Enhanced corrosion inhibition effect of a new hydrazone at steel rebar/chloride-contaminated synthetic concrete pore solution interface

Abstract

In this work, a novel hydrazone derivative namely N'-(furan-2-ylmethylene)-2-(5-methoxy-2-methyl-1H-indol-3-y1) acetohydrazide (FMAH) was synthesized from indomethacin and applied for mitigating the corrosion of the steel rebar exposed to chloride contaminated synthetic concrete pore solution (CISCPS). Electrochemical methods (Electrochemical impedance, Potentiodynamic polarization studies) were used to investigate the corrosion protection properties of the synthesized inhibitor. Further, surface characterization has been performed to understand the inhibition mechanism. The addition of the prepared compound to the CISCPS decreased the corrosion rate of the steel rebar by adsorption of inhibitor molecules on the surface of the steel rebar. The inhibitor showed an inhibition efficiency of 81% at an optimum concentration of 1 mmol/L, after 30 days of immersion. X-ray photoelectron spectroscopy (XPS), atomic force mieroscopy (AFM), and scanning electron mieroscopy interpretations confirmed that FMAH mitigates the corrosion attack on the surface steel rebar.