ARS | Publication request: EP Additive Performance in Biobased vs. Paraffinic Base Oils

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 4, 2009
Publication Date: September 6, 2009
Citation: Biresaw, G., Asadauskas, S.J., McClure, T.G. 2009. EP Additive Performance in Biobased vs. Paraffinic Base Oils. Proceedings of the World Tribology Congress, Kyoto, Japan, Sept. 7-11, 2009.

Technical Abstract: A series of commercial extreme pressure (EP) additives containing sulfur, phosphorus, and chlorine were investigated for their EP properties in soybean (SBO) and paraffinic (PRFN) base oils. The investigations were conducted using a 4-ball (4B) and twist-compression (TC) tribometers. The concentrations of the EP additives in the two types of base oils were also varied. TC tests were conducted as a function of time under starved lubricant film conditions, at fixed contact pressure and speed, until lubricant failure was observed. 4B tests were conducted as a function of load, at constant speed and time, until lubricant failure was observed. The results showed that the EP additives displayed superior performance in SBO than in PRFN base oil. Thus, a formulation with 5% EP additive in SBO performed equal to or better than a formulation with 20% of the same EP additive in PRFN base oil. Analysis of test data prior to lubricant failure indicated that SBO was more effective than PRFN in delaying the onset of the high friction and, hence, the high temperature required to trigger the EP tribochemical reaction.