PEG modified poly(amide-b-ethylene oxide) membranes for CO₂ separation

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• 作者：Anja. Car ; Chrtomir. Stropnik ; Wilfredo Yave ; Klaus-V. Peinemann
• 关键词：Pebax^® ; ; Blend membranes ; Gas separation ; Carbon dioxide
• 刊名：Journal of Membrane Science
• 出版年：2008
• 出版时间：10 January 2008
• 年：2008
• 卷：307
• 期：1
• 页码：88-95
• 全文大小：951 K

文摘

In the present work, membranes from commercially available Pebax^® MH 1657 and its blends with low molecular weight poly(ethylene glycol) PEG were prepared by using a simple binary solvent (ethanol/water). Dense film membranes show excellent compatibility with PEG system up to 50 wt. % of content. Gas transport properties have been determined for four gases (H₂, N₂, CH₄, CO₂) and the obtained permeabilities were correlated with polymer properties and morphology of the membranes. The permeability of CO₂ in Pebax^®/PEG membrane (50 wt. % of PEG) was increased two fold regarding to the pristine Pebax^®. Although CO₂/N₂ and CO₂/CH₄ selectivity remained constant, an enhancement of CO₂/H₂ selectivity (11) was observed. These results were attributed to the presence of EO units which increases CO₂ permeability, and to a probable increase of fractional free-volume. Furthermore, for free-volume discussion and permeability of gases, additive and Maxwell models were used.