Wood Glue from Soybeans
In today’s increasingly environmentally aware society, the ubiquity of formaldehyde in wood manufacturing has been downplayed. A pervasive chemical used as an adhesive in plywood, particle board, and other wood products, formaldehyde is a potential carcinogen and releases volatile organic compounds (VOCs) that can irritate one’s eyes, skin, and mucous membranes. Given its toxicity and derivation from fossil fuels, researchers have been seeking alternative glues from environmentally friendly sources.
This week, researchers from the USDA Forest Products Laboratory in Wisconsin discussed the development of soy-based adhesives at the American Chemical Society’s national conference. Based on soy flour, which has inherent hydrophobic properties, the new glues are said to be as effective as formaldehyde without the negative side effects.
According to Dr. Charles Frihart, “Protein adhesives allowed the development of composite wood products such as plywood in the early 20th century. Petrochemical-based adhesives replaced proteins in most applications based upon cost, production efficiencies, and better durability. However, several technologies and environmental factors have led to a resurgence of protein, especially soy flour, as an important adhesive for interior plywood and wood flooring.”
Although soy-based glues make up less than five percent of wood adhesives currently in use, Dr. Frihart and his colleagues anticipate the use of non-petroleum glues to expand rapidly in the coming years based on their positive environmental attributes.