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


  • The authors gratefully acknowledge the financial support of the Swiss National Science Foundation (SNSF 138213), the ETH Zurich grant ETHIIRA (0-20676-10) as well as the technical assistance of K. A. Fröhlich.


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.