Synthesis in phytic acid medium and application as anticorrosive coatings of polyaniline-based materials

Abstract

Polyaniline (PAni) and PAni/jackfruit latex (Lx) were chemically synthesized in a modified medium, namely aqueous phytic acid (HPhy), in order to obtain effective anticorrosive coatings. Spectroscopic, microscopic and diffractometric results show that PAni structure and morphology are altered because of the acid medium and the presence of latex. Electrochemical assays show that coating ennobles carbon steel surface, however the films are permeable to the electrolytic solution. In addition to that, PAni films shifted corrosion potential (Ecorr) of carbon steel to nobler values (ΔEcorr up to 663mV in the case of PAni/Lx blend) and they presented high adherence to the metal surface, as observed by optical microscopy. The polymeric materials synthesized in HPhy medium were more effective as protective coatings than the one synthesized in H2SO4 medium. The performance of those materials suggests that they can be used as primers for protection of steel surfaces. Moreover, the obtained materials can be likewise appropriate anticorrosive coatings for other metallic materials.