Chemical structure and morphology of polymers are directly related with the membrane separation performance. Poly(imide)s (PIs) are the most widely used polymers in the preparation of membranes for gas separation applications; thus, research on the structural design of polymers is of great interest to develop new membranes. In the present work, we reported the synthesis, characterization, and measurement of the gas transport properties of a new co-poly(imide)s () prepared from a mixture of isomeric diamines. The co-poly(imide) synthetic route involved several steps, starting by a bromination reaction, followed by a double nucleophilic aromatic substitution giving an isomeric mixture of precursors, which suffered a Suzuki-Miyaura C–C cross-coupling reaction followed by the reduction of nitro groups to give two new isomeric diamines. Finally, diamines simultaneously reacted with the dianhydride 6FDA to obtain . The co-poly(imide) had a of 47.7 kDa and a of 74.0 kDa with a PDI of 1.6. The sample exhibited a 10% weight loss at 540 °C, T of 280 °C, BET surface area of 110 m g, and wide-angle X-ray diffraction (WAXD) interchain spacing at 9.5 Å and 6.3 Å. Tensile strength, elongation at break and Young's modulus were 109.6 MPa, 6.66% and 2.18 GPa, respectively. co-Poly(imide) was soluble in various polar aprotic organic solvents such as DMSO, NMP, DMF, DMAc, THF, and chloroform, forming a self-standing dense film whose gas transport properties were measured. Pure gas permeability coefficients for H, CO, O, N, and CH, were 47.28, 24.04, 4.35, 1.02, and 0.76 (Barrer), respectively, which follows a decreasing order by the increasing kinetic diameters of the respective gases. Ideal gas selectivities H/N, O/N, CO/CH, and CO/N were 46.4, 4.3, 31.6, and 23.6, respectively. These gas transport properties were compared with the commercial polymer Matrimid®, showing higher gas permeability coefficients than Matrimid®.

中文翻译：

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衍生自单体异构体混合物的半刚性共聚（酰亚胺）。评估自支撑聚合物膜的气体传输特性

聚合物的化学结构和形貌与膜分离性能直接相关。聚酰亚胺 (PI) 是制备气体分离膜时使用最广泛的聚合物；因此，聚合物结构设计的研究对于开发新型膜具有重要意义。在目前的工作中，我们报道了由异构二胺混合物制备的新型共聚（酰亚胺）的合成、表征和气体传输性能的测量。共聚（酰亚胺）合成路线涉及几个步骤，首先是溴化反应，然后是双亲核芳族取代，得到前体异构体混合物，该混合物经历了铃木-宫浦C-C交叉偶联反应，然后进行还原硝基基团产生两种新的异构二胺。最后，二胺同时与二酐6FDA反应得到。共聚（酰亚胺）的 a 为 47.7 kDa 和 a 为 74.0 kDa，PDI 为 1.6。该样品在 540 °C、T 为 280 °C、BET 表面积为 110 m g 时失重 10%，广角 X 射线衍射 (WAXD) 链间距为 9.5 Å 和 6.3 Å。拉伸强度、断裂伸长率和杨氏模量分别为109.6 MPa、6.66%和2.18 GPa。共聚酰亚胺可溶于各种极性非质子有机溶剂，如DMSO、NMP、DMF、DMAc、THF和氯仿，形成自支撑致密薄膜，并测量其气体传输性能。 H、CO、O、N 和 CH 的纯气体渗透系数分别为 47.28、24.04、4.35、1.02 和 0.76 (Barrer)，其按照相应气体的动力学直径增加而递减。理想气体选择性 H/N、O/N、CO/CH 和 CO/N 分别为 46.4、4.3、31.6 和 23.6。将这些气体传输特性与商业聚合物 Matrimid® 进行比较，显示出比 Matrimid® 更高的气体渗透系数。