Abstract Although ethylene oxide units are often incorporated into polymeric membranes for CO2 separations, high-molecular-weight poly(ethylene oxide) (high-Mw PEO) cannot be used effectively due to its inferior separation performance, despite its good solubility in mild solvents (e.g. water and alcohols) and commercial availability at low cost. A high-performance, defect-free membrane for CO2 separations based on high-Mw PEO was prepared by incorporating the crosslinkable poly(glycidyl methacrylate-g-polypropylene glycol)-co-poly(oxyethylene methacrylate) (PGP-POEM) comb copolymer. The CO2/N2 and CO2/CH4 selectivity of the neat high-Mw PEO membrane was as low as 0.8 and 0.6, respectively, which increased drastically with increasing comb copolymer content, and the thermal and mechanical properties were also improved. The three-dimensionally interweaved network of the comb copolymer occurred within the PEO matrix, which had a considerable effect on the crystalline structure of the membranes. The crystalline morphology of the membranes and the distribution of comb copolymer within the PEO matrix were comprehensively examined according to the comb copolymer content. The comb copolymer effectively suppressed the formation of non-selective defects by filling the interlamellar and interfibrillar regions of the PEO crystallites. The best separation performance was achieved with a comb copolymer loading of 30 wt%, showing a CO2 permeability of 120.9 barrer with CO2/N2 and CO2/CH4 selectivity of 44.9 and 14.5, respectively. The tensile strength and elongation at break reached 7.5 MPa and 1490%, respectively. This work presents an avenue for utilizing a low-cost, commercially-available, high-Mw PEO in gas separation applications, providing insight into the crystalline structure and morphology of these membranes.

中文翻译：

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使用非选择性、高分子量聚（环氧乙烷）膜通过结合梳状共聚物分离 CO2

摘要 尽管环氧乙烷单元经常被加入到用于 CO2 分离的聚合物膜中，但高分子量聚环氧乙烷（high-Mw PEO）尽管在温和溶剂中具有良好的溶解性，但由于其分离性能较差而无法有效使用。例如水和醇）和低成本的商业可用性。通过引入可交联的聚（甲基丙烯酸缩水甘油酯-g-聚丙二醇）-共聚（甲基丙烯酸氧乙烯酯）（PGP-POEM）梳状共聚物，制备了一种基于高分子量 PEO 的高性能、无缺陷的 CO2 分离膜。纯高分子量 PEO 膜的 CO2/N2 和 CO2/CH4 选择性分别低至 0.8 和 0.6，随着梳形共聚物含量的增加而急剧增加，并且热性能和机械性能也得到改善。梳状共聚物的三维交织网络出现在 PEO 基质中，这对膜的晶体结构有相当大的影响。根据梳形共聚物的含量，对膜的结晶形态和梳形共聚物在 PEO 基质中的分布进行了全面检查。梳形共聚物通过填充 PEO 微晶的层间和纤维间区域，有效地抑制了非选择性缺陷的形成。使用 30 wt% 的梳形共聚物负载实现了最佳分离性能，显示出 120.9 barrer 的 CO2 渗透率，CO2/N2 和 CO2/CH4 选择性分别为 44.9 和 14.5。拉伸强度和断裂伸长率分别达到 7.5 MPa 和 1490%。这项工作提供了一种利用低成本、