Microencapsulated flame retardant and preparation method thereof

The invention discloses a microencapsulated flame retardant and a preparation method thereof. The invention aims at the defects of poor compatibility and poor water resistance of a flame retardant and a high polymer material, the method adopts an interfacial polymerization method, the flame retardant, an amine compound and an emulsifier are dissolved in deionized water to form a water phase, then an organic solvent is added into the water phase and dispersed at a high speed to form a water-in-oil emulsion; after the emulsion is stable, a curing agent isocyanate is added; and polymerization reaction is carried out on the isocyanate and the amine compound aggregated on the surface of the flame retardant to form the polyurea microencapsulated flame retardant. Compared with a flame retardant which is not subjected to microencapsulation treatment, the flame retardant subjected to microencapsulation modification of the polyurea has the advantages that the water resistance and the compatibility with macromolecules a