Vitrimer Patches for Epoxy/Carbon Fiber Damage Restoration (VIPER)

The availability of resources diminishes when naval fleets are forward deployed in contested zones. Naval manufacturing applications require minimal resources to carry out mission-critical repairs. Repairing composite structures is increasingly difficult in contested zones where freezers, prepregs, manufacturing equipment, and ovens are not readily available. Instead minimal equipment such as dry fiber, two-part resin, vacuum bags, and heated blankets are used to carry out repairs [1]. This current repair method does come with its drawbacks in terms of strength and performance knockdowns that can create unknown risk for service members operating the vehicles. Moreover, the requirements for vacuum bagging, extensive heating and mixing the resin parts are rather labor intensive. Vitrimers, a type of thermosetting resin with exchangeable bonds (i.e., Covalently Adaptive Network - CAN), has the potential to close the gap of strength knockdown presented by current repair jobs. Additionally, vitrimer composites can simplify the repair process through the use of prepreg kits over standard wet layup repairs for contoured surfaces. ATSP Innovations and team partners Texas A&M University and Terzima LLC propose use of crosslinkable aromatic copolyester oligomers to provide effective field patch repair capabilities without necessitating a wet lay-up process or refrigeration necessary for long-term storage of traditional thermosetting polymer matrix composite prepregs. We propose to produce a suitable vitrimer resin chemistry and resin prepreg for repair kits; Perform patch repair on flat surfaces; demonstrate mechanical property characterization of the vitrimer laminate joints on flat surfaces; and perform patch repair on curved surfaces and mechanical property characterization of the vitrimer laminate joints on contoured surfaces.