The tribological behaviours of dithiocarbamate‐triazine derivatives as additives in mineral oil

Ashless and non-phosphorus hydroxyl-containing dithiocarbamate-triazine compounds,2,4,6-tri[N,N-di-i-octyldithiocarmate-(2′-hydroxyl)-propionylthio]-1,3,5-s-triazine (LDION) were prepared and their tribological behaviour as additives in mineral oil were evaluated using a four-ball tester. Thermal degradation tests were conducted to identify their thermal stabilities using a thermo-gravimetric analyser. The worn surfaces were investigated by X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES) spectroscopy. The results indicate that the additive LDION possesses high thermal stabilities and good load-carrying capacities. Moreover, it has good anti-wear property at all test concentration and under all test loads. The results of XPS and XANES analyses illustrate that the prepared compounds as additives in mineral oil forms a protective film containing oxidised compounds and organic nitrogen-containing compounds and inorganic sulfate on the metal surface during sliding process. Copyright © 2008 John Wiley & Sons, Ltd.