An electrochemical study of the action of a poly(vinylpyridine) derivativeas inhibitor for corrosion of iron in 1M H2SO4

The influence of the addition of Poly(4-vinylpyridine poly-3-oxide ethylene ) (P4VPP3OE) on the corrosion of Armco iron in molar sulphuric acid has bee n investigated by potentiodynamic and polarisation resistance measurements. The polymer studied reduces the corrosion current densities. The inhibitio n efficiency (E%) of P4VPP3OE increases with its concentration and attains 99% at 3.33 10(-5) M. E% obtained from cathodic Tafel plots and polarisatio n resistance methods were in good agreement. The inhibitor was adsorbed on the iron surface according to the Frumkin adsorption isotherm model. Polari sation measurements show also that the compound acts as a cathodic inhibito r.