Abstract
Polymers of intrinsic microporosity (PIMs) arestudied as membranes for energy-efficient and environmentallyfriendly separation technologies, but greener polymerizationmethods are desirable for further scale up. This work aimed tosynthesize the prototypical PIM (PIM-1) via a greener syntheticroute by changing the solvent system to methyl-5-(dimethylami-no)-2,2-dimethyl-5-oxopentanoate (MDDOP), a structural ana-logue of the green solvent Rhodiasolv PolarClean. Mass-basedgreen metrics analysis was performed on MDDOP, determiningatom economy, complete environmental factor, and total carbonintensity, comparing each to synthetic routes to PolarClean. Greenmetrics analysis found MDDOP synthesis produced less waste thanPolarClean. MDDOP solvent capabilities were exemplified via PIM-1 polymerizations using 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobisindane (TTSBI) with either tetrafluoroterephthalonitrile (TFTPN) or tetrachloroterephthalonitrile(TCTPN), varying the temperature (120−160 °C) and reaction duration (50 min−6 h). Recovery of methanol and MDDOPpost PIM-1 synthesis reduced solvent waste by 22%. Reactions using TCTPN produced polymers with higher molar masses thanthose produced using TFTPN. All samples showed varied topology, with evidence of branching and colloidal network. The polymerfrom the most successful reaction conditions (TCTPN, T = 140 °C, 6 h) was fabricated into thick film membranes and tested withpure gases for CO2/CH4 and CO2/N2 gas pairs, performing comparably with PIM-1 synthesized using conventional solvent systems
Original language | English |
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Journal | ACS Sustainable Chemistry & Engineering |
Early online date | 23 Dec 2024 |
DOIs | |
Publication status | E-pub ahead of print - 23 Dec 2024 |
Keywords
- green solvent
- PIM-1
- PIM
- polymers of intrinsic microporosity
- green metrics analysis
- gas separation
- membranes
- green synthesis