大豆绝缘油的氧化路径仿真分析研究

Simulation Analysis on Oxidation Path of Soybean Insulating Oil

本文主要通过分子动力学仿真方法,以大豆绝缘油为研究对象,针对其热氧化过程进行分子动力学研究。模拟了大豆植物绝缘油在氧气氛围中、温升情况下油品的氧化分解路径,分析了植物绝缘油的分解产物,进一步计算了植物绝缘油的氧化活化能。结果表明:棕榈酸、油酸、亚油酸3种物质在氧化反应过程中所需的氧化活化能Ea出现依次降低的趋势,说明棕榈酸、油酸、亚油酸这3种物质的热氧化安定性存在差异。根据反应结束后物质的分解和聚合情况可以将高温氧化反应分为氧化分解反应和氧化聚合反应两种类型,高温氧化反应的生成物主要包括氧化甘油三酯、氧化甘油三酯聚合物以及短碳链的甘油三酯及挥发性化合物3种类型,这3种类型氧化产物的生成方式各不相同,但是所用到的化合物种类却较为相似。氧气在大豆油中容易扩散,植物绝缘油脂肪酸对油品抗氧化性能的影响规律为棕榈酸>油酸>亚油酸,越不饱和的脂肪酸越容易被氧化。

In this paper,the thermal oxidation process of soybean insulating oil was studied by molecular dynamics simulation.The oxidative decomposition path of soybean insulating oil in oxygen atmosphere and temperature rise was simulated.The decomposition products of vegetable insulating oil were analyzed,and the oxidation activation energy of vegetable insulating oil was calculated.The results show that the oxidation activation energy Eaof palmitic acid,oleic acid,and linoleic acid required for the oxidation reaction decreases in turn,indicating that there are differences about the thermal oxidation stability of palmitic acid,oleic acid,and linoleic acid.According to the decomposition and polymerization of substances after reaction,the high temperature oxidation reaction can be divided into two types:oxidative decomposition reaction and oxidative polymerization reaction.The products of high temperature oxidation reaction mainly include oxidized triglyceride,oxidized triglyceride polymer,and short carbon chain triglyceride and volatile compounds.The formation modes of these three types of oxidation products are different,but the types of compounds used are similar.Oxygen is easy to diffuse in soybean oil,and the effect of fatty acids from vegetable insulating oil on the antioxidant properties of soybean oil from high to low is palmitic acid,oleic acid,and linoleic acid.The more unsaturated the fatty acids,the easier they are oxidized.