Abstract:
Polymeric Schiff base containing aniline, formaldehyde and piperazine (AFPP) was synthesized and investigated as corrosion inhibitor for mild steel in 1 M HCl by weight loss measurements, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. Experimental results showed that AFPP is an effective inhibitor for mild steel in 1 M HCl and exhibited 98% inhibition efficiency. Potentiodynamic polarization studies showed that AFPP is a mixed-type inhibitor predominantly cathodic type. The adsorption of inhibitor on the mild steel surface followed Langmuir adsorption isotherm. Activation energy (Ea), standard energy of adsorption (DGads), enthalpy of activation (DH*), and entropy of activation (DS*) of corrosion process were calculated and discussed.