Efficient flame-retardant hard polyurethane foam material with connected phosphaphenanthrene groups

The invention discloses an efficient flame-retardant hard polyurethane foam material with connected phosphaphenanthrene groups. The material comprises, by weight, 2-6 parts of reactive flame retardants, 15-40 parts of additive flame retardants, 80-100 parts of polyether polyols, 5-10 parts of catalysts, 10-20 parts of foaming agents, 2-6 parts of foam stabilizers and 100-150 parts of polyisocyanate. The material realizes multiple compound flame resistance by the aid of the reactive flame retardants TGIC-DOPO and the additive flame retardants including dimethyl methylphosphonate, expansible graphite and aluminum hydroxide, the limit oxygen index of the material reaches 32% or more, the heat release rate peak is reduced to be below 120kW/, average effective combustion heat is reduced to be below 9MJ/kg, total heat release is reduced to be below 9MJ/m , the material has self-quenching properties, extinguishing time is reduced to be below 50 seconds, and the material has high strength, low density and low heat co