Improving corrosion resistance of epoxy coating by optimizing the stress distribution and dispersion of SiO2 filler.

The steel fiber textile overcomes mostly the shortcomings of traditional reinforcement materials. However, the poor corrosion resistance severely limits service life. In this study, based on the mechanism of stress corrosion and electrochemical corrosion, the epoxy resin anti-corrosion coating was designed and prepared. First, the von Mises stress distribution of lamellar and spherical fillers in epoxy resin was studied by finite element simulation, which confirmed that the stress distribution of spherical SiO 2 filler was more uniform when it was stressed. In addition, to optimize the dispersion of spherical SiO 2 in epoxy resin, the spherical polyaniline@SiO 2 (PANI@SiO 2) composites with core-shell structure were produced with in situ polymerization method. Ultrasonic C scanning results showed that the addition of PANI@SiO 2 nano-filler can effectively reduce the defects in epoxy resin. Compared with bare steel fiber, the composites coating of 2 wt% PANI@SiO 2 /epoxy showed the most excellent resistance to stress corrosion and electrochemical corrosion. The capacitance diameter is two orders of magnitude higher, which has good stability in simulated concrete pore solution. This is due to the fact that the addition of PANI@SiO 2 nanomaterials improves the physical shielding properties of epoxy, creating a labyrinth effect, and that PANI can produce passivation on the metal surface. • The finite element results showed that the spherical filler could improve the stress corrosion resistance of the epoxy composite coating. • Spherical PANI@SiO 2 composites with core-shell structure were successfully prepared, and the coating rate of PANI reached 21.04 %. • The addition of PANI@SiO 2 nanofillers could effectively reduce the defects in the epoxy resin. • The impedance spectrum of the 2 wt% PANI@SiO 2 /EP anticorrosive coating was 6 × 105 Ω/cm2 and showed good stability. [ABSTRACT FROM AUTHOR]