POXINAR Membrane Family for Gas Separation | Industrial

Article Cite This: Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

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POXINAR Membrane Family for Gas Separation Enoc Cetina Mancilla,† Hugo Hernández-Martínez,‡ Mikhail G. Zolotukhin,*,† F. Alberto Ruiz-Treviño,*,‡ María Ortencia González-Díaz,§ Jorge Cardenas,∥ and Ullrich Scherf⊥

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Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Ciudad Universitaria, Coyoacán, 04510 México D. F., Mexico ‡ Departamento de Ingeniería y Ciencias Químicas, Universidad Iberoamericana, Pról. Paseo de la Reforma No. 880, Lomas de Santa Fe, 01219 México D. F., Mexico § CONACYT - Centro de Investigación Científica de Yucatán, A.C., Calle 43 No. 130, Chuburná de Hidalgo, 97205 Mérida, Yucatán, Mexico ∥ Instituto de Química, Universidad Nacional Autónoma de México, Apartado Postal 70-360, Ciudad Universitaria, Coyoacán, 04510 México D. F., Mexico ⊥ Macromolecular Chemistry Group, Wuppertal University, Gauss-Strasse 20, D-42097 Wuppertal, Germany ABSTRACT: Poly(oxindolylidene arylene)s (POXINARs), a family polymers with high performance in terms of thermal stability properties and with ether-bond-free aromatic backbones alternating with bulky, torsion resistant oxindolylidene fragments, have been synthesized by superacid catalyzed polyhydroxyalkylation, and their useful physical properties have been assessed to determine their performance as gas separation membranes. The room temperature synthesis allows a variety of fully soluble, high-molecular-weight polymers in a single pot “click” reaction. These polymers can form flexible and transparent films, and they possess high glass transition temperatures (>500 °C); high decomposition temperatures (ranging from 500 to 524 °C); and FFVs (0.130−0.194) comparable to those reported for the polysulfone, polycarbonate, and polyarylate families. However, their selectivity− permeability combinations are very attractive because some fall close to the 2008 upper-bound limits. Membranes made from isatin and 9,9-dimethyl-9H-fluorene (2aD) display P(O2) = 15.4 Barrer for the O2/N2 gas pair and an O2/N2 selectivity of 6.4, whereas for the H2/CH4 gas pair, they display P(H2) = 170 Barrer and a H2/CH4 selectivity of 77.

1. INTRODUCTION The development of polymer membranes for gas separation has been evolving and expanding rapidly.1,2 The scopes of the applications are still extending, stimulated by the development of novel membranes with better chemical, mechanical, thermal, and physical resistance properties (swelling, CO2 plasticization, and aging).3 Currently, the research is focused on the synthesis and evaluation of polymers with precise, well-defined structures.4 Basically, the polymers for gas separation are synthesized by polycondensation aromatic chemistry. It is worth mentioning that regioselectivity and high efficiency of the reactions are absolute necessities for obtaining well-defined and high-molecular-weight polymers. The recent synthesis of poly(oxindolylidene arylene)s, POXINARs, by superacid catalyzed polyhydroxyalkylation of isatin with linear, nonactivated, multiring aromatic hydrocarbons (Figure 1) is a clear example.5,6 The reactions in the presence of CF3SO3H (TFSA) are wide in scope, include simple reaction conditions (room temperature and readily available starting materials and reagents), and generate an inoffensive byproduct (water). Thus, synthesized POXINARs © XXXX American Chemical Society

possess high molecular weights, high thermal stability, and good solubility in organic solvents forming flexible films after casting. It is important that ether-bond-free aromatics in the main chains of the polymers alternate with bulky, torsionresistant oxindolylidene fragments, thereby maintaining the intramolecular rigidity that disrupts chain packing. Moreover, POXINARs represent promising challenges for membrane applications, because their chemical structures (see Figure 1) may be modified appropriately by taking into account the presence of two sites for chemical postpolymerization or incorporation of cross-linkable groups by (1) electrophilic aromatic substitution reactions (aromatic fragments) and (2) nucleophilic substitutions (N−H groups of oxindol rings). Indeed, asymmetric polymeric porous membranes with excellent thermal (TD > 500 °C) and solvent resistance for ultrafiltration in organic solvents were prepared via crossReceived: May 14, 2019 Revised: July 8, 2019 Accepted: July 20, 2019

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DOI: 10.1021/acs.iecr.9b02656 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

Article

Industrial & Engineering Chemistry Research

Figure 1. General reaction scheme for the synthesis of poly(oxindolylidene arylene)s, POXINARs.

