液晶弹性体的合成及其液晶性能

Synthesis and Mesomorphic Properties of Liquid Crystalline Elastomers

将向列型液晶4-烯丙氧基苯甲酰氧基-4-对丁基苯甲酰氧基苯（MN）单体和柔性丙烯酸丁二醇双酯（MC）交联剂接枝到含氢硅氧烷链上,交联剂的摩尔分数由0至21.6%,记为液晶弹性体P1~P8。通过热分析、偏光显微分析等手段对液晶弹性体P1~P8液晶性能进行了研究。结果表明,所有液晶聚合物P1~P8均呈现向列型液晶丝状或纹影织构,液晶弹性体的玻璃化转变温度（Tg）和清亮点（Ti）随交联剂（MC）在链中浓度增加而降低。当交联剂含量为14.4%时,弹性体P7聚合物显示出类似橡胶一样的弹性。所有液晶弹性体的热稳定性均较好,质量损失5%时的热失重温度均在370℃以上。

The nematic liquid crystal monomer 4-butylbenoyloxy-4＇-allyloxybenzoyloxy benzene（MN）,and flexible crosslinker butanediol diacrylate（MC） were grafted to the backbone of polymethylhydrosiloxane（PMHS） with different mole radios of the Mc from 0～21.6 mol%.The liquid crystalline properties of the series of liquid crystalline elastomers P1～P8 were characterized by thermal analysis and polarized optical-microscopic analysis.All the elastomers exhibited nematic thread or schlieren texture.It is also shown that the glass transition temperature（Tg） and isotropic temperature（Ti） decreased with increasing mole radio of Mc in the polymers.When crosslinking density reached 14.4 mol%,the elastomer P7 showed rubber-like elastic behavior.The thermal stability of the polymers were very good up to 370 ℃ with only 5% weight lost.