PDSC法研究在用汽油机油氧化安定性

用高压差示扫描量热（PDSC）程序升温法和恒温法对在用汽油机油的氧化安定性进行了研究。结果表明随着行车里程数的增加,在用汽油机油的起始氧化温度（Ton）和氧化峰值（Tp）不断降低,氧化诱导期时间（OIT）不断缩短,这一结果与油品酸值的增加趋势和碱值的降低趋势相符,均反映了油品在行车试验中的氧化衰败过程。因此PDSC程序升温法和恒温法均可用于在用汽油机油的氧化安定性评价,但是程序升温法与恒温法相比,具有测试条件选择简单的优势,故在对在用汽油机油的氧化安定性进行评价时推荐使用程序升温法。

Evaluation on Oxidation Stability of the Used Gasoline Engine Oil by PDSC

Oxidation stability of the used gasoline engine oil was studied by isothermal and programmed ramp methods of Pressure Differential Scanning Calorimetry(PDSC).The result showed that the oxidation onset temperature(Ton),oxidation peak temperature(Tp) and oxidation induction time(OIT) reduce with the increase of mileage.These results are consistent with the change trend of the basic number and acid number,which indicate the isothermal method and programmed ramp method are effective in oxidation stability evaluation.Moreover,comparing with the isothermal method,the programmed ramp method has the advantage of simple test conditions.Thereby,the programmed ramp method is recommended when oxidation stability is evaluated by PDSC.