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

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.