Polyurethane (PU): As an insulation material, its thermal conductivity is typically ≤0.022 W/(m·K). For example, the closed-cell rate of the core layer of PU sandwich panels exceeds 95%, effectively blocking heat conduction; a 5cm thickness is equivalent to the insulation effect of a 1m thick concrete layer.
Rock wool: Commonly used for fireproof insulation, its thermal conductivity ranges from 0.036–0.043 W/(m·K). Rock wool sandwich panels are widely used in building exterior walls due to their high-temperature resistance (up to 600℃) and environmentally friendly properties.
Glass wool: Its thermal conductivity is similar to that of rock wool, approximately 0.033–0.043 W/(m·K), and it is also a common insulation core material.
Silicon carbide (SiC): As a high-performance semiconductor heat dissipation material, its thermal conductivity is as high as 400–500 W/(m·K), far exceeding that of traditional metals, making it suitable for high-power electronic devices. Aluminum nitride (AlN): With a thermal conductivity of approximately 230 W/(m·K), it is a commonly used insulating substrate material in power modules.
Single-crystal diamond: With a thermal conductivity reaching 2000–2300 W/(m·K), it is currently the material with the highest known thermal conductivity, but its extremely high cost limits its use to extreme heat dissipation scenarios such as supercomputing and high-end AI chips.