Hydro-Responsive Topological Engineering of Cellulose Bioplastics via Dynamic Imine Bonds for Water-Assisted Reprocessing and Closed-Loop Sustainability

The growing crisis of plastic pollution demands urgent adoption of biobased circular economy solutions. A critical step toward this goal is the development of high-performance, closed-loop materials that combine both degradability and recyclability. Cellulose, abundant and completely biodegradable with excellent mechanical properties, offers an ideal platform. However, its extensive hydrogen bonding induces chain rigidity and suppresses plastic deformation, severely limiting processability and industrial adoption. Herein, we developed tannic acid (TA)-modified cellulose nanofibers (CNF) and engineered a dual-network topology using 1,10-diaminodecane (DIM) to fabricate Bioplastic (TA@CNF/DIM). By leveraging synergistic dynamic imine bonds and reversible hydrogen bonding, TA@CNF/DIM enables water-triggered reconfiguration for complex 2D/3D shaping. The TA@CNF/DIM exhibits 101.8 MPa tensile strength, retaining 76.4 MPa after 30 days at 80% relative humidity. Its Strength retention exceeded 86% through 30 hydroplastic reprocessing cycles. Crucially, TA@CNF/DIM can be completely degraded in soil within 120 days, establishing a sustainable closed loop. This research provides new insights into striking a balance between the impressive mechanical properties and efficient plasticity of cellulose-based plastics, thereby contributing to the alleviation of the plastic pollution crisis.