Synthesis and characterization of modified bismaleimide/polysulfone semi‐interpenetrating polymer networks

Abstract

The present work reports a new method of preparing semi‐interpenetrating polymer network (semi‐IPN) membranes through in situ polymerization of bismaleimide (BMI) within polysulfone (PSF). It was found that BMI could be polymerized at ambient conditions in the presence of a proton donor and PSF without the use of an initiator or a catalyst. Chemical structure characterization of these semi‐IPNs by Fourier transform infrared attenuated total reflection (FTIR‐ATR) revealed the possibility of imide cleavage and formation of amic acid when BMI polymerization was continued for a longer time while X‐ray photoelectron spectroscopy (XPS) revealed the protonation of imide nitrogen at shorter polymerization time. It was also found that size of thermoset BMI phase within the PSF thermoplastic has a significant impact on glass‐transition temperature of resulting semi‐IPN. By controlling the thermoset/thermoplastic phase separation of semi‐IPNs through dope composition and formation techniques, gas separation membranes with comparable selectivity and permeance that were up to 12 times higher than corresponding PSF membranes were formed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 369–379, 2006

Formation and thermal stability of BMI-based interpenetrating polymers for gas separation membranes

“…Absence of red or purple color in the case of isopropanol indicates that BMI probably underwent a free radical polymerization as reported elsewhere [24]. The chemical structures of modified BMI-PEI as well as modified BMI-PSF were analyzed by ATR-FTIR and XPS spectroscopy as found elsewhere [25,26].…”

Performance of PEI/BMI semi-IPN membranes for separations of various binary gaseous mixtures☆

“…It was observed that BMI could be polymerized slowly inside and through PEI/NMP solutions at ambient conditions in the presence of ethyl alcohol [11][12][13]. The progress of polymerization was followed by measuring the viscosity, color change and spectroscopic analysis as discussed in details in our earlier work [11].…”

Separation performance of asymmetric membranes based on PEGDa/PEI semi-interpenetrating polymer network in pure and binary gas mixtures of CO2, N2 and CH4

“…The mixed gas selectivity with 6 and 8% PEGDa is 43 ± 10 and 54 ± 9 respectively. In summary, all the formulations, with the exception of the PEGDa/PEI-4% membrane, match or slightly surpass the PEI dense film selectivity and significantly surpassing the dense film selectivity for PEGDa (20). There was no shortfall of the mixed gas selectivity in comparison to the pure gas values within experimental error, which indicated no plasticization.…”

“…Our lab reported semi-IPN membranes having 15 times higher permeance than the parent polymers without a significant decrease in gas selectivity [20][21][22][23]. Recently we have reported the pure gas permeation studies based on semi-IPN membranes of commercially important glassy polymers and poly (ethylene glycol) diacrylate (PEGDa) [24,25].…”