High flame retardancy, which can give composite materials good self-extinguishing or flame-retardant properties; ② Good compatibility, which can be well compatible with composite materials and easy to disperse; ③ Suitable decomposition temperature, that is, it does not decompose at the processing temperature of composite materials, but can rapidly decompose when the composite materials are heated and decomposed to exert its flame-retardant effect; ④ Non-toxic or low-toxic, odorless, non-polluting, and does not produce toxic gases during the flame-retardant process; ⑤ When used with composite materials, it does not reduce the mechanical properties, electrical properties, weather resistance, and heat distortion temperature of composite materials; ⑥ Good durability, which can be retained in composite material products for a long time to exert its flame-retardant effect; ⑦ Widely available and inexpensive.