Poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) membranes are attractive due to high permeability for gases; however, the selectivity of these membranes is insufficient. In this work, the gas selectivity was improved without significant loss of the permeability. For this purpose, PPO was modified via incorporation of the branched copolyimide filler–grafted copolyimide (PI‐g‐PMMA) with polymethyl methacrylate (PMMA) side chains. Two series of mixed self‐supporting PPO/PI‐g‐PMMA films (with variation of the filler content) were prepared and studied as gas separation membranes. The length of the polymide (PI) chain and the density of PMMA grafting were the same in both series, however, in one series the grafted chains contained 50 MMA units, and in the other 150 units. The intermolecular interactions between the PPO matrix and the PI‐g‐PMMA fillers were investigated using viscometry, infrared (IR) spectroscopy, and scanning electron microscopy. The compatibility of the polymer components is limited; however, for both series, the contents of the respective filler are found, which ensures phase segregation only in a microscale. Therefore, the mechanical properties of the films allow their use as gas separation membranes. It is shown that the degree of the segregation as well as the mechanical and gas transport properties of the membranes depend on the length of the PMMA chains, and the membranes with filler‐containing shorter branches (50 MMA units) show better selectivity.

中文翻译：

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具有共聚酰亚胺支化改性剂的双相聚苯醚膜

聚（2,6-二甲基-1,4-苯撑氧）（PPO）膜因对气体的高渗透性而具有吸引力。然而，这些膜的选择性不足。在这项工作中，提高了气体选择性而又没有明显降低渗透率。为此，通过将支链共聚酰亚胺填料-接枝共聚酰亚胺（PI-g-PMMA）与聚甲基丙烯酸甲酯（PMMA）侧链结合来修饰PPO。制备了两类混合的自支撑PPO / PI-g-PMMA混合膜（随填料含量的变化）并作为气体分离膜进行了研究。聚酰亚胺（PI）链的长度和PMMA接枝的密度在两个系列中均相同，但是，一个系列中的接枝链包含50个MMA单元，其他150个单元。使用粘度法，红外（IR）光谱和扫描电子显微镜研究了PPO基质与PI-g-PMMA填料之间的分子间相互作用。聚合物组分的相容性是有限的。然而，对于两个系列，都找到了各自填料的含量，这确保了仅在微尺度上的相偏析。因此，膜的机械性能允许它们用作气体分离膜。结果表明，膜的偏析程度以及机械和气体传输性能取决于PMMA链的长度，带有填料较短分支（50个MMA单元）的膜具有更好的选择性。聚合物组分的相容性是有限的。然而，对于两个系列，都找到了各自填料的含量，这确保了仅在微尺度上的相偏析。因此，膜的机械性能允许它们用作气体分离膜。结果表明，膜的偏析程度以及机械和气体传输性能取决于PMMA链的长度，带有填料较短分支（50个MMA单元）的膜具有更好的选择性。聚合物组分的相容性是有限的。然而，对于两个系列，都找到了各自填料的含量，这确保了仅在微尺度上的相偏析。因此，膜的机械性能允许它们用作气体分离膜。结果表明，膜的偏析程度以及机械和气体传输性能取决于PMMA链的长度，带有填料较短分支（50个MMA单元）的膜具有更好的选择性。