One-step and Scalable Synthesis of EAA-based Reprocessable Vitrimer with Superior Mechanical Properties
Vitrimer uniquely simultaneously combines the opposed thermoset-like properties (mechanical properties, durability, creep/solvent resistance) and thermoplastic-like properties (reshapability, recyclability), thus arousing great enthusiasms in the design, preparation and characterization of vitrimer. From a practical point of view, it is of great value to develop one-step and scalable synthetic procedures for high performance vitrimers. Starting from two highly available and non-expensive commodity materials, namely, ethylene acrylic acid copolymer (EAA) and triglycidyl isocyanurate (TGIC), a series of EAA-TGIC vitrimer materials with varying cross-linking degrees were prepared via a one-step, scalable and practical synthetic approach. Under mild melt compounding conditions, ring-opening of epoxy groups towards carboxyl groups in EAA occurred, resulting in cross-linking of EAA by dynamic β-hydroxyl ester covalent bonds. The formation of covalent cross-linking network in EAA-based vitrimer materials was proved by FTIR and swelling test. The thermo-mechanical, tensile, reprocessing and thermal properties of EAA-TGIC vitrimer were systematically studied. The results showed that EAA-TGIC vitrimer with high gel contents, and thus, excellent solvent resistances, were achieved. Tensile tests revealed that EAA-TGIC vitrimers exhibited premium mechanical properties with well-balanced rigidity and toughness and that the mechanical properties of recovered EAA-TGIC vitrimer remained almost unchanged compared to those of as-prepared EAA-TGIC vitrimer. This study offers a long sought-after solution for the cost-effective recycling of cross-linked polyethylenes and provides new possibilities for keeping difficult-to-recycle cross-linked polyethylenes in the circular loop.
危险品化学品经营许可证（带存储）