Recycling of Epoxy Thermoset and Composites via Good Solvent Assisted and Small Molecules Participated Exchange Reactions
Recycling of Epoxy Thermoset and Composites via Good Solvent Assisted and Small Molecules Participated Exchange Reactions
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DOI：
10.1021/acssuschemeng.8b01538
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发表时间：
2018-07-01
影响因子：
8.4
通讯作者：
Qi, H. Jerry
中科院分区：
文献类型：
--
作者：
Kuang, Xiao;Zhou, Yunying;Qi, H. Jerry
热固性聚合物和复合材料是一类具有重要工业应用的高性能材料。然而，热固性材料及其填充物的回收具有很大的挑战性。在这里，我们提出了一种在常压和温和温度下使用高效有机催化剂通过溶剂混合物的协同效应有效回收环氧热固性聚合物和复合材料的方法。通过选择性酯键断裂过程实现的酸酐环氧网络解聚通过良好的溶剂辅助和醇参与的酯交换反应得到显着增强。环氧热固性材料在常压、170℃下28分钟溶解，质量损失50%，70分钟溶解，质量损失95%。我们证明，该方法可用于在温和温度（接近170℃）、常压、短时间内（1.5小时）从工业增强环氧复合材料产品和商业电子产品中嵌入金属部件中回收碳纤维，且性能不受影响。此外，分解后的环氧低聚物可以重新用作反应成分，用于制备高强度和高模量的新型环氧材料。这项工作为热固性材料的溶解和回收提供了新的见解。
Thermosetting polymers and composites are a class of high-performance materials with significant industrial applications. However, recycling of thermosets and their filling matters are significantly challenging. Here, we propose a method to recycle epoxy thermosetting polymer and composites efficiently by a synergistic effect of a solvent mixture using a highly efficient organic catalyst at an ordinary pressure and mild temperatures. The anhydride epoxy network depolymerization enabled by selective ester bond cleavage process is substantially enhanced by a good solvent assisted and alcohol participated transesterification reaction. The epoxy thermoset can be dissolved in 28 min with 50% mass loss, and 70 min with 95% mass loss at 170 degrees C under ambient pressure. We demonstrate that this method can be used to reclaim carbon fibers from industrial reinforced epoxy composite products and embedded metal parts from commercial electronic products with undiminished properties at a mild temperature (similar to 170 degrees C) under an ordinary pressure in a short time (1.5 h). Moreover, the decomposed epoxy oligomer can be reused as a reactive ingredient for the preparation of new epoxy materials with high strength and modulus. This work provides a new insight into the thermosets dissolution and recycling.