Polyaniline/TiO2/MXene Ternary Composites for Enhancing Corrosion Resistance of Waterborne Epoxy Coatings

Waterborne epoxy (WEP) coatings are employed frequently in modern industry to prevent metals from corrosion. However, the resistance of pure WEP is not sufficient for the application requirements, so one or many kinds of fillers are utilized to improve the corrosion protection of WEP coatings. In this study, PANI/TiO2/MXene ternary composites were prepared by synchronous in situ synthesis and loading of polyaniline (PANI) rods and TiO2 particles onto MXene via a hydrothermal process and incorporated into WEP coatings as an anticorrosive filler. Electrochemical impedance spectroscopy (EIS), acid and base resistance tests, and salt spray tests revealed the excellent anticorrosion property of PANI/TiO2/MXene/WEP. EIS revealed an impedance modulus of 9.84 × 109 Ω·cm2, and the salt spray protection time exceeded 30 days. This superior performance can be attributed to the synergistic effect of the physical shielding of MXene, the passivation of PANI and the photocathodic protection of TiO2. This paper provides a methodology and ideas for the synthesizing and utilizing MXene derivatives and composites in WEP coatings for corrosion protection.