A new segmental local composition model for calculation of thermodynamic properties of binary polymer solutions

A new local composition model, Segmental-Wilson-Non-Random Factor (SWilson- NRF), based on volume fraction is developed. The new activity coecient model consists of the combinatorial (entropy) Flory-Huggins term and the residual (enthalpy) S-Wilson-NRF term. This model, for non-polymeric systems, reduces to nonelectrolyte- Wilson-NRF model. The present model with two dependent adjustable energy parameters is applied to correlation of the activity of solvent for 24 binary polymer systems at various number-average molar masses of polymer and temperatures. Moreover, the results of the present model are compared with the other local composition models such as None-random Two-Liquid (NRTL), NRTL-None-random Factor (NRTL-NRF) models and the Flory- Huggins  model. Finally, the new model is applied for correlation of the excess molar enthalpy of the binary polymer solutions at dierent conditions. As a conclusion, the results of the new model are in good agreement with the experiment.