The tribochemical study of two triazine derivatives as additives in rapeseed oil

Abstract

Two novel S—P–N-type triazine derivatives, 2,4-bis-amino-6-(O, O′-dialkyl dithiophos-phate)-s-1,3,5-triazines (coded DBBT and DPBT) were synthesized. The tribological behaviours of these derivatives as additives in rapeseed oil were evaluated using a four-ball machine. The results show that the triazine derivatives possess excellent extreme pressure capacities, friction-reducing properties, and high thermal stabilities. Under low-load range (196–392 N) and high-additive concentration (5 wt%), DPBT has anti-wear properties superior to zinc dialkyldithiophosphates. The action mechanism was investigated using X-ray photoelectron spectroscopy and scanning electron microscope. It is proposed that the prepared compounds as additives in rapeseed oil form a protective film containing phosphate, sulfate, and organic nitrogen compound on the rubbed surface.