L-Dopa as Corrosion Inhibitor for Mild Steel in Mineral Acid Medium

Abstract

Corrosion inhibition of mild steel was studied using L-Dopa in aqueous hydrochloric acid and sulphuric acid so- lutions. The corrosion behaviours of the steel specimen in the presence of inhibitor weret studied by galvanostatic polari- zation and weight loss techniques. The measured electrochemical data indicated good inhibition of corrosion in both the corrosive medium in presence of L-DOPA. The corrosion inhibition may be explained on the basis of adsorption and for- mation of surface film of L-DOPA on the metal surface. The surface of the steel specimen subjected to electrochemical corrosion in the presence and absence of the inhibitor was studied using scanning electron microscopic images. In the present investigation, L-DOPA is used as corrosion inhibitor for mild steel in aqueous hydrochloric acid and sulphuric acid solutions. The corrosion inhibition efficiency of the compound is studied by potentiodynamic polarization and weight loss studies. The surface morphology of the metal surface before and after corrosion is studied by SEM images. 2. EXPERIMENTAL Analytical Reagent (AR) grade chemicals (sd. fine chemicals, Mumbai) were used for the study. The aqueous solution of sulphuric acid and hydrochloric acid was used as the corrosive media. L-dopa was used as received and the structure of the L-dopa was used as corrosion inhibitor is as shown in Fig. (1).