Corrosion inhibition by polyaniline copolymer of mild steel in hydrochloric acid solution

Abstract

Purpose

The purpose of this paper is to evaluate the inhibitive effect of a polyaniline copolymer, namely, poly(aniline‐co‐o‐anthranilic acid) solution, on the corrosion of carbon steel in hydrochloric acid. The effect of the different concentrations of the corrosion inhibitor also was investigated.

Design/methodology/approach

Fourier transform infrared spectroscopy was used to characterise the polyaniline copolymer. Weight loss measurements, potentiodynamic polarization and electrochemical impedance spectroscopy were carried out to determine the corrosion inhibition efficiency. Scanning electron microscopy was used to observe the morphology of the corroded surface.

Findings

The results indicated that polyaniline copolymer solution acts as an effective corrosion inhibitor for carbon steel in hydrochloric acid solution and that the adsorption of the compound on the metal surface obeys the Langmuir adsorption isotherm.

Practical implications

The corrosion inhibitor could have wide applications in the acid washing industry to reduce the corrosion rate of carbon steel in hydrochloric acid.

Originality/value

This paper reveals a new type of corrosion inhibitor prepared from a polyaniline copolymer.

Citation

Fuhua, S., Xiutong, W., Jianqiang, Y. and Baorong, H. (2011), "Corrosion inhibition by polyaniline copolymer of mild steel in hydrochloric acid solution", Anti-Corrosion Methods and Materials, Vol. 58 No. 3, pp. 111-115. https://doi.org/10.1108/00035591111130488