Sika, adhesives for a Hyperloop prototype
27 July 2026
Every year, the global pulp and paper industry generates over 50 million tons of lignin, a widely available byproduct that is still largely underutilized. Only a minimal fraction is currently used in high value-added applications. Meanwhile, the panel and wood products sector continues to rely heavily on petrochemical-based adhesives, such as urea-formaldehyde and phenol-formaldehyde resins, which are at the center of growing concerns due to formaldehyde emissions, dependence on fossil resources, and overall environmental impact.
A new study published in Science proposes a potential breakthrough: transforming this surplus industrial lignin stream into a high-performance, fully bio-based wood adhesive through a relatively simple ion-exchange-based strategy.
The main innovation does not lie in merely incorporating lignin into existing adhesive formulations, but in a true chemical reconfiguration of the material. Researchers from Northeast Forestry University and partner institutions have converted sodium lignosulfonate, a common industrial byproduct, into lignosulfonic acid.
This transformation significantly alters the material’s behavior, giving it a dual function: an active polymeric structure and an intrinsic macromolecular catalyst. The sulfonic acid groups introduced into the structure promote esterification reactions between citric acid, lignosulfonic acid, and hydroxyl groups present in wood during the hot-pressing process.
The result is the formation of a crosslinked adhesive network held together by covalent bonds, achieved without the use of external fossil-based crosslinking agents or toxic catalysts.
This research thus opens the way to a new generation of more sustainable wood adhesives, based on the intelligent reuse of industrial byproducts and simplified chemical processes, with potentially significant implications for the composite materials and wood-based panel industries.
Industry stakeholders will gather at ABS Europe 2026 – Adhesives Bonding & Sealants, the first event in Italy and the Mediterranean area dedicated to adhesives, glues, sealants, foams, tapes, resins, coatings, laminates, and films, scheduled from 27 to 29 October 2026 at Vicenza Exhibition Center.
