Zhongyi He

Study on phosphorous‐free triazinyl disulfides as additives in combustion engine base oil

Purpose – This paper seeks to study the tribological properties, corrosion inhibition properties and action mechanism of two triazine‐containing disulfides, TOSS and TOMA, as additives in combustion engine base oil (5CST); those properties of an alkyl disulfide dodecyl disulfide and zinc dialkyldithiophosphate (ZDDP) were also evaluated for comparison to discover whether these additives could be used as potential substitute candidates for ZDDP.Design/methodology/approach – Their tribological performances were evaluated using a four‐ball machine. The worn surfaces were investigated by scanning electron microscopy and X‐ray photoelectron spectroscopy (XPS)Findings – The three additives have good load‐carrying capacity and corrosion inhibition properties comparable with those of ZDDP. The anti‐wear properties of the triazine‐containing disulfides TOSS and TOMA are good but a little inferior to those of ZDDP. The friction‐reducing performances of the additives are better than those of ZDDP. The XPS results sh...

Tribological study of OH- and N-containing imidazoline derivatives as additives in water–glycol:

Tribological properties of two hydroxyl- and only active nitrogen-containing water-soluble imidazoline derivatives, benzotriazole-containing imidazoline (BML) and caprylic acid-containing imidazoline (CML), as lubrication additive in water–glycol hydraulic fluid were evaluated with a four-ball tester. And the antirust and anticorrosion behaviors were also investigated. Results show that BML and CML were able to remarkably improve the antirust properties of water–glycol fluid when added at a low adding concentration, and also these performances of BML was better than CML. All additives exhibited good extreme pressure and antiwear properties, and BML showed better tribological properties than CML. Besides, the difference in the tribological and anticorrosion properties of these derivatives was closely related to their different molecular structures. There exists a synergistic tribological effect between benzotriazole and imidazoline group in the tribological and antiwear performances. Furthermore, significant improvement in the tribological performances of BML was detected and attributed to organic nitrogen compounds, iron oxide, and so on in tribofilm on the worn surfaces.