Enabling Recyclable and High-Insulation-Performance Aramid Fiber Reinforced Polymer Composites by Dynamic Borate Ester

Aramid fiber reinforced polymer (AFRP) composites are widely used in ultra-high voltage electrical equipment. However, the irreversible three-dimensional crosslinked structure of traditional thermoset epoxy resin in AFRP makes it difficult to recycle materials from decommissioned equipment, facing challenges of resource waste and environmental pollution. In this paper, an environmentally friendly recyclable AFRP is developed by introducing a dynamic borate ester covalent network and constructing an environmentally friendly epoxy resin system with BDB curing agent. Its interfacial shear strength increases by <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{5 6. 4 6 \%}$</tex> compared with traditional systems, while the AC breakdown strength remains basically the same. The composites prepared by recycled fibers maintain or even exceed the interfacial shear strength and breakdown strength of the original composites. This research provides a feasible solution for the circular utilization of decommissioned materials from GIS equipment and promotes the green and sustainable development of highperformance composites.