Mildly processed chitin used in one-component drinking straws and single use materials: Strength, biodegradability and recyclability

Abstract

We introduce a facile approach toward fully biobased single-use materials based on chitin nanofibers (ChNFs). The chitin is sourced directly from ocean biomass residues (crab shells) and processed under the principles of green chemistry. The material takes advantage of the inherent chemical and structural features of the native chitin, which yield ChNF with a low degree of deacetylation (3.7%), high crystallinity (∼81%) and axial aspect (∼20 μm fibril length). Membranes of densely packed nano-networks are first developed, achieving excellent mechanical strength and self-adhesion, suitable for conversion into objects of tailorable geometries, including small diameter cylindrical drinking straws and conventional tabletop utensils. Van der Waals forces and hydrogen bonding contribute to strong interfiber interaction between chitin crystallites, leading to good interfacial adhesion and excellent mechanical performance. The obtained materials are demonstrated for their recyclability and biodegradability in natural environments, addressing the drawbacks of non-renewable products, considering circularity and end of life. Given the abundance of the sourced chitin, its intrinsic micro-structural design and self-adhesion, this work advances a sustainable alternative to single-use products based on nonrenewable carbon.