Cross Network Composite Aerogel Towards Robust and Fire‐Resist Thermal Insulation Material

Thermal insulation materials with excellent fire safety and mechanical performances are urgently desired. Herein, novel cross network composite aerogels (CNCAs) are designed with cationic amylopectin and polyvinyl alcohol that act as the macromolecular framework and montmorillonite and borax that act as the functional binders. The CNCAs demonstrate low density (0.033–0.043 g cm⁻³), high strength (5.1–18.4 MPa), and anisotropic thermal conductivity. Furthermore, they exhibit high fire safety (limiting oxygen index > 50, UL‐94 V‐0 rating, and negligible heat and smoke release under cone calorimetry testing condition). Particularly, the after‐fire residue can still have an excellent load capacity with a compression modulus of 3.7 MPa. Based on the energy‐dispersive X‐ray spectroscopy results, up to avg. 91.3% of the carbon from the organic polymers remains in the residue. These characteristics not only ensure the safe use of the CNCAs but also expand their application fields and improve their durability.