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Smoldering in Flexible Polyurethane Foams: the Effect of Foam Morphology



Mauro Zammarano, Szabolcs Matko, Roland H. Kraemer, Rick D. Davis, Jeffrey W. Gilman, Li Piin Sung, Douglas M. Fox, Shivani N. Mehta


Smoldering is a self-sustaining heterogeneous oxidation reaction that induces a slow, low temperature, flameless combustion. Flexible polyurethane foams (PUF) are prone to smoldering due to their high air permeability, low density and high specific surface area. Smoldering of PUF poses a serious fire hazard because it typically yields a substantially higher yield of toxic CO per unit mass of fuel than does flaming (though at a lower rate), and because it can initiate flaming (by transition from smoldering to flaming) with heat sources otherwise too weak. Smoldering of upholstered furniture and bedding remains a threat to life and property, despite the promising introduction of Reduced Ignition Propensity cigarettes in all 50 states. Upholstered furniture and bedding remain the most frequent “first items to ignite” that result in residential fire deaths in the United States. According to estimates by the United States (U.S.) Consumer Product Safety Commission (CPSC), a large number of these fire deaths can be attributed to smoldering materials commonly found in upholstered furniture and bedding. Smoldering in PUF has been extensively studied; however, an experimental assessment of the key parameters affecting smoldering propensity of such materials has been limited by the difficulties in obtaining foam samples with consistent and homogeneous properties. Numerical simulation of smoldering combustion of PUF indicated the significance of oxygen supply on the rate of smolder propagation. , , , , Thermal analysis of the foams has been performed in great detail in order to obtain multi-step models of foam pyrolysis and char oxidation that provided input data for models.8 However, morphological description of the PUF has been limited to the simplest terms. In this study we characterize the morphology of conventional PUF (cell size, strut thickness and open versus closed cell structure) by direct morphological indicator (e.g., cell size) or indirect morphological i
Fire and Polymers VI: New Advances in Flame Retardant Chemistry and Science
Publisher Info
ACS, Washington, DC, DC


smoldering, polyurethane, foam, flammability


Zammarano, M. , Matko, S. , Kraemer, R. , Davis, R. , Gilman, J. , Sung, L. , Fox, D. and Mehta, S. (2012), Smoldering in Flexible Polyurethane Foams: the Effect of Foam Morphology, ACS, Washington, DC, DC, [online], (Accessed June 14, 2024)


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Created December 18, 2012, Updated November 10, 2018