Die Autoxidation von metallischem Kupfer und Kupfer(I)-Verbindungen / Investigation on Autoxidation of Metallic Copper and Copper(I) Compounds by Different Methods

Abstract

<jats:title>Abstract</jats:title><jats:p> The corrosion of copper granules under controlled conditions (2.5% NaCl solution, pH 4 buffer, O<jats:sub>2</jats:sub>) was studied using a) the rate of uptake of oxigen and b) the pH stat method. Cu<jats:sup>2+</jats:sup> ions catalyse the corrosion of copper. The surface area of the copper and the temperature influence the rate of corrosion in the expected manner. Experiments in light and dark showed little variation in the results.</jats:p><jats:p>The results obtained by measuring the O<jats:sub>2</jats:sub> uptake and using the pH stat method were confirmed and complemented by electrochemical measurements. (Steady potential/time curves, current/voltage curves, measurement of the polarisation resistance and estimation of Cu<jats:sup>2+</jats:sup> during corrosion via a Cu<jats:sup>2+</jats:sup> sensitive electrode.) The influence on the corrosion of F<jats:sup>-</jats:sup>, CI<jats:sup>-</jats:sup>, Br<jats:sup>- </jats:sup>and I<jats:sup>-</jats:sup>, mineral acid concentration and other inorganic ions was also studied under standard conditions. To ensure the correctness of the interpretation of the results (see reaction scheme), the autoxidation of CuCl and CU<jats:sub>2</jats:sub>O was also studied under standard conditions.</jats:p><jats:p>The experimental results are consistent with the steps (1)-(4) in the reaction scheme. The fastest step is clearly the oxidation of Cu<jats:sup>1+</jats:sup> , which is continuously supplied via the copper surface. The interpretation here presented forms the basis for the understanding of the inhibition of corrosion exhibited by a number of organic compounds.</jats:p>

Inhibitoren der Korrosion 30 (1,2) – Vergleichende Studien über das Verhalten bekannter und bisher unbekannter Inhibitoren der Korrosion des Kupfers unter Standardbedingungen (Sauerstoff, NaCl, pH 4,1, 22°C)

“…Trabanelli [5] Allein im Zeitraurn zwischen 1972i76 werden in ,,Chemical Abstracts" 18 Literaturstellen iiber Untersuchungen mit Benzotriazol als Korrosionsinhibitor fur Kupfer aufgefiihrt.…”