Inhibition of Carbon Steel Corrosion by Polyvinylpyrrolidone in Chloride-Acetate Solution and in Model Stratal Water

The influence of polyvinylpyrrolidone (PVP) with molecular mass of 12 600 and 28 000 at concentrations of 0.2; 0.5 and 1.0 g/dm³ on the corrosion rate of 20 steel in the chloride-acetate solution and in the model stratal water was investigated by gravimetric and electrochemical methods. Under dynamic conditions maximum inhibition of the steel corrosion rate was observed at a PVP concentration of 0.5 g/dm³ in both environments. A further increase in inhibitor concentration to 1.0 g/dm³ reduces the degree of protection more significantly in chloride-acetate solution than in the stratal water. The PVP with a higher molecular mass reveals higher protective properties, which is typical of polymers capable of adsorbing both linearly and in a ball.