Thermodynamic study of poly(ethylene glycol) in water/acetone solutions by viscometry

In this work, the intrinsic viscosities of poly(ethylene glycol) (PEG) with a molar mass of 20,000 g.mol(-1) were measured in water/acetone solutions from (283.1 to 313.1) K. The expansion factors of the polymer chains were calculated from the intrinsic viscosity data. The thermodynamic para meters (entropy of dilution parameter, the heat of dilution parameter,. temperature, polymer-solvent interaction parameter and second osmotic virial coefficient) were derived by the temperature dependence of the polymer chain expansion factor. The thermodynamic parameters indicate that mixtures of water/acetone are changed to the poorer solvents for PEG, by increasing temperature and volume fractions of acetone. Also, the temperature dependency of segment-segment and segment-solvent interactions for PEG in mixed water/acetone, is decreased by increasing volume fractions of acetone.