Mechanism of corrosion inhibition by the 2‐chloroethyl phosphonic acid – Zn²⁺ system

Abstract

The synergistic effect of sodium salt of 2‐chloroethyl phosphonic acid (2‐Cl EPA) and Zn²⁺, in controlling corrosion of carbon steel in a neutral aqueous environment containing 60ppm Cl^–, was evaluated by weight‐loss and electrochemical methods. A formulation consisting of 300ppm 2‐Cl EPA and 300ppm Zn²⁺ was observed to deliver 95 percent inhibition efficiency. A suitable mechanism of corrosion inhibition has been proposed which is based on the results obtained from polarization study and uv‐visible absorption and reflectance spectra. 2‐Cl EPA‐Zn²⁺ system appears to function as a mixed inhibitor. The protective film consisted of Fe²⁺ ‐2‐Cl EPA complex, Zn(OH)₂ and oxides of iron. The film was found to be semiconducting in nature.

Citation

Rajendra, S., Apparao, B.V. and Palaniswamy, N. (2000), "Mechanism of corrosion inhibition by the 2‐chloroethyl phosphonic acid – Zn²⁺ system", Anti-Corrosion Methods and Materials, Vol. 47 No. 3, pp. 147-151. https://doi.org/10.1108/00035590010334106