Bisimidazolium PEG-mediated crosslinked 6FDA-durene polyimide membranes for CO2 separation

Ahn

J of Applied Polymer Sci

et al. 2020

To overcome the plasticization effect in polyimide membranes, many researchers have proposed crosslinking method. This can reduce an inter‐segmental mobility by tightening and rigidifying the polymer chains. However, it is difficult to modify the whole polymer chains throughout the membrane because the reaction can be hindered by the diffusion rate of the crosslinker. In particular, it is hard for bulky crosslinker to penetrate a dense membrane with a small d‐spacing. This study investigated the effect of crosslinking a dense Matrimid membrane with p‐phenylenediamine (p‐PDA) via two different crosslinking methods (i.e., methanol‐swelling crosslinking process [M‐SCP] and liquid‐phase crosslinking process [L‐PCP]). Most of the crosslinking reaction in M‐SCP occurs on the membrane surface due to difficulty in penetration of the bulky p‐PDA into the Matrimid dense membrane. In contrast, the L‐PCP allows uniform crosslinking across the membrane. The membranes crosslinked using L‐PCP showed excellent chemical resistance. Furthermore, the plasticization phenomenon was not observed in the membranes crosslinked using L‐PCP with p‐PDA more than 15%. Meanwhile, the membrane crosslinked using M‐SCP exhibited poor plasticization and chemical resistance properties. These results showed that the L‐PCP method can be more effective for the crosslinking of dense membrane to deliver both high plasticization and chemical resistance.

Section: Introductionmentioning

confidence: 99%

Comparison of liquid‐phase and methanol‐swelling crosslinking processes of polyimide dense membrane forCO₂/CH₄separation

Ahn

J of Applied Polymer Sci

et al. 2020

“…CO 2 separation using polymeric membranes has attracted much interest due to their easy process-ability, low energy consumption, low capital and maintenance cost, module compactness and environmental-friendliness relative to other separation techniques, including cryogenic distillation, amine scrubbing, and pressure swing adsorption [1,2,3,4,5]. To this end, various types of polymer materials have been developedto remove CO 2 from low-quality natural gas, syngas, and flue gas [2].…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, enhanced gas selectivity can be obtained via a combination of enhanced gas diffusivity selectivity and/or increased solubility of the particular gas in the polymer. Here, the diffusivity selectivity is correlated with thesize-sieving capability of the polymer material, and relies on the mobile character of the target gas molecule compared to those of other gas molecules, the structural factors such as the rigidity of the polymer chain and the extent of inter-segmental polymer chain packing [4]. The solubility selectivity, on the other hand, relies on the interactions of the polymer with the penetrant molecule and also on the condensability degrees of the penetrants to the polymer.…”

Section: Introductionmentioning

confidence: 99%

“…Among several polymer materials commercialized for gas separation, polyimides (PI)s have been most widely used because of their excellent physicochemical properties (e.g., thermal and mechanical, and chemical stability [4,10,11,12,13,14,15,16] with a moderate level of permeability. Moreover, these properties, including the permeability levels, can easily be changed by varying their structures using proper monomers.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, these properties, including the permeability levels, can easily be changed by varying their structures using proper monomers. For example, PI membranes obtained from 4,4’-hexafluoro-isopropylidene di-phthalic anhydride (6FDA) exhibiteda high CO 2 /CH 4 separating capability because of suppression of the intra-segmental mobility [4,17]. Nevertheless, most of the polymers with a rigid backbone structure, including PIs, do not satisfy the industrial requirements of high CO 2 /lightgas selectivity, nor of high CO 2 permeability.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A Facile Synthesis of (PIM-Polyimide)-(6FDA-Durene-Polyimide) Copolymer as Novel Polymer Membranes for CO2 Separation

2019

Self Cite

Random copolymers made of both (PIM-polyimide) and (6FDA-durene-PI) were prepared for the first time by a facile one-step polycondensation reaction. By combining the highly porous and contorted structure of PIM (polymers with intrinsic microporosity) and high thermomechanical properties of PI (polyimide), the membranes obtained from these random copolymers [(PIM-PI)-(6FDA-durene-PI)] showed high CO2 permeability (>1047 Barrer) with moderate CO2/N2 (> 16.5) and CO2/CH4 (> 18) selectivity, together with excellent thermal and mechanical properties. The membranes prepared from three different compositions of two comonomers (1:4, 1:6 and 1:10 of x:y), all showed similar morphological and physical properties, and gas separating performance, indicating ease of synthesis and practicability for production in large scale. The gas separation performance of these membranes at various pressure ranges (100–1500 torr) was also investigated.

Network polyimide membranes prepared by interfacial polymerization for hot H₂ purification

et al. 2022

Novel polymeric membranes are to be developed for hot H2/CO2 separation. In this work, network polyimide (PI) membranes are prepared via a simple interfacial polymerization method using low‐cost melamine and pyromellitic dianhydride monomers. The membrane performance surpasses the upper bound of H2/CO2 separation. Moreover, the membranes exhibit a H2/CO2 separation factor of 18.7 at 623 K and a robust performance after treatment with steam and H2S.