Antioxidant is the key additive that protects the lubricating oils from oxidative degradation, allowing the oil to meet the demanding requirements for use in industrial applications. Hindered phenolic antioxidants belong to the most effective antioxidants acting as radical scavengers. Sterically hindered phenolic antioxidants, because of their high antioxidation efficiency and low color contribution, are getting more attention on lubricating oils. Also, another advantage of low toxicity extends the extensive application of these antioxidants.
The research group headed by Prof. Wumanjiang Eli at Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences (XTIPC) has developed an efficient and flexible route for the synthesis of ester-phenolic antioxidant. In the present study, phenolic antioxidative group was introduced into dipentaerythritol isostearate, and a liquid ester-phenolic antioxidant was obtained.
Firstly, higher molecular weight reduces the volatility, which allowed these products to be applicable under high temperature conditions. The volatility and thermal stability were tested by Thermogravimetric (TG)/Differential Scanning Calorimetry (DSC). On the other hand, increasing alkyl chains can improve the solubility in lubricating oils. The antioxidation properties of this liquid ester-phenolic antioxidant were investigated by Rotary Bomb Oxidation Test. Another advantage of this liquid antioxidant is that it can act as antioxidant-modified synthetic ester, a lubricating base oil of excellent lubricant properties.
The results have been published online in Lubrication Science.This work was supported by the National Key Technology R & D Program.
