节点文献
侧链型含异山梨醇基的手性液晶弹性体的合成与性能
Synthesis and Characterization of Chiral Side-chain Liquid Crystalline Elastomers Containing Isosorbide Group
【摘要】 将非液晶手性交联剂4烯-丙氧基苯甲酸异山梨醇双酯(M1)按不同摩尔分数与向列型液晶单体4己-氧基苯甲酸-4′-烯丙氧基联苯单酚酯(M2)接枝共聚到聚甲基含氢硅氧烷链上,制得系列液晶弹性体P1~P8。利用红外、1H NMR、元素分析、X射线衍射测试技术对单体和聚合物的结构进行表征,通过热分析、偏光显微分析、热失重等分析方法研究了手性交联剂对弹性体液晶性能的影响。结果表明,聚合物P1为近晶型液晶聚合物,P2~P3为近晶型液晶弹性体,聚合物P4~P7为胆甾型液晶弹性体,聚合物P8没有液晶性能。系列液晶弹性体的tg随交联剂含量的增加先降低后升高,ti呈降低趋势,液晶相范围也随之变窄。质量损失5%时的热失重温度均在300℃以上。
【Abstract】 A series of new chiral liquid crystalline elastomers was prepared by graft polymerization of a nematic monomer,4-allyloxybiphenyl-4′-hexyloxybenzoate,with a chiral crosslinking agent,isosorbide 4-allyloxybenzoyl bisate,using poly(methyl hydrosiloxane) as the backbone.The chemical structures of the monomers and the polymers obtained were confirmed by FTIR,1H NMR and elemental analysies.The mesomorphic properties were investigated by differential scanning calorimetry,polarizing optical microscopy,and X-ray diffraction.Polymer P1 and elatomers P1~P2 exhibited smectic phase,while elastomers P4~P7 showed cholesteric phase,and P8 displayed no liquid crystal phase.It was found that the glass transition temperatures reduced first and then increased,the isotropization temperatures and the mesophase temperature ranges decreased with increasing the content of the crosslinking unit.The thermal decomposition temperature(at 5% mass loss) of the polymers were greater than 300 ℃.
【Key words】 chiral crosslinking agent; smectic phase; elastomer; Grandjean texture;
- 【文献出处】 应用化学 ,Chinese Journal of Applied Chemistry , 编辑部邮箱 ,2008年10期
- 【分类号】O753.2;O631.3
- 【被引频次】19
- 【下载频次】428