Abstract: The action mechanisms of flame retardants for polypropylene were reviewed, including gas phase flame retardancy, condensed phase flame retardancy, and interrupting heat exchange flame retardancy. The research and development status of some flame retardants of polypropylene such as hydrated metal compounds flame retardants, phosphated flame retardants, intumescent flame retardants, silicone flame retardants, and nanometer flame retardants were introduced. It was pointed out that the development directions of flame retardants of polypropylene were nanometer inorganic flame retardants, intumescent flame retardants, and compound flame retardants with high-efficiency, low-smoke and non-toxicity.

Key words: flame retardant, mechanism, research progress, polypropylene