A Biodegradable, Waterproof, and Thermally Processable Cellulosic Bioplastic Enabled by Dynamic Covalent Modification.

The growing environmental concern over petrochemical-based plastics continuously promotes the exploration of green and sustainable substitute materials. Compared with petrochemical products, cellulose has overwhelming superiority in terms of availability, cost, and biodegradability; however, cellulose's dense hydrogen-bonding network and highly ordered crystalline structure make it hard to be thermoformed. A strategy to realize the partial disassociation of hydrogen bonds in cellulose and the reassembly of cellulose chains via constructing a dynamic covalent network, thereby endowing cellulose with thermal processability as indicated by the observation of a moderate glass transition temperature (T g  = 240 °C), is proposed. Moreover, the cellulosic bioplastic delivers a high tensile strength of 67 MPa, as well as excellent moisture and solvent resistance, good recyclability, and biodegradability in nature. With these advantageous features, the developed cellulosic bioplastic represents a promising alternative to traditional plastics.