Abstract: Polyurethane rigid foam was prepared from polyether polyols and isocyanate，containing DMMP and melamine as flame retardants. The influences of isocyanate index, contents of water, melamine, and DMMP on vertical combustion performance of the foam were studied. When the isocyanate index was 1.20, the content of water, melamine and DMMP were 2, 30, 35 phr, respectively, its vertical flame level reached FV-0 and compression strength was 8.86 MPa.

Key words: polyurethane, foam, melamine, dimethyl methyl phoshpate, vertical combustion performance