Complete conversion of eucalyptus wood to dynamic covalent networks: An in-situ plasticising strategy

Ongoing innovation in bio-based plastics aims to meet more economical and diverse societal needs. However, the dependence on a single biomass source and the generally inadequate wet stability and moisture mechanical properties of traditional bio-based plastics severely limit their competitiveness. We have developed a high mechanical performance, fully bio-based, thermoset in-suit plastic from an almost worthless agricultural and forestry waste (eucalyptus) through a simple and environmentally friendly deconstruction-reconstruction strategy. In this process, the hydrogen and covalent bonds in the lignin and cellulose of eucalyptus are broken and then reorganised through dynamic covalent bonds. The resulting eucalyptus-based plastic exhibits high mechanical strength, excellent water resistance, UV ageing resistance, photothermal performance and light/heat controllable shape memory properties. By preserving the original structure of the lignin and cellulose, its natural degradability is ensured. This strategy for developing full-component plastics from solid agricultural and forestry waste offers a new approach to producing more competitive fully bio-based plastics.