Synthesis and tribological studies of some s-triazine derivatives as environmentally compatible lubricating oil additives

To find some novel ashless, low-phosphorus multifunctional environmentally compatible lubricating oil additives, a series of s-triazine derivatives were synthesized, and their tribological properties as additives in mineral oil, rapeseed oil, and synthetic oil were evaluated using four-ball test machine. The trialkylthiotriazine derivative (OTT) improved the load-carrying capacity of liquid paraffin significantly, but also reduced friction and wear of liquid paraffin significantly. In the sliding process, sulfur contained in OTT reacted with the metal surface and generated FeSO₄ and FeS, while N element in OTT was mainly absorbed in the metal surface as an organic state. The s-triazine bis(dialkyldithiocarbamatyl) derivatives possess high thermal stability and good oil solubility in mineral oil or rapeseed oil. This kind of derivatives had good anticorrosion properties, excellent load-carrying ability, and friction-reducing capacity in rapeseed oil, but did not show good antiwear and antioxidant performance in rapeseed oil. However, such additives show good antiwear and antioxidant performance in hydrotreated base oil. The thiophosphate-containing bis(alkyloxy)-s-triazine derivatives as additive in the rapeseed oil could greatly improve the load-carrying capacity, the antiwear properties and friction reduction properties. This is an abstract of a paper presented at the 11th Annual Fuels and Lubes Asia Conference (Beijing, China 3/15-18/2005).