中文摘要：

引言聚乙烯（PE）是由乙烯单体聚合而成的相对分子质量较高的线性烷烃,是合成树脂中应用最广泛的品种。扩散系数是描述传递现象的基本物性参数,在聚合物材料开发方面具有重要的理论特性和广阔的应用前景。用实验方法测定扩散系数时,操

英文摘要：

The diffusion of benzene,toluene and ethylbenzene in amorphous polyethylene（PE） membrane was studied in this paper,and their diffusion coefficients were analyzed and calculated by molecular dynamics simulation.The diffusion coefficients were calculated with the clustering method.The calculated results have the same trend with experimental results： the diffusion coefficient decreases with increasing molecular weight of organic molecules at the same temperature and increases with temperature for the same organic molecule.It is shown that the diffusion coefficients are reasonable and reliable.The diffusion behavior of three kinds of molecules in polyethylene membrane in a long time（300 ps） scale was simulated and the tracks of molecules were obtained,which show that the molecule movement in the membrane is local vibration combined with prancing diffusion.