Functional Polymers and Sequential Copolymers by Phase Transfer Catalysis. Synthesis of Thermotropic Side-Chain Liquid Crystalline Polymers Containing a Poly(2,6-Dimethyl-1,4-Phenylene Oxide) Main Chain

摘要

Poly(2,6-dimethyl-1,4-phenylene oxide (PPO) containing pendant mesogenic units separated from the polymer main-chain through spacers of three to ten methylene units were synthesized and characterized. The synthetic pathway used for the chemical modification of PPO involved the radical bromination of its methyl groups followed by phase transfer catalyzed esterification of the resulting bromobenzyl groups with potassium omega-(4-oxybiphenyl)alkanoates and potassium omega-(4-methoxy-4'-oxybiphenyl)-alkanoates. Only the resulting polymers containing ten methylene units as spacer and 4,4'-methoxybiphenyl as mesogen present thermotropic liquid crystalline mesomorphism. Keywords: Side-chain thermotropic liquid crystalline polymers.