Photoinduced orientation of H-bonded composite films of non-photoreactive polymer and cinnamic acid derivatives

Abstract

ABSTRACTThis paper describes the thermally amplified photoinduced orientation behavior of H-bonded composite thin films of non-photoreactive polymethacrylate consisting of hexylene spacer groups terminated with benzoic acid (BA) moieties in the side chain (pM6BA) and various monomeric cinnamic acid (CA) derivatives. H-bonds between BAs and CAs cause all the pM6BA/CA derivatives composite films to exhibit liquid crystalline characteristics. Irradiating these films with linearly polarized UV light induces an axis-selective photoreaction of the CA derivatives, while subsequent thermal treatment induces molecular reorientation of the BA side groups, which is accompanied by sublimation of the unreacted CA derivatives. The reoriented films are applicable to an LC alignment layer.