Thee-dimensional structural analysis and rheology on phase-separated structure of polymer blends

得到以下结果：(1)聚合物共混物相分离结构的观察与结构分析利用激光扫描共聚焦显微镜（LSCM）直接测量了聚合物共混物相分离结构的双连续形貌。在三维（3D）中获得了相分离结构。实验得到了界面曲率及其分布的时间演化规律，发现了在相分离过程中界面面积减小的两个基本过程。(2)细化算法的开发开发了用于发现网络结构连通性的man算法。它是基于现有的算法，但通过应用一些改进来提供可靠的结果，包括修改边缘平面的细化规则，更好地处理连接到边缘平面的连接等。利用无限周期极小曲面（IPMS）验证了算法的精度和可靠性。虽然可能需要一些改进，但该算法与数学预测基本一致。(3)将三维细化算法应用于聚合物共混物的相分离形态进一步利用三维细化算法获得聚合物共混物双连续相分离结构的几何和拓扑特征。结果表明，相分离畴在每个结处大部分具有3个支路。在相对于相分离结构的周期性稍短的距离处，界面距离达到最大值。欧拉特性显示了网络的复杂性，表明聚合物共混物的双连续结构在拓扑上相当于一个有2到3个把手的球体。从几何参数和拓扑参数的时间演化中证实了动态自相似性。(4)分散液滴相变形和形状恢复的观察研制了一种装置，用于施加大阶应变，并从两个垂直方向观察变形液滴相的形状。结果表明，液滴形状的改变使界面面积减小。从一个平坦的椭球体开始，形状变为棒状，哑铃状，旋转椭球体，最后回到球体。(5)分散液滴相形状恢复与应力松弛的关系研究了聚苯乙烯和聚碳酸酯共混熔体的分散相变形和形状恢复以及界面应力贡献。仿射变形后的液滴恢复到球形，随应变大小的不同，其最大松弛时间也相应延长。这种恢复过程与平台相吻合，松弛模量出现终端松弛。(6)连续结构聚合物共混熔体的粘弹性研究了因熔体共混而形成的50/50结构的聚苯乙烯和聚甲基丙烯酸甲酯共混熔体的动态粘弹性和应力松弛行为。存储模量的频率依赖性表现为幂律，反映了共混材料的双连续性质。在大阶应变作用下，观察到具有恒定取向角的连续结构的拉伸和收缩。少

The following results were obtained :(l) Observation and structural analysis of phase-separated structure of a polymer blendDirect measurement of phase-separated structure of a polymer blend bicontinuous morphology was done by tuse of laser scanning confocal microscopy (LSCM). The phase-separated structure was obtained in three-dimension (3D). Time-evolution of interfacial curvatures and their distributions were experimentally obtained, from which two basic processes of reducing interfacial area were found to occur in the course of the phase-separation.(2)Development of thinning algorithmAn algorithm to find out the connectivity of network structure was developed. It is based on the existing algorithm but is modified to offer reliable results by applying some improvements that include modification of thinning rules at edge planes, better treatment ofjunctions attaching to the edge planes, etc. Infinite periodic minimal surfaces (IPMS) were used to check the precision and reliability of … More the algorithm. Although a few improvements may be necessary, the algorithm gives reasonable agreement with the mathematical predictions.(3) Application of 3D thinning algorithm to a phase-separated morphology of a polymer blendThe 3D thinning algorithm were further used to obtain geometrical and topological features of the bicontinuous phase-separated structure of a polymer blend. It is found that the phase-separated domain possess, for the most part, 3 branches at each junction. Interjunction distance showed maximum at a distance a little bit shorter than the periodicity of the phase-separated structure. The Euler characteristics, demonstrating complexity of the network, showed that the bicontinuous structure of the polymer blend is topologically equivalent to a sphere with 2 to 3 handles. The dynamical self-similarity has been confirmed from the time-evolution of the geometrical and topological parameters.(4) Observation of deformation and shape recovery of a dispersed droplet phaseAn apparatus was developed to apply large step strains and to observe the shape of a deformed droplet phase from two perpendicular directions. It was found that the droplet shape changes to reduce the interfacial area. Starting from a flat ellipsoid, the shape changes to a rodlike, a dumbbell, an ellipsoid of revolution and finally back to a sphere.(5)Relationship between shape recovery and stress relaxation for a dispersed droplet phaseThe deformation and shape recovery of dispersed phase and the stress contribution from the interface are investigated for a blend melt of polystyrene and polycarbonate. The affinely deformed droplets recover to the spherical shape with the maximum relaxation time depending on the strain magnitude. The process of this recovery corresponds very well with the plateau and terminal relaxation appeared in the relaxation modulus.(6) Viscoelasticity of polymer blend melt with continuous structureThe dynamic viscoelasticity and stress relaxation behavior are investigated for a 50/50 blend melt of polystyrene and poly (methyl methacrylate) with the modulated structure due to melt blending. The frequency dependence of the storage modulus shows a power law, reflecting the bicontinuous nature of the blend. The stretching and contraction of the continuous structure with the constant orientation angle are observed under large step strains. Less