The authors indicate that flexible polyurethane foam (FPUF) is highly flammable with a LOI (limiting oxygen index) as low as 18%, catching fire easily and spreading fire.
They present synthesis and testing of a novel PIN fire safety solution for FPUF, alternative to conventional chlorinated FRs. A melamine phosphorus compound, DPPMA, was synthesised by reacting melamine with diphenyl phosphonic acid (DPPA) in ethanol and water at 90°C for six hours, filtration and drying. This was then added into polyether polyols (GEP-560s), catalysts and surfactant to produce PIN FR-FPUF with 30% DPPMA loading. LOI was increased from 21% to 25% (30% DPPMA) and just 5% DPPMA rendered the FPUF self-extinguishing in CAL TB117-2000 vertical test. The authors conclude that DPPMA provides a potentially high performance fire safety solution for flexible polyurethane foam, acting mainly in the vapour phase.
“Flame retardant flexible polyurethane foams with highly efficient melamine salt”, W-H. Rao et al., Ind. Eng. Chem. Res. (I&EC) 2017, 56 (25), pp 7112–7119 http://dx.doi.org/10.1021/acs.iecr.7b01335