Prediction of mutual diffusion coefficient in polymer solution

The solvent chemical potential derivative (i.e. (partial derivative mu(1)/p artial derivative omega(1))(T,P)) is derived from the thermodynamic relatio n and mutual diffusion coefficients (D) are calculated with original UNIFAC -FV (Model 1) and the modified UNIFAC-FV (Model 2) without any assumption o r simplification. Model 1&2 proposed in this work well correlate the experi mental data of mutual diffusion coefficients in PIB/solvent systems and PMS -BR copolymer/solvent systems. It is shown that Model 1&2 are alternative t ools to Flory-Huggins method for predicting mutual diffusion coefficients i n polymer/solvent systems over wide ranges of temperature and concentration without any assumption. (C) 2000 Elsevier Science Ltd. All rights reserved .