Scientists have developed an eco-friendly process for increasing the fire resistance of timber that also dramatically increases its strength.
The fire-proofing of buildings made from timber materials is an issue of paramount importance in most parts of Australia, given the country’s parched climate and the heightened risk of fire during the torrid summer months.
While methods for fire-proofing timber materials already exist, most of them involve treatments that employ substances that are noxious or hazardous to human health.
Researchers from Stony Brook University have developed a new type of timber flame retardant that is not only sustainable and environmentally friendly, but also radically raises the strength of treated materials.
The flame retardant consists of a phosphorus-based compound called resorcinol bis (RDP) that has already been declared by the EPA to be a preferred substitute for halogenated flame retardants.
The compound penetrates the natural structure of timber materials and interacts with its cellulose, producing a wood-plastic composite that surpasses UL94 V-0 flammability standards. This means that a vertical specimen of the material will stop burning in as little as 10 seconds when set alight, without giving off any lit particles.
According to Miriam Rafailovich, Distinguished Professor from Stony Brook’s Department of Materials science and co-director of the Program in Chemical and Molecular Engineering, a unique advantage of the material is its ability to stifle the spread of a fire without producing hazardous chemicals.
“The breakthrough was in the formulation of a compound that extinguishes a flame without decomposing into toxic byproducts,” said Rafailovich.
Testing by Stony Brook medical experts has also concluded that timber materials treated using RDP pose no hazard to human health, despite the material itself being cytotoxic when in a liquid, unreacted state.
“Preliminary data in our laboratory confirms that when RDP is reacted with cellulose, or clays, such as was done by our students, it is safe and non-cytoxic,” said Dr. Marcia Simon, professor and director of Graduate Studies in the Department of Oral Biology and Pathology at the Stony Brook University School of Dental Medicine.
Another advantage of the treatment process is that can dramatically improve the durability of timber materials by reinforcing their cellulose structure, increasing their strength by as much as five-fold.
The absence of toxic byproducts in combination this strengthening effect could make the process ideal for flame-proofing timber materials employed in the construction of habitable buildings.
Stony Brook has already filed a patent on the process, while its Office of Technology Transfer and Industry Relations has received expressions of interest from a number of companies with respect to potential licensing.