A Multifunctional Bio‐Based Polyester Material Integrated with High Mechanical Performance, Gas Barrier Performance, and Chemically Closed‐Loop

Abstract The development of multifunctional bio‐based materials with closed‐loop chemically recyclable plastics can be a paramount response to the worldwide plastic waste predicament. However, the trade‐off dilemma between the high performance and easy recycling performance of these materials still encounters huge challenges. In this contribution, inspired by the significant contribution of the hydrogen bonding networks to enhanced mechanical and gas barrier performance as well as the cosolvents to enhance recycling performance, a novel polyester material (PBH_yF) synthesized by bio‐based monomers that integrate high‐performance and efficient chemical closed‐loop is presented. PBH_yF show ultra‐high mechanical properties (83.2 MPa, 233.9%) and barrier properties (CO₂ 0.0157 barrer, O₂ 0.0071 barrer, H₂O 5.518E‐15 g·cm/cm²·s·Pa) that are greater than bio‐based materials and most engineering plastics of previous work. More significantly, PBH_yF also exhibits multifunctionality with excellent ultraviolet shielding properties, solvent‐resistant properties, and easy recycling performance. The initial monomers of PBH_yF can be obtained in exceptional yields (>90.0%) and purity (>99.0%) under mild conditions by a simple energy‐efficient rapid chemical‐solvolysis strategy, even with polyolefin blend plastics. Further possesses similar high‐performance repolymerized polyester comparable to the polyester before recycling. Hence, these state‐of‐art high‐performance and easy‐recycling bio‐based materials provide a new approach for a green, sustainable material economy.