Yasaman Shahebrahimi - Department of Chemical and Petroleum Engineering, Islamic Azad University, Masjed Soleyman Branch,Masjed Soleyman, Iran
Seyed Ashkan Zonnouri - Department of Chemical and Petroleum Engineering, Islamic Azad University, Masjed Soleyman Branch,Masjed Soleyman, Iran

In this study, solvent activity of polymer solution has been predicted by Thermodynamics model.The excess Gibbbs energy of non-aqueous polymer solutions is expressed as a sum of contributions of a combinatorial and a residual excess Gibbs energy term. The truncated Freedcorrection to Flory-Huggins expression based on the local composition concept, which is the NRTL,Wilson and UNIQUAC models is developed to account for the contribution of residual excess Gibbs energy. The utility of the model is demonstrated with the successful representation of thevapor-liquid equilibria of several polymer solutions.The results show that the model is valid for the whole range of polymer concentration from dilute solution up to saturation.

Polymer solutions , Thermodynamics model, The excess Gibbbs energy ,Solvent activity