Film-Forming Properties of Blends of High-Oleic Sunflower Oil with Polyalkyl Glycol

The viscosity, density, and elastohydrodynamic film thicknesses of oil-soluble polyalkyl glycols (PAG), high oleic sunflower oil (HOSuO), and their 50/50 (wt.%) blends were investigated. The viscosity and density of the blends were found to be predictable from the corresponding neat oil properties using simple mixing rules. Pressure-viscosity coefficients (PVC) of HOSuO, the two PAGs, and the two 50 wt% HOSuO/50 wt% PAG blends were calculated from measured film thickness data using the Hamrock-Dowson method and compared to values estimated from literature data. Literature pressure-density and viscosity-temperature data for oils with high-oleic acid group content were analyzed using the Tait and Casalini et al. models. Viscosity versus pressure data obtained from these analyses was used to calculate PVC using the Barus and Bair et al. models. The PVC values calculated from the literature data following this procedure showed reasonable agreement with that from film thickness data from this work.