Imidazolium-derived polymeric ionic liquid as a green inhibitor for corrosion inhibition of mild steel in 1.0 M HCl: Experimental and computational study

Recently, many efforts have been widely made to develop techniques for corrosion problems. Ionic liquids with their unique features have been known as high potential materials to achieve high demanding goals. In this work, we synthesized an imidazolium-derived polymeric ionic liquid called poly [3-butyl-1-vinylimidazolium bromide] (PIL). Indeed, the corrosion inhibition properties of that material were investigated for a mild steel specimen immersed into 1.0M hydrochloric acid (HCl) solution by the Tafel plot, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) measurements, and quantum chemical calculation. The adsorption of the PIL onto mild steel surface followed the Frumkin adsorption isotherm model. Based on the results of Tafel plot, it is suggested that the PIL is a mixed type inhibitor with cathodic control predominance. SEM study revealed that the extent of corrosion of the mild steel surface decreased with PIL concentration elevation. Quantum chemical calculations matched the experimental results. The corrosion inhibition efficiency of the PIL exceeded 96% based on Tafel plot measurements.