Abstract:
The inhibition effect of (s)-2-(anthracene-9(10H)-ylideneamino)-5-guanidinopentanoic acid (A9Y5GPA) on carbon steel (CS) in 0.5 M sulphuric acid solution has been investigated using weight loss measurements, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies. The addition of KI to A9Y5GPA enhanced the inhibition efficiency due to synergistic effect. The adsorption of A9Y5GPA and A9Y5GPA+ KI on the carbon steel surface obeys Freundlich and Langmuir adsorption isotherm respectively. The result showed that compound studied was acted as a mixed type inhibitor causing blocking of active sites on the metal. Surface morphology of the carbon steel specimens was evaluated by SEM analysis.