3,6-di(Pyridin-2-yl) pyridazine derivatives as original and new corrosion inhibitors in support of mild steel: Experimental studies and DFT investigational

Abstract

Corrosion inhibition performance of three new synthesized novel compounds namely, 1-((3,6-di(pyridin-2-yl)pyrdazin-4-yl)methyl)-indoline-2,3-dione (FM1), 4-(morpholinomethyl)-3,6-di(pyridin-2-yl)pyridazine (FM2) and 3,6-di(pyridin-2-yl)-4-(p-tolyl)-pyridazine (FM3) on mild steel (MS) was investigated by HCl with 1 M concentration. The corrosion inhibition performance of the synthesized compounds was studied by weight lοss, impedance spectroscopy(EIS) and potentiodynamic polarization (PDP) methods. The results showed that tһe corrosion inhibition efficiency increases with the increase in the concentration of the compounds (FMs). The PDP measurements reveal that the type of these compounds is a mixed-type behavior. The results of impedance studies (EIS) showed that in the presence of FMs, the R ct values increase while the C dl values decrease due to the adsorption of inhibitors (FMs) on the mild steel surface. EIS study showed that there is one capacitance loop related to charge transfer mechanism. The adsorption of (FMs) on the mild steel surface obeys the Langmuir-adsorption isοtherm. The 1-((3,6-di(pyridin-2-yl)pyrdazin-4-yl)methyl)-indoline-2,3-dione (FM1) showed a better inhibition performance in comparison with the FM2 and FM3. The theoretical results which shows also a good correlation with the electrochemical experiments and weight loss measurements.