含有两种介晶基元的侧链聚硅氧烷类液晶的热性能

Thermal Properties of Side-chain Liquid Crystalline Polymethylsiloxane Containing Two Mesogenic Units

将两种液晶单体4-联苯二酚基-4′-（2-乙基己酰基）-4-烯丙氧基苯甲酸酯(M1)和4-烯丙氧基苯甲酰氧基-4′-甲氧基苯(M2)接枝到聚硅氧烷链上， 用IRS、 DSC、 TGA、 POM、 SAXS和WAXD等对所得样品进行了测定。 结果表明， 含有两种介晶基元的聚硅氧烷类液晶， 具有较宽的中介区间（240～255℃）， 比只含一种介晶基元的聚硅氧烷类液晶中介相拓宽约170℃左右， 且低于室温具有液晶相(-18～8.7℃)， 热分解温度在300℃以上， 属于近晶织构。

A series of side-chain liquid crystalline polymethylsiloxane polymers containing different mole ratio of mesogenic monomers 4-(4-allyloxybenzoxy)-4′-(2-ethyl-hexanoyloxy) diphenyl (M1) and 4-allyloxybenzoxy-4′-methoxybenzene (M2) were prepared by graft polymerization. The structure and properties of the ploymers were characterized by IRS, POM, SAXS, WAXD, DSC and TGA. All of the samples PⅠ-PⅤ exhibited over a broad temperature range of liquid crystals (240～255℃), the temperature of mesogenic range increased about 170℃ comparing the polymers only containing M1 or M2. The T-g- of P0-PⅦ were lower than room temperature (from-18℃ to 8.7℃), the temperatures of decomposion were higher than 300℃. All of the samples were smectic mesogenic textures.