Thermodynamic study of poly(ethylene glycol) in water/1-propanol solutions by viscometry

One of the most important transport properties in polymerization processes is the viscosity of polymer solutions. The viscosity of mixtures that contain polymers is much more difficult to predict than the viscosity of mixtures with low molecular weight components [1]. In this work, the intrinsic viscosities of poly(ethylene glycol) with molar mass of 20 kg∙mol-1 were measured in water/1-propanol solutions from (283.1 to 313.1) K. The expansion factors of the polymer chains were calculated from the intrinsic viscosity data. The thermodynamic parameters (entropy of dilution parameter, the heat of dilution parameter, theta temperature, polymer-solvent interaction parameter and second osmotic virial coefficient) were derived by the temperature dependence of the polymer chain expansion factor [2]. The thermodynamic parameters indicate that mixtures of water/1-propanol are changed to the poorer solvents for poly(ethylene glycol) by increasing temperature [3]. Also the thermodynamic parameters indicate that the quality of mixed water/1-propanol for poly(ethylene glycol) is less than pure water.