Abstract: Research progress in flame retardant properties of polystyrene/multiwalled carbon nanotube composites was reviewed. A detailed introduction was given on their thermal degradation behavior and glass transition temperature as well as flammability properties such as heat release rate, mass loss rate, and carbonization performance. The related mechanism was discussed in depth. The influence of the addition amount, aspect ratio, impurity, and surface modification of multiwalled carbon nanotubes on the thermal stability and flame retardant properties of the corresponding composites was analyzed.

Key words: polystyrene, multi-walled carbon nanotube, nanocomposite, thermal stability, fire retardant property