Abstract: Two benzothiazole ester compounds containing boron with different alkyl chain, Di-n-hexyl-[2-(2-benzothiazolylthio)] ethyl boric acid ester (BNS-1) and Dicyclohexyl-[2-(2-benzothiazolylthio)] ethyl boric acid ester(BNS-2), were synthesized and their tribological performance as additives in rapeseed oil （RSO）was investigated using a four-ball testing machine. The anticorrosive properties and oil solubility of these compounds were tested as well. The worn surfaces of the steel ball tested were analyzed by means of scanning electron microscopy (SEM). As a results, benzothiazole ester compounds containing boron as RSO additives exhibited good oil-soluble and anticorrosive properties, as well as enhanced load-carrying capacity. The tribological performance of BNS-2 containing naphthenic groups was even better than that of BNS-1 containing alkyl groups, which indicated that the tribological performance varied with the various molecular structures of the derivatives in RSO.

Key words: benzothiazole compounds, boric acid ester, rapeseed oil, tribological properties