A flexible, thermal-insulating, and fire‐resistant bagasse-derived cellulose aerogel prepared via a refrigerator freezing combined ambient pressure drying technique

Cellulose aerogel is a most promising alternative to the plastic foam owing to its low thermal conductivity, eco-friendliness and renewability, which however suffers from the complex preparation process, poor mechanical property and flammability. Herein, we develop a flexible, thermal-insulating, and fire-resistant cellulose aerogel prepared by a facile refrigerator freezing and ambient pressure drying process, using bagasse and inorganic minerals as the main raw materials. The as-obtained bagasse-derived cellulose (BC) aerogel exhibited a high porosity of 92 %, an acceptable thermal conductivity of 51.5 mW/(m·K) and an excellent compressible cyclability. Furthermore, an inorganic mineral-reinforced bagasse-derived cellulose aerogel (IMr-BC) with improved fire-resistant property was prepared via the same method. The inorganic minerals endowed the original BC aerogel with a superior flame retardancy, which was able to withstand a continuous burning of butane gun at 1300 °C for over 20 min, and its thermal insulation application could be extended to a temperature as high as 1100 °C. These aerogels prepared in this work are expected to be used for thermal management applications in harsh environments.