Some Chemical Reactions of Organic Disulfides in Boundary Lubrication

The Tribological Chemistry of the Oil Blends of Zinc Dialkyldithiophosphate with 2-Mercaptobenzothiazole Derivatives

“…6, we see that peak a, about 2472.4 eV and 2472.7 eV, respectively, in spectra [A] and [B], cannot be attributed to any oxidized forms of sulfur as the sulfoxide peak is located at 2475.0 eV [21]. Whereas the peaks associated with alkyl sulfide are located at approximately 2472.8 eV [24], which are very close to these two peaks. The strong shoulder (labeled S) aligning well with spectrum [D] for ZnS suggests that an amount of ZnS present at the sub-surfaces of thermal films.…”

“…It is very clear that MBTT or MBTA has indeed interacted with ZDDP to form new phosphate in the overall antiwear films. with alkyl sulfide is located at approximately 2472.8 eV [24], which is very close to this peak. Due to peak a adjacent to peak b at high energy side, the sulfides in the sub-surface also contain an amount of ZnS.…”

Effects of Sulfur and a Lubricity Improver on the Tribological Characteristics of Si3N4 Ceramics against Steel in Fuel

“…Different sulfur compounds were formed as a result of the difference in the temperature of the rubbing surfaces. Plaza 11 showed that the concentration of organic disulfides in white oil significantly affected the wear and tribochemical reactions of a steel–steel pair in a four‐ball wear test. An increase in the sulfur concentration decreases wear, whereas iron sulfide preferentially forms under severe conditions of lubrication.…”

Application of ToF-SIMS surface analysis to tribochemistry in metal forming processes

“…An enormous literature has been devoted to testing of new potential additives, which is still going on under the pressure of environmental regulations. Based on more and more powerful surface analytical techniques, and more recently nano-mechanical measurements, innumerable papers study the mechanisms and the products of the reactions: ZDDP's (Zinc di-alkyl-dithiophosphates) form thick films of complex organo-metallic polyphosphates [1][2][3][4][5], chlorinated additives result in iron chlorides [6], sulphur-containing additives build anti-seizure iron sulphide layers [7,8], whereas fatty acids form soaps on metallic surfaces [9]. Studies of multi-additivated lubricants have more recently disclosed interactions and synergies [10,11].…”