Deep eutectic solvents (DESs) have attracted broad attention due to their low cost and toxicity, easy preparation, good biological compatibility and similar characteristics to those of ionic liquids. In this study, a DES system composed of choline chloride and urea has been applied for the controllable degradation of polyurethane (PU). By the combination of Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR) and matrix-assisted laser analytical ionization time-of-flight mass spectrometer (MALDI-TOF-MS), the selective cleavage of carbamate and urea bonds with little damage on carbonate bonds was achieved in the DES system by the regulation of reaction conditions, which favored the recovery of both valuable polycarbonate diol (PCDL) and 3,3′-Dimethyl-[1,1′-biphenyl]-4,4′-Diamine (o-toluidine). The degradation rate of PU and the yield of PCDL reached 100% and 57.4% respectively under mild conditions (1 atm, 170 °C, 8 h). A possible degradation mechanism was proposed based on the experimental results, in which the synergistic effect of choline chloride and urea activated largely the carbamate bond and thus led to a controlled degradation of PU.

深共晶溶剂（DES）由于其低成本和毒性，易于制备，良好的生物相容性以及与离子液体相似的特性而备受关注。在这项研究中，由氯化胆碱和尿素组成的DES系统已用于可控降解聚氨酯（PU）。通过傅里叶变换红外光谱（FT-IR），核磁共振光谱（NMR）和基质辅助激光分析电离飞行时间质谱仪（MALDI-TOF-MS）的组合，氨基甲酸酯和尿素的选择性裂解通过调节反应条件，在DES系统中获得了对碳酸酯键几乎没有破坏的键，这有利于回收有价值的聚碳酸酯二醇（PCDL）和3,3'-二甲基-[1,1'-联苯] -4 ，4′-二胺（邻甲苯胺）。在温和条件下（1 atm，170°C，8 h），PU的降解率和PCDL的产率分别达到100％和57.4％。根据实验结果提出了一种可能的降解机理，其中氯化胆碱和尿素的协同作用在很大程度上激活了氨基甲酸酯键，从而导致了聚氨酯的受控降解。