LAUSR

For the corrosion of carbon steel in 1.0 M HCl solution, the new pyrazolone derivatives (PY1 and PY2) have been identified as active corrosion inhibitors. Clear evidence of the inhibitory effect of pyrazolone derivatives is given by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) measurements. The synthesized compounds were characterized by spectroscopic and 1H-NMR techniques. The purity of compounds was confirmed by TLC. Our findings show that pyrazolone compounds inhibited the corrosion of carbon steel in the acid medium. Inhibition efficiency increases with the increase in concentration of compounds. The inhibition efficiency of PY2 was higher than that of PY1. These inhibitors obey the Temkin adsorption isotherm. It was found that the pyrazolone derivatives act by physisorption on carbon steel.