A study of 2-(dibutylaminomethyl)-thiobenzimidazole as an oil additive

A Mannich condensation compound of 2-(dibutylaminomethyl)-thiobenzimidazole was synthesized and its antiwear (AW) behavior as an additive in a paraffinic base oil was evaluated using a four-ball tester. To investigate the role of scavenging free hydrogen radicals of the novel compound, a thermal degradation test was conducted using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA) (commercialism). The nature of the film formed on the rubbed surface was investigated by X-ray photoelectron spectroscopy (XPS) analysis. On the basis of the experimental results, the novel additive showed good AW ability and good thermal stability. The results of XPS analyses illustrate that the prepared compound as an additive in paraffinic base oil forms a protective film containing ferric sulfide, ferric sulfate and compounds containing sulfur and nitrogen on the rubbed surface.