Influence of 3-acetylpyridine phenylhydrazone on the corrosion of carbon steel in hydrochloric acid

Abstract

The corrosion inhibition capacity of the 3-acetylpyridine phenylhydrazone (APPH) has been investigated by gravimetric studies and electrochemical investigations like EIS and Tafel polarization analyses. Present study reveal that APPH act as a potential corrosion inhibitor on carbon steel even when the molecules are hydrolyzed in acid medium. Polarization studies establish that the molecule show mixed type corrosion inhibition on CS surface. Results obtained from these techniques are comparable and the hydrazone obey Langmuir adsorption isotherm on the corroding metal surface. Thermodynamic parameters of corrosion such as activation energy (Ea), enthalpy and entropy of activation of corrosion (∆H* and ∆S*) have also been estimated. Surface analysis using AFM confirm the adsorption of APPH molecules on the metal surface.