Fracture Toughness Healing in Epoxy Containing Both Epoxy and Amine Loaded Capsules

The feasibility of self-healing epoxy matrices using the same chemistry as the matrix material, namely a standard epoxy-amine system, is demonstrated. The two-component self-healing system is encapsulated in core-shell structures using standard in situ curing in a stirred emulsion and a novel microfluidic encapsulation technique for the epoxy monomer and the amine hardener, respectively. The recovery of fracture toughness after room temperature healing is above 50%, and increases to 100% when shape memory alloy wires are combined with a low temperature cure of the matrix to enhance crack closure. This healing ability is also preserved for higher curing temperatures, demonstrating the potential of this novel approach.