Aminotriazolethiol-functionalized chitosan as a macromolecule-based bioinspired corrosion inhibitor for surface protection of stainless steel in 3.5% NaCl.

Chitosan was chemically functionalized using aminotriazolethiol in a facile single-step synthesis. The macromolecule was evaluated as an inhibitor for corrosion of stainless steel in 3.5% NaCl solution. A detailed electrochemical investigation employing electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) was performed, which showed that the inhibitor acts by adsorption on the steel surface and shows a mixed type behavior with the prevalence of cathodic behavior. The new inhibitor aminotriazolethiol-modified chitosan (ATT-Cht) exhibited excellent water solubility and behaved as an efficient inhibitor against corrosion of stainless steel in 3.5% NaCl showing a corrosion inhibition efficiency of 97.8% at a concentration as low as 100 mg L-1. The results of surface studies using scanning electron microscopy along with energy dispersive X-ray spectroscopy supported the adsorption of the inhibitor on the steel surface.