Shenyang, China – A team at Shenyang Aerospace University has been looking at how to create biobased rigid PU foams with better thermal stability, flame retardancy and smoke suppression properties. This could remove the need to add fire-resistant elements such as silicon, nitrogen or phosphorus, or polymeric flame retardants.
One possibility that has caught attention is chicken feather (CF) protein, and non-combustible gases may be produced during combustion, including CO2, N2, SO2 and water vapour. These dilute the concentration of oxygen, slowing down the fire. The mineral montmorillonite also has potential as an inorganic flame retardant as it produces less smoke and toxic substances when it burns. Both have been shown to have synergistic effects with other flame retardants.
The Shenyang scientists looked at the potential of using hydrostannates, which have a good smoke suppression effect, in conjunction with CF and montomorillonite. They focused on the cobalt analogue, CoSn(OH)6.
They found that when incorporated into rigid PU foam, the combination gave better thermal stability, flame retardancy and smoke toxicity properties. Flame diffusion was successfully inhibited, while the flow of heat and production of flammable gases were also prevented. They suggest that the system has the potential to produce biobased foam composites with high-performing, long-lasting fire- and smoke-resistant properties.
The work has been published in the journal Scientific Reports.
