Pulp mill residues turned into high-performance wood adhesive
Researchers have transformed residues from pulp mills into a fully bio-based wood adhesive with performance comparable to commercial products. The material also showed flame-retardant properties and lower environmental impacts than widely used alternatives.
Large volumes of residues from the pulp and paper industry are currently used for energy recovery. Now, researchers from Stockholm University and international partners have shown that these materials can instead be turned into a high-performance wood adhesive, creating value from existing industrial resources while reducing reliance on fossil-based products.
The study, published in Green Chemistry, demonstrates how compounds derived from pulp mill residues can be used to produce a fully bio-based adhesive. The resulting material achieved a bonding strength comparable to widely used commercial wood adhesives and also exhibited flame-retardant and heat-insulating properties.
"Many industrial residues are currently underutilized and often treated as low-value resources. This study demonstrates how they can instead be transformed into high-value materials with excellent performance and significantly lower environmental impacts. It is a good example of how renewable resources can be used to design more sustainable materials from the start," says Joseph Samec, professor at Stockholm University and researcher in the Mistra SafeChem programme.
Combining performance with sustainability
Developing sustainable alternatives is only part of the challenge. New materials must also perform well enough to replace established products. In the study, the researchers produced an adhesive entirely from raw materials originating from pulp mill residues. Tests showed that the adhesive achieved a bonding strength of 7.69 MPa, placing it in the same performance range as commercially available polyvinyl acetate (PVAc) adhesives. The researchers also found that the material had promising flame-retardant properties. When exposed to a flame, the coating self-extinguished and helped prevent the spread of fire to the underlying wood. In addition, the material demonstrated good heat-insulating performance. These results show that renewable raw materials can be used to create products that deliver both functionality and additional performance benefits.
Lower environmental impacts than commercial alternatives
To understand the environmental implications of the new material, the researchers conducted a life-cycle assessment and compared the adhesive with commercially available polyurethane (PU) and polyvinyl acetate (PVAc) products. The analysis showed that the bio-based adhesive had lower environmental impacts in most of the categories assessed. Depending on the comparison, it performed better than the commercial alternatives in 13 to 15 of the 16 environmental impact categories studied.
"A central ambition of Mistra SafeChem is to support the development of safer and more sustainable chemicals and materials. This work shows how renewable industrial residues can be used to replace fossil-based products while maintaining functionality and reducing environmental impacts," says Joseph Samec.
The findings highlight the potential of using industrial residues as raw materials for advanced materials and products. By combining renewable feedstocks, strong performance and life-cycle assessment, the research demonstrates key principles of Safe and Sustainable by Design.
About the study
Title: Flame-retardant wood adhesive prepared from pulp mill residues
Published in: Green Chemistry (2026)
Researchers from: Stockholm University and international collaborators.
Authors: Lars William Schick, Shida Zuo, Martina Faga, Avinash R. Pai, Saranya Chitsomkhuan, Aleksander Jaworski, Daniel Cracco, Alessandro Marson, Alessandro Manzardo and Joseph S. M. Samec.
Link to the study External link, opens in new window.
The research was supported by Formas, Bio-LUSH, Mistra SafeChem and the Wallenberg Initiative Materials Science for Sustainability (WISE).