Versatile 4, 6-dimethyl-2-mercaptopyrimidine based ionic liquids as high-performance corrosion inhibitors and lubricants

In this study, three 4, 6-dimethyl-2-mercaptopyrimidine (DMMP) based phosphonium ILs were firstly synthesized. The corrosion inhibition behaviors of these ILs for mild steel in 0.5 M H2SO4 aqueous solutions were investigated by electrochemical tests. Results indicated that all of the three ILs exhibited surprising inhibition efficiencies as high as 99%, even at an ultralow concentration of 0.1 mM. The ILs' adsorption behavior on surface obeys Langmuir isotherm, indicating that the ILs inhibit corrosion of mild steel by monolayer adsorption on the mild steel surface. Moreover, due to the superior adsorption capacity on steel surface, DMMP based ILs are expected have great application potentials as high-performance lubricating materials. As expected, DMMP based ILs showed excellent lubrication performances both at 30 °C and 100 °C as compared to PAO and 1-butyl-3-methylimidazolium tetrafluoroborate (LB104). Surface analyses indicated that tribofilms consist of ILs adsorption layer and tribochemical products, such as FeS, Fe2O3 and organic compounds containing CO bonds, are responsible for the predominant lubrication performances. Therefore, versatile ILs designed in this paper have gathered two significant abilities for industrial applications, which are high corrosion inhibiting properties and excellent lubrication performances. This work is believed to be instructive for designing multifunctional ILs and promoting the ILs' application in industry in the future.Graph...
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research