The invention relates to applications of cyclic
phosphorus-
nitrogen synergic
halogen-free
flame retardant, and particularly relates to applications of 2,7-bis(N,N-
dimethylamine)-1,6,3,8,2,7-octahydrodioxadiazole diphosphinic acid, belonging to the field of synthesizing a novel
halogen-free
high polymer material. As a hard segment chain
extender, 2,7-bis(N,N-
dimethylamine)-1,6,3,8,2,7-octahydrodioxadiazole diphosphinic acid is applied to
halogen-free
flame-retardant modification of water-based
polyurethane emulsion. Cyclic
phosphamide flame retardant 2,7-bis(N,N-
dimethylamine)-1,6,3,8,2,7-octahydrodioxadiazole diphosphinic acid as the hard segment chain
extender is embedded into a water-based
polyurethane macromolecular chain; the research shows that due to the addition of the flame retardant, the limit
oxygen index of a
polyurethane membrane can be improved to a greater extent, the
thermal stability of the
polyurethane membrane is enhanced, the carbon residue rate of the material after which is decomposed at high temperature is increased, and the usage amount of the flame retardant is reduced.