Enhancement of Barrier Properties of Nanocellulose-Based Coated Paper via AKD and PAE Incorporation

Environmental concerns associated with conventional plastic packaging have increased the demand for ecofriendly alternatives.Paper, a biodegradable and recyclable material, is a promising substitute; however, its porous and hydrophilic nature limits its barrier performance.To overcome these limitations, this study employed TEMPO-oxidized cellulose nanofibrils (TOCNs) as the primary barrier-coating material.Alkyl ketene dimer (AKD) and polyamideamine epichlorohydrin (PAE) were incorporated as hydrophobizing and crosslinking agents, respectively.The rheological properties of the TOCN-based coating solutions and the resulting coated papers were evaluated through Fourier-transform infrared spectroscopy, water and gas barrier measurements, and mechanical testing.AKD increased hydrophobicity and reduced surface moisture adsorption, whereas PAE enhanced network stability through cross-linking.Their combined addition produced a higher water contact angle and improved water vapor transmission resistance and wet tensile strength.These results indicate that conventional papermaking additives can effectively enhance the barrier properties and structural stability of nanocellulose-based coatings, supporting their potential for high-performance, eco-friendly paper packaging applications.