2. EXPERIMENTAL SECTION 2.1. Materials. Unless otherwise indicated, all starting materials were purchased from Aldrich and used without further purification. Methylene chloride, TFA, TFSA, and biphenyl were distilled. Isatin (1a) and N-methylisatin (1b) were recrystallized with charcoal from ethanol. The monomer 9,9-dimethyl-9H-fluorene was synthesized as follows: Aqueous sodium hydroxide solution (29 mL, 50%) and iodomethane (27.4 g, 193 mmol) were added to a solution of fluorene (13.7 g, 82 mmol) and tetrabutylammonium bromide (8g, 25 mmol) in 64 mL of DMSO at 44 °C. The mixture was stirred at 44 °C for 150 min and then poured onto ice. The precipitate formed was filtered off, washed with water, and dried overnight at room temperature. After recrystallization from ethanol with activated carbon, 11.14 g (69.7%) of 9,9-dimethyl-9H-fluorene was obtained as white crystals. 1H NMR (300 MHz, CDCl3): δ 7.74−7.83 (m, 2H, Ar−H), 7.46−7.53 (m, 2H, Ar−H), 7.33− 7.43 (m, 4H, Ar−H), 1.55 (s, 6H, CH3) ppm. 13C NMR (75 MHz, CDCl3): δ 153.5, 139.1, 127.1, 126.9, 122.5, 119.9, 46.8, 27.1 ppm. Mp. 96.47 °C. 2.2. Polymer Syntheses. Polymers 2aA, 2aB, 2aC, 2bC, and 2bE were synthesized according to a published method.5,6 Polymer 2bF was prepared as reported elsewhere.13 Nonstoichiometric synthesis of polymer 2aD was performed as follows: a 25 mL flask equipped with a mechanical stirrer was charged with isatin (1.1785 g, 8.0 mmol), 9,9-dimethyl-9Hfluorene (1.1971 g, 6.1 mmol), nitrobenzene (4.6 mL), and dichloromethane (4.6 mL). The solution was cooled to 5 °C and TFSA (3.2 mL) was added in one portion to the solution.

linking of polymer 2aA (poly[(2-oxo-2,3-dihydro-1H-indol-3ylidene)([1,1′-biphenyl]-4,4′-diyl)] using reactions with dibromoalkanes7 and functionalization with alkyne side groups, followed by wet-state cyclotrimerization in hot glycerol.8 More recently, polymer 2aA was used as a model for incorporating thermolabile and cross-linkable groups to illustrate how different thermal treatments lead to POXINAR membranes that not only possess attractive gas permeability and selectivity properties but also are more resistant to aggressive solvents and aging.9 An unusual and very interesting example of thermal cross-linking of a 2aA membrane followed by long-term annealing under vacuum (10−3 Torr) was reported;10 the resulting polymers were resistant to solvent swelling and CO2 plasticization up to 18 bar, and the selectivity−permeability combinations for O2/N2 overcome the typical trade-off between permeability and selectivity, falling above Robeson’s 2008 upper-bound limit. Thus, the aim of this work is to report the gas separation performances of six POXINARs synthesized by polymerization of isatines (1a or 1b) with various aromatic hydrocarbons (H− Ar−H) to produce polymers 2aA−D, 2bC, 2bE and 2bF according to the reaction scheme shown in Figure 1. Highly efficient reactions of isatin with aromatics have been reported.11,12 and although a variety of aromatic monomers could be used in polycondensation with isatin, for this work, a set of six monomers was chosen to determine the main structural factors determining the gas separation performances of POXINAR membranes. B


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Figure 2. 1H NMR spectrum of polymer 2aD. Solution in CDCl3 with trifluoroacetic acid.

