Blended polybenzimidazole and melamine-co-formaldehyde thermosets
- Idaho National Lab. (INL), Idaho Falls, ID (United States)
Polybenzimidazole [PBI; poly-2,2’(m-phenylene)-5,5’-bibenzimidazole] is known to have excellent high temperature stability (up to 450 ºC) and superb H2/CO2 selectivity compared to most high performance (HP) polymers. But, PBI has issues in thin-film formation compared to other HP polymers, due to challenging processing techniques. In this work, new blended thermosets were made with PBI and poly(melamine co-formaldehyde) [PMF] to produce stable thin-films after thermal processing at 220-250 ºC. PBI film formation is difficult, and the film tends to fracture and fissure due to loss of processing aids and stabilizers (salt/acid additives) that are found in PBI solutions above10 wt %. The PBI-PMF blended thermosets we report do not have stabilizers, and can be made into dense thin-films. It is remarkable that these thermally processed PBI-PMF films were stable in deionized water for extended periods, whereas many PBI films that contain additives are not. The PBI-PMF films were analyzed using pure and mixed gas permeability measurement techniques. At 250 °C, the data show H2/CO2 gas selectivities greater than 13. Also, from the gas permeation data, the energy of activation (Ep) of a mixed gas stream for PBI-PMF shows that hydrogen permeates more easily than the other gases, while the permeabilities for the larger kinetic diameter gases are greatly diminished. The FT-IR spectra show that the PBI-PMF films have changed from parent PBI after thermal processing, and PMF dominates the spectra even in minor percent compositions. Altogether, the reported PBI-PMF thermoset films show good stability which can be used for high temperature gas separation.
- Research Organization:
- Idaho National Laboratory (INL), Idaho Falls, ID (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE)
- Grant/Contract Number:
- AC07-05ID14517; AC07–05ID14517
- OSTI ID:
- 1357450
- Alternate ID(s):
- OSTI ID: 1326702
- Report Number(s):
- INL/JOU-15-36391; PII: S0376738816303325
- Journal Information:
- Journal of Membrane Science, Vol. 515, Issue C; ISSN 0376-7388
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Unprecedented toughening high-performance polyhexahydrotriazines constructed by incorporating point–face cation–π interactions in covalently crosslinked networks and the visual detection of tensile strength
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journal | January 2020 |
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