Effects on Carbon Molecular Sieve Membrane Properties for a Precursor Polyimide with Simultaneous Flatness and Contortion in the Repeat Unit
Effects on Carbon Molecular Sieve Membrane Properties for a Precursor Polyimide with Simultaneous Flatness and Contortion in the Repeat Unit
复制标题
重复单元中同时具有平坦度和扭曲度对前驱体聚酰亚胺碳分子筛膜性能的影响
DOI：
10.1002/cssc.202001572
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发表时间：
2020-09-01
期刊：
影响因子：
8.4
通讯作者：
Jin, Jian
中科院分区：
文献类型：
--
作者：
Liang, Jiachen;Wang, Zhenggong;Jin, Jian
碳分子筛（CMS）膜具有良好的选择透过性、热稳定性和化学稳定性，是一种很有前途的氢气分离技术。制备高性能的CMS膜，应首先考虑聚合物前驱体的分子结构及其排列。本论文以苯并咪唑类6FDA（2，2 '-双（3，4'-二羧基苯基）六氟丙烷二酐）型聚酰亚胺（PABZ-6FDA-PI）为前驱体制备了CMS膜。通过气体吸附和渗透实验，详细研究了聚酰亚胺前驱体中分子链的平直度和扭曲度对CMS膜气体分离性能的影响。CMS的H（2）渗透率可达9500Barrer，H-2/CH（4）和H-2/CO（2）气体对的理想选择性分别可达3800和13。氢分离（包括H-2/CO2、H-2/N-2和H-2/CH（4）气体对）的综合性能远高于之前报道的聚合物上限。
Carbon molecular sieve (CMS)-based membrane separation is a promising solution for hydrogen separation due to its great advantages on perm-selectivity, thermal stability, and chemical stability. To prepare high-performance CMS membranes, the molecular structure of polymer precursors and their arrangements should be primarily considered. In this work, a benzimidazole-based 6FDA (2,2 '-bis(3,4 '-dicarboxyphenyl) hexafluoropropane dianhydride)-type polyimide (PABZ-6FDA-PI) is chosen as precursor to prepare the CMS membrane. Effects of chain flatness and contortion in the polyimide precursor on gas-separation performance of CMS membranes were studied in detail by gas adsorption and permeation experiment. The H(2)permeability of CMS is up to 9500 Barrer and ideal selectivity of gas pairs of H-2/CH(4)and H-2/CO(2)is up to 3800 and 13, respectively. The comprehensive performance of hydrogen separation including H-2/CO2, H-2/N-2, and H-2/CH(4)gas pairs is located well above previously reported upper bounds for polymers.