Upcycling Waste: Fully Biomass-Derived and Backyard Compostable Imine Thermosets

Abstract

Growing environmental issues and dwindling global petroleum supplies have stimulated interest in biomass thermosets. The development of green and sustainable thermosets without the use of expensive raw materials and toxic solvents is a non-trivial challenge. Widely available shrimp and cellulose waste materials are cheap raw ingredients for the development of materials with excellent properties. Herein, we report fully biomass-derived dynamic imine thermosets, readily generated by reacting chitosan with a novel levoglucosenone diketone. The prepared imine thermosets exhibit enhanced modulus (3.7–7.9 GPa), high glass transition temperature (Tg) (171–176.1 °C) and tunable mechanical properties (tensile strength, 12.5 ± 3.5 to 21.1 ± 3.1 MPa). The as-prepared polymer demonstrated fast stress relaxation behavior and reprocessability owing to the dynamic nature of Schiff base bonds. At the “end of product life”, it can be decomposed in a home compost within 4–5 days. The material has the potential to replace conventional and environmentally destructive thermoset plastics, which currently dominate the market.