From Waste to High-Voltage Insulation: Polyarylate Nanofiber-Driven Recycling of Waste Polyphenylene Sulfide into Biomimetic Insulating Paper

Abstract

Growing stockpiles of end-of-life polyphenylene sulfide (PPS) filter bags from flue-gas purification pose a persistent waste burden, yet conventional disposal or low-value reuse fails to capitalize on their inherent thermal and dielectric robustness. Here we report a hierarchical structural engineering strategy that upcycles waste PPS into an ultrahigh-performance insulating paper by exploiting a biomimetic “feather–branch” topology. Polyarylate (PAR) nanofibers serve as a continuous 3D skeleton, yielding a structurally tunable and defect-suppressible matrix. Under coupled shear-thermal fields, regenerated PPS microfibers interlock with PAR nanofibers to form a dual-level interpenetrating network that establishes cooperative charge/stress dissipation pathways, mitigating local electric-field distortion and suppressing crack initiation and propagation. Consequently, the PPS/PAR nanocomposite paper delivers a breakdown strength of 101.74 kV·mm–1, far exceeding that of commercial aramid paper (23.69 kV·mm–1). The composite also exhibits robust stability under harsh conditions: after thermal aging at 200 °C for 24 h, breakdown strength remains 51.34 kV·mm–1, and after UV irradiation (365 nm, 24 h), it retains 59.96 kV·mm–1, whereas aramid paper degrades to merely 8.75–9.07 kV·mm–1 under the same conditions. This work establishes a scalable route to transform discarded PPS resources into durable, high-reliability insulation through topology-guided multiscale regulation.