Study on tribological properties of 2,5-dialkoxymethylthio-1,3,4-thiadiazoles

Abstract

The properties of extreme pressure, antiwear, friction reduction of four 2,5-dialkoxymethylthio-1,3,4-thiadiazoles and the relations of their structure and tribological properties were evaluated using a four ball test machine, and compared with those of zinc butyloctyldithio-phosphate (ZDDP) and amine salt of thiophosphate complex ester (T307). The results indicate that these compounds possess excellent load carrying capacity, friction reduction and antiwear properties similar to those of ZDDP and T307 under 300 N load, and they exhibit better antiwear properties than ZDDP and T307 above 300 N load. The thermal stability and corrosive properties of these compounds were also investigated. The rubbed surfaces were investigated using electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS). Results of XPS analysis show that a boundary film mainly composed of thiadiazole complex, FeS and FeSO4 were formed on the rubbed surface.