High performance ladder polymers for membrane gas separation.

Abstract

Disclosed herein are ladder polymers containing fused aromatic and non-aromatic rings. Also disclosed are the preparation of these ladder polymers and their use in separation membranes, such as membranes for gas separation. The ladder polymers of the disclosed embodiments are useful as materials for several applications, including membranes for the separation of gases or other liquids or dissolved materials. Thus, embodiments include membranes for the separation of gases or other liquids or dissolved materials, comprising one or more ladder polymers of the disclosed embodiments.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Patent Application No. 62 / 926,004, filed October 25, 2019, the contents of which are incorporated herein in their entirety.

[0002] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with Government support under Contract W911NF-16-1-0018 awarded by the U.S. Army Research Laboratory and under Contract FELLOWSHIP-DGE-156518 awarded by the National Science Foundation. The Government has certain rights in this invention. [Background technology]

[0003] background Separation of industrial chemicals accounts for about 10% of global energy consumption, and improved energy-efficient separation technologies are urgently needed. Compared with separation techniques such as distillation and absorption, membrane-based separation can be up to about 10 times more energy efficient. However, the widespread adoption of membrane-based separation has been constrained by two major challenges: the permeability / selectivity trade-off and plasticization.

[0004] An optimal membrane material for gas separation should have both high permeability and high selectivity. Permeability is a measure of the productivity of the membrane. A membrane with high permeability requires less material and therefore has a smaller footprint. Selectivity is a measure of how effectively the membrane material can separate gas mixtures. In the context of natural gas purification, which primarily involves the separation of CO2 from CH4, membranes with high selectivity will result in higher CH4 recovery. However, there is often a trade-off between permeability and selectivity, such that membranes with high permeability are typically less selective and vice versa. This trade-off is specified by Robeson's upper limit. Polymer membranes that can exceed Robeson's upper limit are extremely rare, although they have great potential as next-generation materials.

[0005] Efforts to design polymeric materials capable of exceeding the upper limit have been primarily focused on the synthesis of polymers containing ladder motifs, called inherently microporous polymers (PIMs). Some PIMs have exceeded the upper limit due to their exceptionally high permeability, but their selectivity remains low (CO2 / CH4 < ca. 40) even after long-term aging.

[0006] Plasticization is another challenge to be overcome for membrane separations. High pressure feed streams (> about 10 atm) are often used for industrial gas separations. Under these conditions, high concentrations of gas molecules sorb to the membrane, leading to membrane softening and thus increased permeability and simultaneously decreased selectivity.

[0007] It is against this background that the need arose to develop the embodiments described herein. Summary of the Invention [Means for solving the problem]

[0008] Summary of the Disclosure Certain aspects of the present disclosure include: [ka] wherein X is selected from an alkylene group, —[O]—, —[S]—, a nitrogen-containing group, and a cyclic group; 1 and Y 2 are independently selected from alkyl groups; R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 is independently selected from a hydride group, an alkyl group, an aryl group, a heterocyclic group, a halogen group, a group containing an -O- moiety, a group containing an -O(CO)- moiety, a group containing an -O(CO)O- moiety, a group containing an -O(CO)N< moiety, a group containing an -S- moiety, a group containing a -B< moiety, a -NO2, a group containing a -N< moiety, a group containing a -P< moiety, a group containing a -(PO)< moiety, a -CHO, a group containing a -(CO)- moiety, a group containing a -(CO)O- moiety, a group containing a -(CO)N< moiety, and a group containing a -Si≡ moiety; X 1 -[O]-, -[S]-, -[B(O)R a ]-, -[NR a ]-, -[P(O)R a ]-, -[(PO)(O)R a ]-, -[CO]-, -[CR a R b ]-, -[C(O)R a (O)R b ]-, and -[Si(O)R a (O)R b ]-, R a and R b are independently selected from hydride groups, alkyl groups, aryl groups, and heterocyclic groups. 1 =Y 2 and X 1 is -[CH2]-, and R 1 =R 2 =R 3 =R 4 =R 5 =R 6 = a hydride group. In some embodiments, the ladder polymer is [ka] wherein n is an integer greater than 1. In some embodiments, the ladder polymer is represented by: [ka] [In the formula, [ka] and n is an aromatic group, and n is an integer greater than 1. In some embodiments, the ladder polymer is represented by: [ka] [wherein n is an integer greater than 1].

[0009] Additional embodiments include [ka] [In the formula, R 1 and R 2 is independently selected from a hydride group, an alkyl group, an aryl group, a heterocyclic group, a halogen group, a group containing an -O- moiety, a group containing an -O(CO)- moiety, a group containing an -O(CO)O- moiety, a group containing an -O(CO)N< moiety, a group containing an -S- moiety, a group containing a -B< moiety, a -NO2, a group containing a -N< moiety, a group containing a -P< moiety, a group containing a -(PO)< moiety, a -CHO, a group containing a -(CO)- moiety, a group containing a -(CO)O- moiety, a group containing a -(CO)N< moiety, and a group containing a -Si≡ moiety; X 1 -[O]-, -[S]-, -[B(O)R a ]-, -[NR a ]-, -[P(O)R a ]-, -[(PO)(O)R a ]-, -[CO]-, -[CR a R b ]-, -[C(O)R a (O)R b ]-, and -[Si(O)R a (O)R b ]-, Ra and R b are independently selected from hydride groups, alkyl groups, aryl groups, and heterocyclic groups. 1 =R 2 = a hydride group, X 1 is -[CH2]-. In some embodiments, the ladder polymer is [ka] wherein n is an integer greater than 1. In some embodiments, the ladder polymer is represented by: [ka] [In the formula, Y 1 and Y 2 are independently selected from alkyl groups; R 1 , R 2 , R 3 , and R 4 is independently selected from a hydride group, an alkyl group, an aryl group, a heterocyclic group, a halogen group, a group containing an -O- moiety, a group containing an -O(CO)- moiety, a group containing an -O(CO)O- moiety, a group containing an -O(CO)N< moiety, a group containing an -S- moiety, a group containing a -B< moiety, a -NO2, a group containing a -N< moiety, a group containing a -P< moiety, a group containing a -(PO)< moiety, a -CHO, a group containing a -(CO)- moiety, a group containing a -(CO)O- moiety, a group containing a -(CO)N< moiety, and a group containing a -Si≡ moiety; X 1 and X 2 are independently -[O]-, -[S]-, -[B(O)R a ]-, -[NR a ]-, -[P(O)R a ]-, -[(PO)(O)R a ]-, -[CO]-, -[CR a R b ]-, -[C(O)R a (O)R b ]-, and -[Si(O)R a (O)R b ]-, R a and Rb are independently selected from a hydrido group, an alkyl group, an aryl group, and a heterocyclic group. 1 =R 2 =R 3 =R 4 = a hydride group, X 1 =X 2 =-[CH2]-, Y 1 =Y 2 =-CH3. In some embodiments, the ladder polymer is [ka] [wherein n is an integer greater than 1].

[0010] Additional embodiments include membranes for gas separation comprising the ladder polymer of any of these embodiments. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 shows the structure and 1H-NMR of CANAL-Me-DMF.

[0012] [Diagram 2] FIG. 2 shows the structure and 1H-NMR of CANAL-Me-S5F.

[0013] [Diagram 3] FIG. 3 shows the structure and 1H-NMR of CANAL-Me-S6F.

