Sustainable Self-Healing Wood Adhesives from Cellulose and Lignin Derivatives via Dual Dynamic Networks
Yufeng Ma, Xuanang Gong, Juqing Cui, Daihui Zhang, Shishuai Gao, Chunpeng Wang, Fuxiang ChuAbstract
Replacing petrochemical thermosetting adhesives with renewable, repairable alternatives remains challenging. We reported a bio-based self-healing adhesive from ethyl cellulose and lignin-derived vanillin. An EC-based macroinitiator (EC-CPADP) was prepared by esterification, and then RAFT graft copolymerization of lauryl methacrylate (LMA) and vanillin glycidyl methacrylate (VGMA) yielded EC-g-P(LMA-co-VGMA). FT-IR and 1H NMR confirmed aldehyde and hydroxyl pendants, enabling crosslinking with polyetheramine via dynamic imine and hydrogen bonds. Varying VGMA content and crosslinker stoichiometry tuned Tg (6.3−49.2 °C) and tensile properties while maintaining high crosslinking (gel fraction up to 94%). The optimized adhesive achieved a 180° peel strength of 6.47 N·cm−1 on wood, outperforming many bio-based adhesives. The dual dynamic network provided room-temperature self-healing with recovery efficiencies of 91.7% and 81.7% after the first and third cycles, respectively. This modular cellulose-graft platform upgrades cellulose and lignin into high-value, tunable, circular adhesives for wood bonding.