Caliari Marco, Teotonico Jacopo, Irigoyen Mikel, Mujika Anje, Isolabella Tommaso, Mantione Daniele, Irusta Lourdes, Grignard Bruno, Vidal Fernando, Detrembleur Christophe, Sardon Haritz
POLYMAT and Department of Polymers and Advanced Materials: Physics, Chemistry and Technology, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizábal, 3, 20018 Donostia-San Sebastián, Spain.
Center for Education and Research on Macromolecules (CERM), CESAM Research Unit, University of Liege, Sart-Tilman B6a, 4000 Liege, Belgium.
J Am Chem Soc. 2025 Aug 20;147(33):30095-30106. doi: 10.1021/jacs.5c07767. Epub 2025 Aug 6.
Modern-day thermosetting polymers should be designed with circular economy principles in mind, considering both their recyclability and end-of-life options. Covalent adaptable networks (CANs) have the potential to address the environmental challenges we face today as, in spite of being thermosets, they can be reprocessed by conventional thermoprocessing methods and are thus recyclable. While in the last years intensive efforts have been devoted to the preparation of CANs using sustainable sources, less attention has been paid to their end-of-life options in case they escape from plastic sorting. Herein, we report the development of a new type of dynamic bond, the ,-acetal bond based on the coupling between CO-based oxazolidone moieties and abundant, potentially biobased polyols. Computational and kinetic studies revealed that this bond underwent rapid dissociative exchange and, crucially, was also susceptible to hydrolytic degradation. We then prepared a range of thermoset materials endowed by double end-of-life features, i.e., CAN behavior and hydrolytic degradation. This was achieved by radical thiol-ene photo-cross-linking of a diallyl monomer bearing the ,-acetal moiety with another alkene-functionalized monomer that did not bear this dynamic bond. CANs with tunable mechanical properties and hydrolytic degradation features were easily obtained by modulating the monomer compositions. The fast-photocuring of the ,-functionalized monomer was then exploited for producing three-dimensional (3D) printed objects, offering the potential for on-demand hydrolytic behavior.
现代热固性聚合物的设计应考虑循环经济原则，兼顾其可回收性和报废处理方式。共价自适应网络（CANs）有潜力应对我们如今面临的环境挑战，因为尽管它们是热固性材料，但可以通过传统热加工方法进行再加工，因此具有可回收性。在过去几年里，人们致力于使用可持续原料制备CANs，但对于它们在逃离塑料分类流程后的报废处理方式关注较少。在此，我们报告了一种新型动态键的开发，即基于CO基恶唑烷酮部分与丰富的、可能是生物基多元醇之间的偶联反应形成的α,β-缩醛键。计算和动力学研究表明，这种键会发生快速的解离交换，而且至关重要的是，它也易于发生水解降解。然后，我们制备了一系列具有双重报废处理特性的热固性材料，即具备CAN行为和水解降解特性。这是通过将带有α,β-缩醛部分的二烯丙基单体与另一种不带有这种动态键的烯基官能化单体进行自由基硫醇-烯光交联来实现的。通过调节单体组成，可以轻松获得具有可调机械性能和水解降解特性的CANs。然后利用α,β-官能化单体的快速光固化来生产三维（3D）打印物体，这为按需水解行为提供了可能性。
