Milligram Scale Flammability Testing of Flame Retardant Polyurethane Foams

To speed up the development of new flame-retardant chemistries for polyurethane foam, there is a strong need for small-scale flammability tests, especially those which work at the milligram scale. In this paper we discuss current results using the only standard milligram heat release test (Pyrolysis combustion flow calorimetry - ASTM D7309) to study how some commercial flame retardants work in flexible polyurethane. Flexible polyurethane foams formulated to pass small flame ignition regulatory tests showed only small reductions in measured heat release when compared to non-flame retardant foams. This suggests that reductions in heat release are not the primary mechanism by which these additives pass these regulatory tests (FMVSS 302, TB-117) and additional testing in combination with ASTM D7309 may be needed to understand performance and further develop this technique for future flame retardant polyurethane chemistries.