Developing of Polyaniline Coating on Rotating Steel Cylinder for Improving Its Corrosion Resistance

This work investigates the possibility of using polyaniline (PANi) coating for improving the corrosion resistance of rotating cylinder subjected to saline solution. Galvanostatic technique was used for PANi layer formation under different conditions of current density, aniline monomer concentration, oxalic acid concentration and solution pH. The potentiodynamic technique was used for examination of PANi coated steel in corrosive medium composed of 3.5% NaCl under different rotating speed ranging from 200 to 1000 rpm. The results show that PANi layer formation at 0.5M aniline concentration, 0.3M oxalic acid concentration, current density of 20mA/cm(2) and solution pH within the range from 1 to 2 has the better performance of the formed PANi layer against corrosion. The results show that coating steel with PANi layer can improve it corrosion resistance by a factor ranging from 1.2 to 1.8 compared to bare steel depending on the conditions at which the polymer layer was formed and the rotating speed.