Abstract
Ionic liquids attracted great attention as green surfactants to apply as corrosion inhibitors for steel in aqueous corrosive medium. In this work, amphiphilic ionic liquid was synthesized by quaternization of ethoxylated octadecylamine with p-toluene sulfonic acid to produce ODPEG-TS. The chemical structure was elucidated using NMR analysis. The surface activity of ODPEG-TS was measured from the relation between surface tension and different concentrations of ODPEG-TS in aqueous and acidic solutions. The corrosion protection of steel in 1M HCl using ODPEG-TS was investigated by different electrochemical techniques. Potentiodynamic polarization data revealed that the ODPEG-TS behaves as a mixed-type inhibitor influencing both the anodic dissolution and cathodic reactions. The protection performance of the ODPEG-TS inhibitor increased with increasing its concentrations. The inhibition action of ODPEG-TS occurred by adsorption of ODPEG-TS inhibitor on the active sides of steel surface according to Langmuir adsorption isotherm.