Alignment of photo-cross-linkable copolymer liquid crystals induced by linearly polarized ultraviolet irradiation and thermal treatment: Effect of copolymerization ratio. 2

作者：Kawatsuki N^*; Matsuyoshi K; Yamamoto T

来源：Macromolecules, 2000, 33(5): 1698-1702.

DOI：10.1021/ma991758+

Linearly polarized (LP) ultraviolet (UV) photoirradiation of methacrylate copolymer liquid crystal films comprising a photo-cross-linkable 4-(2-cinnamoyloxyethoxy)biphenyl side group and a photoinactive 4-cyanobiphenyl group with various copolymer composition has been carried out to induce an optical anisotropy. The effect of the copolymerization ratio on the orientational behavior of the film was investigated by means of UV and FT-IR polarization spectroscopy. For all copolymer films, the orientation of the mesogenic groups was generated with the direction parallel to the electric vector of LP-UV light after annealing the irradiated film near clearing temperature of the copolymer. The maximum optical anisotropy was obtained when the photo-cross-linked side group in the whole mesogenic groups was 4-14 mol %, depending on the copolymer composition. It was suggested that the alignment ability of the cyanobiphenyl group was larger than that of another group.

• 出版日期2000-3-7