Abstract:By using the technique of differential scanning calorimeter (DSC),the dynamic and static oxidative tests were carried out for three kinds of ester oils after reacting with different temperature and different time,which are Di (2ethylhexyl) sebacate of aviation lubricating base oil,50-1-4φ aviation lubricating oil and base oil added with antioxidant.By analyzing the heat flow curves,the incipient oxidation temperature (OIT) and oxidation induction time (OIT) of the different oil samples were obtained,and the thermal oxidation stability of the samples before and after adding antioxidant was evaluated.The results show that the IOT and OIT of the three kinds oil samples are in the range of 206 ℃ to 255 ℃ and 12 min to 31 min.With the increasing of the initial reaction temperature and the extension of reaction time,the IOT and OIT show a general downward trend,that is decreasing firstly,then increasing and decreasing finally,indicating that the oxidation stability of the oil samples becomes worse after the reaction at higher temperature and longer time.The variation of OIT is consistent with IOT,which indicates the evaluation result is basically the same by using the two indexes to evaluate the oxidation stability of oil samples.After the addition of antioxidant,the IOT of the samples of base oil shows an increasing trend,which indicates that the antioxidant improves the oxidation stability of the base oil.For the oil samples of 50-1-4φ,because of the synergistic effect of many kinds of additives,the oxidation stability of the oil product is further improved compared with the oil sample with single antioxidant.