Qaroush Abdussalam K, Saleh Maysoon I, Alsyouri Hatem M, Abu-Daabes Malyuba A, Eftaiha Ala'a F, Assaf Khaleel I, Abu-Zaid Rania, Abu-Surrah Adnan S, Troll Carsten, Rieger Bernhard
Department of Chemistry, Faculty of Science, The University of Jordan, Amman, 11942, Jordan.
WACKER-Lehrstuhl für Makromolekulare Chemie, Technische Universität München, Lichtenbergstraße 4, 85747 Garching bei München, Germany.
Phys Chem Chem Phys. 2022 May 25;24(20):12293-12299. doi: 10.1039/d2cp00837h.
Thermolysis of a urethane end group was observed as a first time phenomenon during activation. This unzipping mechanism revealed a new amine tethering point producing a diamine-terminated oligourea ([10]-OU), acting as a green sorbent for CO capturing. The oligomer backbites its end group to form propylene carbonate (PC), as proved by TGA-MS, which can reflect the polymer performance by maximizing its capturing capacity. Cross polarization magic angle spinning (CP-MAS) NMR spectroscopy verified the formation of the proven ionic carbamate (1:2 mechanism) with a chemical shift at 161.7 ppm due to activation desorption at higher temperatures, , 100 °C () accompanied with bicarbonate ions (1:1 mechanism) with a peak centered at 164.9 ppm. Fortunately, the amines formed from thermolysis explain the abnormal behavior (carbamates bicarbonates) of the prepared sample. Finally, ATR-FTIR proved the decomposition of urethanes, which can be confirmed by the disappearance of the pre-assigned peak centered at 1691 cm. DFT calculations supported the thermolysis of the urethane end group at elevated temperatures, and provided structural insights into the formed products.
在活化过程中首次观察到聚氨酯端基的热解现象。这种解链机制揭示了一个新的胺连接点，生成了二胺封端的低聚脲（[10]-OU），它可作为捕获CO的绿色吸附剂。热重-质谱联用（TGA-MS）证明，该低聚物会回咬其端基形成碳酸丙烯酯（PC），通过最大化其捕获能力，TGA-MS可以反映聚合物的性能。交叉极化魔角旋转（CP-MAS）核磁共振光谱证实了已证实的离子型氨基甲酸盐（1:2机制）的形成，由于在较高温度（100℃）下的活化解吸，其化学位移为161.7 ppm，同时伴有以164.9 ppm为中心峰的碳酸氢根离子（1:1机制）。幸运的是，热解产生的胺解释了所制备样品的异常行为（氨基甲酸盐-碳酸氢盐）。最后，衰减全反射傅里叶变换红外光谱（ATR-FTIR）证明了聚氨酯的分解，这可以通过以1691 cm为中心的预先指定峰的消失来证实。密度泛函理论（DFT）计算支持了聚氨酯端基在高温下的热解，并为形成的产物提供了结构见解。
