Thermotropic Liquid Crystalline Polyesters Using Aromatic Rigid Diols, Unsaturated Fumaric Acid and Flexible Sebacic Acid

Abstract

In the present study, seven different series of thermotropic liquid crystalline polyesters (TLCPs) containing unsaturated fumaroyl chloride and flexible sebacoyl chloride were synthesized using the interfacial polymerization methodology. Homopolyesters prepared with saturated flexible spacer such as sebacoyl chloride were mesomorphic whereas homopolyesters synthesized using unsaturated aliphatic spacer such as fumaroyl chloride that was non-mesomorphic. Aromatic diad and triad based mesogenic diols were selected as rigid moiety for liquid crystalline phase formation. Within each series, copolyesters were synthesized by varying relative mole ratio of the above two aliphatic diacid chlorides. Most of the liquid crystalline polyesters showed solubility in phenol:tetrachloroethane (60:40) at 40 ᵒC.

Synthesis and Studies on Aromatic Copolyester With Anticancer Activity Derived From 4,4’- Dihydroxybiphenyl and 3,5-Dihydroxytoluene

“…9 The incorporation of dimethyl isophthalate units caused improvement in glass transition temperature and augmented the thermal stability, optical characteristics and the gas barrier property in high molar mass butylene carbonate-co-isophthalate polyesters. 10 The thermal changes and melt birefringence property in thermotropic copolyesters prepared by melt polycondensation based on 4,4′-biphenol and bisphenol A has been explored by Tsai, H. B. et al 11 Effects of flexible and rigid spacers in the formation of mesophases among polyesters based on 4,4'-dihydroxy biphenyl have been extensively studied by Wale, A. et al 12 Kim, K. H. et al successfully studied the effects of attached quaternary salt structure and the effect of polymer catalysts on aromatic polyesters containing Isophthaloyl chloride and Diphenolic acid in the polycondensation reaction in aqueous and organic phases. 13 Interfacial polymerization involving phase-transfer reaction of biphenyl derivative and Isophthaloyl chloride resulted in amorphous aromatic polyesters connected to biphenyl units in the side chain whose early degradation AROMATIC COPOLYESTER WITH ANTICANCER ACTIVITY T. Sivaramakrishnan and G. Elango temperatures were observed around 450°C.…”