Determination of thermodynamic properties of poly (2-hydroxy ethyl methacrylate) at infinite dilution by using inverse gas chromatography

Some thermodynamic quantities were obtained for the interactions of poly (2 -hydroxy ethyl methacrylate) (PHEMA) with alcohols, ketones, acetates, arom atics and n-alkanes by the inverse gas chromatography method in the tempera ture range of 130-150 degreesC. The specific retention volumes, Vg degrees, weight fraction activity coefficients of solute probes at infinite dilutio n, Omega (infinity)(1) Flory-Huggins thermodynamic interaction parameters, chi (infinity)(12), between polymers and solvents, the partial molar free e nergy, DeltaG(1)(infinity), the partial molar heat of mixing, DeltaH(1)(inf inity), were determined. All the liquids were found to be nonsolvents for p oly (2-hydroxy ethyl methacrylate) at 130-150 degreesC. The solubility para meters for PHEMA at infinite dilution were found by plotting the graph of [ (delta (2)(1)/RT) - chi (infinity)(12)/VI] versus solubility parameters, de lta (1), of these probes. The solubility parameter values of PHEMA found fr om both the slope and intercept in Fig. 2 are 6.24 (cal/cm(3))(0.5) and 7.0 8 (cal/cm(3))(0.5) at 140 degreesC.