Dynamic Aspects of Rodlike Polymer Solutions and Gels

棒状聚合物是各种高温、高强度材料的基本组成部分。传统的加工方法通常不适用于棒材，因此必须将浓缩溶液加工成纤维和薄膜。然而，与随机线圈聚合物相比，棒状聚合物的溶液行为研究仍然很少。此外，了解棒状聚合物和无规线圈聚合物混合物的动力学非常重要，因为这些混合物是复合材料的前身，其中棒状聚合物增强了传统的无规线圈矩阵。对螺旋多肽扩散的光学研究已经揭示了许多浓缩的、各向同性的溶液。这些研究将扩展到具有随机线圈的混合物以及液晶溶液。一类特殊的多肽，聚烷基谷氨酸，将有助于这些研究。棒状聚合物的热可逆凝胶化是一个令人困惑的现象，但如果棒状聚合物要发展成三维材料而不仅仅是纤维和薄膜，这是一个重要的现象。聚（烷基谷氨酸）s和其他多肽将用于研究棒状聚合物的凝胶化。光散射和示踪剂扩散测量将有助于确定凝胶中聚集和相分离的相对重要性。

Rodlike polymers are the basic components of various high -- temperature, high -- strength materials. Conventional processing methods are often inadequate for rods, so they must be processed from concentrated solutions -- most often into fibers and films. However, the solution behavior or rodlike polymers remains poorly studied compared to random coil polymers. Additionally, it is important to understand the dynamics of mixtures of rodlike and random coil polymers, as these mixtures are the precursors to composite materials in which rodlike polymers reinforce a conventional random coil matrix. Optical studies of the diffusion of helical polypeptides have already revealed much about concentrated, isotropic solutions. These studies will be extended to mixtures with random coils and also to liquid crystalline solutions. A special class of polypeptide, the poly(alkylglutamate)s, will facilitate these studies. Thermoreversible gelation of rodlike polymers is a baffling phenomenon, but an important one if rodlike polymers are to be developed into three -- dimensional materials and not just fibers and films. Poly(alkylglutamate)s and other polypeptides will be used to study the gelation of rodlike polymers. Light scattering and tracer diffusion measurements will help to establish the relative importance of aggregation and phase separation in gelation.