Scholarlink

<p>There is usually a trade-off between the mechanical properties and processability of polymers because the mechanisms underlying these properties are mutually exclusive. Herein, we discovered that rationally designed crosslinking can simultaneously enhance both the mechanical properties and processability of polymers. To achieve this, a dynamically dissociable crosslinker was designed using a reversible Diels-Alder reaction that forms a stable covalently crosslinked network from the linear polymer. During processing, the crosslinked network dissociates to release a small-molecule crosslinking agent, which increases the free volume of the polymer and weakens the non-covalent interactions between the molecular chains. Consequently, the polymer exhibits superior processing performance compared to its linear polymer counterpart. A polyurethane model was designed to demonstrate this strategy. After crosslinking, the strength and toughness of the polyurethane increased significantly compared to those of the linear polyurethane counterpart. Additionally, the solid-liquid transition temperature of the polyurethane decreased from 149 °C to 118 °C, and the processing viscosity decreased by 48%. An application of this technology was demonstrated by producing fibers with the highest tensile strength (78.7 MPa) at the lowest processing temperature (125 °C) reported for melt-spun crosslinked fibers.</p>

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Dynamic crosslinked polyurethane with readily processability and high strength based on the Diels-Alder reaction

  • 期刊论文

  • 发表日期：

    2025年6月27日

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  • Yuepeng Wang,
  • Bo Qian,
  • Zihao Li,
  • Zekai Wu,
  • Yihan Wang,
  • Jiani Wu,
  • Zhengwei You

摘要

There is usually a trade-off between the mechanical properties and processability of polymers because the mechanisms underlying these properties are mutually exclusive. Herein, we discovered that rationally designed crosslinking can simultaneously enhance both the mechanical properties and processability of polymers. To achieve this, a dynamically dissociable crosslinker was designed using a reversible Diels-Alder reaction that forms a stable covalently crosslinked network from the linear polymer. During processing, the crosslinked network dissociates to release a small-molecule crosslinking agent, which increases the free volume of the polymer and weakens the non-covalent interactions between the molecular chains. Consequently, the polymer exhibits superior processing performance compared to its linear polymer counterpart. A polyurethane model was designed to demonstrate this strategy. After crosslinking, the strength and toughness of the polyurethane increased significantly compared to those of the linear polyurethane counterpart. Additionally, the solid-liquid transition temperature of the polyurethane decreased from 149 °C to 118 °C, and the processing viscosity decreased by 48%. An application of this technology was demonstrated by producing fibers with the highest tensile strength (78.7 MPa) at the lowest processing temperature (125 °C) reported for melt-spun crosslinked fibers.