Testing FRs for flexible PU foam

Five flame retardants were tested in flexible polyurethane foam showing performance and fire safety benefits of PIN FRs. Two chlorinated FRs (TCEP, CR) and three PIN FRs (melamine, melamine cyanurate and expandable graphite) were used, each at 15% loading. Resulting polyurethane processing, foam and fire characteristics were measured: viscosity, foaming time and rise height, density, load resistance, elongation at break, tear strength, compression resistance and recovery, cell size, fire performance (LOI, burn distance and burn time, heat release). FR addition deteriorated foam characteristics for nearly every parameter measured but with varying results for different FRs for different parameters. The authors suggest that expandable graphite offered the best overall mechanical performance of the five FRs tested, and also the best fire performance.

TCEP = tris 2-cloropropyl phosphate. CR = chlorinated phosphinyl alkyl phosphate ester.

“Analysis of mechanical and flame-retardant properties of flexible polyurethane foams”, Y. Kim & E. Jeon, J Appl Polym Sci. 2023;140:e54670 https://doi.org/10.1002/app.54670