Synthesis and characterization of mesogen-jacketed liquid crystalline polymers through hydrogen-bonding

In an attempt to construct mesogen-jacketed liquid crystalline polymers through noncovalent interactions, poly(2-vinylbenzene-1,4-dioic acid) and five series of pyridine derivatives were synthesized as hydrogen-bonding donor and acceptors, respectively. The structures of the compounds were confirmed by ¹H NMR, FT-IR, and gel permeation chromatography. A series of complexes with the same degree of polymerization and polydispersity were obtained by mixing the hydrogen-bonding donor and acceptors. The hydrogen-bonds were confirmed by FT-IR spectra. We found that the rigidity and structures of pyridine derivatives and the strength of the hydrogen-bonding all influenced the liquid crystalline behaviors of the resulting complexes. Smectic A and columnar nematic phases were observed in complexes PPANCx and PPANNEC, respectively.