Molecular mass engineering for filaments in material extrusion additive manufacture
Molecular mass engineering for filaments in material extrusion additive manufacture
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DOI：
10.1002/pol.20230559
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发表时间：
2023-09
影响因子：
3.4
通讯作者：
Sierra F. Yost;Christian W. Pester;Bryan D. Vogt
中科院分区：
文献类型：
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作者：
Sierra F. Yost;Christian W. Pester;Bryan D. Vogt
通过材料挤出增材制造通过局部熔化和沉积进行热塑性塑料的3D打印，为复杂物体的近净成形制造提供了一条简单的途径。然而，与传统制造的热塑性塑料相比，这些3D打印结构的机械性能往往较差。这些不利的特征通常归因于印刷道路之间的界面结构。在这里，我们说明了如何调整模型热塑性塑料聚甲基丙烯酸甲酯（PMMA）的分子量分布，以提高3D打印塑料的杨氏模量。设计分子量分布改变了缠结密度，这控制了固态PMMA的强度和熔体中的链扩散。增加低分子量尾部增加了印刷部件的杨氏模量和极限拉伸强度。这些机械性能的变化与先前报道的更复杂的路线相当，这些路线涉及新的化学物质或纳米颗粒，以提高3D打印热塑性塑料的机械性能。控制分子量分布提供了一种简单的途径来改善热塑性塑料3D打印的性能，这种方法可以与更复杂的方法一样有效。
3D printing of thermoplastics through local melting and deposition via material extrusion additive manufacturing provides a simple route to the near net‐shape manufacture of complex objects. However, the mechanical properties resulting from these 3D printed structures tend to be inferior when compared to traditionally manufactured thermoplastics. These unfavorable characteristics are generally attributed to the structure of the interface between printed roads. Here, we illustrate how the molecular mass distribution for a model thermoplastic, poly(methyl methacrylate) (PMMA), can be tuned to enhance the Young's modulus of 3D printed plastics. Engineering the molecular mass distribution alters the entanglement density, which controls the strength of the PMMA in the solid state and the chain diffusion in the melt. Increasing the low molecular mass tail increases Young's modulus and ultimate tensile strength of the printed parts. These changes in mechanical properties are comparable to more complex routes previously reported involving new chemistry or nanoparticles to enhance the mechanical performance of 3D printed thermoplastics. Controlling the molecular mass distribution provides a simple route to improve the performance in 3D printing of thermoplastics that can be as effective as more complex approaches.