Abstract: A multifunctional extreme pressure antiwear additive (MEAD) for gear oil was synthesized using phosphorus pentoxide, alkyl alcohol and polyisobutene succimide as raw materials. The structure of the additive was determined by FT-IR, its oil solubility, anti-corrosive capability, sludge dispersion and tribology performance were tested by oven oxidation, four-ball and SRV tests, as well as compared with conventional extreme pressure antiwear additive. Test results indicate that MEAD additive holds excellent performance of antirust, sludge dispersion, load bearing, anti-wear and friction reducing stability.

Key words: multifunction, EP/AW additive, sludge dispersion, stability of friction