Synthesis of new aromatic azo-schiff compound as carbon steel corrosion inhibitor in 1 M H2SO4; High efficiency at low concentration

Abstract

Schiff base derivative (AS) namely (4-((E)-(4-hydroxy-3-((E)-(phenylimino) methyl) phenyl)diazenyl)benzonitrile) was synthesized and tested as corrosion inhibitor for the carbon steel alloy in 1M sulphuric acid at different concentration (0.005, 0.01, 0.02, 0.04 and 0.08 mM) over temperature rang (303-333) K. Potentiodynamic polarization, weight loss, atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques have been used in the study. The results revealed that the inhibition efficiency increases as inhibitor concentration increases and decreases with the increasing the temperature. The maximum inhibition recorded efficiency 98% and 97.5% by potentiodynamic polarization and weight loss methods respectively at 303 K in the presence of 0.08 mM of AS. Ecorr values Proof that AS act as mixed type inhibitor. Adsorption isotherm of AS on the carbon steel surface obeys Langmuir adsorption isotherms model.