Biobased, Tough, and Programmable Hybrid Polyester Networks with Multirecyclability and On-demand Degradability via Dynamic Cocross-Linking

Developing sustainable, tough, and multifunctional biobased polymers remains a significant challenge. Herein, we report the design and synthesis of biobased hybrid polyester covalent adaptable networks (CANs) by cocross-linking commercially available low-molecular-weight poly(lactic acid) (PLA) diols and aliphatic polycarbonate (APC) diols via dynamic disulfide bonds. These bonds are readily introduced through UV-initiated ring-opening polymerization of thioctic-acid-modified chain ends. The resulting PLA/APC CANs feature homogeneous network structures with excellent optical clarity and well-tunable glass transition temperatures ranging from −12 to 39 °C. Remarkably, they exhibit significantly enhanced toughness, with fracture energy reaching up to 47.2 MJ/m3, which is 68 and 58 times that of neat PLA CAN and neat APC CAN, respectively. Additionally, these networks demonstrate programmable shape memory behavior, including rapid recovery near body temperature with high fixation and recovery ratios and reconfigurability via thermal topological rearrangement. In vitro studies confirmed their excellent biocompatibility. Furthermore, the networks exhibit multirecyclability via both thermal reprocessing and DBU-catalyzed chemical disassembly, as well as on-demand degradation triggered by redox and UV stimuli, and accelerated degradation in reductive buffer solution (pH = 8). This modular strategy offers a generalizable platform for creating tough, programmable, recyclable, and degradable biobased polymers, supporting smart applications, sustainable design, and ecofriendly end-of-life management.