Synthesis, Characterization And Lubrication Performance Of N,S-containing Compounds As Lubricant Additive

As the main part of lubrication oil, extreme pressure antiwear additives play a very important role in protecting machinery and equipment. In boundary lubrication, additives adsorb on metal surface and react with metal to form protective films to reduce the metal-metal contact. With the growing concern of environmental issues, high cost-effective and environment-friendly lubricant additives are attracting a considerable amount of research effort. At present, additive industry in our country is still in a weak position, especially in research and development of the fine chemical, industrial scale, the advanced nature of independent intellectual property rights and research of environment-friendly additives, etc. So it has practical significance to synthesize environment-friendly multifunctional lubricant additives and study their tribological performance.First, on the basis of non-toxic, three categories of additives were prepared with cheap raw materials and these additives were oxadiazole, dithiocarbamate and xanthate derivatives; Their molecular structure was identified by means of 1H NMR, 13C NMR, IR and UV-vis.Second, additives were added to liquid paraffin (LP) by different mass fractions, than their physical and chemical properties were evaluated. The results showed that: the additive had good oil-soluble properties when the concentration was 1.0% and 2.0%; the copper corrosion standard of additives were 1a when their concentration was 3.0%; the additive possessed the similar level of antioxidation performance with ZDDP when the concentration was 1.0%. Thermal stabilities were conducted and all additives started to decompose above 225 oC, which indicated that they could be used as conventional lubricating oils in generic status.Finally, the tribological behavior of the additives and their complex system in LP were evaluated with a four-ball machine. The results showed that compared with ZDDP, oxadiazole and dithiocarbamate derivatives had better extreme pressure (EP) and antiwear (AW) performance, but xanthate derivatives had better EP and commen AW performance. Under certain conditions, the complex system possessed the best synergies in AW and EP.