Micro-nano structured bioplastics from natural biomass enabled by chitin nanofiber binders

Renewable materials derived from biomass are promising alternatives to non-biodegradable petrochemical plastics. Herein, we present a method for producing high-performance bioplastics by using the regenerated chitin nanofibers (ChNFs) as the binder material for micro-scale biomass materials (bamboo microfibers or chitin microsheets). The multi-scale biomass fibers were processed into the slurry and subsequently dried to induce self-assembly. ChNFs adhere to micro-sized materials and form uniform nanoscale entanglements within their pores, enhancing the interfacial interactions among microscale biomass materials, which enable the bamboo-based bioplastic to achieve a tensile strength of 73.74 ± 4.04 MPa. The ChNFs also improve the water stability, maintaining stability in water of 8 h, and enhance hydroplasticity for shaping. Additionally, ChNFs act as an adhesive in a weakly acidic environment, tightly bonding films together through the dissolution and regeneration. The bioplastics are made from natural polysaccharide-based polymers, which can be easily recycled and biodegradable. By combining micro- and nano-biomass materials, this strategy offers a promising route for producing strong, biodegradable, and sustainable biomass plastics as viable alternatives to petrochemical plastics.