Preparation and Corrosion Resistance of Super-Hydrophobic Organic Acid Re-doped Polyaniline

Polyaniline emeraldine base (PANI-EB) was prepared through systhesis of doped polyaniline by oxidative polymerization method in sulfuric acid system and then de-doping by ammonia solution. And then, the polyaniline emeraldine base was re-doped with three different organic acids, p-toluenesulfonic acid (TSA), citric acid (CA) and dodecylbenzene sulfonic acid (DBSA), to form super-hydrophobic structure. The structure and morphology of the prepared polyaniline were characterized with Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). Corrosion resistance of the super-hydrophobic polyaniline was studied by electrochemical testing in 3.5% NaCl solution. The results show that the re-doping of organic acids could improve the hydrophobicity and anticorrosion of organic acid re-doped polyaniline effectively, and their anticorrosion performance improved with the increase of wettability. TSA re-doped polyaniline exhibited the best wettability and anticorrosion.