Variable-pressure infrared studies on the molecular flexibility of the model lubricant 2-ethylhexyl benzoate (EHB)

Abstract

We report a liquid-phase high-pressure infrared study of the model lubricant 2-ethylhexyl benzoate (EHB) between 0 and 40 kbar (at ambient temperature). Changes in band position and bandwidth have been interpreted in terms of in-chain and lateral chain interactions with a net increase in the importance of repulsive potentials and an increase in the distribution of molecular environments. Although changes in the proportion of gauche conformers in the hydrocarbon chain would be expected at higher densities, evidence of such changes are difficult to find in the infrared spectrum.