Thermodynamic Study of Poly(ethylene glycol) in Water/1-Propanol Solutions by Viscometry

In this work, the intrinsic viscosities of poly(ethylene glycol) with a molar mass of 20 kga <...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 from the temperature dependence of the polymer chain expansion factor. The thermodynamic parameters indicate that mixtures of water/1-propanol become weaker solvents for poly(ethylene glycol) with increasing temperature. Also, the thermodynamic parameters indicate that the solvent ability of mixed water/1-propanol for poly(ethylene glycol) is less than that of pure water.