plates. After most of the solvent had evaporated they were removed from the cellulose paper and dried in a vacuum oven with the temperature increasing from 50 to 200 °C (2aA and 2aD) or from 50 to 150°C (all others) where they were kept constant for 2 days to ensure that no solvent was left in the membranes. Finally, the films were cooled slowly to room temperature under vacuum and their thicknesses, measured with a Mitutoyo caliper, generally varied from 40 to 50 μm. The polymer densities of the dry films were estimated at 30 °C in a density gradient column on the basis of well-degassed aqueous zinc chloride solutions. The measured density was then used to calculate the fractional free volume (FFV) by applying the following equation:

The reaction was continued at room temperature for 55 min, and then the resulting dark-green homogeneous solution was poured into methanol. The precipitated white fiber was filtered, extracted with hot methanol, dried in air overnight, and then reprecipitated from N-methyl-2-pyrrolidone (NMP) into methanol. After extraction with hot methanol and the drying stage, the resulting pure white fibrous polymer (1.8676g, 93% yield) had an inherent viscosity, ηinh, of 1.37 dL/g (NMP). 2.3. Polymer Characterization. NMR spectra were recorded on a Bruker Avance 400 Spectrometer operating at 400.13 and 100 MHz for 1H and 13C, respectively. Chloroform-d (CDCl3) and mixtures of chloroform with trifluoroacetic acid were used as solvents for NMR spectra. Infrared (IR) spectra were measured in a Nicolet FT-IR-ATR spectrometer. The inherent viscosities of 0.2% polymer solutions in 1-methyl-2-pyrrolidinone (NMP) were measured at 25 °C using an Ubbelohde viscometer. Thermogravimetric analyses (TGA) were carried out in air and under nitrogen at a heating rate of 10 °C/min on a Q500 TA Instruments unit. The glass transition temperature was evaluated by differential scanning calorimetry (DSC) measured at 10 °C/min with a 2910 TA Instruments unit. 2.4. Membrane Formation, Density, WAXD, and Permeability Coefficient Determination. Dense polymer films, for density and gas permeation measurements, were prepared by solution casting 2 wt % polymer in DMAA (2aA and 2aD) or CHCl3 (all others) onto cellulose paper and glass

FFV =

V (30 °C) − V (0) V (30 °C)

(1)

In eq 1, V(30 °C) is the experimentally measured specific volume of the polymer at 30 °C; V(0) is the occupied specific volume at 0 K, which can be estimated from the van der Waals volume (Vw) using the group contribution method suggested by Bondi14 according to the relation V(0) = 1.3∑Vw. Wideangle X-ray diffraction (WAXD) scans were made for two POXINARs using a Xeuss Xenocs X-ray diffractometer at a Cu Kα wavelength of 1.54 Å. The corresponding d spacing, as an indicator of the average chain spacing, was calculated from the diffraction peak maxima using the well-known Bragg equation: nλ = 2d sin θ. The gas permeability coefficients were measured at 35 °C and 2 bar upstream pressure in a constant volume− C


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Figure 3. 13C NMR spectrum of polymer 2aD. Solution in CDCl3 (●) with trifluoroacetic acid (▼).

Table 1. Polymer Codes, Chemical Structures, Inherent Viscosities, Glass Transition Temperatures, Decomposition Temperatures, Specific Volumes at 30 °C, and Fractional Free Volumes (FFVs) of POXINARs

Inherent viscosity in NMP at 25 °C. bOnset of decomposition temperature in nitrogen. cFractional free volume, according to eq 1. dFrom ref 19.

a

selectivities for the gas pairs He/CH4, H2/CH4, O2/N2, and CO2/CH4 are the ratios of the two pure gas permeability coefficients.

variable pressure permeation cell using a well-degassed polymer membrane, according to protocols established elsewhere.15 Ultrahigh-purity gases He, H2, O2, N2, CH4, and CO2 were allowed to permeate in that order to avoid the CO2 plasticization of the polymer membranes. The permeability coefficients were reported as mean values and were reproducible within an error of ±9%. The reported ideal

3. RESULTS AND DISCUSSION 3.1. Polymer Synthesis and Characterization. On first sight, polymer-forming polyhydroxyalkylation, a two-step D


