【摘要】 将合成的含偶氮基团的液晶单体M与含胆甾基团的手性液晶单体N接枝到含氢甲基硅油上,得到系列手性偶氮类侧链液晶聚合物PY1~PY6.利用红外光谱(IR)、核磁共振谱(1HNMR)对其分子结构进行表征,采用差示扫描量热法(DSC)、偏光显微分析法(POM)、热重分析法(TG)对其介晶性能、相行为及热稳定性进行研究.结果表明,所合成的聚合物PY1~PY6为互变热致液晶,均呈现胆甾相的Grandjean织构.从PY1到PY6随着偶氮单体M含量的增加,tg呈先降后升的趋势,而ti则缓慢下降.该系列聚合物热稳定性良好,5%热失重温度在290℃以上,液晶区间在162~189℃之间.更多还原

【Abstract】 The azo monomer 4-( allyloxybenzoyloxy) azobenzene-4’-ethyl formate( M) and chiral monomer 4-( allyloxybenzoyloxy) isopropionate cholesteryl( N) were grafted onto the backbone of polymethylhydrosiloxane. A newkind of azobenzene liquid crystalline polymers( PY1~ PY6)containing cholesteryl groups was prepared. Their chemical structures were confirmed by FT-IR and1 HNM R spectra,and mesomorphic properties,phase behavior and thermal stability were investigated by DSC, POM and TG. The results showed that PY1~ PY6 are thermotropic cholesteric liquid crystal and display Grandjean texture. With the increasing content of M,tg ascends after a decline,but tidescends slowly. The temperatures when 5% weight loss occurred are higher than 290 ℃ and the mesomorphic temperature ranges are 162 ~ 189 ℃,which reveal that PY1~ PY6 have a high thermal stability and remarkable liquid crystal properties.更多还原