Synthesis and thermal properties of copolymers composed of mesogenic and non-mesogenic monomers

Abstract

Thermal properties of the side chain type liquid crystalline polymer(SLCP)s were deeply influenced by the intermolecular interaction. In order to investigate the effect of hydrogen bonding formed between carboxylic acid groups on thermal properties of the SLCPs, we synthesized the side chain type copolymers containing mesogenic monomer and non-mesogenic monomer with carboxylie acid group. Hydrogen bonding was examined by thermally controlled FT-IR measurements. A mesophase was exhibited for the copolymers containing the mesogenie monomer above 40〜65mol%. The mesophase temperature range(MR) of the copolymers increased in the order of the copolymers with methacrylic acid monomers, with benzoic acid monomers containing a flexible spacer and with benzoic acid monomers. This difference in the MR of the copolymers was demonstrated by FT-IR quantitative analysis of the area of the peak assigned to the dimer structure of the carboxylic acid group.