The Preparation Of Sulfur-and-phosphorus-free Molybdenum Compounds And The Assessment Of Their Antioxidant And Anti-wear Functions

Zinc dialkyl dithiophosphate (ZDDP) is a multifunctional lubricant additive. Phosphorus is harmful to the catalytic converter and sulfur oxides causes air pollution. There is an urgent need to develop sulfur-and-phosphorus-free compounds with antioxidant and anti-wear functions to replace ZDDP. In this study, molybdenum compounds were synthesizedby several vegetable oils, diethanolamine, and molybdenum source infoursynthetic routes. After comparing the four routes, one of them was selected to further study. By optimizing the ratio of raw materials and synthesis conditions, the molybdenum contents of the product and their solubility in oil were improved. The molybdenum levels is1.00～6.47w%. The structurewas measured by FT-IR. The lubricant with sulfur-and-phosphorus-free compoundswere testedtheir oxidation stability byGB/T12581and DSC methods. Results show that the molybdenum compounds can increase both oxidation induction period and oxidation initial temperature of lubricants, which means the molybdenum compounds have good inhibition of oxidation. The anti-wear propertywas tested byFourBall testing. The maximum nonseizure load PB, the wear scar diameter, the SEM images and the EDS spectrum diagram show that the molybdenum compounds have anti-wear performance.