Facilely prepare passive thermal management materials by foaming phase change materials to achieve long-duration thermal insulation performance

Passive thermal management (PTM) materials that can stabilize long-duration temperature are highly desirable in thermal insulation applications such as building insulation, infrared stealth, and protection of electronic devices. Here, we proposed a facile method to prepare PTM materials with improved temperature stabilization performance by foaming a paraffin-based phase change composite with heat-sensitive thermal expansion microspheres (TEMs). For the phase change composite with high paraffin content immobilized by 20 wt% poly(styrene-b-(ethylene-co-butylene)-b-styrene, the addition of 10 wt% TEMs made the porosity up to 92.7% while owned a high energy storage density of 137.8 J/g. The low thermal conductivity (0.045 W m−1K−1) contributed by the high porosity and high phase change enthalpy enabled the resulting materials to exhibit significantly improved PTM performance. The possible applications of our resultant materials in thermal insulation fields such as thermotherapy, infrared shielding and building thermal comfort maintenance were demonstrated through simulation experiments. In view of the low cost, non-toxic raw materials, environmental-friendly and large-scale preparation process as well as the flexible, hydrophobic characteristics, our method and the resultant materials exhibited great potential in thermal insulation applications.