Design And Preparation Of Polyionic Liquids And Tribological Properties Of It As Water-based Lubrication Additives

To meet the challenges of future energy and environmental issues,the adoption of waterbased lubricants to replace traditional oil-based lubricants has received widespread attention from various industries.Water-based lubrication has the advantages of being green and low cost,difficult to ignite,and good cooling performance,but its drawbacks such as low viscosity and poor corrosion resistance limit its application in industrial fields.Thus,there is an urgent need to develop new and efficient additives to improve the corrosion resistance and lubricity of water.Polyionic liquids are polymerized from ionic liquid monomers,which have the excellent properties of both ionic liquids and polymers and can be used as high-performance lubricating additives in water-based lubricants.In this paper,a new type of polyionic liquid is designed,and their interaction and lubrication mechanism in water are analyzed and studied by different forms of compounding with corrosion inhibitors and anion exchange.The main research contents and results are as follows.1.A new type of polyionic liquid PPM was prepared and used with corrosion inhibitors.Its physicochemical properties were studied,and its role as a water-based lubricating viscosity enhancer for the lubrication state of water-based lubrication was investigated.The tribological performance of the lubricant formulated by reciprocating friction testing machine SRV-V and MTM micro traction machine at boundary lubrication condition and mixed lubrication condition.Combined with the technical means of XPS,ECR,and EHL,it is found that it can form a friction chemical reaction film at the sliding interface,and the high viscosity PPM can also produce an oil film greater than 100 nm on the contact surface of the friction sub,helping the lubrication state to move from mixed lubrication to elastohydrodynamic lubrication.2.Three carboxylate anions with different carbon chain lengths were taken to replace the chloride ions in the polyionic liquid PPM.The replaced polyionic liquids exhibited good anticorrosion properties in water.Its tribological mechanism as a water-based lubricating additive at the steel/steel friction sub-interface was tested by SRV micro-motion friction and wear testing machine.It was shown that all three polyionic liquids with different anionic chain lengths could effectively reduce the friction coefficient and wear volume,and PPM-Oa with a carbon chain length of 8 had the best performance.The good viscosity,the adsorption of quaternary ammonium ions and COOH,the polar group of carboxylate,at the sliding interface,and the tribochemical reaction film are responsible for their good lubricating properties.3.The green and non-polluting L-type amino acids were introduced into the polyionic liquid PPM by replacement reaction,and MIC tests showed that they inhibited the growth of both Escherichia coli and Staphylococcus aureus.The results of frictional wear tests showed that the three amino acid-based polyionic liquids significantly improved the lubricating properties of water and effectively reduced the friction coefficient and wear volume.the best performance of PPM-Try lubrication was attributed to the synergistic effect of the large π-bonds in the benzene and imidazole rings and the atoms on the metal surface in the friction interface.