Polyurethane flame retardant is a flame retardant used for polyurethane materials. Its principle is mainly to achieve the purpose of flame retardancy by inhibiting the combustion reaction of polyurethane materials.

Generally, polyurethane flame retardants include reactive flame retardants and additive flame retardants.

Reactive flame retardants can participate in the reaction of polyurethane materials and introduce flame retardant elements into the polyurethane molecular chain, thereby giving the polyurethane material flame retardant properties. For example, phosphorus-containing polyols can be used as reactive flame retardants. By reacting with isocyanate, phosphorus elements are introduced into the polyurethane molecular chain, thereby improving the flame retardant properties of polyurethane materials.

Additive flame retardants add some substances with flame retardant properties to polyurethane materials, such as halogen-containing compounds, phosphorus-containing compounds, hydroxides, etc. These substances decompose when the polyurethane material burns, releasing a large amount of inert gas or water vapor, diluting oxygen and combustibles, thereby slowing down the combustion reaction. In addition, flame retardants can also achieve flame retardancy by improving the thermal stability of polyurethane materials, reducing flammability, and inhibiting the generation of smoke and toxic gases.