Helium Recovery by Membrane Gas Separation Using Poly(o-acyloxyamide)s

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• 作者：Blanca D铆ez ; Purificaci贸n Cuadrado ; 脕ngel Marcos-Fern谩ndez ; Pedro Pr谩danos ; Alberto Tena ; Laura Palacio ; 脕ngel E. Lozano ; Antonio Hern谩ndez
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：August 13, 2014
• 年：2014
• 卷：53
• 期：32
• 页码：12809-12818
• 全文大小：481K
• ISSN：1520-5045

文摘

Poly(o-acyloxyamide)s (PORAs) derived from a poly(o-hydroxyamide) from 2,2鈥?bis(3-amino-4-hydroxyphenyl)hexafluoropropane (APAF) diamine, APAF鈥揚OHA, have been synthesized and evaluated as gas separation materials. PORAs were synthesized from poly(o-hydroxyamide)s by derivatization of the free OH group with an aliphatic acid dichloride or dianhydride that allowed the introduction of acetyl or pivaloyl groups on their structure. All of them showed low鈥搈edium thermal stability due to a degradation of the amide moieties, and most of them (those synthesized from isophthaloyl dichloride (IPC), 2,2鈥?bis(4-carboxyphenyl) hexafluoropropane dichloride (6FC), and 4,4鈥?dicarboxydiphenylsulfone dichloride (DPSC)) showed good mechanical properties. The poly(o-acyloxyamide)s synthesized have shown good permselectivities for He/N₂ and He/CH₄ separations and very good permeability鈥搒electivity balance for He/CO₂ separation. The acetyl PORAs showed better permeability versus selectivity balances than the pivaloyl ones. Moreover, selectivity increased while permeability decreased in the sequence 6F-APAF > IP-APAF > DPS-APAF. Intersegmental distances, d-spacing, were shown to decrease along this sequence, obtaining a nice correlation between permeability and d-spacing. For the He/N₂ and the He/CH₄ pairs of gases, the best permeability鈥搒electivity values are obtained for 6F-APAF-Ac with a He permeability of 33 barrer and selectivities of 84 and 106, respectively. DPS-APAF-Ac gives a He permeability of 13 barrer and a selectivity of 21 for the He/CO₂ separation.