Polyimide aerogels for ballistic impact protection.

The ballistic performance of edge-clamped monolithic polyimide aerogel blocks (12 mm thickness) has been studied through a series of impact tests using a helium-filled gas gun connected to a vacuum chamber and a spherical steel projectile (approximately 3 mm diameter) with an impact velocity range of 150-1300 m s. The aerogels had an average bulk density of 0.17 g cm with high porosity of approximately 88%.