在膜分离过程中,渗透物分子在聚合物膜内的扩散过程,是影响聚合物膜分离性能的关键因素.详细考察了目前被广泛使用的Vrentas-Duda扩散模型,对其进行改进,提出了新的计算ζ的公式.根据新提出的公式,对聚苯乙烯/甲苯(PS/toluene)、聚苯乙烯/乙苯(PS/ethylbenzene)、聚乙酸乙烯酯/甲苯(PVAc/toluene)3种体系中弱极性渗透物分子的扩散系数进行了预测,其较之原Vrentas-Duda扩散模型、Ju改进的Vrentas-Duda扩散模型有更好的预测结果. During the process of membrane separation, the diffusion process of permeate molecules in the polymer membrane is a key factor affecting the performance of the polymer membrane separation.Valeas-Duda diffusion model, which is widely used at present, is investigated in detail, and its diffusion is proposed The new formula for the calculation of ζ is based on the newly proposed formulas for the PS / toluene, PS / ethylbenzene, PVAc / toluene The diffusion coefficients of weakly polar permeate molecules in the system are predicted, which are better than the original Vrentas-Duda diffusion model and the improved Vrentas-Duda diffusion model with Ju.