迁移预测模型中扩散系数的研究

Study on Diffusion Coefficient in Predictive Migration Models

详细介绍了3种典型的半经验化的扩散系数公式,分析其使用范围和局限性。同时,对通过直接计算机模拟得到扩散系数的分子动力学方法进行介绍。与半经验的扩散系数方程相比,分子动力学方法直接地给出了小分子在聚合物中的扩散系数,而且揭示了影响扩散的分子机理。

An objective of this article is to review three of the most generally used semi-empirical diffusion coefficients equations and analyze the application and limits. Another objective is to introduce molecular dynamic simulation and analyze the advantage and disadvantage by the approach. Compared with semiempirical diffusion coefficient models, the molecular dynamics approach directly gives the diffusion coefficient of small molecular in the different polymer models （such as higher temperature and non-polyolefins） by setting corresponding model parameters.