An Evaluation of Fire-Retardant Properties of Polyurethane Flexible Foam Materials by Cone Calorimetry

Polyurethane flexible foam materials have a wide range of industrial applications. These applications include flexible foams for packaging; polyurethane based foam materials for residential upholstered furniture industry, seat cushions in buses, railways, the airline industry, prisons and domestic bedding. There is a substantial need for the development of flexible molded foam materials with improved flame-retardant properties. In this study, an extensive series of flexible molded polyurethane seat cushion materials based on polymeric MDI and polyether polyols were prepared and further modified with commercially available flame retardant additives. The flame-retardant behavior of these foam materials was evaluated using a Cone Calorimeter (ASTM–1354), the instrument that has emerged as an important tool for the analytical testing of materials for their fire properties. Using a Cone Calorimeter, materials with a reduction in peak heat release rate of up to 57% were prepared and with up to a four fold increase in char formation. However, most fire retardant formulations showed an increase in carbon monoxide and smoke generation. Lowest peak heat release rate data were obtained with Firemaster® HP-36 / antimony oxide and Dow Corning powdered siloxane additive, 1-9641 at 25 kW/m 2 exposure and with Fyrol® FR2/FR-T at 35 kW/m 2 exposure.