圧力ジャンプを用いた高分子液体の動的階層構造の研究

在这个项目中，我们重点研究了动态不对称二元混合物中浓度波动在相分离和/或弛豫过程中的粘弹性效应。利用时间分辨小角中子散射研究了动态不对称聚合物共混物中由快速压力变化引起的浓度波动弛豫过程。在高压和高温下，用专为聚合物体系设计的电池在单相共混物内进行压力变化。发现在弛豫过程中散射强度分布随波数(q)的时间变化近似于Cahn-Milliard-Cook线性化理论。理论分析得出了Onsager动力学系数的q依赖关系，其特征为在qξ <-2>处的q^<-2>，其特征长度远大于DAB或PI的旋转半径。估计的ξve与使用Doi和Onuki理论计算的ξve很好地吻合。Doi和Onuki理论考虑了浓度波动弛豫过程中组成聚合物之间的动力学不对称所引起的粘弹性效应

In this project, we focus on the viscoelastic effects during the phase separation and/or the relaxation process 'of the concentration fluctuations in dynamically asymmetric binary mixtures. In particular, we found the following : Relaxation processes of the concentration fluctuations induced by a rapid pressure change were investigated for a dynamically asymmetric polymer blend by using time-resolved small angle, neutron scattering. The pressure change was carried out inside the single phase blend with the cell designed for polymeric systems under high pressure and high temperature. Time change in the scattered intensity distribution with wave number (q) during the relaxation processes was found to be approximated by Cahn-Milliard-Cook linearized theory. The theoretical analysis yielded the q-dependence of Onsager kinetie coefficient which is characterized by the q^<-2>-dependence at qξve >1 with the characteristic length ξve being much larger than radios of gyration of DAB or PI. The estimated ξve agrees' well with that calculated using Doi and Onuki theory which takes into account the viscoelastic effects arising from the dynamical asymmetry between the component polymers in the relaxation of concentration fluctuations