The corrosion inhibition and adsorption of 4-(n-Chlorobenzylideneamino)-5-methyl-2,4-dihydro-1,2,4-triazole-3-thione (n-CBAT) Schiff bases has been investigated on steel electrode in 1.0 M HCl by using weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that all n-CBAT are good inhibitors, and inhibition efficiency follows the order:4-CBAT <3-CBAT <2-CBAT. Polarization curves reveal that all studied inhibitors are mixed type. The adsorption of each inhibitor on mild steel surface obeys Langmuir adsorption isotherm. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability. The effect of temperature on the corrosion behavior with addition of 1×10−3Mof n-CBAT added was studied in the temperature range 30–60◦C. The thermodynamic parameters activation were determined and discussed.
Keywords: Carbon steel; Corrosion inhibition; Schiff bases; Triazole; Electrochemical techniques.