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采用光散射方法研究了聚对苯二甲酰对苯二胺(PPTA)浓硫酸溶液于不同凝固条件下成膜时得到的球晶和草席晶等结构。PPTA的球晶由一些各向异性棒状微晶呈辐射型有序排列聚集而成的。红外二向色性的研究证明,PPTA草席晶中分子链沿“草席方向”高度取向。基于光栅衍射效应的角度依赖性认为,草席结构中条带的亮暗主要是由于它们取向方向上稍有差异引起的。以光栅效应计算了PPTA草席晶结构的长周期数据值及条带的取向状况,得到了较好的结果。根据在切应力作用下液晶的光散射图象认为,草席状结构是在切应力作用下于各向异性液业已形成,快速凝聚的方法可以把该种结构的特征保留在所获得的薄膜之中。
The structures of spherulites and matsubstrates obtained during the film formation under different solidification conditions were studied by light scattering method. PPTA spherulites by a number of anisotropic rod-shaped crystallites were radiation-type ordered aggregation formed. Infrared dichroism studies have shown that the PPTA mast crystal molecular chain along the “mats direction” highly oriented. Based on the angular dependence of the grating diffraction effect, it is believed that the bright and dark bands in the mat structure are mainly due to slight differences in their orientation. The long period data of PPTA matstructure and the orientation of the strips were calculated by grating effect, and good results were obtained. According to the light-scattering images of liquid crystals under shear stress, straw-like structures have been formed in an anisotropic liquid under shear stress and the rapid coalescence method can retain the features of the structure in the obtained film in.