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Industrial & Engineering Chemistry Research Table 2. Polymer Codes, Gas Permeabilities, and Selectivity Propertiesa for POXINAR Membranes permeability coefficients,b P(i)

ideal selectivity, P(i)/P(j)

polymer code

He

H2

O2

CO2

He/CH4

H2/CH4

O2/N2

CO2/CH4

2aA 2aB 2aC 2aD 2bC 2bE 2bF

 53 39 112 70 57 196

80 99 63 170 89 81 303

11.4 15.2 4.2 15.4 10.3 9.4 49

68 106 21 72 52 53 278

 14 106 51 55 28 15

31 26 172 77 70 40 23

4.8 4.5 7.5 6.4 6.1 5.6 4.4

26 28 57 33 41 27 21

Measured at 2 bar upstream pressure and 35 °C. bP(i) in barrers; 1 Barrer = 10−10 (cmSTP3·cm)/(cm2·s·cmHg).

a

values should be above 500 °C (Tg > 500 °C). Their high thermal resistances allow the POXINARs to be termed highperformance polymers, and this is an important property for many polymer applications and for further postmodifications (e.g., thermal cross-linking throughout propargyl groups, as has been reported elsewhere).9,10 The experimental specific volumes and FFVs are comparable to those reported for the well-known polysulfone,20 polycarbonate,21,22 and polyarylate23 families. The chemical structural changes in the repeating units of the polymers affect their packing densities as estimated from FFV. From the set of POXINARs here reported, polymer 2aD and 2bF resulted in the highest FFVs available for permeation. 3.2. Pure Gas Permeability Coefficients and Selectivity. Table 2 summarizes the pure gas permeability coefficients and ideal selectivities for the gas pairs He/CH4, H2/CH4, O2/ N2, and CO2/CH4 measured for the POXINAR membranes. On the basis of the chemical structures and the theory of symmetry,24,25 the polymers could be separated according to their symmetries and the lengths of the monomers forming the repeating units. Thus, biphenyl and terphenyl fragments have axial symmetries that coincide with the axial direction of the corresponding polymer main chain. In contrast, in polymers with just one fluorene group (2aC, 2aD, and 2bC) in the main chain and thus possessing mirror symmetry, the principal symmetry axes of fluorene fragments are perpendicular or lateral to the axial direction of the polymer main chain. The difference between 2aC and 2bC is the −CH3 group replacing the −H atom in 2aC. In polymers 2bE and 2bF, the principal symmetry axis of the corresponding aromatic monomer runs parallel to the axial direction of the polymer main chain, but there are different connector groups (spacers) between the two 9,9-dimethyl-9H-fluorene moieties: a benzo[1,2,5]thiadiazole in 2bE and a tetrafluorophenyl in 2bF. It seems plausible that polymers with different symmetries or lengths of the aromatics in the polymer main chains might show essential differences in the packing of their macromolecules and thus in their gas transport properties. In series from 2aA to 2aD, the length of the repeating unit with a linearly symmetric phenyl group was increased (e.g., biphenyl was replaced with terphenyl), which resulted in increases in permeability coefficients associated with decreases in the H2/CH4 and O2/N2 selectivities, whereas the CO2/CH4 selectivities slightly increased. However, replacing any of the linearly symmetric biphenyls or terphenyls with the laterally symmetric 9H-fluorene or the more bulky 9,9-dimethyl-9H-fluorene group did really produce interesting changes in selectivity and permeability. The replacement with 9H-fluorene decreased the gas permeability, with an appreciable increase in selectivity, whereas the replacement with 9,9dimethyl-9H-fluorene simultaneously increased both the

electrophilic aromatic substitution reaction with a carbinol intermediate, does not look very attractive:

