Biomass Chitosan and Phytic Acid Synergistic Modified Paper with Enhanced Oil/Water Resistance for Eco-Friendly Food Packaging

The development of novel food packaging materials with both eco-friendly and highly oil-resistant has been identified as a critical challenge in the food packaging industry. Herein, a facile strategy for fabricating food packaging paper with dual oil- and water-resistant properties was reported. Specifically, filter paper was used as the substrate, chitosan was employed as the film-forming matrix, and phytic acid was utilized as a crosslinking agent to modify chitosan, resulting in the successful preparation of functional paper with excellent oil and water resistance. The effects of chitosan coating concentration and phytic acid crosslinking time on the oil and water resistance were systematically investigated. The optimal oil and water resistance was achieved when the chitosan coating amount was set at 30 g/m² and cross-linked with a 5% wt phytic acid solution for 10 minutes. Over 24 hours of oil resistance and over 30 minutes of water resistance were observed, which could block oil for more than 24 hours and water for more than 30 minutes, suggesting potential applications in food-contact packaging materials.