In situ investigation of corrosion localised at the buried interface between metal and conducting polymer based composite coatings

Conducting polymers are controversially discussed for application in corrosion protection. In our earlier work we presented a hypothesis for explaining why sometimes very good performance is observed and sometimes fast and disastrous coating break-down, especially in the presence of defects in the coating. By avoiding continuous macroscopic networks of conducting polymer in composite coatings the latter can be prevented, opening up the application of conducting polymers for secure performance in intelligent corrosion protection. In this paper we add further proof. However, at the interface between coating and metal, corrosion induced by galvanic coupling between conducting polymer and the metal still remains a problem, even in the absence of defects in the coating. Now we found that for some metals this corrosion at the buried interface can be studied in situ by Scanning Kelvin Probe microscopy, providing the means to better develop strategies for counter acting this problem.