Experimental and theoretical approach to the anticorrosive efficiency of styrylbenzothiazolium derivatives on mild steel in acidic medium
Khalid Dakhsi, Abdeslam El Amri, Mohamed El Mehdi Mekhzoum, Rachid Bouhfid, Nadia Dkhireche
Abstract
Two benzothiazolium derivatives, BFZ1 and BFZ2, were synthesised and were extensively characterised by ¹H and ¹³C NMR, FTIR spectroscopy and mass spectrometry. Density functional theory (DFT) calculations indicated that BFZ1 is more reactive, whereas BFZ2 is more chemically stable. The anticorrosive performance of these materials on mild steel in 1 M HCl was evaluated via electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation (PDP). Both inhibitors showed high efficiencies of 94% for BFZ1 and 95% for BFZ2 at an optimum concentration of 400 ppm. Scanning electron microscopy (SEM) confirmed the formation of a protective layer on the metal surface. This was also confirmed by the Langmuir isotherm. The results underline the industrial potential of the two molecules FBZ1 and FBZ2 as effective inhibitors of corrosion on metal surfaces in acidic environments.