Synthesis and phase behavior of cholesteric liquid crystal polymers containing glutamic acid in main‐chain

Abstract

Four polymers (P 0 -P 3 ) containing peptide chain as polymer backbone were synthesized by condensation reaction with bis(trichloromethyl)carbonate and triethylamine. The chemical structures of the monomers M 0 -M 3 were confirmed by FTIR and 1 H-NMR. The structure-property relationships of the monomers and polymers are discussed. Their phase behavior and optical properties were investigated by differential scanning calorimetry, thermogravimetric analysis, and polarizing optical microscopy. Monomers M 1 -M 3 and polymers P 1 -P 3 displayed cholesteric phases. The results demonstrated that the melt temperature and clear point of monomers (M 1 -M 3 ) and polymers (P 1 -P 3 ) decreased with the increase of the flexible spacer length in the side-chain, and the mesophase temperature range of the polymers increased with the increase of the flexible spacer length.