Reactive type intumescent flame retardant and synthesis method thereof

The invention discloses a reactive type intumescent flame retardant and a synthesis method thereof, and aims at solving the problems of poor material compatibility, poor machining property, environment pollution caused by high possibility of escape and complicated preparation method in the prior art. The synthesis method comprises the following steps: (1) adding cyanuric chloride and trialkyl phosphite according to a molar ratio of 1:1 into a dichloroethane solvent, and continuously refluxing for 1-2h to generate an intermediate 2; and (2) cooling to room temperature, reacting cyanuric chloride, 2-substituted ethanol and triethylamine according to a molar ratio of 1:1.2:1.2 for 3-5h while controlling the temperature to be 45-55 DEG C or below to generate a target compound 3, namely the reactive type intumescent flame retardant. According to the invention, a carbon source, an acid source and an air source are integrated, heat stability is good, carbon formation property is good, inflame-retarding effect is good, synthesis process is simple and price is low.