Hugoniot based equation of state for solid polyurea and polyurea aerogels

The shock response of solid polyurea and two polyurea aerogels were studied using gas-gun driven plate impact experiments. The materials reported on here are commercially available, brand named AIRLOY, and supplied by Aerogel Technologies, LLC. Polyurea Solid, with nominal density 1.13 g/cm3, and two aerogels, with nominal densities of 0.20 and 0.35 g/cm3, were studied. Most experiments were of the multi-slug type in which a sample of each density was mounted on an oxygen free high conductivity copper or 6061 aluminum baseplate. In these experiments, shock velocity was measured and other shock states calculated by the impedance matching technique. Peak particle velocity obtained in the 0.2 g/cm3 aerogel was > 4.3 km/s, and peak pressure in the solid was > 29 GPa. A break in the data for the solid above particle velocities of 2.0 km/s (∼ 18 GPa) indicates a probable reaction with higher density products. A P − α model with Mie-Grueneisen form for the solid reasonably replicates the data.