The Synthesis, Characterization, and Evaluation of a Polypyrrole/ Aluminum Flake Composite Pigment

Abstract

The goal of this study was to synthesize a polypyrrole/aluminum flake composite pigment to inhibit corrosion on aluminum alloy 2024 T3. This was done in order to remedy some of the problems associated with the application of pure polypyrrole as a coating. Namely these problems are insolubility in common solvents, brittleness, poor adhesion to metal substrates, and catastrophic failure in some conditions due to fast ion incorporation. By incorporating the polypyrrole composite pigment into an epoxy primer, the superior mechanical properties of the epoxy binder can be combined with the corrosion inhibiting properties of the polypyrrole. Results indicated that the dopant of the polypyrrole played a large role in the corrosion inhibition of the substrate. While the sulfate doped sample inhibited corrosion in areas underneath the coating, it did not inhibit corrosion in defect areas. The vanadate doped and molybdate doped pigments did inhibit corrosion in defect areas.