Tribochemical Study of Two Ashless Triazine Derivatives as Additives in Rapeseed Oil

Abstract

The ashless 2,4-bis-dipropylamino-6-(O,O’-dibuthyldithio- phosphate)-s-1,3,5- triazine (PrBT) and 2,4-bis-morpholinyl-6- (O,O’-dibuthyldithiophosphate) -s-1,3,5 -triazine (MoBT), were prepared and their tribological behaviors as additives in rapeseed oil(RSO) were evaluated using a four-ball tester. The worn surfaces of the steel balls were investigated by scanning electron microscopy and X-ray photoelectron spectroscopy(XPS). The results indicate that the additives possess good load-carrying capacities. Moreover, they both have good antiwear and friction-reducing property at relatively middle concentration(1~2 wt%) and under all test loads, and in some condition, these triazine derivatives can replace the zinc dialkylthiophosphate. The results of XPS analyses illustrate that the prepared compounds as additives in RSO forms a protective film containing inorganic sulfide, sulfate, oxidized compounds and organic nitrogen-containing compounds on the metal surface during the sliding process.