Permselectivity improvement of PEBAX® 2533 membrane by addition of glassy polymers (Matrimid® and polystyrene) for CO₂/N₂ separation

Abstract

Two series of novel blend membranes based on poly(ether‐block‐amide) (PEBAX® 2533) and 5 and 10 wt% of two glassy polymers (Matrimid® and polystyrene [PS]) were prepared using a new mixed solvent with a low boiling point for CO2/N2 separation. Fourier‐transform infrared spectroscopy, field emission scanning electron microscopy, and X‐ray diffraction analyses were used to characterize the samples. A decrease in membrane crystallinity was observed by the addition of glassy polymers. The gas permeability measurements were performed to obtain CO2/N2 permselectivity of membranes. The maximum performance was found for the membrane with 5 wt% Matrimid content, for which CO2 permeability and CO2/N2 selectivity increased by 21% and 76%, respectively. Three permeation models were used to predict the CO2 permeability of blend membranes. The Maxwell model showed acceptable coincidence with the experimental data at 5 wt% content of the glassy polymer. For 10 wt% content of glassy polymer, the Lewis‐Neilson model showed the most accurate predictions for CO2 permeability. A method for quantitative comparison of membrane performance was also proposed by defining the geometric closeness to the Robson upper bound limit. Finally, it was found that an increase in the feed pressure improved the membrane performance at high pressures.

Analysis of the Influence of Process Parameters on the Properties of Homogeneous and Heterogeneous Membranes for Gas Separation

“…In the literature, one can find many works devoted to research on gas permeability through membranes made of Pebax ® 2533 copolymer or its modifications [ 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 ]. Therefore, it may be interesting for the readers to compare the results in the literature and the results obtained in the research of this work on the Robeson charts [ 25 , 27 ].…”

Polyimide blend metal–organic framework‐based mixed matrix membrane for gas separation: A review

“…66 Meanwhile, Ansari et al integrated PEBAX 2533 with additive polymers like Matrimid and PSF to separate CO 2 from N 2 . 65 In particular, the blend containing 5 wt% Matrimid improved CO 2 permeability and CO 2 /N 2 selectivity by 21% and 76%, respectively. Figure 8 compares the gas separation performance of the PI/glassy blend and the PI/rubbery blend.…”

“…Meanwhile, the hard polyamide (PA) segment provides better mechanical stability to the membrane. The most common PEBAX polymers are PEBAX 1657 and PEBAX 2533 65 . Mosleh and his coworkers prepared blends of PEBAX 1657 with Matrimid and PES for CO 2 /CH 4 separation.…”

“…Droplets of glassy polymer were distributed in the PEBAX matrix through SEM characterization, demonstrating the blend's immiscibility 66 . Meanwhile, Ansari et al integrated PEBAX 2533 with additive polymers like Matrimid and PSF to separate CO 2 from N 2 65 . In particular, the blend containing 5 wt% Matrimid improved CO 2 permeability and CO 2 /N 2 selectivity by 21% and 76%, respectively.…”

“…The most common PEBAX polymers are PEBAX 1657 and PEBAX 2533. 65 Mosleh and his coworkers prepared blends of PEBAX 1657 with Matrimid and PES for CO 2 /CH 4 separation. By increasing the concentration of glassy polymer (Matrimid or PES), the polymer chain mobility in the blend matrix reduced and caused decreased gas permeability.…”