UV-cured acrylated PANI/graphene oxide nanocomposite coating with superior anticorrosive protection and self-healing abilities

Successfully synthesized polymerizable nanoflakes composed of acrylated polyaniline (Ac-PANI)/graphene oxide (GO) demonstrate synergistic corrosion resistance enhancement. Comprehensive analyses of the chemical composition, thermal stability, and surface morphology of the Ac-PANI/GO (PGO) nanoflakes were conducted using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis (TGA). Subsequently, varying amounts of the prepared PGO were employed to enhance the anti-corrosion performance of the environmentally friendly UV-cured polyurethane matrix. Physico-mechanical properties of the coatings were evaluated through dynamic mechanical thermal analysis, TGA, gel content measurement, and adhesion strength tests. Incorporating 2 wt% PGO resulted in a significant improvement in cross-link density, thermal stability, adhesion strength, and modulus compared to the pure polymer coating. The anti-corrosion performance of the nanoflake filler in both the solution phase and within the coating matrix was demonstrated through electrochemical impedance spectroscopy and polarization tests. The results indicated substantial corrosion mitigation in both states. Under optimal conditions with 2 % wt PGO, impedance values increased by over two orders of magnitude compared to the pure polymer coating. Even after 50 days of immersion, the coating with 2 wt% PGO maintained a high impedance of 1.11 × 109 Ω.cm2, surpassing other coatings. This exceptional anti-corrosion performance was attributed to the synergistic effect of the excellent barrier properties resulting from well-dispersed PGO in the UV-cured polymer matrix and the formation of a passive metal oxide layer induced by the polymerizable Ac-PANI present in the composition of the PGO nanocomposite.