Fire and Engineering Properties of Polyimide-Aerogel Hybrid Foam Composites for Advanced Applications

NASA has had a growing need for high-performance materials for cryogenic insulation, fireproofing, energy absorption, and other advanced applications. New monolithic aerogels are good candidates except for their inherently fragile nature. Modern commercially available aerogels are tougher, but still lack adequate structure and can become a contamination concern in certain applications. Polyimide foam materials have been used for demanding applications that require extreme thermal, chemical, and weathering stability. The combination of aerogel with a high performance polyimide foam fabricated into a hybrid material provides structure to the aerogel, reduces heat transfer, improves vibration attenuation, and retaines the excellent fire properties of the polyimide foam. Incorporation of aerogel material into TEEK-H polyimide foam provides three favorable effects: thermal conductivity is reduced by the aerogel content in the hybrid foams, Peak Heat Release remains low, and the time to Peak Heat Release increases with increasing aerogel content.