High-Strength, Tough, Degradable, and Biobased Aromatic Polyester Networks with Hydrogen-Bonding Pendent Groups

Biopolyesters synthesized by 2,5-furandicarboxylic acid (FDCA) are brittle and difficult to degrade. In this study, we designed a kind of multifunctional FDCA-based polyester network with high strength and toughness, degradability, UV-shielding, and shape memory properties. By introducing magnolol as a diol, a fully biomass-based, fully aromatic polyester with a clickable allyl group was synthesized. Subsequently, the linear aromatic polyester was cross-linked via thiol–ene photoclick reactions. The resulting polyester networks, containing hydrogen-bonding-capable side groups (such as carboxylic acid and hydroxyl moieties), had superior mechanical properties, including both high strength and remarkable toughness, compared to networks lacking these pendent groups. The experimentally measured ultimate tensile strength exceeded 27 MPa, with the maximum elongation at break approaching 270%. These polyester networks exhibited glass transition temperatures (Tg measured by differential scanning calorimetry, DSC) all above room temperature, manifesting as tough thin films at ambient conditions. More notably, these networks demonstrated excellent visible light transparency coupled with efficient UV absorption. Additionally, they were found to possess remarkable shape memory properties. One of the polyester networks exhibited a shape memory transition temperature close to body temperature (37 °C), suggesting a promising biomedical application potential for this material. Furthermore, we found that these polyesters could degrade rapidly in alkaline aqueous solutions, and all networks exhibited degradation periods of less than 24 h. Our work provides a paradigm for the design and preparation of high-strength, high-toughness, and multifunctional biopolyesters.