Carbon foam-reinforced polyimide aerogel composites for thermal insulation with reduced shrinkage

Melamine-crosslinked polyimide (MPI) aerogels are promising for diverse applications owing to their economical cost and impressive performance. However, MPI aerogels tend to suffer severe shrink in the processes of preparation and practical applications. Their upgrades, i.e., carbon foam-reinforced polyimide (CF-PI) aerogel composites, therefore were proposed in this study, to address this issue. The structure, thermal insulation of the resultant composites as well as their mechanical strength were characterized. The CF-PI aerogel composites were observed to have low shrinkage (as low as 9.25 vol.%) and low thermal conductivity (21 mW m −1  k −1 –34 mW m −1  k −1 ), indicative of significantly improved shape stability and exceptional thermal insulation capability. Besides, these aerogel composites also performed well in thermal stability, and did not decompose unless the temperature exceeds 400 °C. All these advantages contribute to the broad application prospects of thus aerogel composites in many aspects, such as thermal insulation for high temperatures, and so on. Graphical Abstract The composite is apparently composed of carbon foam and PI aerogel. Of the two, the carbon foam itself serves as a support frame, and PI aerogel is filled inside as the functional component. When the polymer concentration increases from 4 to 8%, the shrinkage of CF-PI aerogel composites gradually increases.