N-Substituted Fluorinated Polybenzimidazoles: An Easy Post-Modification Strategy for Improved CO2 Separation
This study details synthesizing and characterizing a series of N-substituted aromatic polybenzimidazoles (N-PBIs) obtained via post-polymerization modifications of fluorinated polybenzimidazole (PBI-6F). The modifications involved the introduction at imidazole nitrogen of aliphatic chains bearing te...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:dnet:digitalcsic_::f634e8fe62958eca29da32614e3597e2 |
| Acceso en línea: | http://hdl.handle.net/10261/427338 |
| Access Level: | acceso abierto |
| Palabra clave: | Polybenzimidazole Thermal Decomposition Fluorinated PBI Post-PolymerizationModification CO2 Separation N-Substituted PBIs Tertiary Amine Groups Gas Separation Membrane |
| Sumario: | This study details synthesizing and characterizing a series of N-substituted aromatic polybenzimidazoles (N-PBIs) obtained via post-polymerization modifications of fluorinated polybenzimidazole (PBI-6F). The modifications involved the introduction at imidazole nitrogen of aliphatic chains bearing tertiary amine groups, affording N,N-dimethylethylamine and N,N-dimethylpropylamine N-substituted PBIs, PBI-DMEA, and PBI-DMPA, respectively. Their properties were compared with the performance of N-substituted PBI bearing a pure propyl chain, without an amine group in the end (PBI-Pr). All N-PBIs demonstrated enhanced processability, exhibiting solubility not only in dipolar aprotic solvents but also in such ordinary solvents as chloroform and THF. Their performance as gas separation membranes was tested and showed that the membranes with amine groups in the substituent had enhanced permselectivity for the CO2/CH4 gas pair, which was rather explained by an increase in the solubility parameter of CO2. However, the presence of the aliphatic amines also resulted in an unusually low decomposition temperature for these polymers. The mechanism of thermal decomposition and solubility and diffusivity parameters were confirmed by corresponding calculations. |
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