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 different conditions. as a conclusion, the results of the new model are in good agreement with the experiment.