Comparison of antiwear properties of titanium-containing compounds

In search for environmentally friendly lubricant additives, titanium 2-ethylhexanoate and titanium oleate, which titanium compounds soluble in white oil, have been synthesized, as well as titanium dioxide nanoparticles modified with tetra-(2-ethylhexyl)thiuram disulfide and di(2-ethylhexyl)thiophosphonodisulfide. These titanium compounds have been characterized by elemental analysis, thermogravimetry, and IR spectroscopy. By means of the small-angle X-ray scattering technique, it has been found that the TiO2 nanoparticles have a size of 1–10 nm. Evaluation of antiwear properties of titanium compounds on a ChS-hMT-1 tribometer in a white oil solution shows that the decrease in wear scar diameter is 38–49% compared with the white oil. Analysis of the friction surfaces by atomic-force microscopy and X-ray microanalysis has shown a decrease in roughness of the friction surface caused by the presence of titanium atoms in the surface layers.