Effects of Modified Graphene Additives on Dispersion Stability and Wear Resistance of Lubricating Oil

To investigate the synergistic effect of oleic acid modification and dispersant on the dispersion stability and wear resistance of graphene in base oil. Modified graphene was prepared by using oleic acid as surface modifier and T161 as dispersant. The microstructure of graphene was characterized by SEM and Raman. The effects of oleic acid modification and dispersant T161 on the dispersion stability of graphene were investigated, and the optimal addition amount of T161 was determined. At the same time, the optimum amount of modified graphene was determined by MMU–10 testing machine. And the feasibility of modified graphene in finished lubricating oil was studied. The feasibility of modified graphene in finished lubricating oil was also studied. The results showed that T161 with the addition level of 0.5wt% had the best synergistic effect with oleic acid modification, and there was no obvious precipitation after standing for one week. The sample of modified graphene with 0.075wt% +0.5%T161 showed the best anti-wear effect with a friction coefficient of 0.52. Compared with the finished lubricating oil, the friction coefficient is increased by 26.9%. The results of graphene dispersion stability analysis showed that the synergistic effect of oleic acid modification and dispersant T161 could greatly improve the dispersion stability of graphene in base oil. Graphene added lubrication mechanism for modified graphene particles to fill pits and the presence of adsorption film. Modified graphene will not improve the antiwear and antifriction effect of the finished lubricating oil. The addition of modified graphene destroys the original stability of the lubricating oil.