Lithium-Based Ionic Liquids: In Situ-Formed Lubricant Additive Only by Blending

This article reports a novel way of in situ formation of ionic liquids (ILs) that are used as lubricant additives for steel/steel contacts. The ILs can be generated simply in base oils by mixing small molecules of 2-oxazolidinone, triglyme, or tetraglyme with lithium bis(trifluoromethane sulfonyl) imide in appropriate molar ratios at room temperature. The said ILs can be formed in polyether, polyester, and polyurea grease and show better solubility in these base oils than commonly used ILs such as 1-methyl-3-hexylimidazolium hexafluorophosphate (L-P106). They can significantly improve the friction-reducing and antiwear properties of the base oils.