Synthesis, characterization, and gas permeation properties of 6FDA-2,6-DAT/mPDA copolyimides
Synthesis, characterization, and gas permeation properties of 6FDA-2,6-DAT/mPDA copolyimides
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6FDA-2,6-DAT/mPDA 共聚酰亚胺的合成、表征和气体渗透性能
DOI：
10.1007/s11458-009-0028-5
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Q. Yuan
中科院分区：
文献类型：
--
作者：
Lina Wang;Yiming Cao;Meiqing Zhou;Xiao;Q. Yuan
这项工作的目标是探索新型聚酰亚胺材料，该材料对特定气体具有高渗透性和高选择性。共聚酰亚胺提供了制备具有均聚酰亚胺无法获得的气体渗透性和选择性的膜的可能性。通过两锅法化学酰亚胺化合成了一系列具有不同二胺组成的新型氟化共聚酰亚胺。通过将固体二酐按化学计量添加到二胺中来制备聚酰胺酸。研究了2,2'-双(3,4'-二羧基苯基)六氟丙烷二酐(6FDA)-2,6-二胺甲苯(2,6-DAT)/1,3-苯二胺(mPDA)聚酰亚胺的气体渗透行为。通过IR、DSC和TGA对共聚酰亚胺的物理性能进行了表征。玻璃化转变温度随着2,6-DAT含量的增加而增加。所有共聚酰亚胺均溶于大多数常见溶剂。气体渗透系数随着mPDA含量的增加而降低。然而，随着 mPDA 部分的掺入，H2/N2、O2/N2 和 CO2/CH4 等气体对的选择性渗透性得到了增强。发现H2、O2、N2、CO2和CH4的渗透系数随着渗透气体动力学直径的增大而减小。 6FDA-2,6-DAT/mPDA (3:1)共聚酰亚胺和6FDA-2,6-DAT聚酰亚胺对H2/N2、O2/N2、CO2/CH4具有较高的分离性能。在 35°C 和 0.2 MPa 下，它们的 H2、O2 和 CO2 渗透系数分别为 64.99 Barrer、5.22 Barrer、23.87 Barrer 和 81.96 Barrer、8.83 Barrer、39.59 Barrer（1 Barrer = 10−10cm3(STP)·cm·cm−2·s−1·cmHg−1)，其理想的H2/N2、O2/N2和CO2/CH4选择性渗透率分别为69.61、6.09、63.92和53.45、5.76、57.41。此外，本工作中研究的所有共聚酰亚胺都表现出相似的性能，位于或高于选择性渗透性和渗透性之间现有的上限权衡线。它们可用于商业气体分离膜材料。
The goal of this work is to explore new polyimide materials that exhibit both high permeability and high selectivity for specific gases. Copolyimides offer the possibility of preparing membranes with gas permeabilities and selectivities not obtainable with homopolyimides. A series of novel fluorinated copolyimides were synthesized with various diamine compositions by chemical imidization in a two-pot procedure. Polyamic acids were prepared by stoichiometric addition of solid dianhydride in portions to the diamine(s). The gas permeation behavior of 2,2′-bis(3,4′-dicarboxyphenyl) hexafluoropropane dianhydride(6FDA)-2,6-diamine toluene (2,6-DAT)/1,3-phenylenediamine (mPDA) polyimides was investigated. The physical properties of the copolyimides were characterized by IR, DSC and TGA. The glass transition temperature increased with increase in 2,6-DAT content. All the copolyimides were soluble in most of the common solvents. The gas permeability coefficients decreased with increasing mPDA content. However, the permselectivity of gas pairs such as H2/N2, O2/N2, and CO2/CH4was enhanced with the incorporation of mPDA moiety. The permeability coefficients of H2, O2, N2, CO2and CH4were found to decrease with the increasing order of kinetic diameters of the penetrant gases. 6FDA-2,6-DAT/mPDA (3:1) copolyimide and 6FDA-2,6-DAT polyimide had high separation properties for H2/N2, O2/N2, CO2/CH4. Their H2, O2and CO2permeability coefficients were 64.99 Barrer, 5.22 Barrer, 23.87 Barrer and 81.96 Barrer, 8.83 Barrer, 39.59 Barrer, respectively, at 35°C and 0.2 MPa (1 Barrer = 10−10cm3(STP)·cm·cm−2·s−1·cmHg−1) and their ideal permselectivities of H2/N2, O2/N2and CO2/CH4were 69.61, 6.09, 63.92 and 53.45, 5.76, 57.41, respectively. Moreover, all of the copolyimides studied in this work exhibited similar performance, lying on or above the existing upper bound trade-off lines between permselectivity and permeability. They may be utilized for commercial gas separation membrane materials.