关键词: 功能化离子液体, 1－乙酸乙酯基－3－甲基咪唑四氟硼酸盐, 摩擦学性能, 亚磷酸二正丁酯

Abstract: A new kind of ester-group functionalized ionic liquid, 1-ethoxycarbonylmethyl-3-methyl imidazolium tetrafluoroborate ([EAMIM]BF4), were synthesized. Its physicochemical properties, tribological behavior (at room temperature and 100℃), compatibility and susceptibility to some conventional lube additives were studied and compared with a conventional ionic liquid, 1-butyl-3-methy imidazolium tetrafluoroborate ([BMIM]BF4), which had the same alkyl as the functionalized one. It was found that both ionic liquids had good low-temperature fluidity, low evaporation loss and high thermal stability. Their solubility with most commonly oil-soluble lube additives was poor, except with some having strong polar compounds or with heterocyclic structures, and between these two, [BMIM]BF4 was better. The friction reducing performance of [EAMIM]BF4 was less significant than that of [BMIM]BF4 due to its high viscosity, yet its antiwear ability was better than that of [BMIM]BF4 at both room temperature and 100℃. The addition of antiwear additive di-n-butylphosphite could improve the antiwear performance of [BMIM]BF4, however, negative effect was observed with [EAMIM]BF4.

Key words: functionalized ionic liquid, 1-ethoxycarbonylmethyl-3-methyl imidazolium tetrafluoroborate, tribological behavior, di-n-butylphosphite