Measurements of the Interactions between Polyethylene Glycol and Organic Compounds by Gas Chromatographic Technique

Abstract

Abstract A gas-liquid chromatographic technique was employed to measure the thermodynamic properties of the solutions consisting of polyethylene glycol (PEG) and some organic compounds. Three kinds of PEG with different molecular weights were used as a stationary liquid, and six kinds of organic compounds as a solute. For most of the compounds examined, the retention volume varied with the sample size injected. By using the retention volume at an infinitesimal sample size, thermodynamic properties of organic compounds at infinite dilution in PEG, such as the activity coefficient based on weight fraction, Henry coefficient based on weight fraction, and the partial molar excess enthalpy, were determined. From the results it was found that the particular interactions between organic compounds and PEG such as the hydrogen bond formation is not significant, and the solutions can be regarded as a regular solution. The solubility parameters of PEG-600, -1000, and -4000 at 67.3 °C were found to be 10.0, 9.8, and 9.5, respectively.