Nanochitin as a Strength-Enhancing Agent for Paper-Based Packaging Material

Paper-based packaging materials are a promising solution for the circular economy, but their performance needs significant improvement for broader applications, replacing conventional plastics. This study explores the potential of nanocrystalline chitin as a nanoadditive to enhance the mechanical properties of paper pulp for advanced paper-based packaging solutions. Through systematic morphological, thermal, and spectroscopic characterization, we established a comprehensive interaction mechanism in which initial electrostatic attractions between oppositely charged components facilitate the formation of dynamic, twinkling hydrogen bonds between chitin nanoparticles and paper fibers in the aqueous environment, subsequently evolving into stable hydrogen bonding networks. This molecular architecture significantly enhances the inter-fiber bonding strength and structural integrity. At 2.5 wt % nanochitin concentration, we achieved an 85% increase in tensile index through the formation of additional load transfer pathways via molecular bridge formation. The elucidated structure-property relationships provide fundamental insights into nanochitin-paper fiber interactions, establishing nanochitin as a promising biobased reinforcing agent. These findings present the paper-based packaging industry with a strategic approach to engineer high-performance products while addressing critical environmental challenges.