[0014] [Figure 4] Figure 4(a) shows the simulated structures of the ribbon-like 2D polymer CANAL-Me-iPr (top) and the 3D polymer CANAL-Me-DMF (bottom). Figure 4(b) shows the synthesis of 3D CANAL-fluorene and dihydrophenanthrene polymers. Figure 4(c) shows a photograph of a 50 μm CANAL-Me-DMF film.

[0015] [Figure 5-1] Figure 5(a) shows the N2 sorption isotherms at 77 K for CANAL-Me-DMF and CANAL-Me-iPr. Figure 5(b) shows the pore size distribution derived from the N2 sorption isotherms using a heterogeneous surface model of carbon slit-like pores by NLDFT. Figure 5(c) shows the wide-angle X-ray scattering of CANAL-Me-DMF, CANAL-Me-S5F, CANAL-Me-S6F, CANAL-Me-DHP, and CANAL-Me-iPr films. [Figure 5-2] Figure 5(a) shows the N2 sorption isotherms at 77 K for CANAL-Me-DMF and CANAL-Me-iPr. Figure 5(b) shows the pore size distribution derived from the N2 sorption isotherms using a heterogeneous surface model of carbon slit-like pores by NLDFT. Figure 5(c) shows the wide-angle X-ray scattering of CANAL-Me-DMF, CANAL-Me-S5F, CANAL-Me-S6F, CANAL-Me-DHP, and CANAL-Me-iPr films.

[0016] [Figure 6-1] Figure 6 shows the pure gas permeation properties of CANAL-Me-DMF, CANAL-Me-S5F, CANAL-Me-S6F, and CANAL-Me-DHP for H2 / CH4 2015 (a), CO2 / CH4 2008 (b), H2 / N2 2015 (c), and O2 / N4 2015 (d) upper limits. State-of-the-art PIMs are plotted for their performance after aging (aging period is described in days). Film thickness and test conditions of CANAL polymers: 50-60 μm, T=35 °C, p=1 bar. [Figure 6-2]Figure 6 shows the pure gas permeation properties of CANAL-Me-DMF, CANAL-Me-S5F, CANAL-Me-S6F, and CANAL-Me-DHP for H2 / CH4 2015 (a), CO2 / CH4 2008 (b), H2 / N2 2015 (c), and O2 / N4 2015 (d) upper limits. State-of-the-art PIMs are plotted for their performance after aging (aging period is described in days). Film thickness and test conditions of CANAL polymers: 50-60 μm, T=35 °C, p=1 bar.

[0017] [Figure 7] Figure 7(a) shows the loss of H2 permeability and Figure 7(b) shows the loss of CO2 permeability from aging trends for CANAL-Me-DMF, CANAL-Me-S5F, CANAL-Me-S6F, CANAL-Me-DHP, and some recently reported ladder PIMs. The dashed lines indicate that the percentage increase in selectivity is equal to the percentage loss in permeability.

[0018] [Figure 8] Figure 8(a) shows the mixed gas permeation properties of CANAL-Me-DMF at 35 °C (50 μm, aged for 190 days). Pure gas (p=1 bar, filled circles), variable composition CO2 / CH4 mixed gas (total pressure=2 bar, 20-80% CO2, open circles), and variable pressure 50 / 50 CO2 / CH4 mixed gas permeation results (total pressure=3-27 bar, open diamonds) are shown for the 2008 pure gas (Robeson, LM, J. Membr. Sci. 2008, 320 (1), 390-400) and 2018 mixed gas (Wang, et al., Mater. Today Nano 2018, 3, 69-95) upper limits. FIG. 8(b) shows the permeability of CO2 (circles) and CH4 (diamonds) under a 50 / 50 CO2 / CH4 mixture at varying pressures.

[0019] [Figure 9]Figure 9 shows the pure gas permeation properties of CANAL-Me-DMF and CANAL-Me-iPr for the 2008 CO2 / CH4 (a) and 2015 H2 / N2 (b) upper limits. Film thickness = 100 μm.

[0020] [Figure 10] FIG. 10 shows the diffusion activation energies for gases in CANAL-Me-iPr and CANAL-Me-DMF after aging for 16 days (open squares) and 55 days (filled circles).

[0021] [Figure 11] Figure 11a shows the GPC trace of the CANAL polymer, Figure 11b shows the TGA trace of CANAL-Me-iPr and CANAL-Me-DMF, and Figure 11c shows the tensile properties of CANAL-Me-DMF and CANAL-Me-DHP. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Detailed Description In some embodiments, the ladder polymer has the following chemical formula: [ka] [Wherein, two adjacent * teeth, [ka] The binding to the two asterisks in * is R 3 and R 4 Examples of compounds of formula (1) include: [ka] Examples include:

[0023] In formula (1), X can be a bridging moiety, for example, an alkylene group (including substituted and unsubstituted, and halogenated and non-halogenated alkylene groups), such as -[CH2]-, -[C(CH3)2]-, and -[C(CF3)2]-, -[O]-, -[S]-, nitrogen-containing groups, such as -[N-butyloxycarbonyl]-, -[N-acetate]-, -[N(CH3)]-, and -[NC(CH3)3]-, cyclic groups (including substituted and unsubstituted, and aromatic and non-aromatic cyclic groups), such as [ka] and other groups containing at least one oxygen atom, at least one sulfur atom, at least one nitrogen atom, or at least one carbon atom.

[0024] In formula (1), Y 1 and Y 2 may be the same or different and independently selected from alkyl groups (including substituted and unsubstituted, and halogenated and non-halogenated alkyl groups), e.g., substituents such as -CH, -CHCH, -CH(CH), and -C(CH).

[0025] In formula (1), R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 may be the same or different and independently represent a hydride group, an alkyl group (including substituted and unsubstituted, and halogenated and non-halogenated alkyl groups), an aryl group (including substituted and unsubstituted aryl groups), a heterocyclic group (including substituted and unsubstituted heterocyclic groups), a halogen group, -OR a (or other groups containing the -O- moiety), -O(CO)R a (or other groups containing the -O(CO)- moiety), -O(CO)OR a (or other groups containing the -O(CO)O- moiety), -O(CO)NR a R b(or other groups containing the -O(CO)N< moiety), -SR a (or other group containing the -S- moiety), -B(O)R a (O)R b (or other groups containing the -B< moiety), -NO2, -NR a R b (or other groups containing the -N< moiety), -P(O)R a (O)R b (or other groups containing the -P< moiety), -PO(O)R a (O)R b (or other groups containing the -(PO)< moiety), -CHO, -(CO)R a (or other groups containing a -(CO)- moiety), -(CO)OR a (or other groups containing the -(CO)O- moiety), -(CO)NR a R b (or other groups containing the -(CO)N< moiety), and -Si(O)R a (O)R b (O)R c (or other groups containing a -Si≡ moiety), 1 is a bridging moiety, e.g., -[O]-, -[S]-, -[B(O)R d ]-, -[NR d ]-, -[P(O)R d ]-, -[(PO)(O)R d ]-, -[CO]-, -[CR d R e ]-, -[C(O)R d (O)R e ]-, -[Si(O)R d (O)R e ]-, and at least one oxygen atom, at least one sulfur atom, at least one boron atom, at least one nitrogen atom, at least one phosphorus atom, or other group containing at least one carbon atom; R a , R b , R c , R d , and R emay be the same or different and independently selected from substituents such as hydrido groups, alkyl groups (including substituted and unsubstituted alkyl groups), aryl groups (including substituted and unsubstituted aryl groups), and heterocyclic groups (including substituted and unsubstituted heterocyclic groups).

[0026] In some embodiments, the molecular weight of the polymer (M W ) is from about 50 to about 250 kDa, for example from about 70 to about 170 kDa, as determined by GPC MALLS.

