Properties of Highly Elastic Polymeric Materials

端基聚合物链的末端连接将被用来获得各种已知和可控结构的弹性体。这项技术将被用来实现对橡胶状弹性的更好的分子理解，并获得具有异常吸引人的机械性能的材料。研究的典型聚合物是聚异丁烯、聚丙烯酸酯和甲基丙烯酸酯，具有单峰和多峰网络链长分布，并具有已知数量的悬链不规则性。性能将包括应力-应变等温线、应变诱导结晶和双折射。一些环状物将用于此类反应中的捕获测量和“奥林匹克”网络的准备。其他研究将包括一些不寻常的材料(如一些用于制备高性能材料的凝胶、液晶弹性体、蜘蛛网丝绸和多肽)，以及一些不太常见的变形(双向拉伸、剪切和扭转)。新型增强填料将通过有机金属材料，如硅酸盐、钛酸盐、铝酸盐等的水解、光解或热解来制备。由此产生的填充弹性体将主要通过力学性能测量、电子显微镜、X射线和中子散射技术进行表征。

The end-linking of functionally-terminated polymer chains will be used to obtain a variety of elastomers of known and controlled structure. This technique will be used to achieve a better molecular understanding of rubberlike elasticity and to obtain materials of unusually attractive mechanical properties. Typical polymers investigated will be polyisobutylene, polyacrylates and methacrylates, with both unimodal and multimodal network chain- length distributions and with known numbers of dangling-chain irregularities. Properties will include stress-strain isotherms, strain-induced crystallization, and birefringence. Some cyclics will be used in trapping measurements in such reactions and in the preparation of "Olympic" networks. Additional studies will include unusual materials (such as some gels useful in the preparation of high-performance materials, liquid-crystalline elastomers, spider-web silk, and polypeptides), and some will employ less-common deformations (biaxial extension, shear, and torsion). Novel reinforcing fillers will be prepared by the hydrolysis, photolysis, or thermolysis of organometallic materials such as silicates, titanates, aluminates, etc. The resulting filled elastomers will be characterized primarily by mechanical property measurements, electron microscopy, and X-ray and neutron- scattering techniques.