A material long regarded as little more than a by-product of wood processing may soon find a new role in sustainable packaging. Researchers have developed experimental foams made primarily from sawdust that exhibit mechanical properties approaching those of expanded polystyrene (PS), pointing to a promising renewable alternative for protective packaging.
Published in ACS Applied Polymer Materials, the study demonstrates how forestry residues can be transformed into lightweight cushioning materials using bio-based polymers instead of fossil-derived plastics.
Transforming sawmill residues into high-value materials
To evaluate the concept, the researchers worked with both commercially processed wood powder and untreated sawmill residues. The sawdust was combined with cellulose-based binders, citric acid and other naturally derived ingredients before being molded, frozen, freeze-dried and heat-cured to produce porous, open-cell foams.
Mechanical performance depended largely on the cellulose chemistry used in each formulation. Samples made with carboxymethyl cellulose (CMC) produced rigid structures, while hydroxypropyl cellulose (HPC) generated softer, more flexible foams. By combining both binders, the team produced materials whose compression performance approached that of conventional PS packaging foams.
One particularly encouraging finding was that foams manufactured from coarse sawmill residues performed much like those made from commercially refined sawdust. This suggests that minimally processed wood waste could become a practical feedstock, reducing both processing requirements and raw material costs.
Strong performance under demanding conditions
The researchers also assessed how the foams responded to moisture, solvents and impact.
The biobased materials maintained their structural integrity in water and resisted degradation when exposed to organic solvents such as acetone—behaviour that differs markedly from conventional PS foams. A thin beeswax coating further reduced moisture absorption under high-humidity conditions without compromising the foam's mechanical performance.
Impact testing produced equally promising results. Using a 10-pound (4.5-kg) weight, the researchers found that the sawdust-based foam absorbed more impact energy than PS of similar thickness, causing the weight to rebound approximately 21% less. The results indicate that the material could provide the level of cushioning required for protective packaging applications.
Potential beyond packaging
According to corresponding author Todd Emrick of the University of Massachusetts Amherst, the research was initially driven by the need for more sustainable protective packaging materials used to safeguard products during transportation.
Although the technology remains at an early stage, the researchers believe the material could eventually find applications in sectors ranging from consumer electronics and food packaging to chemicals, biologics and construction materials.
Further studies will be needed to assess long-term durability and the feasibility of large-scale manufacturing. Even so, the work highlights a promising opportunity to convert low-value wood residues into renewable, high-performance materials. For the forest products industry, it also points to a potential new value-added outlet for sawmill by-products beyond their traditional use as fuel or low-grade biomass.
About the study
The study, "Biopolymer Foams Composed of Sawdust: Fabrication and Structural Integrity," was published in ACS Applied Polymer Materials (Vol. 8, Issue 11) on May 20, 2026. Led by researchers at the University of Massachusetts Amherst, the study investigates the use of sawdust and cellulose-based biopolymers to develop renewable foam materials for protective packaging and other lightweight applications.
