Overcoming Strength-Toughness Trade-off of Furandicarboxylic Acid–Based Polyester via Nanoconfined Crystallization

2,5-Furandicarboxylic acid (FDCA)-based polyesters are among the most promising materials for achieving sustainability and recyclability of plastics in the current era of the energy crisis. However, it is difficult to construct one single polyester with integrated high strength, toughness, and gas barrier properties. Inspired by the biomineralization process of nacre, herein we develop a nanoconfined crystallization strategy to manufacture innovative FDCA-based pseudo-mineralization polyester (denoted as PMP) that combines ultrahigh mechanical strength, toughness, and excellent barrier properties. Specifically, large-aspect-ratio boron nitride nanosheets (BNNSs) are used as a lamellar template to induce in situ growth and nanoconfined crystallization of polybutylene furandicarboxylate (PBF), leading to the delicate biomimetic multilayer structure that constricts PBF nanocrystals within the highly oriented BNNS layers. Such a rational material design establishes an ideal structural strengthening mechanism via the "in situ orientation-nanoconfined crystallization-multiple energy dissipation". As a result, ultrahigh mechanical strength (≈92 MPa) and toughness (≈105 MJ/m³) are achieved in one FDCA-based material system. Additionally, high gas barrier properties (e.g., O₂ 5×) are demonstrated owing to the high crystallinity and lamellar structure that hinder the infiltration of gas molecules. This work endows FDCA-based polyesters with integrated performance benefits and provides good possibilities for constructing high-performance biobased materials.