A by-product from the wood industry has been innovatively transformed into safe, reusable hot glue adhesives that could serve as an alternative to hazardous solvent-based adhesives.

Ziwen LV of Beijing University of Forestry, along with a colleague, developed an adhesive from xylan, a component of plant cell walls.

“Xylan acts as a binding agent for cellulose, yet isn’t traditionally considered a ‘glue’ on its own,” stated Nick Aldred, who wasn’t part of the research team at the University of Essex, UK. “This initiative aims to reactivate it as a viable adhesive.”

The LV team chemically modified xylan to create dai-alcohol xylan, utilizing sodium acid and sodium borate in the process.

The resultant adhesive, when extruded from the hot glue gun, boasts a bond strength of 30 megapascals, surpassing that of traditional epoxy resin adhesives. Additionally, it can be reused by remelting, maintaining its adhesive properties even after 10 cycles.

The team also constructed plywood held together with xylan adhesive and found its performance comparable to that of phenol-formaldehyde resin adhesives.

However, there’s a significant limitation: after being submerged in water for one hour, the adhesive melts and the layers disintegrate. The researchers didn’t respond to requests for comment from New Scientist.

Jonathan Wilker from Purdue University, Indiana, highlights the pressing need for sustainable alternatives to the petroleum-based adhesives presently in use.

“[The] combined performance [of the new glue] was quite impressive, especially on wood substrates,” remarked Wilker.

“If we can implement this on a larger scale within the plywood industry, it could be revolutionary,” emphasized Aldred. “Plywood remains one of the last consumer products still containing materials like phenols and formaldehyde, substances that were banned years ago in products such as cosmetics.”