The tribological chemistry of the triazine derivative additives in rape seed oil and synthetic diester

The additives, laurylamino-methylthio-1,3,5-triazine-2,4-dithiol (referred to as TRLA) and diisooctylamino-methylthio-1,3,5-triazine-2,4-dithiol (referred to as TREA), were prepared in our laboratory. The products were characterized by means of infrared spectroscopy (IR) and elemental analysis. Their tribological behaviors as additives in raped seed oil and diester were evaluated using four-ball friction and wear testers as well. The results suggest that all the synthesized compounds have excellent tribological behaviors and they were compared with sulfurized isobutene (referred to as SIB) which is a commercial additive. The results show that they have good tribological properties. The two additives were investigated on thermal films and tribofilms by using X-ray absorption near edge structure (XANES) spectroscopy. The results of surface analysis reveal that the thermal films formed from TREA and TRLA in rape seed oil (referred to as RSO) and diester (referred to as DE), all are consist of iron sulfate; under mild AW conditions, the tribofilms from TRLA and TREA in DE is mainly composed of FeS, while the tribochemcal film from TRLA in RSO is mainly composed of iron sulfite; under EP-1 (the maximum non-seizure load) conditions, the tribochemical films from TRLA and TREA in RSO and DE mainly consist of FeS and FeSO4; under EP-2 (nearly weld load) conditions, the tribochemical films from TRLA and TREA in RSO and DE mainly consist of FeS.