In-situ grafted graphene oxide-based waterborne epoxy curing agent for reinforcement corrosion protection of waterborne epoxy coating

Abstract Well-dispersed graphene oxide (GO) in resin matrix has been found for improving corrosion protection performance of the coatings. In this paper, a new strategy relying on waterborne epoxy curing agent contained GO (GO-WCA) was developed, which was prepared via endcapping, modifying and in-situ grafting process. Wherein, endcapping includes blocking the high-activity hydrogen which is used to modulate curing activity. And the modifying process introduces homologous epoxy segment so as to improve compatibility between curing agent, resin matrix and GO. Attributing to this evolvement of WCA and superior barrier effects of GO, the epoxy coatings cured by GO-WCA exhibit desirable corrosion protection capacity. Besides, the failure mode is discovered as bubbling. This environmentally-friendly waterborne curing agent, only with 4.2 g/L VOC content, is anticipated to become available in diverse waterborne epoxy coatings system with excellent barrier property.