As a derivative of natural polymer cellulose, cellulose acetate has many advantages, such as abundant raw materials, easy to get, environment-friendly and degradable. The aerogel thermal insulation material made of cellulose acetate can not only retain the intrinsic characteristics of cellulose, but also endow the material with new characteristics such as light weight, high strength, high specific surface area and low thermal conductivity, which is highly consistent with the national concept of energy conservation and emission reduction, energy conservation and carbon reduction. Therefore, the development of environment-friendly high-performance biomass gas gel thermal insulation materials is of great significance for promoting China's green low-carbon development and achieving the goal of carbon peak and carbon neutrality.

Fig. 1 Aerogel preparation steps and processing performance of profiled structure

The research group of polymer aerogels proposed a new way to build cellulose acetate aerogels through the homogeneous hybrid strategy of the network skeleton, which solved the common bottleneck problem in the preparation of high-performance biomass aerogels by the atmospheric drying method, realized the collaborative optimization idea of lightweight, high strength, efficient heat insulation, flame retardancy, fire resistance, and heat resistance, and significantly reduced the cost of material preparation and functionalization.

Fig. 2 Micromorphology and pore size distribution of aerogel

The micro nano pore structure size of cellulose acetate aerogel is mainly about 30 nm, which makes the aerogel material have good thermal insulation performance (thermal conductivity at normal temperature and pressure: 0.033W/m − 1 · K − 1). The single-sided heating experiment also shows that the thermal insulation performance of the material is excellent; At the same time, the introduction of aromatic ring structured polymer phase can make the material have good self extinguishing characteristics (self extinguishing when out of fire). It can be seen that the homogeneous hybrid strategy of network skeleton can indeed give the biogas gel good flame retardant and fireproof performance; The mechanical strength of the obtained aerogel was significantly improved, and the compressive stress (3% strain) at low temperature and normal temperature reached 0.6MPa and 0.73MPa respectively. Therefore, the profiled processing performance of the material was also excellent; In addition, the thermal stability of the material was further optimized and improved, and the thermal decomposition temperature increased by nearly 30 ℃, effectively expanding the application temperature limit of biomass gas gel materials.

Fig. 3 Self extinguishing performance test of aerogel

This study will provide theoretical basis and technical support for multi-functional integration, low-cost preparation and practical application of high-performance biomass gas gel thermal insulation materials, including cellulose aerogel and chitosan aerogel gel.

Fig. 4 Thermal stability of aerogel