Abstract: Two kinds of lubricating oil additives containing bisxanthate structure were synthesized and characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (IR), elemental analysis and other technical means. The odor grade, oil solubility, and copper corrosion properties were tested, and the tribological properties in 150N base oil were investigated by a four-ball friction and wear tester. The elemental composition and chemical state of the wear scar surface were analyzed by X-ray photoelectron spectroscopy (XPS). The results showed that both xanthogen polysulfides had good oil solubility and low odor as lubricant additives, and had good copper corrosion properties and extreme pressure and antiwear properties. The antiwear properties of xanthate disulfides were better than those of xanthate polysulfides. The extreme pressure properties of xanthate polysulfides were better than those of xanthate disulfides. The extreme pressure and antiwear properties of both additives were better than that of isobutenyl sulfide under the same conditions.

Key words: polysulfide, xanthate, tribological properties, extreme pressure