氨基酸离子液体作为不同摩擦副润滑剂的性能研究

设计合成了三种具有不同官能团结构的氨基酸类离子液体,采用SRV-Ⅳ微动摩擦磨损试验机考察了其作为Si_3N_4/Si_3N_4和钢/钢摩擦副润滑剂的摩擦学性能,并与丙三醇进行对比,采用扫描电镜和X射线光电子能谱仪分析磨斑形貌和表面元素的化学状态.结果表明:三种氨基酸类离子液体均能适用于两种摩擦副的润滑,并具有良好的减摩抗磨性能.羟基和羧基官能团的存在不仅有效增强了离子液体在基底上的物理吸附作用,同时还促使其与摩擦副发生摩擦化学反应.比较三种离子液体的摩擦学性能发现,同时含有两个羧基的谷氨酸四丁基磷盐离子液体的减磨性能优于其他两种只含一个羟基或羧基基团的离子液体.

Tribological Properties of Amino Acid Ionic Liquids as Lubricants for Different Contacts

Three kinds of amino acid ionic liquids with different functional groups were synthesized,and the tribologicai properties of amino acid ionic liquids were evaluated as lubricants for the Si3N4/Si3N4 and steel/steel contacts by an Optimal SRV-Ⅳ oscillating friction and wear tester,Meanwhile,the glycerol was selected as reference lubricant.In addition,the morphology and chemical state of elements on the worn surfaces were analyzed by a JSM-5600LV scanning electron microscope and a PHI-5702 multifunctional X-ray photoelectron spectrometer.The results show that the three kinds of amino acids ionic liquids can be used as the lubricants for the two contacts and exhibited excellent tribological performance.It is concluded that the hydroxyl and carboxyl functional groups not only enhanced the physical adsorption effectively but also prompted the tribochemical reactions.Besides,the anti-friction and anti-wear properties of glutamic acid tetrabutylphosphorus ionic liquid with two carboxyl functional groups were better than those of the other two ionic liquids with a single carboxyl or hydroxyl functional group.