Synthesis of Polyaniline Nanofiber and its Anticorrosion Property for Q235 Steel in Epoxy Resin

In four kinds of inorganic acids,the polyaniline(PANI) nanofibers were prepared separately by direct mixed oxidation method and interfacial polymerization method.The characterizations of the prepared PANI nanofibers obtained from SEM images show that the higher quality of PANI nanofiber can be obtained by direct mixed oxidation method in compare with that obtained by interfacial polymerization method.Especially when the preparation is in the sulfuric acid system,the excellent nanofibers with uniform diameter and several microns length were obtained.The structural characterizations of the PANI products obtained from the IR and UV spectra indicate that the products obtained in sulfuric acid are the doped PANI.Furthermore,selecting the sulfuric acid-doped PANI as one of the components,the PANI-epoxy composite coating were prepared by mechanical grinding,and then the anticorrosion properties of the prepared composite coatings on the Q235 steel were studied by electrochemical impedance spectra.The results show that the initial shielding protection of the composite coating is improved by the addition of PANI,but after soaking,the protection declines rapidly.