Polymer of Intrinsic Microporosity Incorporating Thioamide Functionality: Preparation and Gas Transport Properties

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• 作者：Christopher R. Mason ; Louise Maynard-Atem ; Nasser M. Al-Harbi ; Peter M. Budd ; Paola Bernardo ; Fabio Bazzarelli ; Gabriele Clarizia ; Johannes C. Jansen
• 刊名：Macromolecules
• 出版年：2011
• 出版时间：August 23, 2011
• 年：2011
• 卷：44
• 期：16
• 页码：6471-6479
• 全文大小：975K
• 年卷期：v.44,no.16(August 23, 2011)
• ISSN：1520-5835

文摘

A novel polymer of intrinsic microporosity, thioamide-PIM-1, has been prepared by postmodification of PIM-1, using phosphorus pentasulfide as a thionating agent in the presence of sodium sulfite. The chemistry was first tested on a low molecular weight model compound, 3,13-dicyanobenzo-1,2,4鈥?5鈥?bis(1,4-benzodioxane). For the polymer, up to 80% conversion of nitrile to thioamide was achieved. Modification leads to a reduction in the BET surface area of the polymer, from 770 m² g^鈥? for the parent PIM-1 to 263 m² g^鈥? on 80% conversion of nitrile to thioamide. After modification, the polymer is no longer soluble in chlorinated solvents such as CHCl₃, but is soluble in polar aprotic solvents such as THF, DMF, DMSO, and DMAc. Self-supported membranes of thioamide-PIM-1 were cast from THF. Single gas permeability measurements showed increased selectivities but reduced permeabilities compared to the parent polymer. Ethanol treatment, which removes occluded THF as well as enhancing free volume, has a pronounced effect on membrane permeability. For the as-prepared membrane, an ideal CO₂/N₂ selectivity of 38.5 was achieved with a CO₂ permeability of 150 barrer. Ethanol treatment increased the CO₂ permeability to 1120 barrer, with a decrease in CO₂/N₂ ideal selectivity to 30.3.