The Synergistic Antiwear Performances of Organic Titanium Compounds Containing Sulfur with Borate Ester Additive

Xin Xu,Jun Ma,Jian-Qiang Hu,Shi-Zhao Yang,Li Guo,Feng Xie

doi:10.1155/2018/2576896

Abstract

Two oil-soluble organic titanium compounds (OTCs) such as titanium dialkyldithiocarbamate (TiDDC) and sulfurized titanate (TiS) were synthesized and identified by Fourier-transform infrared spectroscopy (FTIR). The antiwear and extreme pressure properties of TiDDC or TiS with borate ester containing nitrogen (BNO) additive in mineral base oils were evaluated by four ball tester. The results show that TiDDC and TiS not only possess good antiwear and load-carrying properties, respectively, but also exhibit good antiwear synergism with BNO additive without impairing extreme pressure performances. Moreover, the synergistic antiwear properties of the said additives are improved significantly under the optimum additives ratios. The topography of wear scar and the composition and chemical states of typical elements on the rubbing surfaces were analyzed by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) and X-ray photoelectron spectrometer (XPS). The proposed synergistic antiwear mechanism involves an effective interaction between TiDDC or TiS and BNO additive, respectively.

Highlights

In the field of lubrication, zinc dialkyldithiophosphate (ZDDP) has been widely utilized as a multifunctional lubricant additive exhibiting good antiwear and antioxidative properties in engine oils [1,2,3,4,5]
Organic titanium compounds (PFTCs) as lubricant additives are capable of enhancing antiwear, antioxidation, and fiction reducing performances in the boundary lubrication regime and improving fuel economy in engine oils [14,15,16,17]
It shows that the titanium dialkyldithiocarbamate (TiDDC) and borate ester containing nitrogen (BNO) additives all exhibit better antiwear properties than base oil at each experimental load, and the antiwear properties of TiDDC are better than ZDDP under the same condition

Summary

Introduction

In the field of lubrication, zinc dialkyldithiophosphate (ZDDP) has been widely utilized as a multifunctional lubricant additive exhibiting good antiwear and antioxidative properties in engine oils [1,2,3,4,5]. On phosphorus in the finished engine oils, so as to improve fuel economy, environmental protection, and emissions system compatibility [11,12,13]. It is desirable to partially or totally replace ZDDP with other lubricant additives without reducing the performances of formulated engine oils. Organic titanium compounds (PFTCs) as lubricant additives are capable of enhancing antiwear, antioxidation, and fiction reducing performances in the boundary lubrication regime and improving fuel economy in engine oils [14,15,16,17]. The synergistic antiwear and load-carrying properties of borate ester containing nitrogen (BNO) with titanium dialkyldithiocarbamate (TiDDC) or sulfurized titanate (TiS), respectively, were investigated, and subsequent exploitation of the results for the development of a synergistic antiwear additives composition were offered

Experimental

Results and Discussion

Conclusion