Probing the effect of thickener on tribological properties of lubricating greases

To evaluate the effect of thickener on tribological properties of lubricating greases, four multialkylated cyclopentanes (MACs) greases were prepared by using lithium complex soap, polyurea, sulfonate calcium complex soap and polytetrafluoroethylene (PTFE). The physical properties and tribological behaviors of four MACs greases were investigated in detail, the worn surfaces were also investigated for understanding the friction mechanism. The results show that calcium sulfonate complex grease (CSCG) has impressive and comprehensive performance including high dropping point, good thermal and oxidative stability, excellent lubrication behaviors, which is mainly attributed to the nature and structure of thickener and the synergies of grease-film and tribo-chemical reaction film comprised of sulfates and complicated oxides.