INFLUENCE OF SUBSTITUTED BENZOTHIAZOLES ON CORROSION IN ACID-SOLUTION

Compounds such as 2-aminobenzothiazole (ABT), 2-amino-6-chlorobenzothi azole (ACLBT), 2-amino-6-methyl benzothiazole (AMEBT) and 2-amino-6-me thoxy benzothiazole (AMEOBT) have been synthesized and their inhibitiv e action on the corrosion of mild steel in 1 M HCl has been evaluated using weight loss, potentiodynamic polarization studies and hydrogen p ermeation measurements. Determination of inhibition efficiency in the presence of these compounds at different temperatures clearly indicate s that ACLBT shows the best performance, even at a temperature as high as 60 degrees C. Potentiodynamic polarization studies reveal the fact that ABT and its derivatives act as cathodic inhibitors. All these co mpounds are found to reduce the permeation of hydrogen through mild st eel in HCl solution. The adsorption of these compounds on mild steel f rom HCl solutions obeys Temkin's adsorption isotherm. The adsorption o f 2-amino benzothiazole on the mild steel has been substantiated by Au ger electron spectroscopy.