Tough, Degradable Bioplastics Enabling by Noncovalent Assembly of Polysaccharides and Inorganic Ionic Oligomers

Polysaccharides, as one of the most abundant natural biopolymers, have substantial potential in constructing degradable bioplastics to replace petroleum-based plastics. However, polysaccharides usually exhibit hard and brittle mechanics due to the rigid network derived from the strong intermolecular hydrogen bonding, which greatly limits their application as flexible bioplastics. It still remains a great challenge to weaken the hydrogen bonding network of polysaccharide molecular chains and construct tough polysaccharide-based bioplastics. Herein, we propose a tough and degradable Bioplastic enabled by noncovalent assembly of inorganic ionic oligomers and polysaccharide molecules. By introducing inorganic ionic oligomers as bridging molecules into polysaccharide molecular networks, the hydrogen bonding within polysaccharides is partially neutralized. The multiple interactions (ionic cross-linking and hydrogen bonding) between polysaccharides and inorganic ions at molecular scale and organic–inorganic integrated structure from nanoscale to macroscale are further constructed, which enable the Bioplastic with a tensile strength of 53 MPa and a toughness of 15 MJ m–3, reaching a level similar to that of common plastics. Moreover, the Bioplastic shows excellent solvent resistance, flame retardancy, rapid degradation, and hydroplasticity, indicating that it is an ideal plastic substitute. The organic–inorganic noncovalent assembly tactic hence opens an avenue toward developing tough and degradable bioplastics.