Corrosion Inhibitive Capacity of Vanillin-Based Schiff Base for Steel in 1 M HCl

Abstract

The inhibitive action of novel vanillin-based Schiff base for corrosion of steel in 1 M hydrochloric acid solution was evaluated by experimentally at the temperature range of 301–331 K. The computed inhibition efficiency of the inhibitor increases with the increasing its concentration as on 10 to 50 ppm. At the same time, inhibition efficiency decreases with the increasing temperature as on 301 to 331 K. Therefore, the increasing inhibition efficiency was attributed to the adsorption of inhibitor molecules onto the steel surfaces, and decreasing inhibition efficiency is because of desorption of inhibitor molecules from steel surfaces to the solution. The electrochemical polarization measurements proposed that the examined vanillin-based Schiff base as an inhibitor in nature, which reduces the corrosion of steel, decreases both anodic and cathodic reactions. In this study, the adsorption of the inhibitor complies with the Freundlich adsorption isotherm and depending on that, they chose compound as a corrosion inhibitor for steel in 1 M HCl through the mixture of physisorption and chemisorption. At long last SEM pictures show the visual thought of the development of the defensive layer onto the steel surfaces, which hinders the corrosion.