侧链胆甾液晶聚合物的合成及性能

Synthesis and Properties of Side Chain Cholesteric Liquid Crystalline Polymer

合成了一种新型胆甾液晶单体（M1）和一种向列液晶单体（M2）,通过与聚硅氧烷（PMHS）接枝共聚得到了系列侧链液晶聚合物P1-P6,通过傅立叶变换红外光谱（FT-IR）、差示扫描量热仪（DSC）、热失重分析（TGA）、偏光显微镜（POM）等手段对聚合物的结构、液晶性能及热性能进行了表征。随着胆甾液晶基元的减少,其玻璃化转变温度（Tg）、清亮点（Ti）逐渐降低。聚合物P1-P6均为胆甾型热致液晶,聚合物呈现出典型的胆甾液晶彩色Grand-jean织构、油丝及焦锥织构,并且颜色随温度升高发生变化。

A series of novel thermotropic side-chain cholesteric-liquid crystalline polymers（P1～P6） were synthesized by graft copolymerization of mesogenic monomer cholesteryl（M1） and nematic liquid crystal monomer（M2） upon polymethylhydrosiloxane.The chemical structure of polymers was characterized by Fourier transform infrared spectroscopic（FT-IR）,differential scanning calorimetry（DSC）,thermogravimetry analysis（TG）,polarization microscope（POM） were used to measure their thermal and mesogenic properties.The polymers show thermotropic cholesteric-liquid crystalline properties,and exhibit typical color Grand-jean texture, focal conic texture and oil streaks texture,and the color changes with the increasing of the temperature.The glass transition temperature and clearing point decrease with decreasing the content of the cholesteric mesogenic in the polymers.