High-performance intrinsically microporous dihydroxyl-functionalized triptycene-based polyimide for natural gas separation

Abstract

Please cite this article as: Alaslai N, Ghanem B, Alghunaimi F, Pinnau I, High-performance intrinsically microporous dihydroxyl-functionalized triptycene-based polyimide for natural gas separation, Polymer (2016), doi: 10.1016/j.polymer.2016.03.063. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT AbstractA novel polyimide of intrinsic microporosity (PIM-PI) was synthesized from a 9,10-diisopropyltriptycene-based dianhydride (TPDA) and dihydroxyl-functionalized 4,6-diaminoresorcinol (DAR). The unfunctionalized TPDA-m-phenylenediamine (mPDA) polyimide derivative was made as a reference material to evaluate the effect of the OH group in TPDA-DAR on its gas transport properties. Pure-gas permeability coefficients of He, H 2 , N 2 , O 2 , CH 4 , and CO 2 were measured at 35 °C and 2 atm. The BET surface area based on nitrogen adsorption of dihydroxylfunctionalized TPDA-DAR (308 m 2 g -1 ) was 45% lower than that of TPDA-mPDA (565 m 2 g -1 ).TPDA-mPDA had a pure-gas CO 2 permeability of 349 Barrer and CO 2 /CH 4 selectivity of 32.The dihydroxyl-functionalized TPDA-DAR polyimide exhibited enhanced pure-gas CO 2 /CH 4 selectivity of 46 with a moderate decrease in CO 2 permeability to 215 Barrer. The CO 2 permeability of TPDA-DAR was ~30-fold higher than that of a commercial cellulose triacetate membrane coupled with 39% higher pure-gas CO 2 /CH 4 selectivity. The TPDA-based dihydroxyl-containing polyimide showed good plasticization resistance and maintained high mixed-gas selectivity of 38 when tested at a typical CO 2 natural gas wellhead CO 2 partial pressure of 10 atm.

Synthesis and characterization of new polyimides from diphenylpyrene dianhydride and ortho methyl substituted diamines

“…As it is usually found in other polymers, pure CO 2 and CH 4 permeability coefficients of these polyimides decreased with increasing feed pressure up to 15 atm. 27,29,32,33 This preliminarily results indicates that DPPD-MBDAM, DPPD-HFI and DPPD-BAPHF membranes do not present plasticization up to a testing pressure of 15 atm. Fig.…”

“…This effect is in agreement with previous reports, which indicate that the introduction of ortho methyl substituted groups in the diamine moieties can increase gas permeability coefficients but they follow the usual trade off since there is a decreased in selectivity. 27,28 Apparent gas diffusion coefficients, D, determined from time lag and apparent gas solubility coefficient S, (calculated from D and P), are presented in Table 6. Also the values of diffusivity selectivity, a(D A /D B ), and solubility selectivity.…”

Microporous Organic Materials for Membrane‐Based Gas Separation

“…Both studies indicated that tailoring the pore surfaces with functionalities brought benefits in CO 2 capture from postcombustion gases. The practices of introducing CO 2 ‐philic groups (e.g., OH, COOH, NH 2 ) onto the pore walls of microporous organic membranes were extensively executed by our researchers …”

“…The method of pore modulation to improve CO 2 capture efficiency was extended to other microporous organic membranes including crystalline 2D and amorphous 3D ones, the work of which is summarized in Figure . Based on the survey, it can be concluded that introduced surface functionality and small pores contribute significantly to increasing the selectivity, and fully interconnected pores (equivalently by high surface areas) bring a huge enhancement in gas permeability.…”

Preparation and Gas Separation Properties of Triptycene‐Based Microporous Polyimide

“…[5][6][7][8][9][10][11][12] Polyimide is one of the most promising membrane materials for natural gas and biogas separation due to its excellent properties, such as high gas permselectivity, high thermal and chemical resistance, and excellent mechanical properties. [13,14] from triptycene-based diamine DAT and rigid PMDA. The structure of PMDA-DAT and the synthetic procedure was shown in Scheme 1.…”