Green extract of mate tea as corrosion inhibitor of copper and aluminum

Abstract

Many of the corrosion inhibitors in current use are expensive and toxic so the current trend is to study compounds that are environmentally friendly and efficient. Inhibitors are easy to use and they have the additional advantage that can be applied in situ and without causing significant disruption in the process. In the present work we investigate the influence of the aqueous extract of yerba mate as corrosion inhibitor of copper and aluminum in 0.5 M NaCl and 1 M HCl solutions, using different electrochemical techniques. The following inhibition efficiencies: 56% for copper in 0.5 M NaCl with 25% concentration of extract, 17% for copper in 1 M HCl with 5% concentration of extract, and 99% for aluminum in 0.5 M NaCl for 1% concentration of extract were obtained by potentiodynamic polarization.