Synergistic and antagonistic effects on oxidation stability of antioxidants in a synthetic ester based oil

Synergistic and antagonistic effects have been observed with the four sulfur-, phosphorus- and heavy metal-free antioxidants, hindered bis-phenol, octylated diphenylamine, octylated phenyl-alpha-naphthylamine and tolutriazole derivative, on the oxidation stability, thermal and physicochemical properties of dioctyl sebacate oil. The oxidation stability was evaluated using a rotary bomb oxidation tester. The results from isothermal and catalytic RBOT oxidation tests suggested that ODPA has an antagonistic effect on the OIT. The combination of HP:OPANA:TZ exhibited the highest and most synergistic antioxidant activity. Furthermore, synergism was observed in terms of both oxidation and thermal stabilities through thermogravimetric analysis (TGA).

Research Highlights▶This manuscript deals with the investigation of oxidation stability of ester based oil after blending with various types of antioxidants using RBOT. ▶Synergistic and antagonistic effects of added antioxidants, thermal stability as well as relevant physicochemical properties are also investigated. ▶The co-addition of antiwear to enhance Tribological property is also reported. ▶This paper should be interested by people who work on lubricating oil, especially, ones who work on lubricants for fluid dynamic bearing.