Description: Through the proposed STTR program, NanoSonic and Virginia Tech will create an innovative low viscosity, high Tg copolymer injection repair material and methodology that enables fiber reinforced composite repair within a short time frame in areas with limited user access. The proposed injection repair material will consist of fluidic HybridSil poly(siloxane imide) resins that are molecularly engineered to 1) rapidly infiltrate microcracks within damaged composites areas, 2) covalently bond to functionalized composite fibers for exceptional adhesion and mechanical restoration, and 3) cure on the order of minutes through moisture sensitive moieties. NanoSonic?s composite repair material will contain novel, phase separated morphologies that provide highly efficient load transfer pathways within damaged composite areas, high temperature durability (> 450 oC), and self-leveling properties during curing to provide optimal aerodynamic efficiency. The major phase of the repairing material will consist of a high Tg (> 250 C) polyimide matrix while the minor phase will consist of low Tg (<-100 oC), microphase separated polysiloxanes. A facile three step repair process will be established that involves 1) the priming of composite surface with reactive functional groups through a surface wipe down, 2) defect infusion with reactive nanocomposite resin, and 3) a moisture induced crosslinking reaction. In support of a rapid Phase III transition, NanoSonic?s HybridSil polymeric resins have a current production capacity of 8,000 lbs. / day, a MRL of 4, and have been integrated onto combat active DoD platforms for trial demonstrations.

Benefits: By providing unprecedented combinations of mechanical restoration, ease of use within areas of limited access, and readily tailorable curing chemistries in outdoor environments without the use of external heat or vacuum, NanoSonic envisions considerable post applications of the NASA sponsored technology during Phase II and III efforts with its development partners. Initial applications will include graceful FRP composite repair for a broad spectrum of launch vehicle structures including tanks, fairing, and skirts.

Immediate secondary applications for NanoSonic's HybridSil composite repairing materials will include use on composites throughout the growing commercial space travel industry. Immediate Phase III transition potential will exist within an array of large launch vehicle repair strategies, as well as structural composites within the aerospace, marine, and automotive industries.