Intrinsically flame-retardant phase change material via atherton-todd synthesis: Dual-functionality in thermal energy storage and fire safety enhancement

This study investigates the flammability challenges of organic paraffin-based phase change materials (PCMs) while addressing the inefficiency of traditional additive flame retardants. Through Atherton-Todd synthesis, we engineered a one-step reaction between octadecylamine (ODA) and diethyl phosphite under mild conditions, yielding an intrinsically flame-retardant PCM (designated OD) that synergizes exceptional flame retardancy with robust energy storage capacity, boasting a phase change enthalpy of 123.8 J/g. Due to its superior gas-phase flame-retardant effect, OD extinguishes itself within 15 s after ignition. Comparative analysis shows OD outperforms ODA with a 38.6 % reduction in peak heat release rate and an 8.4 % decrease in total heat release. Advanced pyrolysis studies uncover that OD's thermal decomposition follows a cascade of chain scission, dehydrogenation, deamination, and molecular rearrangement. This work pioneers a molecular engineering strategy for covalently integrating flame-retardant functionalities into PCM matrices while delivering critical technological advancements for deploying fire-safe PCMs in power battery thermal management systems and next-generation energy-efficient architectures.