迁移预测模型中扩散系数研究.pdfVIP

迁移预测模型中扩散系数的研究1 1 * 2 1,3 王平利，王志伟，胡长鹰 ，陈默 (1.暨南大学包装工程研究所，珠海 519070；2.暨南大学食品工程系，广州 510632；3.江南大学包装工程系，无锡 214122） [摘要]：包装材料与食品直接接触导致材料中低分子量物质（如低聚体、填 充剂、添加剂、稳定剂和增塑剂等）从材料迁移到食品，从而影响消费者安全。 为了避免耗时、昂贵且难于进行的迁移实验，迁移预测模型作为一种有效的替代 工具被使用。迁移预测模型中包含两个主要参数：扩散系数和分配系数。预测模 型的关键问题是如何确定这两个主要参数的值。对于扩散系数，国外研究者在实 验的基础上提出了许多半经验化的估测公式。本文详细介绍了三种典型的半经验 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。 关键词：迁移预测模型，扩散系数，半经验化公式，分子动力学方法 Study on diffusion coefficient in predictive migration models WANG Ping-li 1,WANG Zhi-w ei 1, HU Chang-ying 2 , CHEM Mo 1,3 (1.Packaging Engineering Institute, Jinan University, Zhuhai 519070, China; 2.Department of Food Science and Engineering, Jinan University, Guangzhou, 510632,China; 3.Department of Packaging Engineering, Jiangnan University, Wuxi 214122, China) Abstract :Direct contact between plastic materials and food can result in migration of the substance(such as residual monomers, additives, stabilizing agent, filling agent and plasticizing agent)from packaging materials into food. In order to avoid time-consuming and expensive and often complicated to carry out migration tests, predictive migration models are used as an alternative tools. In most of the migration prediction models two main parameters are used: diffusion coefficient ( DP )and partition coefficient( K P ,F ). The centre of predictive migration models is how to determine the main parameters. For diffusion coefficient foreign researches have developed some self-empirical diffusion coefficient equations based on experimental diffusion coefficient date. An objective of this article is to review three of most generally used self-empirical diffusion coefficients equations and analysis the application and limits. Another objective is to introduce molecular dynamics simu