Grafting Vinyl Acetate Onto Polyethylene as an Alternative Matrix for Enhanced Flame Retardant Dispersion and Fire Performance in EVA/PE Materials

ABSTRACT Ethylene‐vinyl acetate (EVA) is widely used but suffers from high flammability, poor thermal stability, and low hardness. It is often blended with polyethylene (PE) and flame retardants to improve performance, yet this often causes poor synergy and uneven filler distribution. In this study, vinyl acetate (VA) is grafted onto PE via melt grafting to obtain PE‐g‐VA, which combines the mechanical strength of PE with the polar dispersion of VA. When compounded with aluminum hydroxide (AH), PE‐g‐VA/AH achieves a limiting oxygen index of 32.1% and a UL‐94 V‐0 rating without melt dripping. Compared with EVA/PE/AH, PE‐g‐VA/AH shows 37.2% higher tensile strength and reductions of 33.3% (PHRR), 26.7% (THR), 36.9% (PSPR), and 60.7% (TSP). These improvements arise from the VA side chains, which enhance AH dispersion and char layer integrity. This work provides a feasible matrix‐modification strategy for high‐performance flame‐retardant composites.