Corrosion inhibition of mild steel in 1 MH 2 SO 4 by polyvinyl pyrrolidone and synergistic iodide additives (original) (raw)

The corrosion inhibition of mild steel in 1M H 2 SO 4 by polyvinyl pyrrolidone (PVP) and the synergistic effect of iodide ions were investigated using weight loss and hydrogen evolution methods in the temperature range of 30 -60 o C. The corrosion rates of mild steel decreased with the increasing concentration of PVP, while the inhibition efficiency (%I) increased. The inhibition efficiency of PVP decreased with rise in temperature, suggesting a physical adsorption mechanism, which was found to follow Freundlich and Temkin adsorption isotherms. The inhibition mechanism was further collaborated by the values of kinetics/thermodynamic parameters obtained from the experimental data. The inhibiting action of PVP was considerably enhanced in the presence of iodide ions and values of the synergism parameter (S 1 ) obtained point to synergistic interactions between PVP and iodide ions.