(Z)-2-benzylidene-2H-[1, 4] benzothiazin-3-one(T1) as New Synthesized Corrosion Inhibitor for Mild Steel in 0.5 M H2SO4

Abstract

The corrosion inhibition of mild steel in 0.5 M H₂SO₄ solution by (Z)-2-benzylidene-2H-[1,4]benzothiazin-3-one: (T1)  has been studied using electrochemical polarization , electrochemical impedance spectroscopy (EIS) and weight loss methods. The corrosion inhibition efficiency measured by all the three techniques was in good agreement with each other. The results showed that T1 is a very good inhibitor for mild steel in acidic media. The inhibition efficiency increases with increasing inhibitor concentration. It acts as a mixed-type inhibitor. EIS plots indicated that the addition of T1 increases the charge-transfer resistance (R_ct), decreases the double-layer capacitance (C_dl) of the corrosion process, and hence increases inhibition efficiency. The adsorption of the T1 on the mild steel surface in acid solution obeys the Langmuir adsorption isotherm.