Hydrogen-bond induced side-chain liquid crystalline polymers based on nicotinic acid derivatives

Supramolecular side-chain liquid crystalline poly(acrylate)s have been prepared by self-assembly of H-bond donor and acceptor complexes through intermolecular complementary hydrogen bond formation. Poly[4-(m-acryloyloxyalkyloxy)benzoic acid]s [m=6 (P1) and 8 (P2)] were employed as polymer components. Liquid crystalline nicotinic acid derivatives (C1, C2, C3, and C4) were used as complementary H-bond donor/acceptor counterparts. The liquid crystalline properties of the nicotinic acid derivatives, the polymers and their complexes were investigated by DSC and POM. Methylene spacers present at the terminal position of the nicotinic acid derivatives played a key role in mesophase arrangements. The columnar phase exhibited by the nicotinic acid derivatives completely disappeared in the H-bonded complexes to afford a nematic phase, thereby substantiating the complex formation.