However, surprisingly, the presence of an electron-withdrawing substituent adjacent to the carbonyl group significantly enhances the electrophilicity of the carbocation formed from the carbonyl group and, at the same time, prevents polyalkylation.16,17 More importantly, the formation of a highly reactive carbinol intermediate (K2 ≫ K1) allows nonstoichiometric polymerization with excess carbonyl compound, giving rise to an essential increase in molecular weight in a shorter period of time.18 As a result, linear high- or even ultrahigh-molecular-weight polymers can be obtained. Curiously, under nonstoichiometric conditions, monomers of not very high purity can be polymerized successfully. Syntheses of the polymers were carried out according to published methods or with slight modifications to perform nonstoichiometric polymerization, as in the case of new polymer 2aD. Superacid catalyzed polyhydroxyalkylation is an electrophilic aromatic substitution reaction. It is often difficult to achieve high regiospecificity in Friedel−Crafts type reactions; more surprising is the fact that polymer-forming reactions proceed exclusively in the para-positions of the terminal phenyl groups. Basically, the 1H NMR spectra of the polymers show highly resolved patterns with no evidence of ortho-substitution. Although the 1H NMR spectra of polymers with fluorene fragments (see Figure 2) present multiplets at 7.1−7.5 ppm, the 13C NMR spectrum (see Figure 3) of the polymer is wellresolved and shows all the resonances anticipated for a linear, all-para substitution pattern. Synthesized polymers 2aA and 2aD were soluble in DMAA, whereas all others were soluble in CHCl3. They formed transparent and flexible films useful for gas permeation measurements. Table 1 summarizes the polymer codes (according to the scheme shown in Figure 1); the chemical structures; and some important physical properties, such as inherent viscosity, glass transition temperature (Tg), decomposition temperature in nitrogen atmosphere (TD, onset), specific volume, and FFV. The inherent viscosity values (0.59− 2.02 dL/g) were in the corresponding range of high molecular weights for polymers5 (i.e., 8 × 10−4 g/mol < Mw < 74 × 10−4 with 1.2 < PDI < 1.7). Thanks to this attribute, it was possible to form flexible and transparent membranes reflecting, at least by the naked eye, the amorphous nature of these POXINARs. Thermal analysis by DSC and TGA revealed that these polymers did not present detectable Tg before their TD values were reached (TD = 500−524 °C), thus implying that the Tg E


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Figure 4. WAXD diffractograms for POXINARs 2aC, isatine with 9H-fluorene, and 2aD, isatine with 9,9-dimethyl-9H-fluorene.

are characterized by having up to three types of d spacing distributions, as revealed by the WAXD diffraction patterns reported in Figure 4 for POXINAR membranes 2aC (9Hfluorene) and 2aD (9,9-dimethyl-9H-fluorene). The d spacing distributions centered around 7−9 Å may partially contribute to the high permeability coefficients of the POXINARs, whereas the low d spacing distributions centered around 4−5 Å may partially explain the high selectivities in this POXINAR membrane family. Thus, it would be interesting to compare the selectivity−permeability combinations shown for these POXINARs in so-called upper-bound Robeson’s plots.29 3.3. Selectivity and Permeability Combination of Properties. Figure 5 describes the selectivity−permeability combination of properties for H2/CH4, O2/N2, and CO2/CH4 in the POXINAR membranes. The 2008 upper-bound limits29 have been included as reference lines, because they are representative of membranes with the best selectivity− permeability combinations of properties reported to that date. The dashed line drawn parallel to the 2008 upper-bound limit represents the performances of POXINARs with the most attractive gas separation performances. For the gas pairs H2/ CH4 and O2/N2, the POXINAR membranes fall close to the 2008 upper-bound limit, especially 2aC and 2aD, the polymers that contain the compact in length and laterally symmetric fluorene groups. For the pair CO2/CH4, the POXINAR membranes fall far away of the 2008 upper-bound limit. The

permeability and the selectivity. Increasing the length of the aromatic segment or portion of the compact main chain in POXINARs 2aD and 2bC with a benzo[1,2,5]thiadiazole or tetrafluorophenyl spacer between two 9,9-dimethyl-9H-fluorenes, producing membranes 2bE and 2bF, led to membranes that possessed either slightly lower permeability and lower selectivity (2bE) or higher permeability and lower selectivity (2bF), compared with their most compact counterparts (i.e., with a single fluorene). The POXINAR membranes with the benzo[1,2,5]thiadiazole spacer showed lower permeability but higher selectivity when compared with the membranes with the tetrafluorophenyl spacer, and this typical trade-off between permeability and selectivity may be explained by changes in their FFVs. In general, the permeability coefficients correlate very well with their packing in the solid state, as determined by their corresponding FFVs reported in Table 1. Even though the FFVs of the POXINARs are similar to the corresponding values of other polymers,26−28 the POXINAR membranes show higher permeability coefficients; that is, the FFV of 2bF, around 0.194, is similar to the corresponding values of both 6FDE-TBAP, a polyimide,26 when thermally imidized (0.196) and the same 6FDE-TBAP (c)26 when chemically cyclodehydrated (0.199), but the POXINAR membrane is more permeable. It is important to mention that FFV calculations do not consider the type of transient hole distribution, and POXINARs, as compared with both 6FDE-TBAP membranes, F


