Taking 1,4-naphthalene dicarboxylic acid (1,4-ND), 2,3-naphthalene dicarboxylic acid (2,3-ND) and tetrabutyl ammonium hydroxide (N₄₄₄₄OH), tetrabutyl phosphonium hydroxide (P₄₄₄₄OH) as raw materials, water-based lubricant additives tetrabutyl ammonium 1,4-naphthalene dicarboxylate (1,4-NDN₄₄₄₄), tetrabutyl phosphonium 1,4-naphthalene dicarboxylate (1,4-NDP₄₄₄₄), tetrabutyl ammonium 2,3-naphthalene dicarboxylate (2,3-NDN₄₄₄₄), and tetrabutyl phosphonium 2,3-naphthalene dicarboxylate (2,3-NDP₄₄₄₄) were prepared in aqueous solution. The additives are not only simple to prepare, but also have good solubility in water. More importantly, they can significantly improve the friction reducing and anti-wear performances of water. On account of the mechanism analysis, it is estimated that the introduction of aromatic ring and more carboxyl groups to the additives play an important role for them to form stable lubrication protective films during the friction process and then to achieve excellent lubrication performance on steel/steel, copper/steel, and aluminum/steel friction pairs. Remarkably, the performances of 2,3-NDN₄₄₄₄ and 2,3-NDP₄₄₄₄ are superior to those of 1,4-NDN₄₄₄₄ and 1,4-NDP₄₄₄₄, which is ascribed to their stronger adsorption on the metal surfaces contributed by the two adsorption targets (two –COO⁻ groups). For 1,4-NDN₄₄₄₄ and 1,4-NDP₄₄₄₄, there is only one –COO⁻ group that can be simultaneously adsorbed on the metal surfaces from the perspective of space configuration. It weakens the adsorption and decreases the effectiveness of the lubrication protective films resulting in the reduced friction reducing and anti-wear properties of 1,4-NDN₄₄₄₄ and 1,4-NDP₄₄₄₄.

Graphical Abstract

Water-based lubricant additives tetrabutyl ammonium 1,4-naphthalene dicarboxylate (1,4-NDN₄₄₄₄), tetrabutyl phosphonium 1,4-naphthalene dicarboxylate (1,4-NDP₄₄₄₄), tetrabutyl ammonium 2,3-naphthalene dicarboxylate (2,3-NDN₄₄₄₄) and tetrabutyl phosphonium 2,3-naphthalene dicarboxylate (2,3-NDP₄₄₄₄) were prepared in aqueous solution. The additives are not only simple to prepare, but also have good solubility in water. More importantly, they can significantly improve the friction reducing and anti-wear performances of water. Evolution of the friction coefficients (a) and wear volume losses (b) for different samples on steel/steel friction pairs.

中文翻译：

---

水性萘二甲酸萘离子液体润滑添加剂的制备及摩擦学性能

以1,4-萘二甲酸（1,4-ND），2,3-萘二甲酸（2,3-ND）和氢氧化四丁基铵（N ₄₄₄₄ OH），氢氧化四丁基phospho（P ₄₄₄₄ OH）为原料材料，水性润滑剂添加剂1,4-萘二甲酸四丁基铵（1,4-NDN ₄₄₄₄），1,4-萘二甲酸四丁基butyl（1,4-NDP ₄₄₄₄），2,3-萘二甲酸四丁基铵（1,4-NDP ₄₄₄₄） 2,3-NDN ₄₄₄₄）和四丁基2,3-萘二甲酸phospho（2,3-NDP ₄₄₄₄）在水溶液中制备。添加剂不仅易于制备，而且在水中具有良好的溶解性。更重要的是，它们可以显着提高水的减摩和抗磨性能。根据机理分析，据估计，在添加剂中引入芳环和更多的羧基对它们在摩擦过程中形成稳定的润滑保护膜，进而在钢/钢上获得优异的润滑性能起着重要的作用。 ，铜/钢和铝/钢摩擦对。值得注意的是，2,3-NDN ₄₄₄₄和2,3-NDP ₄₄₄₄的性能优于1,4-NDN ₄₄₄₄和1,4-NDP _{4444的性能}（2个-COO，这归因于它们对金属的吸附更强表面由两个吸附目标做出了贡献^-基团）。对于1,4- NDN ₄₄₄₄和1,4- NDP ₄₄₄₄，仅存在一个-COO ^-可同时吸附从空间配置的观点来看的金属表面上的基团。它削弱了吸附并降低了润滑保护膜的有效性，导致1,4-NDN ₄₄₄₄和1,4-NDP _4444的摩擦减小和抗磨性能降低。

图形概要

水性润滑剂添加剂1,4-萘二甲酸四丁基铵（1,4-NDN ₄₄₄₄），1,4-萘二甲酸四丁基phospho（1,4-NDP ₄₄₄₄），2,3-萘二甲酸四丁基铵（2，在水溶液中制备3-NDN ₄₄₄₄）和2,3-萘二甲酸四丁基phospho （2,3-NDP ₄₄₄₄）。添加剂不仅易于制备，而且在水中具有良好的溶解性。更重要的是，它们可以显着提高水的减摩和抗磨性能。钢/钢摩擦副上不同样品的摩擦系数（a）和磨损量损失（b）的演变。