Electrochemical and Density Functional Theory Studies of Alkyl Imidazoline on the Corrosion Inhibition of Carbon Steel in Sulfamic Acid Solutions

The corrosion inhibition effects of the 2-undecyl-N-carboxymethyl-N-hydroxyethyl imidazoline on simple steels were indagated in 8 wt.% NH2SO3H media using loss of weight and electrochemical methods in conjunction with adsorption and DFT researches. The anti-corrosion effect of UHCI acquired from EIS study is great and the maximum anti-corrosion efficiency could reach 90.15%. The sorption of UHCI on simple steel conforms to the Langmuir sorption equation. The DFT studies reveal that UHCI is firmly chemisorbed upon the simple steel by the Fe center dot center dot center dot O sigma-type dative bonds and isolates the contact between simple steel and NH2SO3H, thus protecting simple steel from the corrosion of NH2SO3H.