Polybenzimidazole Aerogels with High Thermal Stability and Mechanical Performance for Advanced Thermal Insulation Applications

Advancements in the development of high-performance organic aerogels are essential for cutting-edge thermal insulation applications, where lightweight and durable structures, low thermal conductivity, and exceptional thermal stability are critical requirements. In this work, we present thermally stable and mechanically robust organic aerogels based on cross-linked benzimidazole-rich structures, specifically designed for thermal insulation. These aerogels exhibit a combination of valuable properties, including low density, large specific surface area and high porosity. Their tortuous mesoporous structures effectively reduce heat transfer by limiting gas-phase conduction, resulting in thermal conductivities as low as 23.9 mW m^-1 K^-1. This is coupled with a remarkable resistance to thermal decomposition (Td_1% > 500 °C), surpassing the stability of the original polymer precursor (OPBI). Additionally, the strong polymer network, reinforced by both covalent and noncovalent interactions, provides exceptional mechanical strength, allowing the aerogels to withstand substantial loads without fracturing. This unique combination of low density, high porosity, robust mechanical performance, and superior thermal stability makes these aerogels highly promising for demanding thermal insulation applications, such as thermal protection for space exploration vehicles, fire-resistant suits, and EV battery insulation.