The invention discloses a reactive
intumescent flame retardant for
polyurethane and a synthesis method of the reactive
intumescent flame retardant, relates to a
flame retardant technology, in particular to a novel
intumescent flame retardant which contains an acid source, a
carbon source and a gas source simultaneously and contains a hydroxyl group serving as an
active group. The chemical name ofthe reactive intumescent flame retardant for
polyurethane is 3,9-di{N,N-di(2-ethoxyl)-amino}-2,4,8,10-4-oxo-3,9-diphosphate spiro-3,9-dioxo-[5,5]-
undecane. The structure of the reactive intumescent flame retardant is shown as a formula (I). The synthesis method comprises the following steps of: adding 3,9-di{N,N-di(2-ethoxyl)-amino}-2,4,8,10-4-oxo-3,9-diphosphate spiro-3,9-dioxo-[5,5]-
undecane into water; dropwise adding diethanolameine and
triethylamine at the temperature of 0-5 DEG C; reacting at the temperature of 50-60 DEG C for 4-6 hours; concentrating under reduced pressure; purifying; and performing
vacuum drying to obtain the flame retardant. The flame retardant and the synthesis method of the reactive intumescent flame retardant have the advantages of integration of
phosphorus,
nitrogen and carbon,
high phosphorus and
nitrogen flame-retardant ingredients, no containing of
halogen, nontoxicity, environmental friendliness,
high carbon forming property, high compatibility with apolyurethane
system, simple process, mild synthesis condition and suitability for industrial implementation.