Autoxidation is a set of spontaneous oxygen-mediated radical reactions common to degradation processes of all hydrocarbon-based materials. In this work, EPR (electron paramagnetic resonance) spin-trapping technique was used to study radical species involved in the autoxidation of a sample of synthetic base oil. A sample of polyalphaolefin base oil was aged at 140°C in the presence of oxygen and the difference in the tendency to generate radical species between the aged and non-aged samples of the same base oil was investigated using DMPO (5,5-dimethyl-1-pyrroline N-oxide) spin-trap. The ageing was performed in such a way that a small amount of hydroperoxides, the primary and key intermediate in autoxidation reactions, accumulated in the sample. Subsequently, the degradation of hydroperoxides was triggered by three different means: thermal treatment, introduction of soluble transition metal ions, and UV irradiation. Radical intermediates were monitored by EPR spin trapping; mixtures of peroxyl, alkoxyl, and carbon-centered radicals were detected and their origin was discussed.

自动氧化是一组自发的氧介导的自由基反应，常见于所有基于碳氢化合物的材料的降解过程。在这项工作中，EPR（电子顺磁共振）自旋捕获技术被用于研究参与合成基础油样品自动氧化的自由基物种。聚 α 烯烃基础油样品在氧气存在下在 140°C 下老化，并使用 DMPO（5,5-二甲基-1-吡咯啉 N-氧化物）自旋阱。老化以这样一种方式进行，即在样品中积累少量氢过氧化物，即自动氧化反应的主要和关键中间体。随后，氢过氧化物的降解由三种不同的方式触发：热处理、引入可溶性过渡金属离子和紫外线照射。通过 EPR 自旋捕获监测自由基中间体；检测到过氧、烷氧基和碳中心自由基的混合物，并讨论了它们的来源。