experimental and theoretical studies of schiff bases derived from 3,4-diamino pyridine as corrosion inhibitors for carbon steel n80 in acidic medium

Two schiff base compounds, s1 and s2, were synthesized from 3,4-diaminopyridine with 4-chlorobenzaldehyde and 4-diaminobenzaldehyde, respectively. these compounds were then characterized using various spectroscopic techniques, including ultraviolet-visible spectroscopy, infrared spectroscopy (ftir), proton-nuclear magnetic resonance spectroscopy (1h-nmr), carbon-13 atom magnetic resonance spectroscopy (13c-nmr), and electron ionization mass spectrometry (ei-mass). the tafel curve is a method used to measure electrochemical polarization. the findings of this investigation verified that the corrosion rate was more significant when inhibitors were not present but decreased when s1 and s2 inhibitors were introduced. the study also examined the activation energy and thermodynamic parameters of free energy (δg0), enthalpy (δh0), and entropy change (δs0) using langmuir adsorption isotherms. the electrochemical approach (tafel extrapolation) verified that the developed solvents (s1 and s2) successfully inhibit corrosion by creating a protective film on the surface of the carbon steel.