Anisotropic Foams via Frontal Polymerization
Anisotropic Foams via Frontal Polymerization
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DOI：
10.1002/adma.202105821
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发表时间：
2022-01-15
影响因子：
29.4
通讯作者：
Moore, Jeffrey S.
中科院分区：
文献类型：
--
作者：
Alzate-Sanchez, Diego M.;Cencer, Morgan M.;Moore, Jeffrey S.
泡沫是一类重要的多孔固体，其性能对其基本隔室的体积分数和开放度最为敏感。单元的大小、形状、方向和互连性是其他重要的设计属性。对这些形态特征的控制将允许定制有用材料的制造。虽然冰模板等方法已经生产出具有细长泡孔的泡沫，但仍需要快速、通用且节能的方法来控制泡孔元素的局部秩序和宏观排列。在这里，描述了一种使用正面聚合获得各向异性结构泡沫的快速便捷的方法。泡沫材料是通过前开环复分解聚合 (FROMP) 固化二环戊二烯和发泡剂的混合物而制成的。使用微计算机断层扫描 (micro-CT) 和图像分析协议对材料进行表征，以量化形态特征。泡沫的泡孔结构、孔隙率和硬度随发泡剂、浓度和树脂粘度的变化而变化。此外，使用变量的全因子组合将每个参数与所获得的泡沫的结构相关联。结果表明，使用简单有效的正面聚合方法可以控制生产具有特定形态的泡沫。
The properties of foams, an important class of cellular solids, are most sensitive to the volume fraction and openness of its elementary compartments; size, shape, orientation, and the interconnectedness of the cells are other important design attributes. Control of these morphological traits would allow the tailored fabrication of useful materials. While approaches like ice templating have produced foams with elongated cells, there is a need for rapid, versatile, and energy-efficient methods that also control the local order and macroscopic alignment of cellular elements. Here, a fast and convenient method is described to obtain anisotropic structural foams using frontal polymerization. Foams are fabricated by curing mixtures of dicyclopentadiene and a blowing agent via frontal ring-opening metathesis polymerization (FROMP). The materials are characterized using microcomputed tomography (micro-CT) and an image analysis protocol to quantify the morphological characteristics. The cellular structure, porosity, and hardness of the foams change with blowing agent, concentration, and resin viscosity. Moreover, a full factorial combination of variables is used to correlate each parameter with the structure of the obtained foams. The results demonstrate the controlled production of foams with specific morphologies using the simple and efficient method of frontal polymerization.