A range of epoxy blends were investigated to determine their mechanical properties and suitability for use as healing agents for the repair of fibre-reinforced polymer (FRP) composites. Key requirements for an effective healing agent are low viscosity, and good mechanical performance. A base epoxy resin was selected and blended with a variety of diluents and a toughening agent, and the physical and mechanical properties of the resulting polymers were investigated. Single lap shear strengths of up to 139% of the base epoxy values were demonstrated, while double cantilever beam testing showed specimens healed with optimised epoxy blends can provide recoveries in fracture toughness of up to 269%, compared to 56% in specimens healed with the base epoxy resin. Cross-ply FRP laminate tensile specimens were used to highlight the potential to recover stiffness decay caused by intraply cracking. Following infusion of the damage via embedded vascules, the toughened epoxies were capable of providing complete recovery of stiffness.
Bibliographical noteDate of Acceptance: 26/02/2015, E-pub ahead of print 7 Mar 2015
- Self-healing materials
- Toughened epoxies
- Composite materials