A superelastic polymeric aerogel with ultrahigh fire resistance for thermal insulation in a harsh environment

Aerogels that possess ultrahigh fire-resistance and excellent elasticity are highly demanded for applications in extreme environments. In the reported strategies for improving the fire resistance of polymeric aerogels, the good elasticity of these aerogels is hardly maintained or even sacrificed. Herein, a fire-resistant and superelastic polymeric aerogel was synthesized via self-crosslinking polyimide molecules containing benzimidazole groups. Its outstanding fire-resistance against high temperatures (up to 1300 °C) was proved by flame insulation tests, where a commercial ceramic aerogel was damaged by the flame. Fire safety was further demonstrated by the low release of combustion heat and smoke. In addition, the aerogel exhibited superelasticity and excellent resilience through multiple mechanical tests of compression, bending and tension (1000 cycles). The excellent fire-resistance, along with the other superior properties, makes the polymeric aerogel very promising for applications in the field of thermal insulation under extreme conditions.