Photoalignment of Liquid Crystal on Methacrylate Polymer Films Containing Mesogenic Side Unit of Biphenyl Attached with Photoreactive β-(2-Furylacryloyl) Group

Abstract

Using linearly polarized ultraviolet light, photoalignment of liquid crystals has been carried out on films of methacrylate liquid crystal copolymers with an alkyl group and a photoreactive β-(2-furylacryloyl)oxyethoxybiphneyl mesogenic side group. The rate of photoreaction was about 30 times faster in the β-(2-furylacryloyl) group than in the conventional photoreactive cinnamoyl group. Irradiation of polarized ultraviolet light on polymer film generated pretilt angles of liquid crystal molecules, which varied from 0 to 90 degrees according to copolymerization ratio. High thermal stability for both the LC alignment and pretilt angles were observed after heating the cell at 100℃ for 55 hours.