Fire-retardant characteristics of water-blown molded flexible polyurethanefoam materials

Polyurethane flexible foam materials have a wide range of industrial applic ations. These applications include flexible foams for packaging, polyuretha ne-based foam materials for seat cushions in buses, railways, the airline i ndustry, prisons, and domestic bedding. There is a substantial need for the development of flexible molded foam materials with low heat release rates and smoke release rates. In this study, an extensive series of flexible, mo lded polyurethane seat cushion materials based on polymeric MDI and polyeth er polyols were prepared and further modified with commercially available f lame retardant additives. The flame retardant behavior of these foam materi als was evaluated using Cone Calorimeter (ASTM-E 1354), vertical Bunsen bur ner test for cabin and cargo component materials [FAR 25.853 (a), Appendix F, Part I, (a)(1)(i) and (a)(1)(ii)], and oil burner test for seat cushions [FAR 25.853 (c), Appendix F, Part IT]. Several formulations that passed th e 12-second vertical Bunsen burner test were identified. These include the formulations modified with Firemaster(R) HP-36, Decabromodiphenyl oxide/ant imony oxide/Firemaster(R) HP-36, Fyrol(R) FR-2, and Fyrol(R) FR-2/graphite powder. A formulation modified with Antiblaze(R)-230 and a cross-linking ag ent passed both 12-second and 60-second vertical Bunsen burner tests. But, all of these materials did not pass the oil burner tests for seat cushions. Using the cone calorimeter, materials with a reduction in peak heat releas e rate of up to 57% were prepared and with up to a fourfold increase in cha r residue in the cone. However, most FR formulations showed an increase in carbon monoxide and smoke generation. Lowest peak HRR data were obtained wi th Firemaster(R) HP-36/Sb2O3 and Dow Silicones(R) 1-9641 at 25 kW/m(2) and with Fyrol(R) FR2/cross-linker at 35 kW/m(2) exposure. It appears that ther e is no correlation between cone calorimeter results and vertical Bunsen bu rner test results.