Abstract: Recent research progress in flame retardancy of rigid polyurethane foam/ expandable graphite composites was reviewed. A detailed introduction was given on its preparation method, thermal degradation behavior as well as flammability properties such as limited oxygen index, horizontal and vertical burning rate, heat release rate, CO/CO2 production weight ratio and carbonization performance. The influences of foam density, addition amount, particle sizes, encapsulation treatment of expandable graphite as well as the combination with other flame retardants on thermal stability and flammability of the corresponding foam composites were analyzed. Besides, the relative mechanism was discussed in depth.

Key words: expandable graphite, rigid polyurethane foam, composite, thermal stability, flame retardancy