State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu, 610065, China.
Macromol Rapid Commun. 2022 Jul;43(13):e2100781. doi: 10.1002/marc.202100781. Epub 2022 Jan 17.
Crosslinked polyurethane with excellent mechanical property, solvent resistance, and transparency has become one of the most widely used materials. However, the presence of chemical crosslinks makes it difficult to be reprocessed once molded, which largely restricts its recycling and reusing, resulting in the serious waste problems. Therefore, it is of great significance to prepare a new type of crosslinked polyurethane with reprocessing function. In this work, a novel reprocessable polyurethane (DOPU) based on reversible dibutanone oxime-carbamate bonds is facilely prepared. The gel fraction of DOPUs is all higher than 95%, endowing it with excellent solvent resistance. Meanwhile, the visible light transmittance of DOPUs can reach up to 97.48%. After four thermal recycles, the tensile strength and elongation at break of recycled DOPUs can still remain at 3.21 MPa and 219.09%, respectively. Importantly, the synthesized DOPUs exhibit excellent elastic shape memory and permanent shape reconstruction properties under thermal stimulation. The dibutanone oxime-carbamate bonds can also be degraded under UV irradiation, making this material easily degradable. Hence, this material has potential applications in coatings, elastomers, and some other fields.
具有优异力学性能、耐溶剂性和透明度的交联型聚氨酯已成为应用最广泛的材料之一。然而，化学交联的存在使得其一旦成型后难以再加工，这在很大程度上限制了其回收和再利用，导致严重的浪费问题。因此，制备具有再加工功能的新型交联型聚氨酯具有重要意义。在这项工作中，我们通过简便的方法制备了一种基于可逆二丁酮肟基氨基甲酸酯键的新型可再加工型聚氨酯（DOPU）。DOPU 的凝胶分数均高于 95%，赋予其优异的耐溶剂性。同时，DOPU 的可见光透过率可达 97.48%。经过四次热循环后，回收 DOPU 的拉伸强度和断裂伸长率仍分别保持在 3.21 MPa 和 219.09%。重要的是，所合成的 DOPU 在热刺激下表现出优异的弹性形状记忆和永久形状重构性能。二丁酮肟基氨基甲酸酯键也可以在紫外光照射下降解，使这种材料易于降解。因此，这种材料在涂料、弹性体和其他一些领域具有潜在的应用。
