Nanofibres reduce flammability

Researchers at the US National Institute of Standards and Technology (NIST) have discovered that adding a small amount of carbon nanofibres to the polyurethane foams used in some upholstered furniture can reduce flammability by about 35 per cent when compared to foam infused with conventional fire retardants.

10 years ago, NIST scientists found that nanoclays could be used as an effective fire retardant additive, but researchers have been seeking alternatives because nanoclay flame retardants do not prevent the melting and dripping of polyurethane foam when exposed to a fire.

This molten foam accelerates the burning rate by as much as 300 per cent. It also creates so much smoke that it is a safety hazard.

Researchers added carbon nanofibres to the foam because they knew that adding nanoparticles to a polymer normally increases the viscosity, so it does not flow as easily.

Jeff Gilman, leader of the Materials Flammability Group in the Building and Fire Research Laboratory, said: 'The carbon nanofibres help prevent the foam from dripping in a pool under the furniture and increasing the fire's intensity.'