Hierarchical PBO Nanofiber/PPS Melt-Blown Mats with a Controllable Porous Microstructure for Thermal Protection under Harsh Conditions

Thermal insulation is critical in protecting against excessive heat exposure to minimize burn injuries. However, the current thermal insulation fabrics are still limited because of their inadequate thermal insulation, poor wearability, and a complicated process. Herein, a fibrous network-confined sol–gel transition strategy is developed to fill poly(p-phenylene benzobisoxazole) nanofibers into poly(p-phenylene sulfide) melt-blown mats. The obtained hierarchical nano/microfiber mats (HNMMs) show typical features of high porosity, a low packing density, small pore sizes, and high thermal stability. Benefiting from the synergistic effect, HNMMs demonstrate low thermal conductivity (0.029 W/mK), outstanding heat resistance (43.7 cal/cm2), high air permeability (115 mm/s), and high water vapor transmission [1568 g/(m2·d)]. The comprehensive performances indicate that such HNMMs have promising potential in personal and industrial thermal insulation in harsh environments.