Enhanced Gas Separation Performance of Thermally RearrangedMembranes with 2-Propyl-1 H -imidazole-4,5-dicarbohydrazide

作者：Zan Meng, Yunhua Lu, Yiliu Chen, Dian Sheng, Xiao Guoyong, Zhizhi Hu, Hongyun Zhao · 发表于：Industrial & Engineering Chemistry Research · 年份：2026 · DOI：10.1021/acs.iecr.6c02288 · 研究领域：Membrane Separation and Gas Transport、Membrane Separation Technologies、Extraction and Separation Processes

Abstract Thermally rearranged (TR) membranes have recently demonstrated superior gas permeability and moderate ideal selectivity for gas separation applications. Herein, 2-propyl-1H-imidazole-4,5-dicarbohydrazide (PIDH) was utilized as a modifier via a blending method to further improve the gas separation performance of TR membranes. Specifically, PIDH was blended into poly(amic acid) (PAA) solutions prepared from 2,2′-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FAP) and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA). These solutions were stepwise thermally treated to form polyimide (PI) membranes and corresponding TR membranes. PIDH effectively regulated the stacking behavior and intermolecular interactions of PI molecular chains. With the increase of its mass content from 0 to 0.5%, the glass transition temperature (Tg) of the PI membranes was significantly elevated from 314 to 363 °C. After thermal rearrangement, all modified TR membranes exhibited notably enhanced gas permeability compared with the pristine TR membrane. Specifically, the TR membrane with 2.0% PIDH loading (TR-2.0%) showed excellent permeability coefficients: 112 Barrer for N2, 2287 Barrer for H2, 435 Barrer for O2, and 2668 Barrer for CO2. In contrast, the TR membrane with 1% PIDH loading (TR-1.0%) achieved the highest ideal selectivities, with H2/N2 = 20.95, O2/N2 = 3.92, and CO2/N2 = 25.10. Importantly, the CO2/N2 separation performance of TR-1.0% and TR-2.0% nearly reached the 2008 Robe...