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.