PU foam has a very wide range of uses and involves various fields of the national economy. Because of its special structure, that is, the high involvement rate of oxygen, its flame retardant treatment is particularly important. Then, if it is best to modify it from its structure, an isocyanurate structure can generally be introduced into the PU chain to increase the charring tendency of the system to reduce its flammability. However, this method is limited in application, and it is often used as an additive or reactive flame retardant.
1 added flame retardant --- generally liquid halogen-containing phosphate esters and phosphonates. The solid-state flame retardants include: melamine, red phosphorus, zinc borate, chlorinated paraffin, ATH, TBC, and the like. No matter what kind of flame retardant is required to be compatible with the components in the PU, there will be no "burning" phenomenon.
2 Reactive flame retardants—Mainly a variety of liquid and solid phosphorus-containing or halogen-containing polyols.