Adsorption and corrosion inhibitive properties of P(2-aminobenzothiazole) on mild steel in hydrochloric acid media

Abstract

Corrosion inhibition of mild steel in hydrochloric acid solutions using electropolymerized Poly 2-aminobenzothiazole, P(2ABT), was evaluated using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy measurements at different temperature. Results showed that the inhibition efficiency increases with increasing the concentration of P(2ABT) up to 12.7 × 10−6 mol L−1 and decreases with raising the temperature. Polarization curves indicate that the studied compound acts as anodic inhibitor. Thermodynamic activation parameters for both dissolution and adsorption processes are calculated and discussed as well as the adsorption isotherms are calculated. Gibbs free energy value confirms the physical nature of the adsorption, also the mechanism of inhibition is discussed. Scanning electron microscopy is used to study the surface morphology of mild steel in hydrochloric acid solution in the absence and presence of 12.7 × 10−6 mol L−1 P(2ABT). Data obtained from all techniques are in a good agreement with each other.