Synthesis of ploy(p-methoxyphenol) and evaluation of its antioxidation behavior as an antioxidant in several ester oils

• Ploy(p-methoxyphenol), denoted as PMOP, was synthesized as an antioxidant.
• PMOP has good antioxidation performance at high temperature.
• PMOP has better antioxidation ability than several hindered phenolic antioxidants.
• PMOP does not hurt the anticorrosion and tribological properties of base oils.
• Possible working mechanism of PMOP is discussed.

Ploy(p-methoxyphenol), denoted as PMOP, was synthesized via an enzymatic polymerization method with p-methoxyphenol as the monomer. The corrosion resistance, tribological properties and thermal stability of as-synthesized PMOP were examined. The antioxidation behavior of as-synthesized PMOP as an antioxidant in ester oils was evaluated by rotary oxygen bomb test and pressurized differential scanning calorimetry. It was found that PMOP exhibits excellent antioxidation ability at 150 °C and 210 °C in various base oils. Besides, PMOP has much better antioxidation ability in synthetic ester oil like di-iso-octyl sebacate than several commonly used commercial hindered phenolic antioxidants.