Synthesis and characterization of cholesteric liquid crystal elastomer films

A series of liquid crystal elastomer films (the P-BC series) have been synthesized by grafting liquid crystal (LC) monomer 4-allyloxybenzoic acid cholesteryl ester (M-B) and crosslinking agent [1,1'-biphenyl]-4,4'-diyl bis(undec-10-enoate) (M-C) onto polymethylhydrosiloxane catalyzed by hexachloroplatinic acid at 60 degrees C. The P-BC series are cholesteric liquid crystal elastomers (LCEs). The glass transition temperatures (T-g) of the P-BC series are between 23-33 degrees C, and the LC range is above 200 degrees C. The temperatures of 5% weight loss of the P-BC series are above 300 degrees C, which shows good thermal stability. The P-BC series display good orientation. P-B3C3 shows a good ability of shape recovery above T-g.