Polymer membranes with excellent thermomechanical properties and good gas separation performance are desirable for efficient CO₂ separation. A series of copolyimide membranes are prepared for the first time using PIM-PI-1, a hard segment with high CO₂ permeability, and poly(ethylene glycol)/poly(propylene glycol) (PEG/PPG), a soft segment with high CO₂ selectivity. Two different unit polymers are combined to compensate the limitations of each polymer (e.g., the fast aging and moderate selectivity of PIM-PI-1 and the poor mechanical properties and lower permeability of PEG/PPG). The corresponding PIM-(durene–PEG/PPG) membranes exhibit an excellent combination of mechanical properties and gas separation performance compared to the typical PI-PEG-based copolymer membrane. The improved mechanical property is attributed to the unique chain threading and the reinforcement between the spiro unit of PIM and the flexible PEG/PPG at the molecular level, which has not previously been exploited for membranes. The PIM-(durene–PEG/PPG) membranes show a high CO₂ permeability of 350–669 Barrer and a high CO₂/N₂ selectivity of 33.5–40.3. The experimental results are further evaluated with theoretical results obtained from molecular simulation studies, and a very good agreement between the experimental results and simulation results is found. Moreover, the PIM-(durene–PEG/PPG) copolymer membranes display excellent anti-aging performance for up to 1 year.

中文翻译：

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PIM-PI-1 和聚（乙二醇）/聚（丙二醇）基机械坚固的共聚酰亚胺膜具有高 CO2 选择性和抗老化性能：联合实验 - 计算探索

具有优异热机械性能和良好气体分离性能的聚合物膜是有效分离CO _{2 的}理想选择。首次使用具有高 CO ₂渗透性的硬链段 PIM-PI-1 和具有高 CO ₂渗透性的软链段聚（乙二醇）/聚（丙二醇）（PEG/PPG）制备了一系列共聚酰亚胺膜。CO ₂选择性。结合两种不同的单元聚合物以弥补每种聚合物的局限性（例如，PIM-PI-1 的快速老化和中等选择性以及 PEG/PPG 的机械性能差和渗透性较低）。与典型的基于 PI-PEG 的共聚物膜相比，相应的 PIM-(durene-PEG/PPG) 膜表现出优异的机械性能和气体分离性能。改进的机械性能归因于独特的链穿线以及 PIM 的螺单元与分子水平的柔性 PEG/PPG 之间的增强，这在以前未被用于膜。PIM-(durene-PEG/PPG) 膜显示出350–669 Barrer的高 CO ₂渗透率和高 CO ₂ /N ₂选择性为 33.5–40.3。实验结果进一步与分子模拟研究的理论结果进行了评估，发现实验结果与模拟结果非常吻合。此外，PIM-(durene-PEG/PPG) 共聚物膜显示出优异的抗老化性能长达 1 年。