Tribological Behavior of Plant Oil-Based Extreme Pressure Lubricant Additive in Water-Ethylene Glycol Liquid

摘要

A water-soluble lubricant additive(RSOPE)was prepared by esterification reaction using fatty acid from rubber seed oil.The RSOPE was added into water-ethylene glycol(W-EG)solution as lubricant additive.Dispersion stability and rheological properties were investigated.We used a four-ball tribotester to assess the lubrication performance of W-EG based fluid with the RSOPE additive.The stainless-steel surface was analyzed using scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).Good dispersion stability was observed in the RSOPE/W-EG solutions.Furthermore,non-Newtonian fluid behavior at low shear rates and Newtonian fluid behavior at high shear rates was exhibited.The addition of RSOPE into water-glycol reduced the friction coefficients(COF)and wear scar diameters(WSD).The maximum non-seizure loads(PB)increased from 98 N to 752 N and the W-EG solution with RSOPE had good corrosion resistance properties.Good tribological performances for W-EG solution with RSOPE were attributed to the boundary tribofilm composed of iron oxide,iron phosphide and so on.