A new group of liquid reactive nitrogen and nitrogen-phosphorus flame retardants
for self-extinguishing polyurethane expanded polymers.
Part III. Applications to rigid polyurethane foams
Polimery 2000, No 6, 428
SummaryA method is described to produce self-extinguishing rigid polyurethane foams (PTPUR) containing new liquid reactive nitrogen or nitrogen—phosphorus flame retardants based on melamine. Selected property data of the foams are given (Tables 1–4). The compounds were found to flame-retard rigid PTPUR, especially when augmented with bromine retardants. Since the nitrogen flame retardants have an autocatalytic effect, PTPUR can be prepared with only a minor amount or no catalyst added. This effect enables the toxic and volatile amine catalysts to be eliminated. The density of the PTPUR was 18–35 kg/m3. The oxygen index of the foams rose from 19.6 to 21.9% (no bromine retardant added) and to 24.1% (bromine retardant added). The new flame retardants were found to result in a reduced compression strength of the rigid PTPUR.