Construction of recyclable poly(ionic liquid)-alginate hydroplastic based on dynamic ionic bonds

The current methods of plastic production and disposal are unsustainable, presenting significant environmental risks. Although eco-friendly processing holds promise for mitigating these challenges, overcoming the associated technological obstacles remains a critical issue. Herein, we developed a hydroplastic material, PIL-Alg plastic, synthesized through the interaction of polyionic liquids (PILs) and sodium alginate. This material combines the inherent cation cross-linking of alginate with the anion-exchange properties of PILs, resulting in a highly adaptable plastic with excellent reshaping, recycling, and flame-retardant properties. PIL-Alg plastic demonstrates superior thermal stability, with a limiting oxygen index (LOI) of 28.5 and no melting behavior at elevated temperatures. Mechanical testing shows a tensile strength of 62.1 MPa, indicating robust performance. Unlike traditional biodegradable plastics, PIL-Alg does not require industrial composting and can be recycled without degradation. This work demonstrates the potential of PIL-Alg plastic as a sustainable, high-performance alternative to conventional plastics, aligning with circular economy principles.