Physicochemical Characterization of the Synthetic Lubricating Oils Degradation under the Effect of Vehicle Engine Operation

The degradation analysis of three categories the synthetic lubricating oils during operation of the vehicle engine was undertaken according the number of kilometers covered, using the evaluation of viscosity, basicity, pour point, flash point, formation of heavy metals from the engine abrasion phenomena, that will detect by inductively coupled plasma optical emission spectrometry (ICP/OES), and the differentiation of the chemical composition of virgin and degraded lubricating oil using gas chromatography associated with mass spectrometry (GC/MS). These analyzes reveal the regular decrease of the viscosity, the basicity, the flash point and the significant evolution of the iron and lead content and the formation of polycyclic aromatic hydrocarbons. Thus, the important degradation of the additives tends to thicken the lubricating oil and consequently the continuous increase in the pour point.