Herein, a new approach to achieve gas separation materials with improved resistance to plasticization (obtained by partial pyrolysis of new polyimide blends) is presented. Blends of an aromatic polyimide (formally, 6FDA-6FpDA) and aliphatic-aromatic copolyetherimides based on the same polyimide in combination with other aliphatic polyimide, having polyethylene oxide moieties, were obtained. After their synthesis and characterization, a selective elimination of the polyether by thermal treatment was carried and the obtained partially-pyrolyzed materials were tested as gas separation membranes.

For neat blends, permeability was shown to decrease when PEO content increases. This effect is due to polyethylene oxide (PEO) chains encroaching on free volume because phase segregation was minimized. When these blends were subjected to thermal treatment at relatively low temperatures in air or in N₂, it was clearly observed that all the polyether moieties were selectively eliminated from the structure, which gave rise to an increase of permeability. Higher permeabilities were obtained after a thermal treatment at 390 °C in N₂. Degradation of PEO chains after a 290 °C treatment in air produced materials with permeability values lower than those observed under N₂. In both cases, even though PEO was selectively and wholly eliminated, permeability was not totally recovered to give the values observed for neat 6FDA-6FpDA due probably to a combination of shrinkage and crosslinking of the membrane produced during the thermal process. Crosslinking provides the materials with an increased resistance to plasticization, in particular the best improvement against plasticization proceeded from the thermal treatments of blends at 290 °C in air.

在本文中，提出了一种新的方法来获得具有改进的抗塑化性的气体分离材料（通过对新的聚酰亚胺共混物进行部分热解而获得）。获得基于相同聚酰亚胺的芳族聚酰亚胺（正式名称为6FDA-6FpDA）和脂族-芳族共聚醚酰亚胺与具有聚环氧乙烷部分的其他脂族聚酰亚胺的共混物。在它们的合成和表征之后，进行了通过热处理的聚醚的选择性消除，并且将所获得的部分热解的材料作为气体分离膜进行了测试。

对于纯净的共混物，当PEO含量增加时，渗透率会降低。这种影响是由于聚环氧乙烷（PEO）链侵犯了自由体积，因为相分离被最小化了。当在空气或N _2中在相对较低的温度下对这些共混物进行热处理时，可以清楚地观察到，所有聚醚部分均被选择性地从结构中消除，这导致了渗透性的提高。在N _2中在390°C的温度下热处理后可获得更高的磁导率。空气中290°C处理后PEO链的降解产生的渗透率值低于在N ₂下观察到的渗透率值。在这两种情况下，即使选择性和完全消除了PEO，渗透率也无法完全恢复，无法给出纯净的6FDA-6FpDA所观察到的值，这可能是由于热过程中产生的膜的收缩和交联所致。交联为材料提供了更高的抗塑化性，尤其是在290°C的空气中对共混物进行热处理后，抗塑化性得到了最好的改善。