Water-dispersible macromolecular antioxidants for toughening and strengthening cellulose membranes

Biodegradable packaging materials from cellulose are eco-friendly alternatives to traditional petroleum-based plastics. Balancing its mechanical properties as well as protective values (antioxidation, oxygen barrier, etc.) is critical. However, most studies to improve its antioxidation performance were accompanied by sacrificed mechanical properties. In the current work, a series of linear -COOH functionalized phenolic polymers were prepared from phenolic compounds (vanillin, 3,4-dihydroxy benzaldehyde) through a facile tri-component thiol-aldehyde polycondensation. While circumventing the cumbersome protection-deprotection of phenol groups, the one-pot strategy also affords water dispersible polymers for fabricating composites with cellulose nanofibers in an aqueous medium. After introducing 5–10 wt% of the copolymers, a minor soft phase was formed inside the composites, contributing to enhanced mechanical strength, toughness, antioxidation capability, and ultra-violet blocking performance, while its oxygen barrier property was well maintained.