[0027] An example of a ladder polymer given by formula (1) is represented by the following chemical formula (or a positional isomer thereof): [ka] As mentioned above, the positional isomers of formula (2) may contain one or more cyclobutyls, e.g., * This includes cases where the carbon atom is positionally shifted to an adjacent carbon atom represented by: [ka]

[0028] In formula (2), X is selected from the bridging moieties as described above for formula (1), and Y 1 =Y 2 =Y, which is selected from the substituents as described above for formula (1); X 1 is -[CH2]-, and R 1 =R 2 =R 3 =R 4 =R 5 =R 6 = a hydride group, and n is an integer greater than 1, e.g., 2 or greater, 3 or greater, 4 or greater, 5 or greater, 10 or greater, 20 or greater, 50 or greater, or 100 or greater.

[0029] In some embodiments, the ladder polymer of formula (2) is synthesized by reacting a dihalo (e.g., dibromo)fluorene derivative with norbornadiene via a catalytic arene-nobornene cyclization reaction (e.g., in the presence of a palladium catalyst) to form a fluorenedinorbornene, followed by polymerization with a dihalo (e.g., dibromo)benzene disubstituted with Y to form the ladder polymer.

[0030] Another example of a ladder polymer given by formula (1) is represented by the following chemical formula (or a positional isomer thereof): [ka] As stated above, positional isomers of formula (3) include those in which one or more cyclobutyls are positionally shifted, for example, to adjacent carbon atoms.

[0031] In formula (3), X is selected from the bridging moieties as described above for formula (1), and Y 1 =Y 2 =Y, which is selected from the substituents as described above for formula (1); X 1 is -[CH2]-, and R 1 =R 2 =R 3 =R 4 =R 5 =R 6 = a hydride group, and n is an integer greater than 1, e.g., 2 or more, 3 or more, 4 or more, 5 or more, 10 or more, 20 or more, 50 or more, or 100 or more; [ka] or other aromatic groups (including substituted and unsubstituted, and halogenated and non-halogenated).

[0032] In some embodiments, the ladder polymer of formula (3) is synthesized by reacting a dihalo (e.g., dibromo)fluorene derivative with norbornadiene via a catalytic arene-norbornene cyclization reaction (e.g., in the presence of a palladium catalyst) to form a fluorene dinorbornene, followed by reaction with a halo (e.g., bromo), aminobenzene disubstituted with Y to form a fluorene norbornyl benzocyclobutene diamine, followed by polymerization with a dianhydride to form the ladder polymer.

[0033] Further examples of ladder polymers given by formula (1) are represented by the following chemical formulas (or positional isomers thereof): [ka] As stated above, positional isomers of formula (4) include those in which one or more cyclobutyls are positionally shifted, for example, to adjacent carbon atoms.

[0034] In formula (4), X is selected from the bridging moieties as described above for formula (1), and Y 1 =Y 2 =Y, which is selected from the substituents as described above for formula (1); X 1 is -[CH2]-, and R 1 =R 2 =R 3 =R 4 =R 5 =R 6 = a hydride group, and n is an integer greater than 1, e.g., 2 or greater, 3 or greater, 4 or greater, 5 or greater, 10 or greater, 20 or greater, 50 or greater, or 100 or greater.

[0035] In some embodiments, the ladder polymer of formula (4) is synthesized by reacting a dihalo (e.g., dibromo)fluorene derivative with norbornadiene via a catalytic arene-norbornene cyclization reaction (e.g., in the presence of a palladium catalyst) to form a fluorenedinorbornene, followed by reaction with a halo (e.g., bromo), aminobenzene disubstituted with Y to form a fluorenenorbornylbenzocyclobutene diamine, followed by polymerization with dimethoxymethane to form the ladder polymer.

[0036] In additional embodiments, the ladder polymer comprises multiple moieties each represented by the following formula (or a positional isomer thereof): [ka]

[0037] In formula (5), R 1 and R 2 may be the same or different and independently represent a hydride group, an alkyl group (including substituted and unsubstituted, and halogenated and non-halogenated alkyl groups), an aryl group (including substituted and unsubstituted aryl groups), a heterocyclic group (including substituted and unsubstituted heterocyclic groups), a halogen group, -OR a (or other groups containing the -O- moiety), -O(CO)R a (or other groups containing the -O(CO)- moiety), -O(CO)OR a (or other groups containing the -O(CO)O- moiety), -O(CO)NR a R b (or other groups containing the -O(CO)N< moiety), -SR a (or other group containing the -S- moiety), -B(O)R a (O)R b (or other groups containing the -B< moiety), -NO2, -NR a R b (or other groups containing the -N< moiety), -P(O)R a (O)R b (or other groups containing the -P< moiety), -PO(O)R a (O)Rb (or other groups containing the -(PO)< moiety), -CHO, -(CO)R a (or other groups containing a -(CO)- moiety), -(CO)OR a (or other groups containing the -(CO)O- moiety), -(CO)NR a R b (or other groups containing the -(CO)N< moiety), and -Si(O)R a (O)R b (O)R c (or other groups containing a -Si≡ moiety), 1 is a bridging moiety, e.g., -[O]-, -[S]-, -[B(O)R d ]-, -[NR d ]-, -[P(O)R d ]-, -[(PO)(O)R d ]-, -[CO]-, -[CR d R e ]-, -[C(O)R d (O)R e ]-, -[Si(O)R d (O)R e ]-, and at least one oxygen atom, at least one sulfur atom, at least one boron atom, at least one nitrogen atom, at least one phosphorus atom, or other group containing at least one carbon atom; R a , R b , R c , R d , and R e may be the same or different and independently selected from substituents such as hydrido groups, alkyl groups (including substituted and unsubstituted alkyl groups), aryl groups (including substituted and unsubstituted aryl groups), and heterocyclic groups (including substituted and unsubstituted heterocyclic groups).

[0038] An example of a ladder polymer given by formula (5) is represented by the following chemical formula (or a positional isomer thereof): [ka]

[0039] In formula (6), R 1 =R 2 = a hydride group, X 1 is -[CH2]-, and n is an integer greater than 1, e.g., 2 or more, 3 or more, 4 or more, 5 or more, 10 or more, 20 or more, 50 or more, or 100 or more.

[0040] In some embodiments, the ladder polymer of formula (6) is synthesized by reacting a 1,4 dihalo (e.g., dibromo) durene with norbornadiene to form a dinorbornene, followed by polymerization with a dihalo (e.g., dibromo) substituted durene via a catalytic arene-norbornene cyclization reaction (e.g., in the presence of a palladium catalyst) to form the ladder polymer.

[0041] In a further embodiment, the ladder polymer comprises multiple moieties each represented by the following formula (or a positional isomer thereof): [ka]

[0042] In formula (7), Y 1 and Y 2 may be the same or different and independently selected from alkyl groups (including substituted and unsubstituted, and halogenated and non-halogenated alkyl groups), e.g., substituents such as -CH, -CHCH, -CH(CH), and -C(CH).

