Sj. Zhang et al., THE SYNTHESIS AND THERMOTROPIC LIQUID-CRYSTALLINE BEHAVIOR OF NOVEL MAIN-CHAIN POLY(ARYL ETHER KETONE)S CONTAINING A LATERAL PHENYL GROUP, Liquid crystals, 24(2), 1998, pp. 311-314
Novel main chain poly(aryl ether ketone)s containing a lateral phenyl
group were synthesized by nucleophilic substitution reactions of 4,4'-
biphenol and phenylhydroquinone with either 4,4'-difluorobenzophenone
or 1,4-bis(4-fluorobenzoyl)benzene and their thermotropic liquid cryst
alline properties were characterized by a variety of experimental tech
niques. Thermotropic liquid crystalline behaviour was observed in the
copolymers containing 50 and 70mol% biphenol. Melting (T-m) and isotro
pization (T-i) transitions both appeared on the DSC thermograms. A ban
ded texture was formed after shearing the sample in the liquid crystal
line nematic state. As expected, each of the copolymers had a relative
ly lower melting transition than the biphenol-based homopoly(aryl ethe
r ketone)s because of the copolymerization effect of the crystal-disru
pting monomer phenylhydroquinone.