Molecular Engineering of Liquid Crystalline Polymers by Living Polymerization. 7.Influence of Copolymer Composition on the Phase Behavior pf Poly(11-((4-cyano-4'Biphenyl)oxy)undecanyl Vinyl Ether-co-2-((4-Cyano-4'-Biphenyl)oxy)ethyl Vinyl Ether)

摘要

This paper describes the synthesis of poly 11-4-cyano-4 '-biphenyl)oxyundecanylvinyl ether-co-2-(4-cyano-4'biphenyl)oxyethyl vinyl ether A/B poly(6-11)-co-(6-2)A/B where A/B refers to the molar ratio between the monomers 6-11 and 6-2, with number average molecular weights above 15, by living cationic polymerization. The phase behavior of the resulting copolymers was discussed as a function of copolymer composition. Within this range of molecular weights, in the first heating scan poly(6-11) exhibits a melting and an enantiotropic sa phase, while poly(6-2) only a glass transition temperature. Depending on composition, poly(6-11-CO6-2)A/B either display an enantiotropic nematic, enantiotropic sa or both enantiotropic nematic and anantiotropic sa phases.