Investigation of antiwear additives for diester

Abstract

PurposeThe purpose of this paper is to study tribological properties of two novel additives in the diester and provide adequate information on the relationship between the diester and the additives.Design/methodology/approachThe two 2‐mercaptobenzothiazole derivatives, referred to as BZIA, BZOA, are synthesized with one pot; their tribological performances are evaluated using a four‐ball friction and wear tester, and the worn surface was analysed with scanning electron microscope and X‐ray photoelectron spectroscopy (XPS).FindingsThe two compounds as the additives in the diester possess excellent load‐carrying capacities, rather good anti‐wear (AW) and friction reduction properties. According to the XPS results, both the additives reacted with counter‐face metal and generated a sulphur‐containing inorganic film and a complex adsorption film. The inorganic film obtained with the additive BZOA consisted of FeS2, FeSO4 and Fe2(SO4)3, whereas the inorganic film obtained with the additive BZIA consisted of FeS2 or FeS. The adsorption layer for the two additives contained N‐containing compounds.Research limitations/implicationsThe interaction of the two additives with the diester needs to be further explored.Practical implicationsTwo useful, environmentally friendly, AW lubricating oil additives are synthesized with one pot.Originality/valueThe paper provides a study of some N, S‐containing heterocyclic compounds as environmentally friendly lubricating oil additives.