Huang Yun-Shuai, Zhou Yang, Zeng Xiaolong, Zhang Dachuan, Wu Si
Hefei National Laboratory for Physical Sciences at the Microscale, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, China.
DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056, Aachen, Germany.
Adv Mater. 2023 Oct;35(41):e2305517. doi: 10.1002/adma.202305517. Epub 2023 Aug 26.
Thermoset plastics, highly desired for their stability, durability, and chemical resistance, are currently consumed in over 60 million tons annually across the globe, but they are difficult to recycle due to their crosslinked structures. The development of recyclable thermoset plastics is an important but challenging task. In this work, recyclable thermoset plastics are prepared by crosslinking a commodity polymer, polyacrylonitrile (PAN), with a small percentage of a Ru complex via nitrile-Ru coordination. PAN is obtained from industry and the Ru complex is synthesized in one step, which enables the production of recyclable thermoset plastics in an efficient way. In addition, the thermoset plastics exhibit impressive mechanical performance, boasting a Young's modulus of 6.3 GPa and a tensile strength of 109.8 MPa. Moreover, they can be de-crosslinked when exposed to both light and a solvent and can then be re-crosslinked upon heating. This reversible crosslinking mechanism enables the recycling of thermosets from a mixture of plastic waste. The preparation of recyclable thermosets from other commodity polymers such as poly(styrene-coacrylonitrile) (SAN) resins and polymer composites through reversible crosslinking is also demonstrated. This study shows that reversible crosslinking via metal-ligand coordination is a new strategy for designing recyclable thermosets using commodity polymers.
热固性塑料因其稳定性、耐用性和耐化学性而备受青睐，目前全球每年的消费量超过6000万吨，但由于其交联结构，它们很难回收利用。开发可回收的热固性塑料是一项重要但具有挑战性的任务。在这项工作中，通过将商品聚合物聚丙烯腈（PAN）与少量钌配合物通过腈 - 钌配位进行交联来制备可回收热固性塑料。PAN来自工业生产，钌配合物一步合成，这使得能够以高效的方式生产可回收热固性塑料。此外，这种热固性塑料表现出令人印象深刻的机械性能，杨氏模量为6.3 GPa，拉伸强度为109.8 MPa。而且，它们在光照和溶剂作用下可以解交联，然后加热时又可以重新交联。这种可逆交联机制使得能够从混合塑料废料中回收热固性塑料。还展示了通过可逆交联由其他商品聚合物如聚（苯乙烯 - 共丙烯腈）（SAN）树脂和聚合物复合材料制备可回收热固性塑料的方法。这项研究表明，通过金属 - 配体配位的可逆交联是使用商品聚合物设计可回收热固性塑料的一种新策略。
