A Low Cost Production Process for Large High Temperature Polymer Matrix Composites

Eltron Research & Development Inc. and the Southwest Research Institute® will focus on three primary objectives during Phase II of this Air Force Office of Scientific Research (AFOSR) STTR program, building upon the success realized during Phase I work. First, we will be prepared to transition High Temperature Vacuum Assisted Resin Transfer Molding (HTVARTM) needed in Phase III, by optimizing and extending the proprietary process developed during Phase I research for the production of carbon fiber reinforced polyimide composites. Second, we will have a product ready for evaluation by key end-users in the military aerospace community by performing key qualification tests. Third, we will reduce risk and speed the transfer of this technology to the DoD by engaging key partners in both aerospace composite production and application. BENEFIT: Use of this technology in the production of high temperature polymer matrix composites offers a number of benefits. It affords significant cost reduction when compared to the autoclave process, because expensive up-front capital equipment is eliminated. Large structures can be produced in a single operation without the need for lengthy and rate-limiting cure schedules associated with prepreg materials. The process is particularly useful with emerging liquid processable polyimides and does not involve the use of excessive solvent (as in prepreg systems) thereby reducing worker exposure to volatile organic compounds. Military and commercial applications for this process exist in the aerospace industry. For example; aircraft nacelles (the structure that surrounds the jet engine) currently employ high-temperature epoxies and/or bismaleimides (BMIs) in components such as the nacelle and thrust reverser panels. Epoxy components in the immediate vicinity of the engine must be protected by insulation because their hot/wet service temperature is about 138°C/350°F; BMIs are a little higher. The reduced cost of this manufacturing process combined with the higher service temperature capability of liquid processable polyimide resins could make this technology a competitive choice for nacelle manufacturers and remove the added expense and weight of the protective insulation. Other potential commercial applications exist where the replacement of traditional structural materials with a high service temperature capability polymer matrix composite results in reduced weight and cost of ownership.