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systematic changes introduced in these membranes can give useful information for tailoring even better membranes, at least for the pairs of gases shown here. If a comparison between POXINARs based on isatin and biphenyl moieties (2aA) and those based on isatin and the laterally symmetric 9,9-dimethyl9H-fluorene (2aD) is made, it should be noted that both permeability and selectivity have been improved. A partial explanation is the fact that the FFV has been increased from 0.141 (2aA) to 0.187 (2aD) without loss of their high barriers to rotation introduced by the bulky, torsion-resistant oxindolylidene fragment; the bulky 9,9-dimethyl-9H-fluorene also presents high barriers to rotation, thereby maintaining as a whole the intramolecular rigidity in a high FFV POXINAR. Decreasing or increasing the FFV of 2aD by simultaneously incorporating a more bulky −CH3 instead of the −H in the isatin and increasing the length of the repeating unit using the spacer benzo[1,2,5]thiadiazole or tetrafluorophenyl to produce the polymers 2bE and 2bF leads to membranes that follow the typical trade-off between permeability and selectivity. The tetrafluorophenyl spacer increases permeability but at the expense of selectivity, whereas benzo[1,2,5]thiadiazole decreases both permeability and selectivity. Thus, it seems that POXINARs with polymer repeating units tailored with compact in length 9H-fluorene or 9,9-dimethyl-9H-fluorene are the most productive membranes in terms of selectivity− permeability combinations for the separation of H2/CH4 and O2/N2. Single fluorene moieties in the repeating units of POXINARs impede the free rotation of the para-connected phenyl rings, as compared with the other polymers with biphenyl, terphenyl, or higher polymer repeating units containing benzo[1,2,5]thiadiazole or tetrafluorophenyl.

6. CONCLUSIONS A series of high-performance aromatic poly(oxindolylidene arylene)s (POXINARs) with ether-bond-free aromatics in their backbones alternating with bulky, torsion resistant oxindolylidene fragments has been synthesized via superacid catalysis in a one pot “click” reaction. The syntheses allow for the production of high-molecular-weight polymers that form flexible, transparent membranes with high glass transitions (>500 °C) and high thermal decomposition temperatures (500−524 °C). These membranes are easy to process because they are fully soluble in common organic solvents. Membranes of isatin with compact and laterally symmetric groups, such as 9H-fluorene or the more bulky 9,9-dimethyl-9H-fluorene, are good candidates for separation of the gas pairs H2/CH4 and O2/N2. The poly(oxindolylidene arylene)s, made from compact isatin that bears a H atom as a lateral group and the laterally symmetric and compact 9H- and 9,9-dimethyl-9H fluorenes, are two attractive membranes because they fall close to the upper-bound limits. Polymer 2aD has a P(H2) and P(O2) of 170 and 15.4 Barrer, with associated H2/CH4 and O 2 /N 2 selectivities of 77 and 6.4, respectively. The incorporation of spacers into the main chains of polymers 2bE and 2bF leads to membranes that follow the typical tradeoff between permeability and selectivity. It seems plausible that the synthesis of new POXINARs possessing shape-persistent structural combination of indole groups with laterally symmetric aromatic fragments would afford membranes that are more efficient.

