采用硅氢加成法合成了含偶氮苯侧链的聚硅烷液晶聚合物,用FTIR、DSC和偏光显微镜对聚合物结构及液晶特性进行了表征。采用473nm偏振光对聚合物膜进行了光致取向,用偏光显微镜对取向结果进行了表征,发现偏振光倾斜照射后侧链偶氮苯基团发生了面外垂直取向。采用量高法测量了取向前后膜的接触角,根据接触角计算了膜的表面能。聚合物膜在取向前接触角为94.5°,偏振光照射取向后降低为76.5°,表明光照使聚合物膜从疏水变为亲水,膜的表面能明显增加。结合锥光显微镜观察到的干涉图结果,提出了极性偶氮苯基团面外垂直排列取向提升膜表面能的机理。
Azobenzene containing side-chain liquid crystalline polymer was synthesized by hydrosilation reaction of poly(methylhydrosiloxane) with the azo monomer.The chemical structure and its liquid crystalline properties were investigated by FITR,DSC and POM with a hot stage.Photo-alignment treatment was performed on the polysiloxane film by using a linearly polarized light source with the wavelength of 473 nm.A static contact angle mea-surement was carried out and the surface free energy was also calculated from the contact angles of a drop of water on the polymer film.The water contact angles was decreased from 94.5° to 76.5° after the light irradiation.We conclude that the changes in the hydrophilic of LC polymer were influenced by the surface compositions upon the photoinduced reorientation of the azobenzene side groups perpendicularly towards the film surface,which was confirmed by conoscopic POM observation results.