Inhibition Mechanism of Some Vinylalkylimidazolium-Based Polymeric Ionic Liquids against Acid Corrosion of API 5L X60 Steel: Electrochemical and Surface Studies

A corrosion inhibition mechanism of API 5L X60 steel exposed to 1.0 M H2SO4 was proposed from the evaluation of three vinylalkylimidazolium poly(ionic liquids) (PILs), employing electrochemical and surface analysis techniques. The synthesized PILs were classified as mixed-type inhibitors whose surface adsorption was promoted mainly by bromide and imidazolate ions, which along with vinylimidazolium cations exerted a resistive effect driven by a charge transfer process by means of a protective PIL film with maximal efficiency of 85% at 175 ppm; the steel surface displayed less surface damage due to the formation of metal-PIL complex compounds.

Automated summary

The corrosion inhibition mechanism of API 5L X60 steel exposed to 1.0 M H2SO4 was evaluated using three vinylalkylimidazolium poly(ionic liquids) (PILs), which showed promising surface protection by surface adsorption and charge transfer processes.