Study on Thermal Oxidation and Viscosity Degradation for Synthetic Aviation Lubricant Fluids

Abstract

The thermal oxidation and viscosity degradation for poly-α-olefins (PAO) and di-esters (DOS) was studied under the GC/MS investigation. Through the oxidative pyrolysis conditions, these two synthetic base fluids were characterized to get their simulated "areo-engine" conditions' for thermal stability, such as oxidative and kinematic viscosity variation. The experimental results suggests that the oxidation products generated from oxidation reactions of DOS is mainly single esters, di-esters, ketone, ether, organic acids and alcohol, which results much bigger total acid values than that of PAO treated in similar conditions. The substantial increment of the kinematic viscosity of DOS reveals its limited thermal oxidation stability compared to PAO.