The synergistic role of azomethine group and triazole ring at improving the anti-corrosive performance of 2-amino-4-phenylthiazole

Abstract

2-Amino-4-phenyl-N-benzylidene-5-(1,2,4-triazol-1-yl)thiazole (APNT) and 2-amino-4-phenylthiazole (APT) were selected as the investigated subject to study the effect of replacement and addition on the corrosion inhibitory efficiency of mild steel in a 1 M HCl environment. Experimental results from weight loss techniques show that the substitution of triazoles in the thiazole ring, as well as the addition of benzildine to the amino group, increases the anti-corrosion efficacy of APNT (98.1%), which is higher than that of ATP (94.7%) with the same reaction conditions, the concentration (500 ppm) of the corrosion inhibitor, as well as the temperature (303 K) of the solution and the exposure period (5 h). The experimental results exhibit that increasing the APNT and APT concentrations will improve the inhibition efficiency. The experimental findings obtained from weight loss measurements are dependent on the interpretation of the scanning electron microscopy photographs. The adsorption of APNT or APT molecules on the mild steel surface followed Langmuir adsorption model. Moreover, the quantum chemical demonstrate that the substitution of a triazole in the thiazole ring and also the addition of benzylidene in the APNT are the adsorption sites, and increase the interaction of the APNT molecules with the iron atoms on the surface of mild steel.. A comparative theoretical study of APNT and APT molecules, as corrosion inhibitors were performed using density functional theory (DFT) with the B3LYP functional basis set. Density functional theory (DFT) data have illustrated the mechanism of adsorption of APNT as tested inhibitor on the mild steel surface.

Keywords

• 2-amino-4-phenylthiazole
• Corrosion inhibitor
• DFT
• Langmuir
• Adsorption