High-Performance, Adhesive-Free, Sustainable Biomass-Based Materials Via a Selective in Situ Oxidation Interface

Biomass materials, such as plywood, fiberboard, and particleboard, have extensive applications in construction formwork, furniture, and decoration. However, the majority of biomass materials are joined using adhesives such as urea-formaldehyde and phenol-formaldehyde resins. Adhesive-free bonding is a sustainable method for fabricating biobased materials, which allows for the efficient use of bioresources. However, the limited adhesion strength and water resistance hinder the use of an adhesive-free method for creating high-performance biomass composites. Here, we present a straightforward and effective method for making adhesive-free biomass composites. The strategy includes selectively oxidizing biomass in situ, followed by adhesive-free bonding through one-step molding. During this process, cross-linking networks are formed within the biomass interface using covalent and hydrogen bonds. Adhesive-free biomass composites possess exceptional adhesion strength and water resistance. Furthermore, the proposed method exhibits exceptional versatility in terms of raw materials, irrespective of the biomass variety or specific surface area (such as low specific surface area in wood veneer and high specific surface area in bamboo fiber or bagasse particles). Moreover, the strategy exhibits excellent surface formability, allowing for the creation of intricate pattern textures on the biomass composites during shape-forming. This strategy shows promise for converting biomass resources into sustainable and high-value-added products.