Self-reinforced chitosan composites for high-performance food packaging

The next generation of packaging must safeguard food today while protecting the planet tomorrow. Achieving this vision requires materials that unite mechanical strength, biodegradability, and circularity within a chitosan-based system. We pioneer a bio-self-reinforcement strategy via a self-reinforced chitosan (CS) composite (SR-CS), embedding electrospun CS nanofibers within a CS bio-resin matrix. This chitosan-based self-reinforced composite platform advances the replacement of petroleum-based packaging with bio-derived alternatives engineered for immediate performance and long-term environmental compatibility. Self-reinforcement delivers a 746% increase in tensile strength (11.76 MPa) alongside a substantial rise in Young's modulus, while preserving desirable flexibility. The enhanced mechanical performance is attributed to the incorporation of CS nanofibers within the CS matrix. Thermogravimetric analysis indicates an elevated onset degradation temperature of 326 °C, supporting suitability for thermal processing and storage. SR-CS film exhibits >98% UV shielding and reduced moisture absorption, and complete biodegradation within 30 days under soil burial conditions. Antibacterial assays show potent inhibition of Escherichia coli and Staphylococcus aureus, linked to CS's polycationic character and increased interfacial area. Shelf-life studies demonstrate that cherry tomatoes retain ∼80% of their initial weight after 21 days, outperforming conventional packaging. Collectively, SR-CS offers a multifunctional, scalable route to sustainable food-packaging within future circular bio-economies.