ABSTRACT
Extensive research and field studies have resulted so far in novel approaches by which conducting polymer (CP)-based coatings seem promising in replacing effectively the chromate-based processes because of the favorable self-healing property of CPs. Through the implementation of novel approaches and evaluation results, a deeper understanding of how corrosion protection by CPs works is simultaneously gained. In view of Chapter 3, corrosion protection by CPs can be understood so far by several mechanisms: (1) active electronic barrier, (2) anodic protection and self-healing either through “ennobling effect” or controlled inhibitor release after an electrochemical triggering due to corrosion initiation, (3) cathodic protection through a displacement of the oxygen reduction reaction (ORR) from the metalelectrolyte interface to the CP-electrolyte interface, and (4) physical barrier between metal and environment. From previous chapters, it became clear that more than one mechanism can work simultaneously providing anticorrosion protection. Therefore, the success or failure of an organic coating depends on a variety of factors, usually more than one. Although much more research is certainly needed to understand the mechanisms by which CP-based coatings can prevent or retard corrosion of metals and alloys, the knowledge acquired so far by numerous studies may lead researchers to properly design coatings based on CPs by avoiding their negative effects and improving their protective efficiency. Many approaches for designing effective CP-based coatings can be found in Chapter 4 among different coating formulations, all aiming both to improve the anticorrosion performance and prolong the lifetime of coatings. These include different top coats of CP primers, CP-based blends, composites, and paints with CP as additives.
