Side chain liquid crystal polysiloxanes and their low Tg copolymer analogues

A number of side-chain liquid crystal homopolymers derived from poly-(hydrogenmethylsiloxane) and their copolymeric analogues with the same mesogenic side chains appended to a poly(hydrogenmethyldimethylsiloxane) backbone have been prepared. The homo and copolymers exhibit the same mesophase types, but markedly different Tg values, mesophase transition temperatures and isotropisation enthalpies. These differences are interpreted in terms of the relative DP values and flexibilities of the backbones for the homo and copolymers.