Efficiency of Alkaloids Crude Extract of Cinnamomum Zeylanicum as Corrosion Inhibitor of Mild Steel in Sulfuric Acid Solution

The efficiency of alkaloids crude extract of Cinnamomum zeylanicum in the inhibition of corrosion of mild steel is evaluated in sulfuric acid solution. The results show that the inhibitory  efficacity of the extract increases with the increase of the inhibitor concentration to reach a value of 97.82% at 400 ppm. The potentiodynamic polarization measurements reveal that the presence of the crude alkaloids reduces significantly the current and shifts the corrosion potential to higher values. The electrochemical impedance measurements show an increase in the charge transfer resistance with the increase of the inhibitor concentration. It was also found that the adsorption process of the active molecules on the surface of the metal is a physisorption and follows the Langmuir isotherm model, which confirms the efficiency of the crude alkaloids extracted from Cinnamomum zeylanicum in the protection of mild steel in H₂SO₄ solution.