Elastic, antiflaming phenolic aerogels for advanced thermal protection at extreme environments

Abstract

In practical applications, thermal protection demands materials with reliable structural stability under extreme conditions. Phenolic aerogels exhibit remarkable thermal protection capabilities; however, their inherent brittleness and porous structure make them susceptible to catastrophic failure when subjected to mechanical stresses or thermal oxidation. To address this, robust phenolic composite (PFR@SiO2) aerogels were synthesized through a three-step process involving sol-gel generation, ambient-pressure drying, and chemical vapor deposition. The resulting PFR@SiO2 aerogels display impressive mechanical properties, as well as a high degree of flame resistance. Furthermore, under fatigue stress/strain cycling tests or ultrahigh-temperature oxidation circumstance, such phenolic composite aerogels also exhibit exceptional structural stability. Overall, these combined properties position the PFR@SiO2 aerogels as a promising material system for robust thermal superinsulation under extreme conditions.