Inhibition study of mild steel corrosion in hydrochloric acid by new class synthesized 1,4-benzothiazine derivative

Inhibition performance of 2-(3-oxo-2,3-dihydro[1,4] benzothiazin-4-yl)acetic acid named (P1), newly syn thesized on the electrochemical behavior of mild steel in molar hydrochloric acid was investigated by using the we ight-loss method, potentiodynamic polarization and electroche mical impedance spectroscopy (EIS) measurements. EI S diagrams show that adsorption of (P1) increases the transfer resistance and decrease the capacitance o f interface metal/solution. The inhibition efficiency for this compound studied increased with the increase in the inhibitor concentrations to attain 93% at the 10-3M of (P1). Effect of temperature is also studied between 308 a nd 353 K. Correlation between quantum chemical calculations a nd inhibition efficiency of the investigated compou nd is discussed using the Density Functional Theory metho d (DFT)