In this paper, the synthesis and reaction mechanism of hexachlorocyclotriphosphazene were briefly introduced. The flame-retardant mechanism of cyclotriphosphazene-based flame retardants was also summarized. The reactive-type hydroxyl, amino, epoxy, alkenyl, and carboxyl, cyclotriphosphazene and the additive-type alkoxy and aryloxy cyclotriphosphazene flame retardants were elaborated on their synthesis and application. The thermal stability and flame retardant properties of cyclotriphosphazene-based flame retardant materials were summarized. The development trend of cyclotri...
