The Synthesis And Tribological Characteristics Of Novel N-Containing Boric Acid Derivatives

The lubricant additives, containing sulfur and phosphorus, are important parts of lubricating oil, and they are vital components of industrial processes. These additives make a good performance in many fields, however, they own a very big weakness in the aspect of environmental protection and biodegradability. Thus it is urgent to develop novel efficient additives to replace totally or partially the traditional additives.In this paper, Two kinds of N-containing boric acid derivatives, referred to as ODOB-Ca and DPOB, were synthesized and the tribological behaviors were discussed. They are characterized by means of infrared spectroscopy and element analysis. The test of the TGA shows good thermal stabilities of the two additives. Their hydrolytic stabilities are investigated by means of saturation vapor pressure. Their tribological behaviors as additives in mineral oil and synergetic effects with traditional additives (ZDDP and sulfurized olefin) are evaluated by four-ball friction and wear tester as well. Friction mechanism were investigated on the tribofilms by using scanning electron microscope(SEM) and X-ray photoelectron spectroscopy(XPS). Some valuable results were obtained as follows:1, Two kinds of N-containing boric acid derivatives, referred to as ODOB-Ca and DPOB, were synthesized, and The test of the TGA shows good thermal stabilities of the two additives, with decomposition temperature more than200℃。Their hydrolytic stabilities are investigated by means of saturation vapor pressure. The results show the hydrolytic stabilities of ODOB-Ca and DPOB are better than T154B’s, three times and ten times respectively.2, The synergetic effects two compounds with ZDDP in mineral oil performed well in terms of the anti-wear and anti-friction property. X-ray photoelectron spectroscopy (XPS) surface analysis results indicated that the tribofilms were consisted of B2O3, and what’s more, the additives had interaction with ZDDP, resulting in the change of triblfilms.3, The synergetic effects two compounds with ZDDP in mineral oil performed well in terms of the anti-wear property, but not in anti-friction property. The tribofilms formed from ODOB-CA/DPOB and T321were analysed by XPS, and the results showed that there existed B2O3, iron oxide and sulphate. They made up the tribofilms which had taken an important part in anti-wear property.