[0043] In formula (7), R 1 , R 2 , R 3 , R 4 R 5 , R 6 , R 7 and R 8may be the same or different and independently represent a hydride group, an alkyl group (including substituted and unsubstituted, and halogenated and non-halogenated alkyl groups), an aryl group (including substituted and unsubstituted aryl groups), a heterocyclic group (including substituted and unsubstituted heterocyclic groups), a halogen group, -OR a (or other groups containing the -O- moiety), -O(CO)R a (or other groups containing the -O(CO)- moiety), -O(CO)OR a (or other groups containing the -O(CO)O- moiety), -O(CO)NR a R b (or other groups containing the -O(CO)N< moiety), -SR a (or other group containing the -S- moiety), -B(O)R a (O)R b (or other groups containing the -B< moiety), -NO2, -NR a R b (or other groups containing the -N< moiety), -P(O)R a (O)R b (or other groups containing the -P< moiety), -PO(O)R a (O)R b (or other groups containing the -(PO)< moiety), -CHO, -(CO)R a (or other groups containing a -(CO)- moiety), -(CO)OR a (or other groups containing the -(CO)O- moiety), -(CO)NR a R b (or other groups containing the -(CO)N< moiety), and -Si(O)R a (O)R b (O)R c (or other groups containing a -Si≡ moiety), 1 and X 2 may be the same or different and independently represent a bridging moiety, e.g., -[O]-, -[S]-, -[B(O)R d ]-, -[NR d ]-, -[P(O)R d ]-, -[(PO)(O)R d ]-, -[CO]-, -[CR d R e ]-, -[C(O)Rd (O)R e ]-, -[Si(O)R d (O)R e ]-, and at least one oxygen atom, at least one sulfur atom, at least one boron atom, at least one nitrogen atom, at least one phosphorus atom, or other group containing at least one carbon atom; R a , R b , R c , R d , and R e may be the same or different and independently selected from substituents such as hydrido groups, alkyl groups (including substituted and unsubstituted alkyl groups), aryl groups (including substituted and unsubstituted aryl groups), and heterocyclic groups (including substituted and unsubstituted heterocyclic groups).

[0044] In some embodiments, the compound of formula (7) is [ka] It is.

[0045] An example of a ladder polymer given by formula (7) is represented by the following chemical formula (or a positional isomer thereof): [ka]

[0046] In formula (8), R 1 =R 2 =R 3 =R 4 = a hydride group, X 1 =X 2 =-[CH2]-, Y 1 =Y 2=-CH3, and n is an integer greater than 1, e.g., 2 or greater, 3 or greater, 4 or greater, 5 or greater, 10 or greater, 20 or greater, 50 or greater, or 100 or greater. In some embodiments, the ladder polymer of formula (8) is synthesized by reacting 1,4 dihalo (e.g., dibromo) durene with norbornadiene to form a dinorbornene, followed by polymerization with a dihalo (e.g., dibromo) substituted xylene via a catalytic arene-norbornene cyclization reaction (e.g., in the presence of a palladium catalyst) to form the ladder polymer.

[0047] In a further embodiment, the ladder polymer comprises multiple moieties each represented by the following formula (or a positional isomer thereof): [ka] For example, this formula may be used in the following chemical formula: [ka] [In the formula, R is R for formula (1) 1 and n is an integer greater than 1, e.g., 2 or greater, 3 or greater, 4 or greater, 5 or greater, 10 or greater, 20 or greater, 50 or greater, or 100 or greater.

[0048] The ladder polymers of the present disclosure are useful as materials for several applications, including membranes for the separation of gases or other liquids or dissolved materials. Thus, embodiments include membranes for the separation of gases or other liquids or dissolved materials, comprising one or more ladder polymers of an embodiment of the present disclosure. In some embodiments, the one or more ladder polymers are in the form of a membrane. In some embodiments, the membrane is about 20 to about 200 μm thick, for example, about 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200 μm thick. EXAMPLES

[0049] The following examples describe specific aspects of some embodiments of the present disclosure to illustrate and provide a description for those skilled in the art. The examples should not be construed as limiting the present disclosure, as they merely provide specific methodologies useful in understanding and practicing some embodiments of the present disclosure.

[0050] Characterization methods. 1 H and 13 C NMR experiments were performed in CDCl3 using a Varian Mercury 400. Chemical shifts are reported in ppm using residual protiated solvent as internal standard (CHCl3 1 H: 7.26 ppm and 13C: 77.00 ppm). Data are reported as chemical shift, multiplicity (s = singlet, m = multiplet, br = broad signal, and related combinations), and integrals as follows: Gel permeation chromatography (GPC) was performed in THF on two PolyPore columns (Agilent) in series with a DAWN multi-angle laser light scattering (MALLS) detector and an Optilab T-rEX differential refractometer (both from Wyatt Technology). No calibration standards were used, and dn / dc values ​​were obtained for each injection by assuming 100% mass elution from the column. Electron ionization (EI) mass spectrometry was performed on an Agilent (HP) 7890 / 5975 single quadrupole GC-MS system. Thermogravimetric analysis (TGA) was performed on a TA instruments TGA550 under nitrogen flowing at 25 mL / min. Samples were heated from 30 to 600 °C at 10 °C / min. The polymer film density was determined using a Mettler Toledo analytical balance density kit. Deionized water was used as the buoyant liquid since the hydrophobic nature of the hydrocarbon ladder polymer prevents water uptake. The FFV was calculated using the Bondi group contribution method. 1 Wide-angle X-ray scattering (WAXS) experiments were carried out under vacuum on a system including an Osmic staggered parabolic multilayer optics with a Rigaku 002 Cu microfocus X-ray source. The WAXS instrument is equipped with a Dectris Pilatus 300K detector.

[0051] Materials. HPLC grade tetrahydrofuran (THF) was purchased from a commercial supplier, transferred to a glove box after sparging with nitrogen, and used for the polymerization reactions. All other reagents were obtained from commercial suppliers and used as received. 2',7'-Dibromo-spiro(cyclohexane-1,9'-fluorene), 2',7'-dibromo-spiro(cyclopentane-1,9'-fluorene), and 2,7-dibromo-9,10-dihydrophenanthrene were synthesized according to literature procedures.

[0052] General procedure for the synthesis of dinorbornenes. Synthesized according to our previously reported procedure. To a flame-dried glass pressure tube, aryl dibromide (1 equiv.), Pd(OAc)2 (0.04 equiv.), and PPh3 (0.08 equiv.) were added. The tube was transferred to a nitrogen-filled glove box and Cs2CO3 (2 equiv.), norbornadiene (10 equiv.), and 1,4-dioxane (1 mL / mmol of aryl dibromide) were added. The tube was then sealed with a Teflon cap and removed from the glove box. The mixture was stirred at 150° C. for 48 h, then cooled to room temperature and then passed through Celite to remove inorganic salts, which was washed with CHCl3 (3×15 mL). The filtered solution was concentrated and purified by silica chromatography to give the dinorbornene as a mixture of syn and anti isomers. Synthesis and permeation experiments

[0053] This example reports the synthesis and characterization of a five-membered ring-containing norbornylbenzocyclobutene (NBC) ladder polymer that performs above the Robeson upper limit for multiple industrially relevant gas pairs and is plasticization resistant at high CO2 pressures. This material has nearly three orders of magnitude higher permeability, exceeding approximately twice the ideal selectivity of industrial membranes such as cellulose acetate. This material also has the highest selectivity for CO2 / CH4, H2 / CH4, H2 / N2, and H2 / CO2 of any ladder polymer reported to date.

