Abstract: Based on the structural characteristics of cardanol, the molecular structure of environment-friendly antioxidant was designed. A new structure of phenolic antioxidant was synthesized by epoxidation and tert-butylation of cardanol. The structure of the synthesized antioxidant was characterized by F-T infrared spectroscopy and ¹³C-NMR spectroscopy, and its application in different base oils was investigated. The antioxidant properties and compatibility with amine antioxidants were studied. The results showed that the molecular structure of the synthesized phenolic antioxidant was 2-tert-butyl-5-epoxypentadecylphenol; in different types of lube base oils, especially in ester base oils, the synthesized antioxidant had good antioxidant performance. Besides, in dioctylsebacate, the synthesized antioxidant had good compatibility and synergistic effect with amine antioxidant, which was suitable for use as lubricating oil / grease additive.

Key words: cardanol, lubricating oil and grease, environment friendly, antioxidant, oxidation resistence