Brief Introduction:

Polymer materials and composites, particularly rigid polyurethane foam and unsaturated polyester resins, find widespread application across infrastructure, engineering, transportation, and aerospace industries owing to their lightweight nature, thermal and electrical insulation properties, heat resistance, and resistance to solvents. However, the above-mentioned materials are prone to ignition due to the high content of carbon and hydrogen in their main chains, resulting in significant heat and smoke production during combustion. Consequently, the halogen-free flame-retardant structures containing elements such as phosphorus and nitrogen have been integrated into the matrix or main chain not only to enhance the flame resistance, but also accompanied by enhanced mechanical properties, superior thermal insulation, or improved degradability.