热致型光敏液晶高分子在液晶场中光交联反应的研究

PHOTOCROSSLINKING REACTION OF THERMOTROPIC PHOTOSENSITIVE LIQUID CRYSTALLINE POLYMERS IN LIQUID CRYSTALLINE FIELD

研究了具有肉桂酸酯侧链基的热致型液晶高分子的光交联行为．结果表明，在２０ｍｉｎ紫外光照射的条件下，形成液晶相的液晶高分子膜的光交联凝胶百分率要明显高于尚未形成液晶相的同种高分子膜．对形成液晶相的高分子膜，在环境温度低于液晶各向同性温度Ｔ时，温度对光交联凝胶百分率的影响甚微．这表明，由于液晶高分子中致介单元的聚集和有序排列形成的微区结构也影响了大分子链侧基肉桂酸酯的聚集状态．从而使其光化学性质发生变化．

ehavior of photocrosslinking reaction of side-chain liquid crystalline copolymer P(MPAEB-co-VBC)and P(MPAHB-co-VBC) was investigated.When the sample membrane was irradiated by ultraviolet ray at room temperature for 20 minutes,the percent of gel for quenched membrane was higher than unquenched one for both P (MPAEB-co-VBC)and P(MPAHB-co-VBC),but did not change for homopolymer.When the temperature of samples was changed from room temperature to 100℃, there was not dear difference in percent of gel for quenched P(MPAEB-co-VBC)and P(MPAHB-co-VBC) membranes.It was concluded from there observations,that because of ordered arrangement of mesogen groups in L.C.copolymer,physicocrosslinking macromolecules,which had domain structure,was formed.The domain structure could influence aggregational condition of cinnamate groups in the L.C.polymer chains and resuted in different characteristics from amorphous one.