phase behavior of liquid-crystalline copolymer/liquid crystal blends

Thermodynamic phase behavior was studied for blends between side-chain liqu id-crystalline (SCLC) copolymers and a low molecular weight liquid crystal (LC). SCLC copolymers, Copolyx having x mol fraction of a benzoic acid unit and 1 - x mol fraction of. cyanobiphenyl group in their side chain, were p repared by radical polymerization and mixed with a low molecular weight LC, 4-cyano-4'-n-hexyloxybiphenyl (6OCB). The phase diagram of the Copoly0.24/ 6OCB blend exhibited an upper critical solution temperature which was not o bserved for homopolymer systems. Employing SCLC copolymers having two diffe rent kinds of mesogens in polymer/low molecular weight LC blends enabled us to obtain the new type of phase diagram. (C) 2000 Elsevier Science Ltd. Al l rights reserved.