[0054] Two types of NBC ladder polymers containing five-membered rings are reported: fluorene- and norbornylbenzocyclopentene-containing NBC ladder polymers. Fluorene NBC ladder polymers can be synthesized in two steps. First, dibromofluorene derivatives are reacted with norbornadiene via catalytic arene-norbornene cyclization (CANAL) to form fluorene-dinorbornenes, which are subsequently polymerized with dialkyldibromobenzenes to form ladder polymers (fluorene NBC ladders, Scheme 1). Fluorene NBC diamines are also synthesized, which can then be polymerized with dimethoxymethane or dianhydrides to obtain Troger's base polymers (fluorene NBC TB, Scheme 1) or polyimides (fluorene NBC PI, Scheme 1), respectively. The synthesis of norbornylbenzocyclopentene-containing NBC polymers involves benzylic activation of 1,4-dibromodurene to give dinorbornenes, followed by CANAL polymerization (Scheme 2). [ka] [ka]

[0055] We synthesized CANAL-Me-DMF, an example of a fluorene NBC ladder polymer. Its chemical structure and 1 The 1 H-nuclear magnetic resonance (NMR) spectrum is shown in FIG. DMF. [ka]

[0056] The reaction was carried out with 5 mmol of 2,7-dibromo-9,9-dimethylfluorene. Purification by silica chromatography using a mobile phase of 9 / 1 hexane / dichloromethane (DCM) afforded DMF as an off-white solid (1.1 g, 59%). 1H NMR (400 MHz, CDCl3) δ 7.43 (s, 1H), 7.41 (s, 1H), 7.15 (s, 1H), 7.14 (s, 1H), 6.25 (s, 4H), 3.16 (s, 4H), 2.83 (m, 4H), 1.53-1.39 (m, 6H), 1.34-1.25 (m, 2H), 0.95-0.99 (m, 2H); 13 C NMR (100 MHz, CDCl3) δ 153.1, 153.0, 145.1, 145.0, 144.7, 144.6, 138.9, 138.8, 136.94, 136.92, 136.90, 136.88, 116.54, 116.48, 113.22, 113.21, 47.07, 47.05, 46.84, 46.76, 46.7, 41.96, 41.95, 41.9, 41.64, 41.60, 28.2, 28.0, 27.7.EI-MS m / z C 29 H 26 + Calculated value: 374.2, actual value: 374.2. S5F. [ka]

[0057] The reaction was carried out with 1.5 mmol of 2',7'-dibromo-spiro(cyclopentane-1,9'-fluorene). Purification by silica chromatography using a mobile phase of 19 / 1 hexane / DCM gave S5F as an off-white solid (360 mg, 75%). 1 H NMR (600 MHz, CDCl3) δ 7.70-7.38 (m, 2H), 7.13-7.12 (m, 2H), 6.25 (s, 4H), 3.15-3.14 (m, 4H), 2.83-2.81 (m, 4H), 2.13-2.02 (m, 8H), 1.31-1.29 (m, 2H), 0.99-0.96 (m, 2H); 13C NMR (150 MHz, CDCl3): δ 153.74, 153.70, 145.15, 145.04, 144.23, 144.17, 138.99, 138.95, 136.77, 136.75, 136.71, 136.69, 116.61, 116.56, 112.65, 112.64, 57.52, 57.49, 46.95, 46.92, 46.64, 41.82, 41.80, 41.75, 41.74, 41.46, 41.43, 40.69, 40.24, 39.82, 27.14, 27.09, 27.05. S6F. [ka]

[0058] The reaction was carried out with 2.5 mmol of 2',7'-dibromo-spiro(cyclohexane-1,9'-fluorene). Purification by silica chromatography using a mobile phase of 19 / 1 hexane / DCM gave S6F as an off-white solid (490 mg, 47%). 1 H NMR (600 MHz, CDCl3) δ 7.45-7.43 (m, 2H), 7.38-7.37 (m, 2H), 6.26 (s, 4H), 3.18-3.17 (m, 4H), 2.84-2.82 (m, 4H), 7.96-1.88 (m, 4H), 1.79-1.68 (m, 6H), 1.32-1.28 (m, 2H), 0.99-0.96 (m, 2H); 13C NMR (150 MHz, CDCl3): δ 152.53, 152.50, 144.39, 144.37, 144.32, 139.19, 139.15, 136.77, 136.75, 136.74, 136.72, 118.19, 118.13, 112.91, 112.89, 49.94, 49.40, 47.00, 16.98, 46.65, 41.84, 41.83, 41.76, 41.74, 41.52, 41.49, 36.60, 36.17, 35.75, 25.70, 22.8., 22.77, 22.71. DHP. [ka]

[0059] The reaction was carried out with 5.4 mmol of 2,7-dibromo-9,10-dihydrophenanthrene. Purification by silica chromatography using a mobile phase of 19 / 1 hexane / DCM, followed by recrystallization in hexane gave DHP as an off-white solid (660 mg, 34%). 1 H NMR (400 MHz, CDCl3) δ 7.45-7.43 (m, 2H), 6.94-6.93 (m, 2H), 6.23 (s, 4H), 3.18-3.15 (m, 4H), 2.81-2.80 (m, 8H), 1.54-1.32 (m, 2H), 1.32-1.26 (m, 2H); 13 C NMR (100 MHz, CDCl3): δ 144.82, 144.72, 136.82, 136.75, 136.69, 136.67, 134.75, 121.44, 121.39, 117.44, 47.32, 47.27, 41.70, 41.47, 41.44, 30.26.

[0060] General procedure for the synthesis of CANAL polymers. To a flame-dried glass pressure tube was added dinorbornene (0.5 mmol), p-dibromo-p-xylene (132 mg, 0.5 mmol), Pd(OAc)2 (2.2 mg, 0.01 mmol), and PPh3 (5.2 mg, 0.02 mmol). The tube was transferred to a nitrogen-filled glove box and Cs2CO3 (326 mg, 1 mmol), butylated hydroxytoluene (1 mg), and THF (1 mL) were added. The tube was then sealed with a Teflon cap and removed from the glove box. The mixture was stirred at 150 °C for 24 h, then cooled to room temperature, 10 mL of CHCl3 was added, and the mixture was stirred at 70 °C for 30 min. The mixture was then centrifuged and the supernatant was filtered through Celite, concentrated, and precipitated into ethyl acetate. The solid was dried in vacuum, dissolved in CHCl3, and then precipitated in methanol to give the polymer as an off-white solid. CANAL-Me-DMF [ka]

[0061] Off-white solid (200 mg, 76%). 1 H NMR (400 MHz, CDCl3) δ 7.29 (br, s, 2H), 7.01 (br, s, 2H), 3.24-3.13 (br, s, 8H), 2.34 (br, s, 4H), 2.02 (br, s, 6H), 1.39 (br, s, 6H), 0.71 (br, s, 4H). GPC MALLS M n = 48 kDa, M w = 99 kDa. CANAL-Me-S5F [ka]

[0062] Off-white solid (230 mg, 100%). 1GPC MALLS M n = 38 kDa, M w = 100 kDa. CANAL-Me-S6F [ka]

[0063] Off-white solid (170 mg, 70%). 1 GPC MALLS M n = 23 kDa, M w = 67 kDa. CANAL-Me-DHP [ka]

[0064] The reaction was carried out with 0.36 mmol of monomer to give CNAAL-Me-DHP as an off-white solid (100 mg, 68%). 1 H NMR (500 MHz, CDCl3) δ 7.30 (s, 2H), 6.81 (s, 2H), 3.26 (s, 4H), 3.12 (s, 4 H), 2.75 (s, 4H), 2.33 (s, 4H), 2.02 (s, 6H), 0.80-0.72 (m, 4H). GPC MALLS M n = 75 kDa, M w = 170 kDa.

[0065] Polymer Film Formation. For a typical polymer casting, 100 mg of polymer was dissolved in 6 g of chloroform (approximately 2 wt% solution) and the solution was transferred to a flat 5 cm Petri dish containing a Norton® fluorinated ethylene propylene liner (WELCH Fluorocarbon, Inc.). The Petri dish was covered with a watch glass to slow evaporation. The solvent evaporated in 1-2 days to form a flat film.

