The invention discloses an intrinsic flame-retardant polypropylene foam material and its preparation method, including the following steps: mixing polypropylene powder, peroxide initiator and polymer monomer A uniformly to obtain Grafted Polymer 1 via solid-phase grafting; blending Grafted Polymer 1 with ungrafted polypropylene powder and extruding through a twin-screw extruder, then adding amino phosphate flame retardant via a side feeding system at the middle section of the extruder for secondary grafting to prepare Grafted Polymer 2; subjecting Grafted Polymer 2 to rigidity enhancement reaction with excessive isocyanate groups through high-temperature steam; and performing supercritical foaming on the obtained material to produce the final foam product. Through double grafting and rigidity modification, the melt strength of the material is improved. Adopting supercritical fluid foaming, the overall process is clean and environmentally friendly. The prepared halogen-free foam material contains both nitrogen and phosphorus elements with high flame retardant efficiency, solving the problems of low melt strength and poor fire resistance of conventional polypropylene.
Area Code: CN
Application Number: CN202411553799.7
