梯形聚倍半聚硅氧烷在制备液晶定向膜方面的应用

The Application of Ladderlike Polysiloxaneson the alognment layer for Nematic Liquid Crystals

梯形有机硅材料具有优异的成膜性能，有玻璃样的透明性，能耐高温和辐照，且固化条件温和，易于接上侧链进行修饰，是一种有发展前途的液晶定向膜基体材料。本文介绍了液晶定向膜的几种制备方法：（１）摩擦和结构修饰方法；（２）以接枝肉桂酸酯侧链的梯形聚硅氧烷为基材通过线性光聚合反应的方法；（３）从接枝偶氮苯和肉桂酸酯侧链的梯形聚硅氧烷通过摩擦和紫外光辐照相结合的方法。所得到的液晶定向膜具有很好的稳定性和较高的预倾角。

The ladderlike polysiloxanes(LPS) and its derivatives possess excellent transparency, mechanical properties, film_forming ability and resistance to irradiation and heat, and can be cured under milder conditions. These advantages enable this materials to be a promising candidate as the orientation media for the LCDs. This report is dealing with the applocation of modified LPS in forming LC alignment films by three approaches:(1) fabricated by rubbing technique and side_chain modification; (2) fabricated by linearly photopolymerization (LPP) based on the LPS grafted with cinnamoyl side_chains; (3) by combining rubbing and UV_irradiation based on LPS containing cinnamate and azobenzene side chains. These alognment layers featured a high surface pretilt angle and good stability.