Mid Sweden University

Lightweight materials with high strength are desirable for advanced applications in transportation, sports equipment, construction, automotive, and aerospace. Aspen is fast growing, has low flammability, and is renewable and readily available. In this study, we present a continuous, high-yielding, efficient, scalable, and sustainable approach for the fabrication of strong materials from aspen by synergistic selective chemical modification and continuous hot pressing. FTIR analysis revealed changes in the chemical composition of the wood polymers, including the introduction of anionic groups, while SEM images showed morphological and structural transformations such as smoother surfaces and a more compact wood structure. The proposed strategy achieved up to 258 MPa (530% increase) in tensile strength by combining enhanced ion-bonding and hydrogen-bonding with the alignment of cellulose nanofibrils and the solidification of softened, depolymerized lignin through cross-linking reactions. This work demonstrates the continuous large-scale production of lightweight, strong structural materials under energy-efficient and mild modification conditions, suitable for the green fabrication of next-generation advanced materials from wood.