Adsorption and inhibitive effect of N-[(4{[(Z)-(4-hydroxy phenyl) methylidene] amino} phenyl) sulfonyl acetamide on the corrosion of mild steel in HCl medium

Abstract

In this study, the inhibitive effects of Schiff’s base, N-[(4{[(Z)-(4-hydroxy phenyl) methylidene] amino} phenyl) sulfonyl acetamide (4-HPMAPSA) on mild steel corrosion in 1.0 M HCl(aq) at different temperatures were investigated using weight loss and scanning electron microscope. The Fourier transform infrared spectrum and X-ray diffraction pattern of 4-HPMAPSA were obtained. It was found that the inhibition effectiveness of 4-HPMAPSA relies on the temperature, 4-HPMAPSA concentration and exposure period. 4-HPMAPSA hinders mild steel corrosion and exhibits a maximum inhibitive efficiency of 88.5 % at 0.5 g of 4-HPMAPSA at 303 K. The activation energy (Ea) value (45.0 to 52.3 kJmol-1) with an average of 47.7 kJmol-1 was obtained for the 4-HPMAPSA-inhibited reaction and 35.1 kJmol-1 for the uninhibited. The thermodynamic values calculated for the 4-HPMAPSA-inhibited reaction show that the process is spontaneous and endothermic. With an R2 value of 0.9646 to 0.9999, Langmuir isotherm best described the 4-HPMAPSA uptake behaviour.