The effect of glucose, maltose, starch and sodium butyrate on the corrosion of copper in chloride solutions

The effects of glucose, maltose, starch, sodium butyrate molecules on thecorrosion behaviour of cupper in chloride solutions have been investigated. Theeffects of these ions have been studied in two pH values (4.0 and 8.0). The three-electrode technique has been employed as the electrochemical method. Thecathodic and anodic current-potential curves of copper were drawn starting from theopen circuit potential measured against SCE. Polarization resistances weredetermined by electrochemical impedance spectrocopy. The obtained resultsindicate that at pH=4,0 the organic molecules (glucose, maltose, starch) andchloride together reduce the corrosion rate of copper more than does chloride alone,and render it passive. It was found that the corrosion rate of copper decreases instarch and chloride solutions at pH=8.0.Key Words: Copper, Corrosion, Inhibition, Passivation, EIS.