Abstract: According to the percolation theory, a new model which is used to describe the solvent self diffusion in polymer solution has been established. The solvent self diffusion coefficient of PS-toluene, PS-benzene, PS-ethylbenzene and PS-THF systems has been correlated by using the new model at different temperatures and concentrations and the critical volume fraction of solvent self-diffusion at different temperatures has been estimated. The results show that below the glass temperature of PS, the new model not only has a satisfactory correlated accuracy, but it is suitable for a large range of temperature and concentration.

Key words: Self-diffusion coefficient, Polymer solution, Percolation theory