In situ preparation of anti-corrosion ionic liquids as the lubricant additives in multiply-alkylated cyclopentanes

Methoxy tris-ethoxy methylene benzotriazole (BTAG3) was synthesized and has good solubility in multiply-alkylated cyclopentanes (MACs) only when equal molar ratios of lithium salts, LiBF4, LiPF6, LiSO3CF3 or LiTFSI, were co-added into MACs due to the formation of ionic liquids (ILs), [Li(BTAG3)]BF4, [Li(BTAG3)]PF6, [Li(BTAG3)]SO3CF3 and [Li(BTAG3)]TFSI. The as-synthesized ILs have better solubilities in MACs than the conventional imidazolium ILs, 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (L-F108) and 1-butyl-3-methylimidazolium tetrafluoroborate (L-B104) or the unfunctionalized lithium-based IL, [Li(G3)]TFSI, which are insoluble in MACs. They were evaluated as anti-wear and anti-corrosion additive of MACs for steel–steel contact at room temperature (RT). It was found that the ILs possessed excellent friction-reducing and anti-wear properties in MACs compared with zinc dialkyldithiophosphate. Besides, the presence of benzotriazole means that these synthetic ILs have good anti-corrosion properties compared with the conventional IL, L-B104.