Facile Preparation of Nanofiber-Reinforced Poly( <i>p</i> -phenylene Benzobisoxazole) Paper with Water as Solvent

Poly(p-phenylene benzobisoxazole) (PBO) fibers exhibit poor hydrophilicity, which necessitates the use of highly corrosive acids as solvents during papermaking. This severely restricts the research and development of PBO paper. To address this limitation, the present study proposes an innovative and environmentally benign strategy for fabricating high-performance PBO paper using water as the solvent. In this strategy, nanofibers with excellent hydrophilicity are employed as stabilizers, which adsorb onto the surface of PBO fibers through π–π stacking interactions, thereby significantly improving the aqueous dispersibility of PBO fibers. Furthermore, the interlacing and interconnection of nanofibers effectively enhance the interfacial interactions between PBO fibers, leading to a substantial improvement in the overall performance of PBO paper. Compared with the pristine PBO paper, the modified one exhibits a 23-fold increase in tensile strength and a 1.6-fold increase in electrical breakdown strength, while retaining its inherent flexibility, thermal resistance, dielectric properties, and processability. This work holds great significance for promoting the large-scale production of PBO paper and expanding its applications in fields requiring high thermal resistance, wave transmission capability, and electrical insulation performance.