Preparation and thermal-mechanical properties of physical and chemical dual-reinforced SiO₂ aerogels

Considering that the poor mechanical properties limit the application of SiO₂ aerogels in fire insulation, polyurethane sponges, and mica were used to enhance the mechanical properties of SiO₂ aerogels in this study. The effects of polyurethane sponges with different pore sizes and mica content on the thermal-mechanical properties of composite aerogels were investigated. The internal structure of the composite aerogels was analyzed by scanning electron microscopy. Moreover, the chemical structure and composition of the composite aerogels were characterized and analyzed. The results demonstrate that polyurethane sponges and mica can effectively enhance the mechanical properties of composite aerogels. However, the addition of mica increased the thermal conductivity. The experimental data will further expand the engineering application of SiO₂ aerogels.