Corrosion Inhibition Efficiency of Metal Complex of Carboxymethylchitosan in 3.5% NaCl

The effectiveness of zinc carboxymethylchitosan metal complex (ZCMC) as a copper corrosion inhibitor in 3.5% NaCl solutions was investigated using electrochemical impedance spectroscopy, Tafel extrapolation techniques and SEM/EDX. The potentiodynamic polarisation investigations demonstrate that ZCMC is a good inhibitor for copper in neutral media. In 3.5% NaCl solutions, it more significantly reduces the anodic reaction rate than the cathodic reaction rate and increases the open circuit potential of copper. This Cu(II) is generated by oxidation of the Cu(I) ion formed at the beginning of the corrosion process in the aerated solution of NaCl. SEM-EDX studies confirmed the absence of the deterioration products on the copper surface.