A by-product of the timber industry has been turned into a safe and reusable hot-gun glue that could replace solvent-based adhesives that are toxic to humans and the environment.
聽at Beijing Forestry University in China and colleagues created the glue from a xylan, a component of plant cell walls.
鈥淴ylan is the material that holds cellulose together, although it is not itself a 鈥榞lue鈥� in the traditional sense,鈥� says at the University of Essex, UK, who wasn鈥檛 involved in the study. 鈥淭his work aims to re-purpose it as a glue.鈥�
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Lv鈥檚 team used sodium periodate and sodium borohydride to chemically modify the xylan, turning it into dialcohol xylan.
They say the resulting glue, which is extruded from a hot gun, has a bonding strength of 30 megapascals, surpassing conventional adhesives, including epoxy resin. The glue could also be reused by re-melting it, and maintained its original adhesion strength even after 10 cycles.
The team also constructed plywood, with three sheets of thin walnut timber held together by the xylan glue, and found it performed comparably with those made with phenol鈥揻ormaldehyde resin adhesives.
But the xylan plywood had a significant drawback. After soaking in water for one hour, the glue dissolved, causing the layers to separate. The researchers didn鈥檛 respond to New 杏吧原创鈥檚 requests for comment.
at Purdue University, Indiana, says sustainable replacements are needed for all of the petroleum-based adhesives currently in use.
鈥淸The] bonding performance [of the new glue] looked to be substantial, particularly with wood substrates,鈥� says Wilker . 鈥淭he life cycle assessment and water resistance results fell a bit short of incumbent glues now in use.鈥�
鈥淚f it can be rolled out at scale in the plywood industry, it could be transformative,鈥� says Aldred. 鈥淧lywood is one of the last remaining consumer products containing materials like phenol and formaldehyde, which were banned in products like cosmetics years ago.鈥�
Nature Sustainability
