Physics Of Solid State Polymerization

固态聚合是一种常用的技术 用于增加缩聚物的分子量 在本体聚合完成之后。 固态 聚合提供了最有吸引力的路线之一， 获得极高的强度、高模量、热 稳定、耐化学腐蚀的聚合物。 该技术涉及 将聚合物加热到所观察到的温度的约50 ℃以内， 熔化温度在大气中，其中各种 分子量构建反应被驱动朝向 通过除去低分子量缩合物完成 副产品 固态聚合的化学是 相对较好理解的是， 热致聚合物的拉伸强度大幅增加 还没有完全阐明。 这项工作旨在更好地了解 有时会出现在 定向热致聚合物的固态聚合。 有助于端基分析的特定聚合物 集群，流动性和反应将被综合在 为了阐明端基迁移率的影响， 反应性或聚集性。 结束数量的变化 组，并将使用固态 固态退火后的NMR。 的热处理效果 将使用一些化学和物理技术进行分析。 希望这项工作将阐明最佳的 合成坚硬、坚固、化学性质 耐腐蚀、基本无缺陷、高介电性能， 轻质材料。

Solid state polymerization is a technique commonly employed for increasing the molecular weight of condensation polymers after bulk polymerization has been completed. Solid state polymerization offers one of the most attractive routes for obtaining extremely high strength, high modulus, thermally stable, chemically resistant polymers. The technique involves heating the polymer to within about 50oC of the observed melting temperature in an atmosphere in which various molecular weight building reactions are driven towards completion by the removal of low molecular weight condensation byproducts. The chemistry of solid state polymerization is relatively well understood, the mechanisms responsible for the enormous increase in tensile strength of thermotropic polymers have not been fully elucidated. This work is aimed at obtaining a better understanding of the large increase in tenacity that sometimes occurs during the solid state polymerization of oriented thermotropic polymers. Specific polymers that facilitate analysis of end group clustering, mobility, and reaction will be synthesized in order to elucidate the effect of end group mobility, reactivity, or clustering. The changes in the number of end groups, and their proximity will be followed using solid state NMR after solid state annealing. The effect of heat treatment will be analyzed using some chemical and physical techniques. It is hoped that the work will elucidate the optimal mechanisms for the synthesis of stiff, strong, chemically resistant, essentially defect-free, high dielectric, and lightweight materials.