Aromatic Nitrogen Heterocycles Enable High‐Performance and Closed‐Loop Recyclable Multifunctional Biomass‐Derived Sustainable Poly(Butylene Succinate) Polyester Materials

Biomass‐derived materials are promising candidates for sustainable plastics, yet the long‐standing trade‐off between high performance and efficient, facile chemical recyclability remains unresolved. Here, we present an aromatic nitrogen heterocycle–encoded coupling mechanism that overcomes this limitation in a fully biomass‐derived polyester material. We utilize abundant biomass feedstocks, including dimethyl pyridine‐3,5‐dicarboxylate, succinic acid, and 1,4‐butanediol—to craft the biomass‐derived polyester material (PABP) through a simple melt polymerization process. Pyridine units embedded in the polyester backbone simultaneously enhance chain packing and intermolecular interactions while enabling hydrogen‐bond‐assisted nucleophile activation. This dual role yields biomass‐derived polyesters with high mechanical strength (64 MPa), low oxygen permeability (0.096 barrer), and effective ultraviolet shielding (84.6%). After biaxial stretching, the PABP‐2 shows further improved performance, reaching a tensile strength of 136 MPa, an oxygen permeability of 0.095 barrer, and low haze (19.4%), surpassing most reported biaxial‐stretched counterparts. Crucially, the same heterocyclic nitrogen atoms facilitate chemical recycling by promoting ester bond cleavage under mild conditions. This enables rapid depolymerization, with monomers recovered in high yield (>89.0%) and purity (>95.2%). Monomers are repolymerized to regenerate materials with properties comparable to the original polyester. This work establishes a general strategy for coupling high performance with easy recyclability in sustainable materials.