Thermal insulating property of an optically-active polyurethane-based silicon aerogel

Improving the mechanical property of the silicon aerogel while maintaining its excellent thermal insulation performance is still a big challenge in developing the next-generation thermal insulation materials. To solve this problem, the optically active polyurethane aerogel composite is developed via the sol-gel method to combine the advantages of the thermal insulation performance of the silicon aerogel and the mechanical property of the end-capped siloxane optically-active polyurethane. The prepared composite is characterized by the SEM, the Fourier transform infrared spectroscopy, the absorption-desorption curve, the thermal analysis, and the mechanical property. Results show that the composite has intact pores with high surface area and pore volume, leading to excellent thermal insulation and mechanical performance. Moreover, its thermal insulation performance is greatly enhanced due to the better distributed small pores and the thermal reflective effect of binaphthyl groups which collaboratively block heat loss from thermal conduction and thermal radiation. The thermal stability is similar to silicon aerogel and its heat resistance temperature is 445?. The addition of macromolecular polymers increases the contact points between particles, the contact areas between particles of the network skeletons, and the supporting effect of the skeleton material, which ensures the stability of the material structure. The compressive modulus of prepared composite is up to 2.465 MPa, which is 600 times more than that of the pure SiO2 aerogels.