Metal triflates as catalytic curing agents in self-healing fibre reinforced polymer composite materials

A self-healing, high performance, fibre reinforced polymer (FRP) composite material is demonstrated by employing a Lewis acid-catalysed epoxy self-healing agent (SHA) within a laminate manufactured using existing industrial methods. Thermal cure analysis and mechanical testing is employed to characterise the self-healed polymer. A bio-inspired series of vascules incorporated into an FRP composite material facilitates the delivery of SHAs to exposed fractured crack planes. Healing is effected by ring-opening polymerisation (ROP) of an epoxy resin using novel metal triflate catalysts injected after Mode I crack opening displacement. Strong adhesive compatibility with the host matrix confers full recovery of mechanical properties (>99% healing). An in-house developed Lewis acid-catalysed self-healing system, comprised of solid-phase metal triflate catalysts and diglycidyl ether bisphenol A (DGEBA) epoxy resin, is employed to achieve full fracture toughness recovery of the fibre reinforced polymer composite material. Mechanical testing of the healed material clearly shows a ductile failure, a failure mechanism not typically associated with inherently brittle materials such as epoxy.