High-Performance Poly(p-phenylene benzobisoxazole) Aerogel Fibers

Natural materials characterized by highly oriented structures are typically lightweight yet strong and hard yet tough. These seemingly incompatible mechanical properties are highly desirable in man-made materials, particularly in aerogel fibers, which often lack ordered structure. In this study, we report tough poly(p-phenylene benzobisoxazole) aerogel fibers (PBOAF) through a nanostructured design that introduces longitudinally oriented gradient pores, achieved by controlling the drafting orientation and skin-core layer structure. The orientation facilitates nanofibers to be closely aligned, which enhances interchain interactions, improves interlayer shear strength, and minimizes stress concentration. The mechanical properties of the prepared aerogel fibers are among the top reported for aerogel fibers , exhibiting a tensile strength of 55.3 MPa and toughness of 25.2 MJ m^-3, while maintaining high porosity (>91.5%) and substantial specific surface area (238.1 m² g^-1). Fabrics composed of PBOAF exhibit low thermal conductivity (0.037 W m^-1 K^-1) and demonstrate applicability across a broad temperature range (-196 to 200 °C). This investigation proposes a viable pathway for developing multifunctional thermal management fabrics.