The effect of molecular composition of naphthenic mineral oil on the glass transition temperature

Differential scanning calorimetry (DSC) has been applied to analyze the glass transition temperature of refined hydrogenated naphthenic mineral oils. The impact of the aromatic content and the degree of hydrogenation have been studied. A change in aromatic content for refined hydrogenated mineral oils was found to give only a limited impact on the glass transition temperature of the oil. A silica gel separation was conducted and by using the hereby obtained fractions as components in the Fox equation, the glass transition temperature was calculated. The calculated values for the oils are in agreement with the values obtained in the DSC measurement. The aromatic content and the viscosity of mineral oils influence Tg. However, for the oils in this study, the change in Tg was small for relatively large changes in aromatic content.