Tunable Mechanical Properties in Biodegradable Cellulosic Bioplastics Achieved via Ring-Opening Polymerization

The development of bioplastics is advancing globally to promote a sustainable society. In this study, we designed cellulosic dual-network bioplastics to address the need for sustainable materials with balanced mechanical properties and biodegradability. Cellulose was used as the first network, and the second network was functionalized to enhance mechanical strength while preserving biodegradability. The dynamic covalent moieties within the second network were generated through dithiolane ring-opening polymerization. The ultimate tensile strength and flexural elongation were controlled within 8.8-193 MPa and 3.3-32.5%, respectively, depending on the degree of dynamic bonds. Moreover, the bioplastics exhibited gradual biodegradability, achieving approximately 30% degradation within 2 weeks. Interestingly, our bioplastics demonstrated the ability to coexist with plants, as their degradation did not negatively affect cell viability or plant growth. This study provides a promising approach to developing advanced bioplastics that reach sustainability goals while offering tunable mechanical properties.