The Synthesis Of Liquid Crystal Polymers Containing Different Flexible Chain And Photochemical Properties Research

The liquid crystal polymer containing photosensitve group could generate axis-selective [2 + 2] cycloaddition photoreaction with the linearly polarized ultraviolet light(LPUV), which formed anchoring force. When the exposed film was annealed in the LC temperature range, molecules would arrange along the direction of anchor point as to the self-assemble of molecule. Then the film was fully exposed, so that the anisotropic of the film was fixed by the photoreaction of functional groups in the molecule.In this paper, five monomers with coumarin photosensitive group were designed and synthesized. All the structures were confined by FT-IR and 1HNMR spectra. Their liquid crystal properties were measured by DSC and POM. Four homopolymers were synthesized from corresponding monomers by a free radical solution polymerization. The polymers photoreaction performance were studied, photoinduced and non photoinduced liquid crystal monomers and polymers orientation were studied.The results indicated that four monomers and two homopolymers had liquid crystal properties. Molecular structures had effect on the photochemical reaction of polymers. In two orientation methods, the annealing temperature of non photoinduced liquid crystal molecules orientation were higher than photoinduced liquid crystal molecules orientation. The optical anisotropy of the photoinduced orientation was fixed after exposed 10 min, The optical anisotropy of the non photoinduced orientation was fixed after exposed 15 min. The orientation performance of M1 and M2 was better than that of P2 and P3.