Effect of 2,2′ benzothiazolyl disulfide on the corrosion of mild steel in acid media

Abstract

2,2′ benzothiazolyl disulfide (BTDS) has been synthesised and their inhibiting action on mild steel corrosion in 1 M HCl and 0.5 M H2SO4 at 308 K has been investigated using weight loss, EIS, polarization and SEM study. BTDS showed better efficiency in 0.5 M H2SO4 compared to 1 M HCl. Polarization studies revealed that BTDS is a mixed type inhibitor in both acids predominantly cathodic in 1 M HCl where as predominantly anodic in 0.5 M H2SO4. Thermodynamic parameters i.e. free energy of adsorption, enthalpy, entropy and activation energy were calculated, the values of these parameters showed good interaction. © 2009 Elsevier Ltd. All rights reserved.