Plasticization-Resistant Carboxyl-Functionalized 6FDA-Polyimide of Intrinsic Microporosity (PIM-PI) for Membrane-Based Gas Separation
KAUST DepartmentAdvanced Membranes and Porous Materials Research Center
Biological and Environmental Sciences and Engineering (BESE) Division
Chemical Engineering Program
Physical Science and Engineering (PSE) Division
Online Publication Date2019-10-14
Print Publication Date2020-03-25
Permanent link to this recordhttp://hdl.handle.net/10754/660383
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AbstractA novel trimethyl-substituted carboxyl-containing polyimide was synthesized via a one-pot high-temperature polycondensation reaction of 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 3,5-diamino-2,4,6-trimethylbenzoic acid (TrMCA). The polyimide (6FDA-TrMCA) displayed a Brunauer-Emmett-Teller surface area of 260 m2 g-1, demonstrating intrinsic microporosity, in contrast to the related low-free volume COOH-functionalized polyimide 6FDA-DABA. Compared to the nonfunctionalized 6FDA polyimide analogue made from 2,4,6-trimethyl-m-phenylenediamine (TrMPD)-also known as 6FDA-DAM-carboxyl functionalization in 6FDA-TrMCA resulted in reduced surface area, lower fractional free volume, and tighter average chain spacing. Gas permeabilities of 6FDA-TrMCA were typical of functionalized polyimides of intrinsic microporosity (PIM-PIs). For example, at 2 atm and 35 °C, 6FDA-TrMCA showed pure-gas H2 and CO2 permeability of 193 and 144 barrer, coupled with H2/CH4 and CO2/CH4 selectivity of 61 and 45, respectively. Notably, in mixed-gas permeation tests with an equimolar CO2-CH4 mixture at a CO2 partial pressure of 12 atm, 6FDA-TrMCA demonstrated performance located on the 2018 mixed-gas upper bound with a CO2 permeability of â¼98 barrer and CO2/CH4 permselectivity of 38. As the first reported COOH-functionalized PIM-PI homopolymer, 6FDA-TrMCA revealed excellent resistance against CO2-induced plasticization at least up to a CO2 partial pressure of 15 atm, covering the range of typical wellhead CO2 partial pressures (5-10 atm).
CitationAbdulhamid, M. A., Genduso, G., Wang, Y., Ma, X., & Pinnau, I. (2019). Plasticization-Resistant Carboxyl-Functionalized 6FDA-Polyimide of Intrinsic Microporosity (PIM–PI) for Membrane-Based Gas Separation. Industrial & Engineering Chemistry Research. doi:10.1021/acs.iecr.9b04994
SponsorsThis work was supported by baseline funding (No. BAS/1/ 1323-01-01) from King Abdullah University of Science and Technology (KAUST). I.P. wishes to thank Professor Don Paul for teaching him the essentials of polymer science and many stimulating discussions.
PublisherAmerican Chemical Society (ACS)