Repetitive self-healing of Diels-Alder grafted graphene nanoplatelet reinforced carbon fiber reinforced polymer composites with outstanding mechanical properties.

The concept of using bio-inspired healing mechanisms in fiber-reinforced polymer (FRP)-based laminated composites is one of the trending areas of research for lightweight high-performance materials. To introduce self-healing in laminated composites, we developed Diels-Alder (DA) grafted graphene nanoplatelets (GNPs) and introduced them into carbon-fiber-reinforced polymer (CFRP) composites. The DA-grafted GNPs provided dual benefits, such as repetitive self-healing along with an increased mechanical performance of the modified CFRP. The GNPs were functionalized with DA adducts, i.e., bismaleimide and furfurylamine via a facile functionalization approach. The highest healing efficiency evaluated using double cantilever beam (DCB) tests was observed as ∼87% with more than 10 times repeated healing cycles. The innovative concept and strategy proposed in this work could be a gateway to a new area of research to upscale for industrialization of DA-based repetitive self-healable and durable CFRP-based composites.