Water-driven dynamic dual-network structure enables hydroplastic polymers with ultrahigh strength and tunable performance

Hydroplastic polymers have attracted much attention due to their good combination of hydroformability and environmental sustainability. However, the instability of the network structure of hydroplastic polymers constructed from a single non-covalent physical interaction makes it challenging to achieve satisfactory mechanical properties and hydroforming simultaneously. Herein, a cellulose hydroplastic polymer (Cel-hydroplastic) was proposed that is fabricated by constructing a dynamic dual cross-linking network (boronic ester and hydrogen bonds) between cellulose nanofibers (CNF) and synthetic copolymer containing a catechol structure (PHD). Notably, CNF promotes water-driven reorganization of the dynamic dual network, which allows Cel-hydroplastic to switch arbitrarily between 2D and 3D shapes. Meanwhile, introducing CNF enables Cel-hydroplastic with high mechanical strength (tensile strength: 128.30 MPa dry; 44.50 MPa at relative humidity 90 %). Furthermore, Cel-hydroplastic can be easily recycled and efficiently biodegraded in natural environments. Overall, these outstanding properties position Cel-hydroplastic as a promising candidate for the next generation of environmentally friendly materials.