Microstructure and Thermal Insulation Property of Silica Composite Aerogel

Tetraethyl orthosilicate was selected as a matrix of heat insulating materials among three silanes, and an anti-infrared radiation fiber was chosen as a reinforcement for silica aerogel insulation composite. The silica aerogel was combined well and evenly distributed in the anti-infrared radiation fiber. The heat insulation effect was improved with the increase in thickness of the aerogel insulation material, as determined by the self-made aerospace insulation material insulation performance test equipment. The 15 mm and 30 mm thick thermal insulation material heated at 250 &deg
C for 3 h, the temperatures at the cold surface were about 80 &deg
C and 60 &deg
C, respectively, and the temperatures at 150 mm above the cold surface were less than 60 &deg
C and 50 &deg
C, respectively. The silica aerogel composites with various thicknesses showed good thermal insulation stability. The silica insulation composite with a thickness of 15 mm exhibited good heat insulation performance, meets the thermal insulation requirements of general equipment compartments under low-temperature and long-term environmental conditions. The thermal conductivity of prepared silica aerogel composite was 0.0191 W&middot
m&minus
1&middot
k&minus
1 at room temperature and 0.0489 W&middot
1 at 500 &deg
C.