Figure 5. Selectivity−permeability combination of properties for the gas pairs (a) H2/CH4, (b) O2/N2, and (c) CO2/CH4, at 35 °C and 2 bar upstream pressure, for POXINAR membranes. G


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Kudla, C. J.; Scherf, U. A high molecular weight aromatic PhOLED matrix polymer obtained by metal-free, superacid-catalyzed polyhydroxyalkylation. Macromolecules 2009, 42, 9225−9230. (14) Van Kravelen, D. W. Properties of Polymers: Their Correlation with Chemical Structure; their Numerical Estimation and Prediction from Additive Group Contributions; Elsevier: Amsterdam, Netherlands, 1960. (15) Camacho-Zuniga, C.; Ruiz-Trevino, F.A.; Zolotukhin, M.G.; del Castillo, L.F.; Guzman, J.; Chavez, J.; Torres, G.; Gileva, N.G.; Sedova, E.A. Gas transport properties of new aromatic cardo poly(aryl ether ketone)s. J. Membr. Sci. 2006, 283, 393. (16) Olah, G. A.; Klumpp, D. A. Superelectrophilic solvation. Acc. Chem. Res. 2004, 37 (4), 211−220. (17) O’Connor, M. J.; Boblak, K. N.; Spitzer, A. D.; Gucciardo, P. A.; Baumann, A. M.; Peter, J. W.; Chen, C. Y.; Peter, R.; Mitton, A. A.; Klumpp, D. A. Condensations of aryl trifluoromethyl ketones with arenes in acidic media. Tetrahedron Lett. 2010, 51 (38), 4984−4987. (18) Guzman-Gutierrez, M. T.; Nieto, D. R.; Fomine, S.; Morales, S. L.; Zolotukhin, M. G.; Hernandez, M. C. G.; Kricheldorf, H.; Wilks, E. S. Dramatic Enhancement of Superacid-Catalyzed Polyhydroxyalkylation Reactions. Macromolecules 2011, 44, 194−202. ́ (19) del Carmen Gutierrez-Guzmán, M. Sintesis y Propiedades de ́ Nuevos Polimeros basados en la Isatina y sus Derivados. Ph. D. Thesis, Universidad Nacional Autónoma de México, México D. F., Mexico, 2010. (20) McHattie, J. S.; Koros, W. J.; Paul, D. R. Gas transport properties of polysulphones: 3. Comparison of tetramethylsubstituted bisphenols. Polymer 1992, 33 (8), 1701−1711. (21) Hellums, M. W.; Koros, W. J.; Husk, G. R.; Paul, D. R. Gas transport in halogen-containing aromatic polycarbonates. J. Appl. Polym. Sci. 1991, 43, 1977−1986. (22) Pixton, M. R.; Paul, D. R. Gas transport properties of polyarylates Part I: Connector and pendant group effects. J. Polym. Sci., Part B: Polym. Phys. 1995, 33, 1135−1149. (23) McCaig, M. S.; Seo, E. D.; Paul, D. R. Effects of bromine substitution on the physical and gas transport properties of five series of glassy polymers. Polymer 1999, 40, 3367−3382. (24) Bunker, F. R.; Jensen, P. Fundamentals of Molecular Symmetry; CRC Press: Boca Raton, 2018. (25) Carter, R. L. Molecular Symmetry and Group Theory; Wiley, 2005. (26) Calle, M.; Lozano, A. L.; De Abajo, J.; De la Campa, J. G.; Alvarez, C. Design of gas separation membranes derived of rigid aromatic polyimides.1. Polymers from diamines containing di-tertbutyl side groups. J. Membr. Sci. 2010, 365, 145−153. (27) Guzmán-Lucero, D.; Palomeque-Santiago, J. F.; CamachoZúñiga, C.; Ruiz-Treviño, F. A.; Guzmán, J.; Galicia-Aguilar, A.; Aguilar-Lugo, C. Gas Permeation Properties of Soluble Aromatic Polyimides Based on 4-Fluoro-4,4’-Diaminotriphenylmethane. Materials 2015, 8, 1951−1965. (28) Tanaka, K.; Kita, H.; Okano, M.; Okamoto, K.-i. Permeability and permselectivity of gases in fluorinated and non-fluorinated polyimides. Polymer 1992, 33, 585−592. (29) Robeson, L. M. The upper bound revisited. J. Membr. Sci. 2008, 320, 390−400.

