The need to optimize mechanical properties and thermal properties has motivated the development of flame retardant polypropylene system for several decades. The recent research progress of intumescent flame retardant polypropylene is reviewed in this paper

including developments of novel charring agents and new techniques on modification of flame retardant systems. Meanwhile

the synergistic effect of the flame retardant system on the mechanical properties is introduced in flame retardant polypropylene; especially on the impact strength of flame retardant polypropylene. The trends of the future development of the flame retardant polypropylene system have been proposed.