Excellent lubrication performance and superior corrosion resistance of vinyl functionalized ionic liquid lubricants at elevated temperature

In order to improve the lubrication performance and inhibit the serious corrosivity of conventional ionic liquids (ILs) at elevated temperatures, a series of vinyl functionalized ILs were synthesized in this work. The corrosion behavior of the ILs was evaluated with copper sheet corrosion test and their tribological properties were investigated on an Optimol SRV-IV oscillating friction and wear tester at elevated temperatures. The results showed that ILs with vinyl group, such as 1-vinyl-3-butyl imidazolium tetrafluoroborate (VBImBF4), can reduce corrosion effectively and its extreme pressure reached up to 1500 N at 150 °C. Based on the XPS analysis, ILs with vinyl group could interact with the iron surface and a protecting layer would form on the surface of steel possibly. Thus, ILs lubricants with good lubricating performance and low corrosivity at elevated temperature were achieved.

► A series of olefin/vinyl functionalized imidazolium ionic liquids was synthesized.
► The lubricant possesses superior corrosion resistance and high load carrying capacity.
► The good performance is ascribed to the coordination of olefin group with fresh iron.
► The strong absorption and the tribochemical reaction film lead to excellent performance.