AUTHOR INFORMATION

Corresponding Authors

*E-mail: [email protected] (F.A.R.-T.). *E-mail: [email protected] (M.G.Z.). ORCID

Enoc Cetina Mancilla: 0000-0003-3512-1024 Mikhail G. Zolotukhin: 0000-0001-7395-7354 F. Alberto Ruiz-Treviño: 0000-0002-6476-8137 María Ortencia González-Díaz: 0000-0002-0946-9206 Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS The authors acknowledge financial support from CONACYT (Grants CB-2012-01-184156 and 251693) and DGAPAUNAM (PAPIIT and IN203517). Thanks are due to E. R. Morales, S. Morales, G. Cedillo, A. Lopez Vivas, and Alejandro Pompa for technical help.

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REFERENCES

(1) Baker, R. W. Membrane Technology and Applications, 2nd ed.; John Wiley & Sons, Ltd.: Chichester, 2004. (2) Pandey, P.; Chauhan, R. S. Membranes for gas separation. Prog. Polym. Sci. 2001, 26, 853. (3) Park, H. B.; Jung, C. H.; Lee, Y. M.; Hill, A. J.; Pas, S. J.; Mudie, S. T.; Van Wagner, E.; Freeman, B. D.; Cookson, D. J. Polymers with cavities tuned for fast selective transport of small molecules and ions. Science 2007, 318, 254−258. (4) Yampolskii, Y.; Freeman, B. D. Membrane Gas Separation; John Wiley & Sons, Ltd.: Chinchester, 2010. (5) Hernandez, M. C. G.; Zolotukhin, M. G.; Fomine, S.; Cedillo, G.; Morales, S. L.; Frohlich, N.; Preis, E.; Scherf, U.; Salmon, M.; Chavez, M. I.; et al. Novel metal-free superacid-catalyzed “click” reactions of isatins with linear nonactivated multiring aromatic hydrocarbons. Macromolecules 2010, 43, 6968−6979. (6) Cruz, A. R.; Hernandez, M. C. G.; Guzman-Gutierrez, M. T.; Zolotukhin, M. G.; Fomine, S.; Morales, S. L.; Kricheldorf, H.; Wilks, E. S.; Cardenas, J.; Salmon, M. Precision synthesis of narrow polydispersity, ultra high molecular weight linear aromatic polymers by A2 + B2 nonstoichiometric step-selective polymerization. Macromolecules 2012, 45, 6774−6780. (7) Pulido, B. A.; Waldron, C.; Zolotukhin, M. G.; Nunes, S. P. Porous polymeric membranes with thermal and solvent resistance. J. Membr. Sci. 2017, 539, 187−196. (8) Pulido, B. A.; Chisca, S.; Nunes, S. P. Solvent and thermal resistant ultrafiltration membranes from alkynefunctionalized highperformance polymers. J. Membr. Sci. 2018, 564, 361−371. (9) Hernández-Martínez, H.; Ruiz-Treviño, F. A.; Ortiz-Espinoza, J.; Aguilar-Vega, M. J.; Zolotukhin, M. G.; Marcial-Hernandez, R.; Olvera, L. I. Simultaneous thermal cross-linking and decomposition of side groups to mitigate physical aging in poly(oxyindole biphenylylene) gas separation membranes. Ind. Eng. Chem. Res. 2018, 57 (13), 4640−4650. (10) Ortiz-Espinoza, J.; Ruiz-Treviño, F. A.; Hernández-Martínez, H.; Aguilar-Vega, M. J.; Zolotukhin, M. G. Gas transport properties in cross-linked and vacuum annealed poly(oxyindole biphenylylene) membranes. Ind. Eng. Chem. Res. 2018, 57, 12511−12518. (11) Klumpp, D. A.; Yeung, K. Y.; Prakash, G. K. S.; Olah, G. A. Preparation of 3,3-daryloxindoles by superacid-induced condensations of isatins and aromatics with a combinatorial approach. J. Org. Chem. 1998, 63, 4481−4484. (12) Gasonoo, M.; Klumpp, D. A. Synthesis of functionalized 2oxindoles by Friedel−Crafts reactions. Tetrahedron Lett. 2015, 56, 4737−4739. (13) Hernandez, M. C. G.; Zolotukhin, M. G.; Maldonado, J. L.; Rehmann, N.; Meerholz, K.; King, S.; Monkman, A. P.; Frohlich, N.; H


POXINAR Membrane Family for Gas Separation | Industrial

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