An-Najah Staff

A new corrosion inhibitor, namely diethyl 2-(2-oxop yrrolidin-1-yl) ethyl phosphonate (P1) was synthesized and its action on the corrosion of stee l in 0.5 M H 2 SO 4 solution has been studied. Weight loss measurements, potentiodynamic polarisat ion and linear polarisation resistance (Rp) and impedance spectroscopy (EIS) methods have been used. The inhibition efficiency increases with the concentration of P1 to attain 86% at 5.10 -3 M. We have noted a good agreement between gravimetric and electrochemical methods (po tentiodynamic and Rp polarisation and impedance spectroscopy (EIS)). Polarisation measure ments show also that the pyrrolidone derivative acts essentially as a cathodic inhibitor . The cathodic curves indicate that the reduction of proton at the steel surface is an acti vating mechanism. P1 adsorbs on the steel surface according to Langmuir adsorption model. Eff ect of temperature is also studied in the 298-353 K range.