Anti-iCorrosion Performance of Polypyrrole/Polyaniline Composite Conductive Polymers

Composite conductive polymers consisting of polypyrrole(PPy) and polyaniline(Pani) were synthesized successfully using cyclic voltammetry technique with 0.3 mol/L oxalic acid in the corresponding monomer solutions.The properties of the anticorrosion assembled with conducting polymers were investigated by IR,polarization curve,SEM,electrochemical impedence spectroscopy and free corrosion potentials.The result has shown that in 1 mol/L H2SO4,composite conductive polymers have the redox reaction with the stainless steel substrate,deactivating the stainless steel surface.When the molar ratio of aniline and pyrrole is 1∶ 3,the prepared composite conductive polymers protect stainless steel with the minimum corrosion current,the highest corrosion potential,and the longest protected time.Electrochemistry impedance measurements indicate that the polypyrrole and polyaniline have the redox reaction with the stainless steel substrate,promoting the stainless steel surface passivation;however,the deactivated membrane may be destroyed and cause the stainless steel to be corroded when Cl-diffuses to the stainless steel surface.