Mechanically Robust and Reprocessable Acrylate Vitrimers with Hydrogen-Bond-Integrated Networks for Photo-3D Printing
Mechanically Robust and Reprocessable Acrylate Vitrimers with Hydrogen-Bond-Integrated Networks for Photo-3D Printing
复制标题
用于照片 3D 打印的具有氢键集成网络的机械坚固且可再加工的丙烯酸酯 Vitrimers
DOI：
10.1021/acsami.0c19520
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发表时间：
2021-01-13
影响因子：
9.5
通讯作者：
Zhang, Kui
中科院分区：
文献类型：
--
作者：
Gao, Hong;Sun, Yingchun;Zhang, Kui
可再加工的丙烯酸酯玻璃体需要增强其强度以扩大在照片三维（photo-3D）打印中的应用。然而，通过在丙烯酸酯玻璃体中添加纳米填料或多功能树脂来改善机械性能的方法不适合光3D打印，因为光透射率减弱导致光聚合固化速度慢，或者大收缩导致尺寸精度降低。目前，我们展示了一种新策略，通过将氢键和可交换的β-羟基酯结合成丙烯酸酯玻璃体来开发一种机械坚固且可再加工的3D打印热固性材料。为了实现这一目的，首先由甲基丙烯酸缩水甘油酯和辛二酸合成了含有β-羟基酯的二丙烯酸酯预聚物。然后，包含合成的二丙烯酸酯预聚物和丙烯酰胺的用于3D打印的树脂配方在交联网络中生成交换的β-羟基酯和侧酰胺。在这里，由酰胺基产生的氢键作为牺牲键在外部负载下耗散巨大的机械能。添加20wt%丙烯酰胺后，平均拉伸强度和杨氏模量分别达到40.1和871MPa，分别提高了约4.4和3.85倍。交联的vitrimer的网络重排可以通过动态酯交换反应来实现，氢键在高温下逐渐消失，从而赋予印刷结构可再加工性。成功制作了各种光3D打印或紫外线照射形状，并将它们溶解在乙二醇中可以再次重塑。
Reprocessable acrylate vitrimer needs to enhance its strength to expand the application in photo-three-dimensional (photo-3D) printing. However, the methods for improving mechanical properties by the addition of nanofillers or a multifunctional resin into acrylate vitrimers are inappropriate for photo-3D printing due to the low curing speed of photopolymerization induced by weakening light transmittance or reduction of dimensional accuracy caused by large shrinkage. At present, we demonstrate a new strategy for developing a kind of mechanically robust and reprocessable 3D printing thermosets by combining hydrogen bonds and exchangeable beta-hydroxyl esters into acrylate vitrimers. To realize this purpose, diacrylate prepolymer containing beta-hydroxyl esters was first synthesized from glycidyl methacrylate and suberic acid. Then, the resin formulations for 3D printing comprising the synthesized diacrylate prepolymer together with acrylamide generate exchanged beta-hydroxyl ester and pendent amide in cross-linked networks. Here, hydrogen bonds resulting from the amide group as sacrificial bonds dissipate vast mechanical energy under an external load. With the inclusion of 20 wt % acrylamide, the average tensile strength and Young's modulus are up to 40.1 and 871 MPa, which increased by about 4.4 and 3.85 times, respectively. The network rearrangement of cross-linked vitrimers can be achieved through the dynamic ester exchange reactions with gradual disappearance of hydrogen bonds at elevated temperatures, imparting reprocessability into the printed structures. Various photo-3D printing or UV irradiation shapes were successfully produced, and these dissolved in ethylene glycol could be remolded again.