U.S.-Italy Cooperative Research: Rheology of Liquid Crystalline Polymers

这个美国-意大利奖将支持一项研究合作， Donald G.教授弗吉尼亚理工学院的贝尔德和 州立大学和该大学的朱塞佩·马鲁奇教授 那不勒斯。 研究人员计划评估现有的 描述液体流动行为的分子理论 结晶聚合物（LCP），并开发替代品 如果有必要的话。 更具体地说，调查人员计划 目的：（1）评价和检验土井首次提出的理论， 比较理论预测与实验结果， 溶致和热致体系;（2）进行 同步流变实验和结构测量， 为了发展应力（变形）和流体之间的关系， （3）确定可能的发展方向 反映LCP结构的本构理论。 高芳族聚酯的研究引起了人们的极大兴趣 和表现出液晶有序性的聚酰胺。 高模量 纤维和薄膜，以及在某些情况下的注塑部件， 用这些聚合物生产的。 在处理这些 聚合物、结构和取向是在流动到 在柔性链聚合物中没有发现的程度。 因此在 为了设计液晶聚合物的工艺， 建立应力和流动之间的关系是必要的 生成结构。 通过结合实验专业知识， 美国方面在理解LCP的流变学与 那不勒斯大学集团的理论优势， 研究人员应该能够提供更深入的见解， LCP的变形与结构之间的关系。

This U.S.-Italy award will support a research collaboration between Professor Donald G. Baird of the Virginia Polytechnic Institute and State University and Professor Giuseppe Marrucci of the University of Naples. The investigators plan to evaluate an existing molecular theory for describing the flow behavior of liquid crystalline polymers (LCP's) and to develop an alternative approach, if necessary. More specifically, the investigators plan to: (1) evaluate and test a theory first proposed by Doi, comparing theoretical predictions with experimental results for both lyotropic and thermo-tropic systems; (2) carry out simultaneous rheological experiments and structural measurements in order to develop relations between stress (deformation) and fluid structure; and (3) determine possible directions for developing constitutive theories reflecting the structure found in LCP's. There is considerable interest in the high aromatic polyestesters and polyamides that exhibit liquid crystalline order. High modulus fibers and films, and in some cases injection-molded parts, can be produced with these polymers. During the processing of these polymers, structure and orientation are generated during flow to a degree not found in flexible chain polymers. Consequently, in order to design processes for liquid crystalline polymers, it is necessary to establish the relation between stress and flow generated structure. By combining the experimental expertise of the U.S. side in understanding the rheology of LCP's with the theoretical strengths of the University of Naples group, the researchers should be able to provide deeper insights into the relation between deformation and structure for LCP's.