Abstract: Synthetic hydrocarbon aviation lubricating oil was oxidized at different temperatures (180 ° C, 200 ° C, 230 ° C, 250 ° C, and 300 ° C) with metals Cu and Fe as catalysts in a high temperature oxidation accelerator. The kinematic viscosity, acid value and pour point of the oil after reaction were measured, and the correlation coefficient between the three was calculated by the binary correlation method. The compositions of oxygenated oils were analyzed by GC/MS. Three rules are found: (i) highly negative correlations between kinematic viscosity and acid value, kinematic viscosity and pour point; highly positive correlation between acid value and pour point; (ii) highly positive correlation between relative contents of n-alkanes, iso-paraffins, olefins and other compounds and changes of the acid value and pour point after oxidation, but highly negatively correlated with the change of kinematic viscosity; and (iii) highly negative correlation between the relative contents of DIOA and antioxidants and the changes of the acid value and pour point of the oil after oxidation, but highly positively correlated with the change of kinematic viscosity.

Key words: aviation lubricating oil, high temperature oxidation, correlation, composition analysis.