UV-Assisted Direct Ink Writing of Dual-Cure Polyurethanes
UV-Assisted Direct Ink Writing of Dual-Cure Polyurethanes
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DOI：
10.1021/acsapm.3c02806
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发表时间：
2024-02
影响因子：
5
通讯作者：
Matthew M. Hausladen;Gabriela Diaz Gorbea;Lorraine F. Francis;Christopher J. Ellison
中科院分区：
文献类型：
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作者：
Matthew M. Hausladen;Gabriela Diaz Gorbea;Lorraine F. Francis;Christopher J. Ellison
直接墨水书写（DIW）为将各种软材料打印成复杂物体提供了一种独特的途径。然而，弹性体材料的快速DIW与最终打印形状的控制仍然是一个挑战。在这项工作中，我们提出了一种通过双固化方法通过uv辅助DIW （UV-DIW）打印商用热固化聚氨酯弹性体的方法。混合双固化树脂由光聚合丙烯酸酯单体和热固化聚氨酯单体组成，可快速固定形状，提供量身定制的弹性体机械性能。通过调整丙烯酸酯和聚氨酯网络的组成，实现了广泛的机械性能，从软弹性体（E ~ 2 MPa）到硬质塑料（E ~ 1 GPa）。通过原子力显微镜研究了相行为和网络互渗，发现双固化聚合物具有亚微米尺寸的两相微观结构，并且随着成分的变化而发生基体反转。聚氨酯弹性体可通过UV-DIW打印，丙烯酸酯含量极低（20 wt %），具有优异的机械性能，包括高伸长率（>600%）和韧性（>10 MJ m-3）。结果表明，该方法可以生成具有不同刚度区域的多材料零件，可用于气动软执行器等应用，相邻区域和层之间具有良好的粘附性。
Direct ink writing (DIW) offers a unique avenue for printing a variety of soft materials into complex objects. However, rapid DIW of elastomeric materials with control over the final printed shapes remains a challenge. In this work, we present a methodology for printing a commercial thermally curable polyurethane elastomer via UV-assisted DIW (UV-DIW) through a dual-cure approach. The hybrid dual-cure resin consists of photopolymerizable acrylate monomers for rapid shape fixation and thermally curable polyurethane monomers to provide tailorable elastomeric mechanical properties. By tuning the composition of acrylate and polyurethane networks, a wide range of mechanical properties were achieved, ranging from soft elastomers (E∼ 2 MPa) to rigid plastics (E∼ 1 GPa). Phase behavior and network interpenetration were investigated through atomic force microscopy, revealing that the dual-cured polymers had two-phase microstructures with submicron domain sizes and a matrix inversion as the composition varied. The polyurethane elastomers were printable via UV-DIW with minimal acrylate content (20 wt %) and have excellent mechanical properties, including high elongation (>600%) and toughness (>10 MJ m–3). It was demonstrated that this approach can generate multimaterial parts with regions of disparate stiffness, useful in applications such as pneumatic soft actuators, with excellent adhesion between adjacent regions and layers.