Synthesis, Characterization And Properties Of Novel Heterocyclic Compounds Containing Nitrogen And Sulful As Lubricant Additives

There has been a growing concern for the use of environmentally friendly lubricants because of the worldwide interest in environmental issues. The specially formulated lubricants with additive packages are largely used to reduce the wear and friction of these machines.In recent years, with the strict requirement on operation conditions and environmental protection, there are new requests on the development of lubricating oil additives such as without phosphor, metals, or chlorine contained in additives, Therefore, the development of new lubricating oil additives aroused great attention , such as ashless, multifunctional, reducing environmental pollution lubricating oil additives. It has been reported that large amounts of new multifunctional lubricant additive are heterocyclic compounds containing N element, which are consisted of extreme pressure element and heterocyclic group containing N, S. Heterocyclic compounds with compact structure are widely used as extreme pressure additive, anti-wear additive, antioxidant additive and metal-blunt additive. Especially Heterocyclic compounds have good extreme pressure (EP) and anti-wear (AT) properties, which improved load of the lubricating oil greatly, meanwhile they have good anti-corrosion properties, eviedently Heterocyclic compounds are bright future multifunctional lubricant additive.In this paper, 31 compounds of containing N or S lubricating oil additives were synthesized. Their synthetic conditions were investigated. Moreover, molecular structures of the compounds were characterized by 1H NMR, 13C NMR, IR and UV.Their dissolution in liquid paraffin and crossive properties were studied. Most compounds could be dissoluted in liquid paraffin with 1.0% weight, and show crossiveless for sheet corpper. Derivatives started to thermally decompose above 150℃, which indicated that they could be used as conventional lubricating oils in generic status. Tribological behavior of new compounds as lubricating additive in liquid paraffin were evaluated on the four-ball tester. The anticorrosion property and thermal stability were also investigated. The worn steel surfaceswere analyzed by means of optical microscope, scanning electron microscope and X-ray photoelectron spectroscopy. The results showed that the novel additive added in the liquid paraffin could greatly reduce the friction coefficient and the wear scar diameter, and enhance the maximum nonseizure load. Meanwhile it exhibited good corrosion resistance and thermal stablility due to tribochemical reaction and formation of the tribo-film, which consisted of ferror oxide/ferrous oxide, organic compound containing nitrogen and metallic chelate containing nitrogen on the worn surface during rubbing.