Shelf-Stable, Low-Temperature Cure Epoxy Film Adhesive for On-Aircraft Bonded Repair

Epoxy film adhesives used for on-aircraft bonded repairs require refrigerated storage and have relatively short shelf-lives. Adhesives that are storage-stable at ambient temperature for one to two years but process and cure at low temperatures are needed to economically utilize bonded repair technology on aircraft. Foster-Miller proposes to develop a shelf-stable epoxy film adhesive (SSEFA) that can be stored for one year at 43C (110F) without loss in processibility or performance and then undergo rapid cure upon heating to 200F. The cured adhesive will meet MIL-A-25463B requirements and will have lower life cycle costs compared to currently available film adhesives. In Phase I, we will examine two approaches to producing a one-part, shelf-stable, 200F cure epoxy film adhesive that is ideal for on-aircraft bonded repair. The one part adhesive developed in the proposed program will require no metering or mixing, a desirable feature that will eliminate problems associated with improperly formulated adhesives. In Phase I, we will demonstrate feasibility of achieving target adhesive shelf-stability, reactivity and performance using an epoxy paste adhesive. The Technology will be extended to film type adhesives in Phase II> The SSEFA will find wide application as an adhesive for aircraft, spacecraft, automobiles, ships, and industrial structures. We have assembled teaming partners who are leaders in the key enabling technologies to work with us in the Phase I and Phase II programs.