Photothermal healing performance of oxidized carbon black/epoxy vitrimer composite coating for metal protection

Epoxy vitrimers with thermal-healing ability are widely studied to prolong the service life of materials. But the conventional preparation and healing strategy, involving external catalysts, preheating, hot press or/and heating the entire coating, are not applicable for the large-scale applications. In this work, a room-temperature brushable oxidized carbon black (OCB)/epoxy vitrimer composite based on dynamic transesterification reaction with excellent protective performance and localized photothermal-healing was prepared by solvent method. No external catalysts, preheating and hot press was needed in the preparation process. The experimental results demonstrate that the composite coatings exhibited an excellent metal protective performance. The effective non-contact local photothermal-healing can be achieved in 20 Min., and the scratch width can apparently narrow over 95 % and the impedance moduli of the composite coatings can be recovered from 263 Ω·cm2 to above 108 Ω·cm2. The OCB/epoxy vitrimer composite coating, combining ideal metal protective performance with non-contact local photothermal-healing performance, has great promise for many practical applications in large-scale, such as metal protection and solar-energy collector.