Halogen-free flame-retardant rigid polyurethane foam and a preparation method

The present invention discloses a halogen-free flame-retardant rigid polyurethane foam and a preparation method by the components in parts by weight, the polyurethane foam from a polyol mixture of 100 parts, 105 to 180 parts of polyisocyanate, halogen-free compound 20 to 80 parts of a flame retardant, 1 to 50 parts foaming agent, 1 to 3 parts of catalyst complex, 2 to 4 parts of a crosslinking agent and a foam stabilizer consisting of from 1 to 2 parts. The resulting product of the present invention has high flame retardancy, a halogen-free material used, combustion does not produce toxic gases such as hydrogen halide, with environmental characteristics; use of raw materials readily available, low cost, thereby greatly reducing the present invention polyurethane foam manufacturing cost; polyurethane foam of the present invention further has a wide range of applications, and is applicable to the insulation board, pipe insulation and other refrigeration freezer and refrigerator insulation industry.