Silicon-containing polyarylacetylene aerogel with heat resistance and ablative property for high-temperature insulation

Owing to the high porosity and low thermal conductivity of organic aerogels, they have been widely used to develop lightweight heat insulation materials. However, their applications in high-temperature environments such as in aerospace applications are usually limited by the heat resistance or ablative property of the organic matrix. In this study, we prepared a novel organic aerogel for high-temperature insulation by the sol–gel method and freeze-drying. The matrix is the thermosetting silicon-containing polyarylacetylene (PSA) resin with excellent comprehensive properties, namely, high heat stability, low volatile component content, and high-temperature ceramic performance. The obtained PSA aerogel retains the heat resistance (T d5 = 634.8°C) and ablative properties (Y r800 = 92.6%) of the PSA resin, and the internal regular macropores and high porosity (70%) result in an extremely low weight (0.1200 g cm −3 ), low thermal conductivity (0.039 W m −1 K −1 )), and efficient heat insulation. Thus, this is an ideal material for high-temperature insulation in the aerospace field.