Environmentally Benign Repair of Composites Using High Temperature Cyanate Ester Nanocomposites

摘要

Interlaminar fracture, or delamination, is a common failure mode which often occurs in composites as a result of low energy impact or manufacturing defects. In this project, we have designed and evaluated a new class of environmentally benign, low viscosity cyanate ester resins reinforced with nanosize reinforcement for the repair of advanced composites. The use temperature limit for this repair technology is high because of the polymer's high glass transition temperature of greater than 500 F (260 C) and onset of decomposition above 750 F (400 C). The prepolymer also has near infinite room temperature stability, facilitating reduced wastes due to spoilage compared to traditional thermosets. In demonstrations of the technology on bismaleimide (BMI)/carbon composite panels, the strength of damaged composites that were repaired with the technology through a resin injection process exceeded the strength of the virgin undamaged composite material. This technology will reduce the environmental hazards associated with current composite repairs and open up new repair opportunities specifically for high temperature composites, such as BMI matrix composites.