High Temperature Finishes/Sizings for Polyimide Matrix Composites

New high-temperature sizings are needed to improve the properties and durability of carbon/polyimide composites. Compatibility with weaving and braiding operations and improved wetting during prepregging or resin infusing polyimide resin is also needed. Achieving these characteristics will result in reducing life cycle costs for jet engine composites through better property translation, reduced scrap, and reduced processing time. The overall objective of the proposed Phase II program is to demonstrate the use of reactive finishes for bonding carbon fibers to polyimide resins that impart superior strength and environmental durability to composite parts for DOD applications. Secondary objectives include development and characterization of aqueous-based finish systems with long term stability, development of a material property database, including aging effects, and determination of compatibility with weaving, prepregging, and resin infusion (RTM, VARTM, RFI) operations. In addition, an aqueous based reactive finish will be developed that is compatible with application during carbon fiber manufacturing. Development of an aqueous finish will greatly reduce costs while also improving health and safety. These reactive finishes are expected to be compatible with weaving, braiding, prepregging, and resin infusion operations. They will also improve the strength, thermo-oxidative stability, and hygrothermal stability of the resulting carbon/AFR-PE4 composites.