Investigation of Thermodynamic Properties of SIS, SEBS, and Naphthenic Oil by Inverse Gas Chromatography

The thermodynamic properties of styrene-b-butene/ethylene-b-styrene, styrene-isoprene-styrene, and naphthenic oil, were investigated by means of inverse gas chromatography using 13 different kinds of solvents as the probes. Some thermodynamic parameters such as specific retention volume, weight fraction activity coefficient, Flory—Huggins interaction parameter, partial molar heats of mixing and solubility parameter, etc. were obtained to judge the interactions and the solubility between the polymer and solvents and the solubility of the polymers in these solvents. The results indicated that n-pentane, n-hexane, chloroform, tetrahydrofuran, and diethyl ether were good solvents for these polymers at experimental temperatures. The solubility parameter of styrene-b-butene/ethylene-b-styrene, styrene-isoprene-styrene, and naphthenic oil were calculated to be 16.99, 16.84, 14.39 (J/cm 3 ) 1/2 at 298.15 K by inverse gas chromatography, respectively, which were consistent with that obtained by intrinsic viscosity method, small group contribution method, or solubility parameter-surface tension method.