A High‐Strength, Moldable, and Sustainable Bioplastic Enabled by Water‐Mediated Dual‐Bond Reconstruction and Crystal Structure Deformation

Environmental pressures from petrochemical plastics have accelerated the search for sustainable, biomass‐derived materials. However, current research predominantly relies on energy‐intensive, complex bottom‐up fabrication processes, often yielding bioplastics with insufficient mechanical properties, poor processability, and limited thermal stability. This study reports a water‐mediated strategy based on crystal structure deformation and a proposed dual‐bond network comprising reconstructed hydrogen bonds and possible aldehyde‐mediated covalent or hemiacetal/acetal‐type interactions to transform natural wood into a lightweight, high‐strength, acid‐resistant, organic solvent‐resistant, thermally stable, transparent, and recyclable bioplastic (referred to as plasticized wood). This strategy employs alkaline treatment and oxidant activation to disrupt crystalline cellulose, while water enhances chain mobility and reactivity and may facilitate aldehyde‐hydroxyl bonding interactions during hot pressing. Subsequent water removal reconstructs the hydrogen‐bond network, while spectroscopic changes indirectly support possible aldehyde‐mediated network strengthening. The resulting plasticized wood exhibits exceptional mechanical properties, achieving a longitudinal tensile strength of ∼250 MPa and a flexural strength of ∼85 MPa, together with stability, recyclability, chemical degradability, and clear degradation behavior under soil‐burial conditions. This work provides a sustainable pathway for biomass valorization and highlights plasticized wood as a viable and environmentally friendly alternative to conventional plastics.