Characterization of the Structure-Processing-Performance Relations of Phenylethynyl Phthalic Anhydride Crosslinked Fluorinated Polyimides (AFR-PEPA- N) and Their Carbon Fiber Composites

摘要

The overall goals of this program were to conduct fundamental characterization and development studies of the structure-processing- performance relations of phenylethynyl phthatic anhydride crosslinked fluorinated polyimides (AFR-PEPA-N) and their carbon fiber composites for applications for future Air Force vehicles and associated propulsion systems. The technical areas that were primarily pursued and documented in this final report are i) The stress-thermal cycling of polyimide composites in extreme thermal environments; ii) Cure characterization of the phenylethynyl oligomer end caps, oligomer morphology and chemical modification of oligomer end groups; iii) Characterization of optimum cure conditions versus onset of network degradation; and iv) Development of failure modeling methodology of composites in extreme service environments.