Free Energies and Phase Diagrams of Polymeric Systems from Computer Simulations

CTS-97-4907 S. Kumar/Penn。虽然聚合物混合物在实际应用中得到了广泛的应用，但从分子结构和相互作用的知识来预测它们的热力学性质是一个尚未解决的问题。我们认为，对聚合物相行为的定量理解对于设计具有特定应用所需性能的大分子材料是必要的。有了这个目标，在这项工作中，我们建议利用我们和其他人开发的新的模拟方法，来列举以下几种工业相关聚合物混合物的自由能或化学势和相图：(a)烃基混合物的相平衡，其中成分是不同的单体结构；(b)不同微观结构的共聚物对非混相聚合物混合物的增容作用；(c)受限聚合物混合物的相行为，例如在油漆和润滑剂中遇到的聚合物混合物。这种基于对工业相关聚合物混合物性质的分子理解也将有助于聚合物热力学分子模型的发展和关键评估。

ABSTRACT CTS-97-4907 S. Kumar/Penn. State U. While polymer mixtures are utilized extensively is practical applications, the prediction of their thermodynamic properties from a knowledge of molecular structure and interactions is an unsolved problem. It is our assertion that a quantitative understanding of polymer phase behavior is necessary to design macromolecular materials with desired properties for specific applications. With this goal, in this work we propose utilize new simulation methods, developed by us and by others, to enumerate the free energies or the chemical potentials and the phase diagrams of the following classes of industrially relevant polymer mixtures: (a) The phase equilibria of hydrocarbon based blends where the components are of disparate monomer structure; (b) The compatibilization of immiscible polymer mixtures by copolymers of different microstructure; and (c) The phase behavior of confined polymer mixtures, such as those encountered in paints and in lubricants. This molecular based understanding of the properties of industrially relevant polymer mixture will also assist in the development and the critical evaluation of molecular models of polymer thermodynamics.