Compressive Behavior of Crosslinked Mesoporous Aerogels at High Strain Rates

Aerogels have exceptional properties such as high dielectric constant, high thermal insulation and high acoustic damping. Their applications, however, have been slow due to the well-known fragility and hygroscopic behavior. These problems have been resolved by nanoencapsulating a thin layer of polymers on the silica nanoparticles without clogging the pores. The resulting crosslinked aerogels are ductile, stable in water, and mechanically strong. In analogy to polymer-crosslinked silica aerogels, the mesoporous surfaces of silica-derived co-continuous mesopores have been coated conformally with isocyanate-derived polymers, and a new class of crosslinked templated silica aerogels was synthesized with ordered nanostructure. In this paper we characterize the dynamic compressive behavior of these crosslinked mesoporous aerogels, namely X-MP4, X-MP4-T045 and X-MP4-T310, at high strain rates using a long split Hopkinson pressure bar. The stress-strain relations at high strain rates have been determined. Results indicate that these materials have extremely high specific energy absorption capability.