Thermal stability enhancement mechanism of engine oil using hybrid MoS2/h-BN nano-additives with ionic liquid modification

Abstract One of the primary causes of lubricating oil failure in automobile engines is thermal degradation caused by high temperatures, which prejudices the lube oil capacity between friction pairs. This research aims to comprehensively investigate the effect of the h-BN/MoS2 hybrid nanoparticles and ionic liquid (IL) on the thermal performance of engine oil (5 W-40). The rheological results showed that nanolubricants (NL) behave like non-Newtonian fluids and IL promoted the viscosity value of lubricant due to the extension of alkyl chains. The thermal peculiarities of lube oil were analyzed by thermogravimetric (TGA/DTG/DSC) analysis to explore the thermal stability of h-BN/MoS2 hybrid nano-lubricants modified by IL and further revealed how IL improved the thermal characteristics. The results strongly showed the synergistic effect between the IL and h-BN/MoS2 hybrid nanoparticles produces a complicated interaction at high temperatures, forming a layer of film which can delay the erosion of high temperature on the surface of the nanoparticles. Ultimately, this study revealed a delay of burnout temperature in thermal degradation by approximately 8.1% under the use of hybrid nano-lube oils in a wide temperature range.