Tribological evaluation of S-(1H-benzotriazole-1-yl) methyl N,N-dialkyldithiocarbamates as additives in rapeseed oil

Three S-(1H-benzotriazole-1-yl) methyl N,N-dialkyldithiocarbamates were synthesized and their tribological behaviors as additives in rapeseed oil (RSO) were evaluated using a four-ball tester. Thermal degradation tests were conducted to identify their thermal stabilities using thermogravimetric analyzer (TGA). The worn surface of the steel ball was investigated by X-ray photoelectron spectroscopy (XPS). The results indicate that the additives possess excellent load-carrying abilities and high thermal stabilities, but have no antiwear and friction-reducing properties. Based on the results of XPS analysis, it can be seen that tribochemical reactions occur between the synthesized compounds and metal surfaces during the sliding process.