CALOTROPIS PROCERA EXTRACT (CPE) AS CORROSION INHIBITOR FOR COPPER IN NITRIC ACIDIC MEDIUM

The corrosion of copper in 2M HNO3 in the presence of calotropis procera separate has been researched utilizing, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PP), electrochemical frequency modulation (EFM) and weight loss techniques. Polarization studies demonstrated that, this extract acts as mixed- type inhibitor. Inhibition proficiency of this extract has been found to vary with concentration and temperature. The adsorption of this extract on the surface of copper from the corrosive arrangement has been found to obey Temkin adsorption isotherm. The thermodynamic parameters of copper corrosion in 2M HNO3 were resolved and discussed. The SEM examination and Atomic Force Microscopy (AFM) of the copper surface revealed that the compound prevented from corrosion by adsorption on its surfaces. FTIR results showed that the inhibition mechanism was by absorption process, through the functional groups present in the extract molecules.