“Three birds with one stone” strategy for building easily reprocessable cellulosic thermosetting resins

Cellulose is the most abundant natural polypolysaccharide and is an ideal raw material to replace petroleum-based plastics. However, natural cellulose is difficult to be thermo-processed like conventional plastics because of the rich and strong hydrogen bonds interactions. In this study, a series of dialdehyde derivatives of cellulose (DACs) were prepared by periodate oxidation of cellulose, and cellulose covalent adaptive networks based on acetal dynamic covalent bonds (ACCs) were prepared using dipentaerythritol as a crosslinker for DAC. This strategy can introduce acetal bonds, weaken hydrogen bonds, and reduce rigidity to kill three birds with one stone. The excellent reprocessing performance of ACCs is attributed to the reconstruction of the cellulose hydrogen bond network by acetal bonds, and the reversible exchange reaction of the acetal bonds at high temperatures endows the cellulose chains with mobility, allowing ACCs to be remodeled by hot pressing at 90°C for 15 min. The excellent stability and reprocessability of ACCs hold the promise of replacing current non-renewable petroleum-based plastics and provide inspiration for the development of other types of biomass plastics.