Mesomorphic properties of side-chain type polymers containing hydrogen bonding group

Side chain type liquid crystalline polymer(SLCP)s with a carboxylic acid or an amide group in the side chain were synthesized by radical polymerization to examine the influence of intermolecular interaction on thermal properties of the polymers. An enantiotropic smectic phase was induced for the butoxyazobenzene copolymers containing 50-60 mol% of carboxylic acid moiety, while two smectic phases were observed for amide type SLCPs with butoxy group as a mesogenic terminal group. It demonstrates that intermolecular hydrogen bonding formed between carboxylic acid groups and between each mesogenic group in the side chain plays an important role to exhibit the liquid crystalline phase by thermally controlled FT-IR measurements.