Study on Synthesis of Doped Polyaniline with Alumina and its Anticorrosion Properties as an Additive in Paint Coating

In this study, polyaniline nanocomposite with aluminum oxide (PANI/Al2O3) was synthesized in situ polymerization method and the anti-corrosion ability of nanocomposite was investigated. Products were identified by chemical analysis of Fourier Transform InfraRed (FT-IR) spectroscopy, X-ray crystallography (XRD), and thermal weighing calorimetric analysis (TGA). Also, anti-corrosion properties were analyzed by Open Circuit Potential (OCP)analysis, Electrochemical Impedance Spectroscopy (EIS), and potentiodynamic polarization curves. To investigate anti-corrosion performance, different percentages of nanocomposites (3, 6, 9, and 12 %) were added to industrial paint and applied to steel sheets as a coating. The results of corrosion performance illustrated that the steel sheets coated with PANI/Al2O3 nanocomposites along with the paint, have less corrosion compared to the samples of pure steel sheets and the cases coated with PANI/Al2O3 nanocomposites. Also, the 6 % coating containing PANI/Al2O3 nanocomposite along with paint on steel sheets showed the best anti-corrosion properties. The open-circuit potential analysis results make it clear that the coatings containing PANI/Al2O3 nanocomposite with paint have a higher performance compared to pure paint coatings in 3 wt% NaCl solution. EIS analysis revealed resistance of the coating containing 6 % PANI/Al2O3 along with the paint is more than other samples in 3 % NaCl solution.