Effect of polyaniline-modified glass fibers on the anticorrosion performance of epoxy coatings

Polyaniline (PANI) and different mass ratios of polyaniline/glass fiber (GB) composites (PANI/GB, PGB) were prepared through in situ oxidative polymerization. The chemical structure of composites was investigated via Fourier transform infrared spectroscopy and X-ray diffraction. Epoxy coatings loaded with different mixtures of PANI and GB were applied on steel substrate and exposed to NaCl solution. The morphological properties and corrosion resistance of the coatings were investigated through environmental scanning electron microscopy, electrochemical impedance spectroscopy, and salt spray tests. Results showed that the addition of PANI, GB, and PGB composites caused an improvement in corrosion resistance. The greatest improvement in corrosion resistance was exhibited by the coatings loaded with mass ratio of 1:1 of PANI/GB. This enhancement was attributed to the corrosion resistance of PANI and penetration resistance of GB. Moreover, the uniform distribution of PGB composites in the epoxy resin is an important parameter affecting corrosion resistance of the coatings.