Olazabal Ion, González Alba, Vallejos Saúl, Rivilla Iván, Jehanno Coralie, Sardon Haritz
POLYMAT, University of the Basque Country UPV/EHU, Joxe Mari Korta Center, Avda. Tolosa 72, 20018 Donostia-San Sebastian, Spain.
Department of Chemistry, Faculty of Science, University of Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain.
ACS Sustain Chem Eng. 2023 Jan 9;11(1):332-342. doi: 10.1021/acssuschemeng.2c05647. Epub 2022 Dec 27.
The importance of systematic and efficient recycling of all forms of plastic is no longer a matter for debate. Constituting the sixth most produced polymer family worldwide, polyurethanes, which are used in a broad variety of applications (buildings, electronics, adhesives, sealants, etc.), are particularly important to recycle. In this study, polyurethanes are selectively recycled to obtain high value-added molecules. It is demonstrated that depolymerization reactions performed with secondary amines selectively cleave the C-O bond of the urethane group, while primary amines unselectively break C-O and C-N bonds. The selective cleavage of C-O bonds, catalyzed by an acid:base mixture, led to the initial polyol and a functional diurea in several hours to a few minutes for both model polyurethanes and commercial polyurethane foams. Different secondary amines were employed as nucleophiles to synthesize a small library of diureas obtained in good to excellent yields. This study not only targets the recovery of the initial polyol but also aims to form new diureas which are useful building blocks for the polymerization of innovative materials.
对所有形式的塑料进行系统且高效的回收利用，其重要性已不再是一个可争论的问题。聚氨酯是全球产量排名第六的聚合物家族，广泛应用于各种领域（建筑、电子、粘合剂、密封剂等），对其进行回收利用尤为重要。在本研究中，聚氨酯被选择性回收以获得高附加值分子。结果表明，用仲胺进行的解聚反应能选择性地断裂聚氨酯基团的C-O键，而伯胺则无选择性地断裂C-O键和C-N键。由酸碱混合物催化的C-O键的选择性断裂，在数小时至数分钟内，对于模型聚氨酯和商业聚氨酯泡沫都能生成初始多元醇和功能性二脲。使用不同的仲胺作为亲核试剂，合成了一小批产率良好至优异的二脲库。本研究不仅旨在回收初始多元醇，还旨在形成新的二脲，这些二脲是创新材料聚合的有用结构单元。
