Dynamically Crosslinking Cellulose Nanofibers and Epoxy Soybean Oil toward Tough, Recyclable, and Degradable Bioplastics
Xinhan Zhang, Pengfei Li, Jinsong Zeng, Jindian Su, Jun Xu, Jinpeng Li, Bin Wang, Wenhua Gao, Kefu Chen
Abstract
Developing cellulose nanofiber-reinforced bio-based recyclable and biodegradable plastics can be a fundamental solution to the global accumulation of plastic waste. Herein, we present a bio-based supramolecular plastic with a “reinforced-concrete” architecture achieved through the establishment of cellulose nanofiber crosslinking network and dynamic boron oxide crosslinking between cellulose nanofibers (CNF) and epoxy soybean oil. Termed as DACNF-ESO, this bio-based supramolecular plastic exhibits an impressive tensile strength of ≈41 MPa while maintaining flexibility. After being subjected to a high temperature (150 °C) or water immersion for 7 days, the tensile strength of DACNF-ESO plastic remains superior to that of polyethylene (PE) plastics. The dynamic reversibility of boron oxide in DACNF-ESO plastic enables temperature adaptability and welding capability and allowed for multiple recycling cycles. Complete degradation of DACNF-ESO in soil without the generation of any harmful substances can be achieved within a period of 80 days. The present study offers a novel design principle for high-performance recyclable polymers as sustainable alternatives to conventional plastics. Moreover, both in vivo and in vitro tests demonstrate the exceptional biocompatibility of DACNF-ESO plastics, thereby expanding their potential applications in food, biological medicine, cosmetics, and flexible electronic substrates.