Transverse tensile strength of unidirectional fibre-reinforced polymers and self-healing of interfacial debonding

A study of the healing of interfacial debonding in fibre-reinforced polymers (FRPs) was performed. In the composite, a microencapsulated healing agent and a solid chemical catalyst are dispersed within the coating layer on the surface of the fibres. Healing is triggered by crack propagation through the microcapsules, which then release the healing agent into the crack plane. Subsequent exposure of the healing agent to the chemical catalyst initiates polymerisation and bonding of the crack faces. Self-healing is demonstrated on flat tensile specimens of neat epoxy (no fibres) and unidirectional FRPs. The ratio of tensile strengths of the virgin and healed materials is used to quantitatively measure crack healing.