Cure On Demand Conductive Sealant for Rapid OML Repair

The use of sealants in aircraft assembly and repair is extensive. Sealants are used to wet install fasteners, for sealing overlapping surfaces, for butt joints between panels, and for seam sealing. Aerospace sealants are typically two component polysulfide or polythioether compositions that can cure by oxidation, for example with MnO2, or by cross linking with epoxy resins. In order to engineer a sealant with rapid cure, the open time must be extremenly short. Premixed and frozen sealants have improved storage and application, but there is still room for enhancement. In this Phase I program, Luna proposes to demonstrate the feasibility of incorporating cure on demand functionality into a conductive aerospace adhesive. The resulting product would be one that does not need to be premixed, is stable at room temperature, has a long open time, and cures quickly when desired. In the Phase I program, Luna will develop the cure on demand resin chemistry, formulate a conductive sealant, and demonstrate application and performance properties. BENEFIT: The development of the cure on demand resin technology will be applicable to a range of sealants and adhesives for commercial and military aerospace applications. The cure on demand sealant will save costs and increase efficiency by avoiding critical mixing steps. Waste will also be significantly reduced because only the sealant that is used is cured. Unlike standard two component selants, unused Luna sealant will remain uncured and can be used later.