A potential approach to replace sulfurized olefins with borate ester containing xanthate group in lubricating oil

To develop a potential substitute for sulfurized olefins, a borate ester derivative containing xanthate group (titled BXT) was synthesized and characterized. Meanwhile, its tribological properties in rape-seed oil were evaluated using four-ball tribometer. The results indicate that BXT shows excellent tri-bological capacity such as load-carrying, friction-reducing and antiwear property. Moreover, the syn-thesized compound has no noticeable odor, shows little corrosion to copper, and exhibits better ther-mal stability compared with sulfurized olefins. In order to study the action mechanism of BXT in friction process, analysis of the worn surface was carried out using a three-dimensional non-contact surface profilometer and XPS analyzer.