Synthesis and characterization of cholesteric liquid crystal elastomer films

A series of liquid crystal elastomer films (the PBC series) have been synthesized by grafting liquid crystal (LC) monomer 4-allyloxybenzoic acid cholesteryl ester (MB) and crosslinking agent [1,1'-biphenyl]-4,4'-diyl bis(undec-10-enoate) (MC) onto polymethylhydrosiloxane catalyzed by hexachloroplatinic acid at 60 °C. The PBC series are cholesteric liquid crystal elastomers (LCEs). The glass transition temperatures (Tg) of the PBC series are between 23-33 °C, and the LC range is above 200 °C. The temperatures of 5% weight loss of the PBC series are above 300 °C, which shows good thermal stability. The PBC series display good orientation. PB3C3 shows a good ability of shape recovery above Tg.