Degradation of epoxy coatings cooperated with polyaniline nanowires in the outdoor environment

Abstract

Polyaniline (PANI)/epoxy composite coatings, as heavy‐duty corrosion protection coatings, might have great promise applications in marine and industrial environments. The weak weather resistance of epoxy resins, especially under the sunlight, directly reduces the service life of the epoxy composites coatings. Herein, the degradation behaviors of epoxy coatings with and without PANI nanowires in the outdoor environment were investigated by the multiple techniques and methods. The cracks occurred on the coating surface were observed by Field Emission Scanning Electron Microscopy, and the density change of the methyl group in the coatings was characterized by Attenuated Total Reflectance‐Fourier Transform Infrared spectroscopy. In addition, the mechanical properties including adhesion, hardness, flexibility and impact resistance of the coating were tested. The corrosion protection performance of epoxy coatings cooperated with and without PANI nanowires was investigated by Electrochemical Impedance Spectroscopy technique. A series of experimental results demonstrated that the degradation of the coating containing PANI nanowires was slowed down, which is attributed to that PANI nanowires served as the antioxidant and free radical scavenger in the epoxy coatings, and prolonged the service life of the epoxy resin.

UV aged epoxy coatings ̶ Ecotoxicological effects and released compounds

“…Furthermore, the UV resistance of polymers can be improved by different additives as light screens, UV absorbers, radical scavengers or quenchers ( Hawkins 1984 ). Recent studies demonstrated that the UV resistance of epoxy coatings can for example be enhanced by polyaniline nanowires ( Gao et al., 2021 ) or TiO 2 nanoparticles blended with poly-dimethylamino siloxane ( Fadl et al. 2020 ).…”