[0066] Pure gas permeation experiments and analysis. Experiments were carried out in a constant volume variable pressure apparatus at 35° C. and 1 bar upstream pressure unless otherwise stated. Prior to the permeation experiments, the polymer films were either heated under vacuum at 120° C. for 24 hours or heated under vacuum at 120° C. for 24 hours and then immersed in liquid methanol for 24 hours. The films were then masked with epoxy on brass supports and further degassed in the permeation apparatus at 35° C. under high vacuum (<0.02 Torr) for 8 hours. Variable temperature pure gas permeation experiments were carried out at 25, 35, 45, and 55° C.

[0067] The gas permeability, P, was determined using the following equation:

number

number

number

number

number

number

[0068] The ideal permselectivity (α) of a gas pair A / B is defined as follows: α=P A / P B (S2) In the formula, P A and P B are the permeability coefficients of gases A and B, respectively. The ideal diffusivity and solubility selectivity of the gas pair A / B are defined by Equations 5 and 6, respectively. α D =P A / P B (S3)

number

[0069] After CANAL-Me-DMF films were cast from chloroform solution, they were either heated to about 120°C for about 24 hours (Figure 9) or treated in liquid methanol for about 24 hours and then air-dried (red circles, Figure 6). After aging, CANAL-Me-DMF films showed high permeability for H2, CO2, and O2, and exceptionally high permselectivity for H2 / CH4, H2 / N2, O2 / N2, H2 / CO2, and CO2 / CH4 (Table 1). The combination of high permeability and high permselectivity allows CANAL-Me-DMF to comfortably exceed the 2008 Robeson upper limits for H2 / CO2 and CO2 / CH4, and the 2015 upper limits for H2 / CH4, H2 / N2, and O2 / N2 (Figure 6).

[0070] All of these CANAL polymers exhibited high BET surface areas, as calculated using their nitrogen sorption isotherms. Interestingly, a comparison of 3D CANAL polymers, such as CANAL-Me-DMF, with a representative 2D CANAL polymer, CANAL-Me-iPr, showed that both polymers had the same BET surface area of ​​770 m 2 g -1 Although the BET surface areas of the CANAL-Me-DMF were significantly higher at low pressures (p / p0 = 10), CANAL-Me-DMF consistently provided higher N2 sorption capacity at low pressures (p / p0 = 10). -6 ~10 -2 ) (inset in Fig. 5a), which indicates a larger total ultra-micropore volume as derived using a non-uniform surface model of carbon slit-like pores from non-local density functional theory (NLDFT) (Fig. 5b). Wide-angle X-ray scattering of these polymers showed the broad peak typically observed for PIMs due to the contrast between voids and polymer chains. The peak for CANAL-Me-DMF was shifted to a higher q region relative to that of CANAL-Me-iPr, which corresponds to a smaller average intersegment distance of 6.4 Å versus 7.7 Å for CANAL-Me-iPr (Fig. 5c).

[0071] Films of CANAL-fluorene and CANAL-DHP polymers were mechanically robust and showed no damage after repeated bending and twisting (Figure 4c). In contrast, films of 2D CANAL polymers were significantly more brittle, despite their higher MW. CANAL-Me-DMF and CANAL-Me-DHP exhibited Young's moduli of 0.72 GPa and 3.1 GPa, and elongations at break of 6% and 11%, respectively (Figure 11c). 3D CANAL polymers are thermally stable up to at least 350 °C without a detectable glass transition (Figure 11b). 50-60 μm thick films of all polymers can be readily prepared by casting from their chloroform solutions. After pre-treating the film using typical conditions for PIMs (heating in vacuum at 120°C for 24 hours, then soaking in methanol, then air drying) to remove any residual casting solvent and erase any history, we performed pure gas permeation experiments (T=35°C, p=1 bar) using the following gases in order: Ar, H2, CH4, N2, O2, and CO2. A fresh film of CANAL-Me-DMF showed high permeability but only moderate selectivity (Table 1). Surprisingly, upon aging, the separation performance of CANAL-Me-DMF improved dramatically. Physical aging is a process commonly observed for PIMs that reduces microporosity as the polymer chains become more densely packed. Aging of PIMs typically significantly reduces permeability and moderately increases selectivity, shifting performance parallel to or to the left of the upper limit. Remarkably, aging of CANAL-Me-DMF clearly moved its performance beyond the upper limit of the state-of-the-art for several industrially important gas pairs, such as H2 / CH4, H2 / N2, O2 / N2, and CO2 / CH4 (Fig. 6, Table 1).

[0072] Compared to polysulfone (PSF), a commonly used membrane polymer for H2 / CH4 separation, CANAL-Me-DMF is two orders of magnitude more permeable and three times more selective. For CO2 / CH4 separation, CANAL-Me-DMF offers two times more selectivity and 100 times more permeable than cellulose acetate (CA), a widely used commercial membrane. With an H2 permeability of >2000 barrer and an H2 / CH4 selectivity reaching nearly 200, the H2 / CH4 separation performance of aged CANAL-Me-DMF also far exceeds any other PIM, which typically has an H2 / CH4 selectivity of <50 (Figure 6a). Compared to PIM-BTrip, a PIM consisting of benzotriptycene and benzodioxane units, which performs above the 2015 H2 / CH4 upper limit, CANAL-Me-DMF is nearly four times more selective for H2 / CH4 (Table 1, Figure 6a). Aged CANAL-Me-DMF also showed exceptional CO2 / CH4 selectivity of about 50 and high CO2 permeability of about 600 barr. The CO2 / CH4 selectivity of aged CANAL-Me-DMF is about 50% higher than that of the state-of-the-art PIM-BTrip (Figure 6a). Most importantly, CANAL-Me-DMF meets the minimum CO2 / CH4 selectivity of 40 recommended for natural gas refining applications while maintaining high permeability for hundreds of barr.

[0073] Interestingly, the CANAL-fluorene polymers with cyclic substituents, CANAL-Me-S5F and CANAL-Me-S6F, as well as CANAL-Me-DHP, all exhibited similar ultra-high performance to CANAL-Me-DMF upon aging (Figures 6-7). Compared to the CANAL-fluorene polymers, CANAL-Me-DHP became more selective, reaching CO2 / CH4 and H2 / CH4 selectivities of 68 and 621, respectively, while still maintaining high CO2 and H2 permeabilities of 94 and 860 barrers, respectively, after 158 days (Table 1). Plotting the increase in selectivity against the loss in permeability after aging provides a direct visualization of the aging profiles among the various PIMs (Figure 7). The 3D CANAL polymers stood out from other PIMs reported in recent years for their favorable aging trends. The moderate loss in permeability for the 3D CANAL polymers is in the range observed for other PIMs in recent years, but the increase in selectivity for the 3D CANAL polymers is much larger. For example, the H2 / CH4 selectivity for CANAL-Me-DMF increased >20-fold upon aging compared to a <3-fold increase for SBF-PIM-1, consisting of spirobifluorene and dibenzodioxane units (Figure 7a), while their loss of H2 permeability was similar. For CO2 / CH4, the selectivity of the CANAL-fluorene polymers increased 4-5-fold upon aging compared to a <2-fold increase for other state-of-the-art PIMs (Figure 7b). Considering the non-polar hydrocarbon structure of the 3D CANAL polymers and thus the absence of polar gas-polymer interactions, the ultra-high selectivity of the polymers may be attributed to their extraordinary size sieving ability. [Table 1] [ka]

