Dynamic Processes in Glassy Polymers

这项研究是一个实验核磁共振之间的合作努力， 研究小组和理论化学研究小组， 研究玻璃状聚合物的动力学。 实验 该小组将联合收割机现有的现代固体核磁共振技术与 新的实验（旋转回波，双共振C-13-F-19 NMR 和旋转回波移相H-1 NMR）来研究动力学 聚碳酸酯中主链苯环的180 °翻转， 聚碳酸酯类塑料。 将对这些系统进行调查 在各种物理条件下，包括高外部 流体静压 链条将被大量检查， 聚合物-聚合物界面 苯环翻转很有趣 因为它们监测固体的缓慢密度波动， 其与物理性质如韧性有关。 到 详细了解这些密度波动，一组平行的 使用广义朗之万动力学的计算实验 将采用模拟技术。 这种计算机方法 模拟已经专门开发，以允许模拟 玻璃状固体中的慢动作。

This research is a collaborative effort between an experimental NMR research group and a theoretical chemistry research group to investigate the dynamics of glassy polymers. The experimental group will combine existing techniques of modern solids NMR with new experiments (rotational-echo, double-resonance C-13--F-19 NMR and rotational-echo dephasing H-1 NMR) to investigate the dynamics of 180o flips of the main-chain phenyl rings in polycarbonates and polycarbonate-like plastics. These systems will be investigated under a variety of physical conditions including high external hydrostatic pressure. Chains will be examined in bulk and at polymer-polymer interfaces. Phenyl ring flips are of interest because they monitor the slow density fluctuations of the solid, which are related to physical properties such as toughness. To understand these density fluctuations in detail, a parallel set of computational experiments using a Generalized Langevin Dynamics simulation technique will be undertaken. This method of computer simulation has been specifically developed to allow the simulation of slow motions in a glassy solid.