@article{7abc29a884474a5f8cf4eb350c21ed2f,
title = "Gas separation properties of polybenzimidazole/thermally-rearranged polymer blends",
abstract = "Polybenzimidazole (PBI) is highly selective for H2 removal from mixtures with CO2, but it exhibits low gas permeabilities. Celazole{\textregistered} PBI was blended with more permeable HAB-6FDA-CI, an ortho-functional thermally rearrangeable polyimide, to improve its gas permeabilities while attempting to maintain high selectivity. A compatibilizer, 1-methylimidazole, enhanced phase dispersion when added to the casting solutions. Films containing 20–40 wt% polyimide exhibited a matrix-droplet morphology as observed by scanning and transmission electron microscopy. Heat treatment at 400 °C under inert atmosphere thermally rearranged the polyimide in the blends. After heat treatment, H2/CO2 selectivities at 35 °C doubled for Celazole{\textregistered} and 20–33 wt% polyimide compatibilized blends, exceeding the 2008 upper bound. Simultaneous increases in both H2 permeability and H2/CO2 selectivity were observed after heat treatment for the 33/67 wt% HAB-6FDA-CI/Celazole{\textregistered} compatibilized blend, which exhibited over twice the H2 permeability of Celazole{\textregistered} and similar selectivity. Heat treatment reduced free volume and induced para-crystallinity in the PBI phase of the blends as evidenced by x-ray scattering. Thermally treated blend films were mechanically flexible and exhibited elastic moduli and tensile strengths similar to Celazole{\textregistered}, despite having low elongation at break.",
keywords = "Gas transport, Polybenzimidazole, Polyimide, Polymer blend, Thermal rearrangement",
author = "Moon, {Joshua D.} and Bridge, {Alexander T.} and Colton D'Ambra and Freeman, {Benny D.} and Paul, {Donald R.}",
note = "Funding Information: This work was supported by the U.S. Department of Energy Office of Science , Office of Basic Energy Sciences [grant number DE-FG02–02ER15362 ], the National Science Foundation Graduate Research Fellowship Program [grant number DGE-1610403 ], and the National Science Foundation [Cooperative Agreement No. EEC-1647722 ]. We gratefully acknowledge partial support of this work by the Australian-American Fulbright Commission for the award to B.D.F. of the U.S. Fulbright Distinguished Chair in Science, Technology and Innovation sponsored by the Commonwealth Scientific and Industrial Research Organization (CSIRO). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Funding Information: This work was supported by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences [grant number DE-FG02–02ER15362], the National Science Foundation Graduate Research Fellowship Program [grant number DGE-1610403], and the National Science Foundation [Cooperative Agreement No. EEC-1647722]. We gratefully acknowledge partial support of this work by the Australian-American Fulbright Commission for the award to B.D.F. of the U.S. Fulbright Distinguished Chair in Science, Technology and Innovation sponsored by the Commonwealth Scientific and Industrial Research Organization (CSIRO). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. The authors would like to acknowledge Michelle Dose for synthesizing HAB-6FDA-CI, Dr. Steve Swinnea for running WAXS and SAXS and providing data interpretation, Dr. Andrei Dolocan for providing SEM training, Dr. Rajkiran Tiwari for performing ultramicrotoming, and Dr. Karalee Jarvis for running TEM/STEM/EDS and providing data interpretation. Publisher Copyright: {\textcopyright} 2019 Elsevier B.V. Copyright: Copyright 2019 Elsevier B.V., All rights reserved.",
year = "2019",
month = jul,
day = "15",
doi = "10.1016/j.memsci.2019.03.067",
language = "English",
volume = "582",
pages = "182--193",
journal = "Journal of Membrane Science",
issn = "0376-7388",
publisher = "Elsevier BV",
}