[0074] The exceptional gas separation performance of CANAL-Me-DMF is further demonstrated by CO2 / CH4 mixed gas permeation experiments. First, the CO2 / CH4 mixed gas permeation properties of CANAL-Me-DMF were evaluated with 20-80% CO2 at 2 bar total pressure (Figure 8a, open circles). For all three compositions, the selectivity remained at 49, compared to the ideal selectivity of 44 determined by pure gas experiments. The higher mixed gas selectivity is likely due to competitive sorption effects, suggesting no significant plasticization at CO2 partial pressures <2 bar. The decrease in CO2 permeability with increasing CO2 partial pressure can be explained by a dual-mode sorption model, which predicts that the solubility of gas in glassy polymers decreases with increasing pressure. Next, we evaluated the mixed gas permeation properties of CANAL-Me-DMF in 50 / 50 CO2 / CH4 at variable pressures. As the CO2 partial pressure increases from 1 bar to 14 bar, the permeabilities of both CO2 and CH4 first decrease, then both increase at CO2 partial pressures >8 bar (Figure 8b). The initial decrease in permeability is due to a combination of dual-mode and competitive sorption effects, both of which decrease the solubility of CO2 and CH4. However, as pressure continues to increase, plasticization, which increases the diffusivity of both gases, overcomes both the dual-mode and competitive sorption effects, resulting in an increase in CO2 and CH4 permeability, and a decrease in mixed gas selectivity. Despite plasticization, the CO2 / CH4 mixed gas selectivity remains >35 even at 14 bar CO2 partial pressure, bringing the mixed gas performance of CANAL-Me-DMF well above the 2018 mixed gas upper limit, and even above the 2008 pure gas upper limit. The unprecedented performance of CANAL-Me-DMF for CO2 / CH4 separation makes it particularly attractive for sweetening natural gas.

[0075] The same aging trend and greatly enhanced performance were not observed from the previously reported 2D CANAL polymer, suggesting a notable effect of the ladder chain conformation on aging and separation performance. CANAL-Me-iPr showed little or no increase in selectivity, but permeability decreased upon aging (Table 2, Figure 9). For example, the H2 / CH4 selectivity of CANAL-Me-iPr increased by only 25% after 55 days, while its H2 permeability decreased by 35%. In contrast, CANAL-Me-DMF showed a 650% increase in H2 / CH4 selectivity and only about 17% decrease in H2 permeability after the same aging period. The dramatically different aging profiles between 3D and 2D CANAL polymers immediately led us to investigate the origin of the improved selectivity for CANAL-Me-DMF. We determined the diffusion (D) and solubility (S) coefficients based on the dissolution-diffusion model (P=DS). As CANAL-Me-DMF aged, the solubility coefficient remained relatively constant, but the diffusion coefficients of larger gases, such as N2 and CH4, decreased much more rapidly than those of smaller gases, such as CO2 and O2. For example, after 55 days of aging, the diffusion coefficient of CH4 decreased by about 90%, while the diffusion coefficient of O2 decreased by about 63% (Table 3). The constant solubility coefficient over aging suggests that the total free volume of the polymer remained constant. However, the large decrease in diffusion coefficient over time for the larger gases suggests that the connection between the free volume elements, or the transport "bottleneck", narrowed as aging occurred. Notably, the results demonstrate that these "bottlenecks" collapse to slow down the transport of larger gases (larger than N2, which has a kinetic diameter of 3.64 Å) without significantly affecting the transport of smaller gases (smaller than O2, which has a kinetic diameter of 3.46 Å), resulting in enhanced size selectivity as a result of aging. In contrast, for CANAL-Me-iPr, permeability for all gases decreased to roughly the same relative extent, with smaller changes in selectivity (Table 2). [Table 2] [Table 3]

[0076] Variable temperature pure gas permeation experiments were performed. The diffusion activation energies were calculated using the Arrhenius equation after aging for both CANAL-Me-DMF and CANAL-Me-iPr and are plotted as a function of the square of the gas kinetic diameter (Figure 10). CANAL-Me-DMF showed higher diffusion activation energies for all four gases tested: CO2, O2, N2, and CH4. Since both types of CANAL polymers are hydrocarbons that do not have specific polar interactions with the gases, the higher activation energies suggest a narrower diffusion "bottleneck" in CANAL-Me-DMF than in CANAL-Me-iPr. The slope of the best fit line in Figure 10 is the energy selectivity, which is 6.0 and 2.7 kJ mol for CANAL-Me-DMF and CANAL-Me-iPr, respectively. -1 Å -2 Furthermore, a comparison of fresh and aged CANAL-Me-DMF revealed an increased gradient for the aged membrane (Figure 10). The larger gradient of the size-dependent diffusion barrier for aged CANAL-Me-DMF is responsible for its dramatically enhanced selectivity.

[0077] Additional data for CANAL-Me-DMF is provided below. [Table 4]

[0078] The exceptionally high CO2 / CH4 makes it feasible to use CANAL-Me-DMF for biogas processing, in some cases with a CO2 content of > about 40%. The application of membrane technology for biogas is currently quite rare, as industrial membranes have low selectivity and generally cannot result in methane streams with sufficiently high purity. Furthermore, H2 / CH4 and H2 / N2 separations are important for hydrogen production, and O2 / N2 separations are important for nitrogen production.

[0079] To determine whether CANAL-Me-DMF is susceptible to plasticization, pure gas permeation experiments are performed with upstream CO2 pressures up to about 17 atm. A clear indication of plasticization is when the permeability increases with increasing upstream pressure. As shown in Figure 8, no significant increase in CO2 permeability is observed up to about 8 bar, demonstrating the high plasticization resistance of CANAL-Me-DMF. Ladder polymers with comparable pure gas transport properties were observed to plasticize at lower upstream pressures, resulting in much lower selectivity in mixed gas permeation experiments. These results indicate that the selectivity of CANAL-Me-DMF remains high even when exposed to mixed gas streams.

[0080] We synthesized another example of a fluorene NBC ladder polymer, CANAL-Me-S5F. Its chemical structure and 1 The H-NMR spectrum is shown in FIG.

[0081] A further example of a fluorene NBC ladder polymer, CANAL-Me-S5F, was synthesized. Its chemical structure and 1 The H-NMR spectrum is shown in FIG. definition

[0082] As used herein, the singular terms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to one object can include a plurality of objects unless the context clearly dictates otherwise.

[0083] As used herein, the terms "substantially", "substantial", "approximately" and "about" are used to describe and explain slight variations. When used with an event or circumstance, the term can refer to an instance where the event or circumstance occurs exactly, and an instance where the event or circumstance occurs fairly close. When used with a numerical value, the term can refer to a variation of less than or equal to ±10% of the numerical value, for example, less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.

[0084] In addition, amounts, ratios, and other numerical values ​​are sometimes presented in a range format herein. It is to be understood that such range formats are used for convenience and brevity, and include numerical values ​​explicitly specified as the limits of the range, but should be understood flexibly to include all individual numerical values ​​or subranges encompassed within the range, as if each numerical value and subrange were explicitly specified. For example, a ratio range of about 1 to about 200 should be understood to include the explicitly recited limits of about 1 and about 200, but also include individual ratios such as about 2, about 3, and about 4, and subranges such as about 10 to about 50, about 20 to about 100, etc.

