光致变色液晶高分子研究（Ⅳ）──含苯甲酸－4－甲氧基苯酯介晶基元和偶氮苯光色基元侧链共聚硅氧烷的液晶行为  

Studies on Photochromic Liquid Crystalline Polymers(Ⅳ)──Liquid Crystalline Behavior of Side-Chain Copolysiloxanes Cotaining 4-Methoxyphenyl Benzoate Mesogens and Azobenzene Photochromic Groups

作　　者：张其震[1] 王艳 侯建安[1] 徐懋[1] 

机构地区：[1]山东大学化学系,中国科学院化学研究所

出　　处：《高等学校化学学报》1994年第10期1563-1566,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金;中国科学院高分子物理联合开放实验室(化学所)资助

摘　　要：用热台偏光显微镜和ＤＳＣ法研究了含苯甲酸－４－甲氧基苯酯介晶基元和偶氮苯光色基元侧链共聚硅氧烷（ＰＳⅡ）的液晶性．将非介晶基元并入液晶均聚物ＰＳⅡ－１，共聚物ＰＳⅡ－２、ＰＳⅡ－３的液晶态类型不变，ＰＳⅡ－４仅存在近晶相，ＰＳⅡ－５～８无双折射现象，保持共聚物液晶性的最低含介晶基元单体的极限摩尔含量为８０％。在液晶共聚物中，非介晶基组分含量增加时，其Ｔ＿ｍ、ΔＨ＿ｍ和ΔＳ＿ｍ降低；非介晶组分在１０ｍｏｌ％时，Ｔ＿ｉ、ΔＨ＿ｉ和ΔＳ＿ｉ具有最小值。The liquid crystalline properties of side-chain copolysiloxanes containing 4-methoxyphenyl benzoate mesogens and azobenzene photochromic groups were characterized by polarized microscopy with a hot stage(POM)and DSC.On incorporation of nonmesogenic units into polysiloxane PS Ⅱ-1 the type of mesophase did not chang for copolymers PS Ⅱ-2 and PS Ⅱ-3,but smectic texture is only preserved for copolymer PS Ⅱ-4.The mole fraction limit of mesogenic units needed for mesophase existence of copolysiloxanes of mesogenic monomers with monomers,which do not contain mesogenic fragments,is to be 80 mol%;In the composition region of mesophase existence the lowering of melting temperature is accompanied by the increasing of nonmesogenic component content of copolymers and their isotropic temperature,enthalpy and entropy pass through a minimum at 10 mol%of nonmesogenic units of PS Ⅱ-3,as shown in Fig,3.

关 键 词：光致变色 液晶 共聚硅氮烷 近晶相 

分 类 号：O743.5[理学—晶体学]