The Polymer Society of Korea

Abstract

Flame retardancy is essential for heat-dissipating polymer composites for high-temperature electronic applications requiring fire safety. Conventional flame-retardant strategies often rely on additive chemistries that compromise recyclability and thermal transport. Here, we present a flame-retardant–agent-free approach to impart fire resistance to covalent adaptable networks (CANs) while enhancing thermal conductivity and recyclability. A segregated filler network is formed by incorporating hexagonal boron nitride (hBN) into the CANs matrix, where hBN assembles at matrix boundaries to form continuous pathways. This architecture suppresses flame propagation by limiting oxygen penetration while enabling thermal conduction. The resulting composites achieve flame retardancy and high thermal conductivity without sacrificing CANs reprocessability. Moreover, depolymerization enables recovery of the polymer matrix and hBN fillers, providing a sustainable platform for electronic materials.