Application of inverse gas chromatography to the examination of annealing processes of semi-synthetic base oils

The Flory-Huggins chi1,2infinity parameter and solubility parameter delta2 determined by means of inverse gas chromatography (IGC) were successfully used in the physicochemical characterisation of oxidation products of mineral oil-poly-alpha-olefin mixtures. Application of IGC parameters allows one to examine the changes occurring during three different oxidation procedures: classical oxidation in a stainless steel reactor, in a GC column and separate oxidation of the mixture's components. Changes in chi1,2infinity values reflect the changing affinity of mixtures to different types (dispersive, polar, hydrogen bonding) of intermolecular interactions and their potential miscibility and solubility.