二聚酸离子液体作为水基润滑添加剂的摩擦学性能研究  

Tribological Properties of Dimer Acid Ionic Liquids as Lubricant Additives in Water-Based Fluid

作　　者：张铭建 陈云龙 李维民[2,3] 程顺峰 ZHANG Mingjian;CHEN Yunlong;LI Weimin;CHENG Shunfeng(College of Life Sciences,Qingdao Agriculture University,Shandong Qingdao 266041,China;State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Gansu Lanzhou 730000,China;Zibo Innovation Center of High-End Synthetic Lubricating Materials,Shandong Zibo 255000,China)

机构地区：[1]青岛农业大学生命科学学院,山东青岛266041 [2]中国科学院兰州化学物理研究所固体润滑国家重点实验室,甘肃兰州730000 [3]淄博高端合成润滑材料创新中心,山东淄博255000

出　　处：《摩擦学学报(中英文)》2024年第12期1739-1751,共13页Tribology

基　　金：国家自然科学基金项目(51975560);中国科学院兰州化学物理研究所重点项目(KJZLZD-1);泰山学者工程;山东省重点研发计划(2020CXGC011002)资助。

摘　　要：以不同链长的二元脂肪酸作为阴离子,以二异丙醇胺作为阳离子,合成了4种羧酸铵型离子液体(CAILs),并研究了其作为水-二乙二醇(WDG)添加剂的溶解性和摩擦学性能,随后采用光学显微镜(OM)、扫描电子显微镜(SEM)、聚焦离子束-透射电子显微镜(FIB-TEM)、石英晶体微天平(QCM)和X射线光电子能谱(XPS)对试验后的磨痕进行二维形貌的观察和化学组成的分析.结果表明:4种离子液体在水-二乙二醇中有良好的溶解性(>4.0%,质量分数)和稳定性.此外,4种离子液体都能增强WDG的减摩性能,但只有二聚酸离子液体(DC_(36)-DIPA)增强了WDG的抗磨性能,同时提高了WDG的承载能力(500 N),表现出最佳的摩擦学性能.OM、SEM、FIB-TEM、QCM和XPS结果表明:质量分数0.5%DC_(36)-DIPA在钢-钢摩擦副表面生成了厚度约为60~70 nm、以铁氧化物为主要成分的摩擦膜,这层摩擦膜通过DC_(36)-DIPA分子在金属表面的吸附以及润滑剂与摩擦副之间的摩擦化学反应而形成,起到减摩抗磨的作用.In this study,four ammonium carboxylate-type ionic liquids(CAILs)were synthesized with four dicarboxylic acids and diisopropanolamine and used as water-based lubricant additives,with their tribological performance and lubrication mechanisms investigated.Infrared spectroscopy and nuclear magnetic resonance(NMR)were used to show that the synthesized CAILs additives had well-defined molecular structures.The four CAILs had been shown to have good solubility and dispersion stability in water-diethylene glycol(WDG)solution.Tribological tests of the four CAILs in WDG were carried out using a TE77 long-range reciprocating friction tester to evaluate the lubrication performance of them as additives in a ball-and-disc configuration for steel-steel sliding contacts.The four CAILs reduced the friction coefficients of the WDG base fluid to varying extents but only the dimeric acid ionic liquids(DC_(36)-DIPA)effectively reduced the wear volume,suggesting that DC_(36)-DIPA possessed the best friction reduction and anti-wear performance under the studied conditions.The influence of concentration of DC_(36)-DIPA was further examined at four concentrations of 0.5%,1.0%,1.5%,and 2.0%(mass fraction).Results showed that the friction coefficients did not show any significant difference,a concentration of 0.5%DC_(36)-DIPA exhibited the smallest wear volume.This suggested that the concentration could significantly affect the anti-wear performance of the water-based lubricants.It may be related to the change of molecular structure and existing status of DC_(36)-DIPA in the base fluid with effects such as self-assembly.To verify this speculation,small angle scattering(SAXS)tests were performed.It was found that DC_(36)-DIPA exhibited scattering differences at different concentrations,which may indicate that DC_(36)-DIPA exists in different molecular morphology in the solution.It may undergo a transition from vesicle to micelle for the four concentrations.This could be the main reason for the large difference in the anti-wear performance o

关 键 词：离子液体 吸附 摩擦化学反应 润滑机制 

分 类 号：TH117.1[机械工程—机械设计及理论]