Synthesis and characterization of a series of optically active side-chain cholesteric liquid crystalline polymers

A series of thermotropic side-chain cholesteric-liquid crystalline polymers (P0-P8) were synthesized by graft copolymerization of mesogenic monomer cholesteryl undecylenate (M1) and chiral monomer menthyl undecylenate (M2) upon polymethylhydrosiloxane. The chemical structure of polymers was characterized by FT-IR. DSC, TGA, POM, WAXD, SAXS were used to measure their thermal properties and mesogenic properties. The polymers show thermotropic cholesteric-liquid crystalline properties with a broad mesogenic region, and exhibit typical color Grand-jean texture and oil streaks texture of cholesteric liquid crystalline. The thermotropic mesogenic property of the polymers is weakened when the concentration of the monomer M2 is over 30%. The polymers are thermal stable at about 310°C.