Thermal Insulating and Mechanically Strong Polyimide Aerogel Composites Reinforced by Polyhedral Oligomeric Silsesquioxane-Grafted Carbon Nanotubes

In the ship industry, developing thermal insulation materials with exceptional high-temperature resistance, structural stability and light weight is essential. Herein, polyimide (PI) composite aerogels were synthesized. Carbon nanotubes (CNTs) introduced cross-linking structures within the aerogel matrix, effectively reducing shrinkage and forming micrometer-scale pores. Furthermore, the rigid cage-like structure of polyhedral oligomeric silsesquioxane (POSS) generated additional nanoscale pores. This multiscale pore structure enhanced both compressive strength and thermal insulation properties. The PI-CNT-POSS composite aerogel with a 2 wt% CNT content (PI-CP2) demonstrated outstanding overall performance, with compressive strength, modulus and thermal conductivity values of 167.7 KPa, 360.3 Kpa and 40.6 mW/(m·K), respectively, possessing remarkable advantages over the neat PI aerogel. Consequently, this PI composite aerogel can be used as a promising material for heat management in complex environments.