ABSTRACT Improving the flame retardancy of epoxy resin (EP) is an imperative yet challenging task for its applications in electronic packaging and aerospace. In this study, a novel bio‐based phosphorus–nitrogen flame retardant (PTM) was successfully synthesized from phytic acid (PA), 1,3,5‐tris(2‐hydroxyethyl) cyanuric acid (THEIC), and melamine (MEL) and added to EP to further prepare PTM/EP composites. The chemical compositions and bonding states characterized by Fourier transform infrared (FTIR), liquid nuclear magnetic resonance (NMR), and X‐ray photoelectron spectroscopy (XPS), confirmed the flame‐retardant constituents of PTM. Compared with pure EP, the PTM/EP5 composite demonstrated superior flame retardancy and smoke suppression, achieving a UL‐94 V‐0 rating and a high limiting oxygen index (LOI) of 34.0%. Additionally, the peak heat release rate (pHRR), total heat release (THR), and total smoke release (TSP) of the PTM/EP5 composite decreased by 84.33%, 62.04%, and 66.67%, respectively. The impressive flame retardancy and smoke suppression performance of PTM/EP were attributed to the phosphorus–nitrogen synergistic intumescent mechanism facilitated by PTM. This study provides an effective and sustainable flame‐retardant strategy for EP composites, offering new insights into the green development of P–N flame‐retardant systems.
Yu et al. (Wed,) studied this question.