Synthesis, Characterization and Tribological Properties of Butoxy Dithiocarbonate Acetic Ester as Lubricating Additives

Three novel butoxy dithiocarbonate acetic esters were synthesized and their molecular structures were determined by H1-NMR,13C-NMR, IR, UV-Vis and elemental analysis. The thermal stability of the target products were also invested by thermogravimetric apparatus (TGA). The tribological behaviors of the novel compounds as lubricating additives in liquid paraffin were evaluated on a four-ball friction and wear tester, The worn steel surfaces were analyzed by means of optical microscope, scanning electron microscope (SEM) and X-ray photoelectron spectrometer (XPS). The results showed that the three novel additives in the liquid paraffin exhibited excellent anti-wear, load-carrying capacities in base stock, which was better than that of ZDDP. The analytical results of the worn steel surface indicated the occurrance of tribochemical reaction and the excellent performance of novel additives due to the formation of a boundary film. The film was composed of ferror oxide, ferrous oxide and organic compound containing sulfur.