Dual-Cure Resins for Rapid Composite Repair and Fabrication

A new family of dual-cure thermoset resins is proposed for formulating adhesives that can be processed at room temperature for bonding composite materials and metals. The proposed research explores the feasibility of modifying convertional thermoset resins such as polyepoxides with other compatible and complementary curing polymers to produce new classes of UV light initiated, ambient temperature curing adhesives. The ultimate objective is to develop an easily processed adhjesive with high adhesion to reinforcing fibers and cured composite materials, no cure sensitivity to oxygen, and the ability to be used in composite fabrication processes such as pultrusion. The proposed hybrid systems cure by a combination of chemical processes which take advantage of complementary reactions and thus result in faster cure rates than either conventional resin system alone. In the proposed study, the candidate materials for these resin blends will be identified, a new type of UV-activated curing agent synthesized, the compatibility of different resin components predicted by computer simulation, structure-property profiles determined and the ability to cure into useful materials by UV light initiation demonstrated. Adhesion properties of the candidate formulations and controls with metals and fiber-reinforced composites will be measured and compared.