Biobased Self-healable Photoluminescent Polyacylhydrazones Imparted by Supramolecular Interactions

With the rise of circular economy, self-healing polymers have attracted significant attention for their longer lifespan and greater recyclability compared with traditional thermoplastics and thermosetting polymers. However, addressing the instability of self-healing units to develop high-performance materials remains a challenge. Herein, we report a series of superior self-healing polyimine derivatives, biobased polyacylhydrazones (bio-PHys), via aldehyde-hydrazide condensation. The coexistence of amide bonds and imine bonds, which provide hydrogen bonding and dynamics, imparts remarkable mechanical properties (tensile strength of 103 MPa, elongation at break of 180%) to bio-PHys, along with notable self-healing capabilities under glass transition temperature (Tg). Bio-PHys also exhibits potential for scalable production, excellent processability, and photoluminescence characteristics. We explored its application in adhesive-free laminated substrates and thoroughly investigated the aggregation-induced emission of the acylhydrazone group. Furthermore, we utilized bio-PHys to create recyclable smart paper for anticounterfeiting and dynamic information storage. This work presents a novel approach to developing high-performance self-healing polymers.