液晶聚合物/柔性链聚合物共混体系相分离形态

利用元胞动力学方法在二维情况下对浓度、取向序参量的含时Ginzberg-Landau方程进行数值求解,研究了液晶聚合物/柔性链聚合物共混体系的相分离动力学,考察了浓度、取向有序过程的耦合对相分离形态的影响.结果表明,此耦合作用对相分离的时间进程以及相分离图样的空间排布都有影响.液晶聚合物的取向有序相当于增加了两组分间的不相容性而促进两相分离;两个序参量在热力学方面的耦合使液晶聚合物趋向于沿着界面方向取向,而动力学方面的耦合使液晶聚合物分子沿着其取向方向扩散,相分离图样的空间排布由这两种效应共同决定通过极化率张量的定义用数值方法模拟得到了相分离体系的小角光散射图样,结果表明,散射强度分布具有方位角依赖性,它是由浓度、取向序参量的空间变化共同决定的.

Phase Separating Morphology of Liquid Crystalline Polymer/Flexible Polymer Blend

The phase-separation kinetics of liquid-crystalline polymer/flexible polymer (LCP/FP) blend wa studied with the coupled time-dependent Ginzberg-Landau equations for compositional order parameterand orientational order parameter Sij, which were numerically solved by means of the cell dynamical system in two dimensions. The influence of coupling between compositional and orientational ordering processes on the phase separating morphology was investigated. It was found that the orientational ordering promoted the compositiona ordering, i.e., the increasing of the magnitude of orientational order equaled the decreasing of the compatibility between two phases. Moreover, the spatial distribution of phase-separated structures is determined by both the thermodynamic factor, which means the nematic direction of LCP domains parallel to the interface is preferable, and kinetic factors, which imply LCP has a tendency to diffuse parallel to the nematic direction. The small-angle light scattering patterns are numerically reproduced by means of the optical Fourier transformation of spatial variation of the polarizability tensoraij, and the azimuthal dependence of the scattering intensity distribution i interpreted.