热致可逆变色胆甾液晶聚合物的制备和光学性能研究

合成了两种胆甾液晶单体,4-烯丙氧基苯甲酸胆甾醇酯M1和4-{4-[(4-烯丙氧基)-苯甲酰氧基]丁氧羰基}苯甲酸胆甾醇酯M2。将两种单体按一定比例与含氢聚硅氧烷(PMHS)共聚得到了一系列侧链液晶聚合物P1-P6。采用红外光谱(FT-IR)、核磁共振(1 H NMR)、差示扫描量热(DSC)、偏光显微镜(POM)和X射线等手段对单体及聚合物的结构、液晶性能和相行为进行了表征。通过分析表明单体M1、M2和聚合物为热致胆甾型液晶,聚合物在常温具有选择性反射现象,在升温—降温—再升温的过程中反射波长随温度升高发生蓝移,且聚合物具有良好的热稳定性和可逆变色性。

Synthesis and optical properties of chelostic liquid crystalline polymers with thermal reversible colorific change

A series of side-chain liquid crystalline polymers(P1-P6) were synthesized with poly(methylhydrogeno)siloxane and two cholesteric liquid crystalline(LC) monomers 4-allyloxybenzoylcholeseterate(M1) and 4-{4-[(4-(allyloxyl)-benzoyl]-butyloxocarbonyl}-benzoatecholesteryl(M2).The mesomorphic properties were investigated by fourier transform infrared(FT-IR),proton nuclear magnetic resonance spectra(1H NMR),differential scanning calorimetry(DSC),thermogravimetric analyses(TGA),polarizing optical microscopy(POM),and X-ray diffraction(XRD) measurements.All the monomers and polymers show cholesteric mesophase with very wide mesophase temperature ranges.Polymer films demonstrate the reversible change of reflective color,and blue shift was observed from low temperatures to high temperatures on the first heating and cooling,even second heating,the results indicate that the polymers show nice thermal and optic stability.