Corrosion resistance of itaconic acid doped polyaniline /nanographene oxide composite coating

Graphene oxide (GO) and polyaniline (PANI) are very unique materials with broad potential in corrosion protection coating. To achieve the maximum stability and anti-corrosion effect in a polar medium, firstly itaconic acid doped PANI (DP) was readily prepared by a one-step method, followed by forming a GO and DP composite (GODP). Characterization by Fourier transform infrared spectroscopy and ultraviolet-visible absorption spectra provides evidence for the successful doping of itaconic acid in PANI. X-ray diffraction analysis shows that the d-spacing of the GO sheets increases slightly with the intercalation of DP. The morphological studies show disordered structures in GODP compared with the original GO sheets due to the introduction of PANI molecules and the interaction of functional groups on the surface of the GO sheets. Thermogravimetric analysis reveals the good thermal stability of DP and GODP. Quantum calculation further confirms the successful doping of itaconic acid, and the effective complex of GO and DP, providing a quantitative understanding of the curing mechanism. The crosslinking interaction among the GODP, curing agent, and epoxy resin facilitates the formation of a compact coating, leading to excellent corrosion resistance toward Mg alloy.