Vapor Pressure Osmometry and Its Applications in the Osmotic Coefficients Determination of the Aqueous Monomer Glycol and Polymer Polyethylene Glycol Solutions at Various Temperature

Based on the principle and calibration of vapor pressure osmometer and its application in the thermodynamics of the aqueous solutions, the results on aqueous solutions of monomer glycol, PEG 200, PEG 400, PEG 1500 and PEG 2000 over the different concentration range at various temperatures were reported. Using a linear least-square fitting routing, the osmotic coefficients were fitted by a simple polynomial equation. It was found that the relationship between the molar osmotic coefficients (Φ) and the molar concentration (c) of the solutions are in a quite good agreement with the fitted polynomial equation at various temperatures over the different concentration range. The experimental results also show that over the studied concentration range and at various temperatures, the concentration dependence of the molar osmotic coefficients of the aqueous solution systems with the solutes of PEG 200, PEG 400, PEG 1500 and PEG 2000 are totally presented in a rising trend, and their temperature dependence of the osmotic coefficients of the aqueous solution systems of the molar concentration exhibits their own regularities, respectively. The aqueous glycol solution system exhibits the properties of the dilute solution.