TY - JOUR
T1 - Effect of UV irradiation and physical aging on O2 and N2 transport properties of thin glassy poly(arylene ether ketone) copolymer films based on tetramethyl bisphenol A and 4,4′-difluorobenzophenone
AU - Liu, Qiang
AU - Shaver, Andrew T.
AU - Chen, Yu
AU - Miller, Gregory
AU - Paul, Donald R.
AU - Riffle, J. S.
AU - McGrath, James E.
AU - Freeman, Benny D.
N1 - Funding Information:
This material is based upon work supported by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences under Award Number DE-FG02-02ER15362 . Financial support from the NSF Science and Technology Center for Layered Polymeric Systems (Grant No. 0423914 ) is also gratefully acknowledged. The authors would also like to acknowledge Air Products and Chemicals, Inc. for their financial support. This study was also partially supported by the International Institute for Carbon Neutral Energy Research (WPI-I 2 CNER), sponsored by the Japanese Ministry of Education, Culture, Sports, Science and Technology . Finally, the authors would like to thank the Center for Nano- and Molecular Science at University of Texas at Austin for use of its clean room facilities.
Publisher Copyright:
© 2016 Elsevier Ltd. All rights reserved.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2016/3/22
Y1 - 2016/3/22
N2 - Modification of membranes to improve gas separation properties has been of considerable interest. Crosslinking is one route to modify membranes, but such studies need to be performed on thin membranes to quantify the impact of such modifications at thicknesses relevant to industrial membranes. In this study, the influences of UV irradiation and physical aging on O2 and N2 gas permeation properties of thin (∼150 nm) glassy, amorphous poly(arylene ether ketone) (PAEK) copolymer films at 35°C and 2 atm were investigated. Thin PAEK copolymer films, prepared from tetramethyl bisphenol A (TMBPA) and 4,4′-difluorobenzophenone (DFBP), were UV irradiated on both sides in air or N2 at 254 nm or 365 nm, which induced crosslinking and, in some cases, photooxidation. Gas permeability decreased and O2/N2 selectivity increased as UV irradiation and aging time increased. At 254 nm, samples irradiated in air have lower permeability coefficients and higher selectivities than samples irradiated in N2, which was ascribed to additional decreases in free volume due to photooxidation in samples irradiated in air. Additionally, samples irradiated in air at 254 nm exhibit less physical aging than uncrosslinked and samples irradiated in N2 at 254 nm, possibly due to interactions among photooxidative polar products that may restrict polymer chain mobility, thereby lowering the aging rate. The influence of water vapor on physical aging of samples irradiated in air was examined. Finally, irradiation at 254 nm leads to more extensive crosslinking and/or photooxidation than irradiation at 365 nm, possibly due to greater UV absorption by the polymer and the higher probability of radical formation at the lower wavelength.
AB - Modification of membranes to improve gas separation properties has been of considerable interest. Crosslinking is one route to modify membranes, but such studies need to be performed on thin membranes to quantify the impact of such modifications at thicknesses relevant to industrial membranes. In this study, the influences of UV irradiation and physical aging on O2 and N2 gas permeation properties of thin (∼150 nm) glassy, amorphous poly(arylene ether ketone) (PAEK) copolymer films at 35°C and 2 atm were investigated. Thin PAEK copolymer films, prepared from tetramethyl bisphenol A (TMBPA) and 4,4′-difluorobenzophenone (DFBP), were UV irradiated on both sides in air or N2 at 254 nm or 365 nm, which induced crosslinking and, in some cases, photooxidation. Gas permeability decreased and O2/N2 selectivity increased as UV irradiation and aging time increased. At 254 nm, samples irradiated in air have lower permeability coefficients and higher selectivities than samples irradiated in N2, which was ascribed to additional decreases in free volume due to photooxidation in samples irradiated in air. Additionally, samples irradiated in air at 254 nm exhibit less physical aging than uncrosslinked and samples irradiated in N2 at 254 nm, possibly due to interactions among photooxidative polar products that may restrict polymer chain mobility, thereby lowering the aging rate. The influence of water vapor on physical aging of samples irradiated in air was examined. Finally, irradiation at 254 nm leads to more extensive crosslinking and/or photooxidation than irradiation at 365 nm, possibly due to greater UV absorption by the polymer and the higher probability of radical formation at the lower wavelength.
KW - Gas separation
KW - Physical aging
KW - Poly(arylene ether ketone)
KW - UV crosslinking
UR - http://www.scopus.com/inward/record.url?scp=84958062026&partnerID=8YFLogxK
U2 - 10.1016/j.polymer.2016.01.075
DO - 10.1016/j.polymer.2016.01.075
M3 - Article
AN - SCOPUS:84958062026
SN - 0032-3861
VL - 87
SP - 202
EP - 214
JO - Polymer
JF - Polymer
ER -