Gravimetric, electrochemical and quantum chemical studies of some pyridazine derivatives as corrosion inhibitors for mild steel in 1 M HCl solution

• Three pyridazine derivatives were tested as corrosion inhibitor for mild steel.
• The inhibition efficiencies follow the order of PPYS > PPYO > MPYO.
• The inhibition efficiency increases with inhibitor concentration and temperature.
• The inhibitor molecules form a good protective film on the mild steel surface.
• Experimental and quantum chemical studies agree well.

The corrosion inhibition performances of three pyridazine derivatives, 6-methyl-4,5-dihydro-2H-pyridazine-3-one (MPYO), 6-phenyl-2H-pyridazine-3-one (PPYO) and 6-phenyl-2H-pyridazine-3-thione (PPYS) for mild steel in 1 M HCl solution were studied by gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Some thermodynamic parameters were calculated and discussed. The effect of molecular structure on the inhibition efficiency was theoretically studied by density functional theory (DFT). Experimental and theoretical studies agreed well and confirmed that PPYS is the best corrosion inhibitor among the studied organic compounds which was related to the presence of a more favorable adsorption center of S atom in its molecular structure.

The corrosion inhibition performances of three pyridazine derivatives for mild steel in 1 M HCl solution were studied by gravimetric, potentiodynamic polarization, electrochemical impedance spectroscopy and quantum chemical studies. PPYS is the best corrosion inhibitor among the studied organic compounds which was related to the presence of a more favorable adsorption center of S atom in its molecular structure.Figure optionsDownload as PowerPoint slide