手征性侧链液晶高分子取向结构的研究

用偏光显微镜，红外二色性和Ｘ 射线衍射研究了一种手征性侧链液晶高分子的相态织构和弛豫行为．偏光显微镜观察这种侧链液晶高分子冻结取向液晶态薄膜时，可观察到与剪切方向垂直的明暗相间的条带织构．红外二向色性的结果表明，取向态中侧链上的介晶基元倾向于与剪切方向垂直排列．取向和非取向膜的Ｘ射线衍射揭示了该侧链液晶高分子具有反铁电性液晶的两套反相螺旋结构．取向薄膜在液晶态的弛豫行为表明，取向作用能促进侧链高分子近晶相层状结构的生长，而且介晶基元的取向在弛豫过程中能保持下来．

STUDIES ON STRUCTURE OF ORIENTED FILM OF A CHIRAL SIDE CHAIN LIQUID CRYSTALLINE POLYMER

The peculiarities of orientation in a chiral side chain liquid crystalline polymer by action shear stress were studied.The mesophases and phase transition temperatures of chiral side chain LCP Ps 11 are:crystalline Sc * phase (90℃), Sc * S A phase (98℃) an S A isotropic phase (117℃), determined by DSC and POM with a hot stage. The polymer Ps 11 shows typical focal conic texture is S A phase and straited focal conic texture in twisted Sc * phase. A typical banded texture with parallel bands extended in a direction perpendicular to the shear direction can be observed during quenching from the sheared melt at the temperature of S A phase. The width of bands is about 1μm. Infrared dichroism of the oriented film reveal that the orientation of the side chains containing mesogen tend to be normal to the shear direction in the oriented film, which means the smectic layers tend to parallel to shear direction because of mesogenic director normal to layer. X ray diffraction pattern indicates that the bilayered superstructure of smectic phase,which can be attributed to an antiferroelectric ordering exist in this polymer.The relaxation behavior of the oriented film exhibits that orientation history is useful for the growth of smectic layer and ordered focal conic texture can rapidly be formed in the oriented film during the heat treatment.