Gas Permeability and Selectivity in Thermally Modified Poly(oxyindole biphenylylene) Membranes Bearing a tert-Butyl Carbonate Group

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• 作者：Suzanne Sánchez-García ; F. Alberto Ruiz-Treviño ; Manuel J. Aguilar-Vega ; Mikhail G. Zolotukhin
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2016
• 出版时间：June 29, 2016
• 年：2016
• 卷：55
• 期：25
• 页码：7012-7020
• 全文大小：465K
• 年卷期：0
• ISSN：1520-5045

文摘

The gas permeability and ideal selectivity in poly(oxyindole biphenylylene) polymers that bear a tert-butyl carbonate side group, PN-BOC, have been measured, at 35 °C and 2 bar. It is found that the thermal degradation of the thermo-labile side group, BOC, at moderate temperatures and times, is useful for designing membranes that overcome the typical trade-off between permeability and selectivity. TGA, FTIR-ATR, and DSC analysis reveal that thermal treatments of PN-BOC at 150 °C and short periods of time, 5–60 min, allow the design of membranes with better selectivity–permeability combinations than the pure PN-BOC precursor. For the gas pairs O₂/N₂ and CO₂/N₂, the PN-BOC₅ thermally treated membranes for 5 min show O₂ and CO₂ permeability coefficients higher by a factor of 2.3 with respect to that measured in PN-BOC, while retaining their selectivity. For the gas pairs H₂/CH₄ and CO₂/CH₄, the PN-BOC₆₀ thermally treated membranes for 60 min show a H₂ and CO₂ permeability coefficient higher by a factor of 1.7 and 1.4, respectively, while selectivity increases with respect to that of the PN-BOC precursor by 45% for H₂/CH₄ and 24% for CO₂/CH₄.