New Methods to Characterize the Surface and Interface Acid–Base Properties of Some Hydrocarbons by Inverse Gas Chromatography

Abstract

The thermodynamic surface and interfacial properties of some hydrocarbons used as process oils in rubber industry were determined using the inverse gas chromatography technique at infinite dilution. In this paper, four different common process oils, such as distillated aromatic extract, treated distillate aromatic extract, mildly extracted solvate, and hydro-processed naphthenic oil, were studied. An important effect of the temperature on the dispersive component of the surface energy of different hydrocarbons was proved. These hydrocarbon materials exhibit a strong dependency of their surface acid–base properties on the temperature. The specific surface enthalpy and entropy, as well as the acid–base constants KA, KD and the amphoteric constant K of hydrocarbon surfaces, strongly depend on the temperature. It was proved that the hydro-processed naphthenic oil presents the highest acidity relative to other hydrocarbon materials.