Polyimide-Based Membrane Materials for CO2 Separation: A Comparison of Segmented and Aromatic (Co)polyimides

Abstract

A series of new poly(ethylene oxide) (PEO)-based copolyimides varying in hard segment structure are reported in this work as CO2 selective separation membranes. Their structural diversity was achieved by using different aromatic dianhydrides (4,4′-oxydiphthalic anhydride (ODPA), 4,4’-(hexafluoroisopropylidene)diphthalic anhydride (6FDA)) and diamines (4,4′-oxydianiline (ODA), 4,4′-(4,4′-isopropylidene-diphenyl-1,1′- diyldioxy)dianiline (IPrDA), 2,3,5,6-tetramethyl-1,4-phenylenediamine (4MPD)), while keeping the content of PEO (2000 g/mol) constant (around 50%). To get a better insight into the effects of hard segment structure on gas transport properties, a series of aromatic polyimides with the same chemistry was also studied. Both series of polymers were characterized by 1HNMR, FTIR, WAXD, DSC, TGA, and AFM. Permeabilities for pure He, O2, N2, and CO2 were determined at 6 bar and at 30 °C, and for CO2 for pressures ranging from 1 to 10 bar. The results show that OPDA-ODA-PEO is the most permeable copolyimide, with CO2 permeability of 52 Barrer and CO2/N2 selectivity of 63, in contrast to its fully aromatic analogue, which was the least permeable among polyimides. 6FDA-4MPD-PEO ranks second, with a two times lower CO2 permeability and slightly lower selectivity, although 6FDA-4MPD was over 900 times more permeable than OPDA-ODA. As an explanation, partial filling of hard domain free voids by PEO segments and imperfect phase separation were proposed.

Synthesis and Characterization of Microwave-Assisted Copolymer Membranes of Poly(vinyl alcohol)-g-starch-methacrylate and Their Evaluation for Gas Transport Properties

“…Other combination of gases i.e., CO 2 /CH 4 , O 2 /N 2 and O 2 /H 2 the selectivity value decreased 4.8, 2.8 and 0.96 respectively. The reason for the decrease in the selectivity value is due to reduction in partial pressure gradient and due to coupling effect [26,27]. This effect is explained clearly in two different ways [28,29], one is the plasticization effect of the membrane.…”

Recent Advances in Development of Waste-Based Polymer Materials: A Review

“…Highly cross-linked structures resulted in the high-performance properties of those materials. This group of polymers includes: phenol-formaldehyde resin [110], urea-formaldehyde [111], polyesters [112], epoxides [113], polyimides [114], and polyurethanes [115].…”

Electrospun Copoly(ether imide) Nanofibers Doped with Silver-Loaded Zeolite as Materials for Biomedical Applications

“…The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsapm.2c00892. XRD, SEM images, EDX spectra, EDX analyses, synthesis of co-PEI, characterization of co-PEI, FTIR spectrum, 1 H NMR spectrum, 13…”

“…Jeffamine is a group of poly­(ether amine) with two reactive amine groups attached at the chain ends of poly­(propylene oxide) (PPO), poly­(ethylene oxide) (PEO), or mixed PPO/PEO building blocks. The introduction of flexible segments derived from the Jeffamine comonomer into the structure of polyimide or poly­(ether imide) may improve the properties. − Thus, the structure and content of flexible segments will optimize the properties of the copolymers that could be used in a large number of biomedical applications. The nonionic and hydrophilic characteristics of the flexible segments provide good compatibility to the copolymers …”