Design and characterization of multi-functional ternary composites with a hierarchically porous and filled-microperforated plate structure

To effectively overcome the shortcomings of common polyurethane (PU) insulation materials in terms of flame retardancy, mechanical properties, and sound absorption, a new multi-functional insulation material needs to be developed. Here, simple materials such as PU and silica aerogel (SA) combined with a special three-dimensional spacer fabric were used to design an innovative SA/PU/spacer fabric (SPS) ternary composite. It integrates a “hierarchically porous” and “filled-microperforated plate” structure. The superior structure design endows the new type of composite with a remarkable performance while maintaining low density (0.198 g/cm 3 ). Specifically, the SPS composite was difficult to ignite by alcohol lamps compared with PU and SA/PU, and its thermal conductivity and compression modulus can reach 0.0392 W/(m·k) and 1.5 MPa, respectively. Moreover, the average absorption coefficient of the SPS composite (7.5 mm thickness) is 0.62, and its noise reduction coefficient per unit thickness (0.37) exceeds most reported sound absorption materials. From these results, the SPS composite provides a convenient and low-cost method to improve the overall performance of traditional thermal insulation material, which is of great significance in the fields of construction and transportation.