Improvement of the corrosion protection of polypyrrole coating for CT3 mild steel with 10-camphorsulfonic acid and molybdate as inhibitor dopants

This paper presents the doping influence of both molybdate anion and 10-camphorsulfonic acid (CSA) on the characterization and corrosion protection properties of polypyrrole (PPy) film prepared on passivized CT3 mild steel. The effect of CSA and molybdate anion concentrations on the properties and morphology of PPy film was characterized by Raman, FTIR, EDX and SEM methods. The doping of both CSA and molybdate anion into the PPy film can lead to an increase in the thermal stability and redox properties of the PPy film. The PPy film doped with both CSA and molybdate anion displayed excellent anti-corrosion ability for CT3 mild steel in comparison with the PPy film and PPy film doped with only CSA or molybdate anion. Furthermore, the salt spray test was also carried out to more effectively evaluate the corrosion protection of doped PPy film for mild steel.