Poly(ether ester) lonomers as Water-Soluble Polymers for Material Extrusion Additive Manufacturing Processes
Poly(ether ester) lonomers as Water-Soluble Polymers for Material Extrusion Additive Manufacturing Processes
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DOI：
10.1021/acsami.7b01777
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发表时间：
2017-04-12
影响因子：
9.5
通讯作者：
Long, Timothy E.
中科院分区：
文献类型：
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作者：
Pekkanen, Allison M.;Zawaski, Callie;Long, Timothy E.
水溶性聚合物作为添加剂制造(AM)的牺牲性支撑物，促进了印刷品的复杂特征。除了聚乙烯醇之外，很少有水溶性聚合物能够使材料挤出AM在本工作中，具有特殊流变性和力学性能的荷电聚醚酯S被用作低温挤出型AM的新型材料。聚乙二醇酯(PEG8K)与间苯二甲酸二甲酯的熔融酯交换反应使S的聚醚酯具有足够的相对分子质量，使其具有机械完整性。定量离子交换提供了具有不同反离子的聚醚酯S的文库，包括一价阳离子和二价阳离子。动态力学和拉伸分析表明，这些聚合物在熔融温度以下的力学性能没有显著差异，这表明最终部件的性能变化不大。然而，流变学分析揭示了熔融状态下二价反阳离子(Ca~(2+)、Mg~(2+)和Zn~(2+))的有利作用，并显示出粘度增加两个数量级。此外，时间温度叠加确定了模数、熔体粘度和流动活化能的升高，这表明高分子链之间的分子内相互作用和更高的表观分子量。特别是，聚(PEG(8k)-co-CaSIP)的挤出为挤出定义明确的部件提供了巨大的机会。独特的熔体流变性突出了这些聚醚酯离聚体是制造可溶部件的低温材料挤出添加剂的理想候选者。
Water-soluble polymers as sacrificial supports for additive manufacturing (AM) facilitate complex features in printed objects. Few water-soluble polymers beyond poly(vinyl alcohol) enable material extrusion AM. In this work, charged poly(ether ester)s with tailored rheological and mechanical properties serve as novel materials for extrusion-based AM at low temperatures. Melt transesterification of poly(ethylene glycol) (PEG, 8k) and dimethyl 5-sulfoisophthalate afforded poly(ether ester)s of sufficient molecular weight to impart mechanical integrity. Quantitative ion exchange provided a library of poly(ether ester)s with varying counterions, including both monovalent and divalent cations. Dynamic mechanical and tensile analysis revealed an insignificant difference in mechanical properties for these polymers below the melting temperature, suggesting an insignificant change in final part properties. Rheological analysis, however, revealed the advantageous effect of divalent countercations (Ca2+, Mg2+, and Zn2+) in the melt state and exhibited an increase in viscosity of two orders of magnitude. Furthermore, time temperature superposition identified an elevation in modulus, melt viscosity, and flow activation energy, suggesting intramolecular interactions between polymer chains and a higher apparent molecular weight. In particular, extrusion of poly(PEG(8k)-co-CaSIP) revealed vast opportunities for extrusion AM of well-defined parts. The unique melt rheological properties highlighted these poly(ether ester) ionomers as ideal candidates for low-temperature material extrusion additive manufacturing of water-soluble parts.