STATISTICAL THERMODYNAMICS OF ASSOCIATED POLYMER-SOLUTIONS

The lattice-fluid theory for polymer solutions has been modified to account for strong interactions (hydrogen bonding) between the polymer and solvent. The resultant model is an equation-of-state model able to describe thermodynamic properties of these systems over an extended range of external conditions from the ordinary liquid state up to the critical or supercritical state. The general case is treated where the solvent self-associates and cross-associates with the polymer. The model has been tested against consistent sets of experimental data on vapor pressures, heats of mixing, and volumes of mixing of chloroform + polyether solutions. It is shown that the model is able to predict the sigmoidal-shaped isotherms characteristic of these systems.