[0085] In general, "substituted" refers to an organic group (e.g., an alkyl group) in which one or more bonds to a hydrogen atom contained in the group are replaced by a bond to a non-hydrogen or non-carbon atom. Substituted groups also include groups in which one or more bonds to a carbon or hydrogen atom are replaced by one or more bonds, including double or triple bonds, to a heteroatom. The present disclosure is understood to include embodiments in which, for example, "substituted alkyl" optionally contains one or more alkenes and / or alkynes. Substituted groups are substituted with one or more substituents unless otherwise specified. In some embodiments, substituted groups are substituted with 1, 2, 3, 4, 5, or 6 substituents. Exemplary substituents include halogens (i.e., F, Cl, Br, and I); hydroxyl; alkoxy, alkenoxy, alkynoxy, aryloxy, aralkyloxy, heterocyclyloxy, and heterocyclylalkoxy groups; aryl groups; heteroaryl groups; cycloalkyl groups; heterocyclyl groups; carbonyl (oxo); carboxyl; esters; urethanes; oximes; hydroxylamines; alkoxyamines; aralkoxyamines; thiols; sulfides; sulfoxides; sulfones; sulfonyls; sulfonamides; amines; N-oxides; hydrazines; hydrazides; hydrazones; azides; amides; ureas; amidines; guanidines; enamines; imides; isocyanates; isothiocyanates; cyanates; thiocyanates; imines; nitro groups; nitriles (i.e., CN), and the like.

[0086] Substituted ring groups, such as substituted cycloalkyl, aryl, heterocyclic and heteroaryl groups, also include rings and fused ring systems in which a bond to a hydrogen atom is replaced with a bond to a carbon atom. Thus, substituted cycloalkyl, aryl, heterocyclic and heteroaryl groups can also be substituted with substituted or unsubstituted alkyl, alkenyl, and alkynyl groups, as defined below.

[0087] Alkyl groups include straight chain and branched alkyl groups having 1 to about 20 carbon atoms, typically 1 to 12 carbons, or in some embodiments, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. Examples of straight chain alkyl groups include groups having 1 to 8 carbon atoms, such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, and n-octyl groups. Examples of branched alkyl groups include, but are not limited to, isopropyl, iso-butyl, sec-butyl, tert-butyl, neopentyl, and isopentyl groups. Representative substituted alkyl groups may be substituted one or more times with substituents such as those listed herein. As previously mentioned, the present disclosure is understood to include embodiments in which, for example, "substituted alkyl" contains one or more alkenes and / or alkynes, as appropriate.

[0088] Cycloalkyl groups are cyclic alkyl groups, including but not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. In some embodiments, cycloalkyl groups have 3-8 ring members, while in other embodiments, the number of ring carbon atoms ranges from 3-5, 3-6, or 3-7. Cycloalkyl groups further include monocyclic, bicyclic, and polycyclic ring systems, such as bridged cycloalkyl groups, as well as fused rings, such as but not limited to decalinyl, as described below. In some embodiments, polycyclic cycloalkyl groups have three rings. Substituted cycloalkyl groups may be substituted one or more times with non-hydrogen and non-carbon groups, as defined above. However, substituted cycloalkyl groups also include rings substituted with straight or branched chain alkyl groups, as defined above. Representative substituted cycloalkyl groups can be mono- or more than one substituted, such as, but not limited to, 2,2-, 2,3-, 2,4-, 2,5-, or 2,6-disubstituted cyclohexyl groups, which can be substituted with substituents such as those listed above. In some embodiments, the cycloalkyl groups have one or more alkene linkages but are not aromatic.

[0089] An aryl group is a cyclic aromatic hydrocarbon that does not contain heteroatoms. Aryl groups include monocyclic, bicyclic and polycyclic ring systems. Thus, aryl groups include, but are not limited to, phenyl, azulenyl, heptalenyl, biphenylenyl, indacenyl, fluorenyl, phenanthrenyl, triphenylenyl, pyrenyl, naphthacenyl, chrysenyl, biphenyl, anthracenyl, indenyl, indanyl, pentalenyl, and naphthyl groups. In some embodiments, aryl groups contain 6-14 carbons in the ring portion of the group, and in others 6-12 or even 6-10 carbon atoms. The phrase "aryl group" includes groups that contain fused rings, such as fused aromatic-aliphatic ring systems (e.g., indanyl, tetrahydronaphthyl, etc.), but does not include aryl groups that have other groups, such as alkyl or halo groups, attached to one of the ring members. Rather, groups such as tolyl are referred to as substituted aryl groups. Representative substituted aryl groups can be mono-substituted or more than one substituted. For example, mono-substituted aryl groups include, but are not limited to, 2-, 3-, 4-, 5-, or 6-substituted phenyl or naphthyl groups, which can be substituted with substituents such as those listed above.

[0090] Heterocyclic groups include aromatic (also called heteroaryl) and non-aromatic ring compounds containing three or more ring members, one or more of which are heteroatoms, such as, but not limited to, N, O, S, or B. In some embodiments, heterocyclic groups contain 3-20 ring members, while other such groups have 3-6, 3-10, 3-12, or 3-15 ring members. Heterocyclic groups encompass unsaturated, partially saturated, and saturated ring systems, such as imidazolyl, imidazolinyl, and imidazolidinyl groups. The phrase "heterocyclic group" includes fused ring species, including those containing fused aromatic and non-aromatic groups, such as, for example, benzotriazolyl, 2,3-dihydrobenzo[1,4]dioxinyl, and benzo[1,3]dioxolyl. The phrase also includes bridged polycyclic ring systems containing heteroatoms, such as, but not limited to, quinuclidyl. However, the phrase does not include heterocyclic groups that have other groups such as alkyl, oxo or halo groups attached to one of the ring members. Rather, these are referred to as "substituted heterocyclic groups."Heterocyclic groups include, but are not limited to, aziridinyl, azetidinyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, thiazolidinyl, tetrahydrothiophenyl, tetrahydrofuranyl, dioxolyl, furanyl, thiophenyl, pyrrolyl, pyrrolinyl, imidazolyl, imidazolinyl, pyrazolyl, pyrazolinyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, thiazolinyl, isothiazolyl, thiadiazolyl, oxadiazolyl, piperidyl, piperidyl, Perazinyl, morpholinyl, thiomorpholinyl, tetrahydropyranyl, tetrahydrothiopyranyl, oxathiane, dioxyl, dithianyl, pyranyl, pyridyl, pyrimidinyl, pyridazinyl, pyrazinyl, triazinyl, dihydropyridyl, dihydrodithiinyl, dihydrodithionyl, homopiperazinyl, quinuclidyl, indolyl, indolinyl, isoindolyl, azaindolyl (pyrrolopyridyl), indazolyl, indolizinyl, benzotriazolyl, benzimidazolyl, benzofuranyl , benzothiophenyl, benzothiazolyl, benzoxadiazolyl, benzoxazinyl, benzodithiinyl, benzoxathiinyl, benzothiazinyl, benzoxazolyl, benzothiazolyl, benzothiadiazolyl, benzo[1,3]dioxolyl, pyrazolopyridyl, imidazopyridyl (azabenzimidazolyl), triazolopyridyl, isoxazolopyridyl, purinyl, xanthinyl, adeninyl, guaninyl, quinolinyl, isoquinolinyl, quinolizinyl, quinoxalinyl, quinazolinyl Examples of such radicals include aryl, cinnolinyl, phthalazinyl, naphthyridinyl, pteridinyl, thianaphthalenyl, dihydrobenzothiazinyl, dihydrobenzofuranyl, dihydroindolyl, dihydrobenzodioxinyl, tetrahydroindolyl, tetrahydroindazolyl, tetrahydrobenzimidazolyl, tetrahydrobenzotriazolyl, tetrahydropyrrolopyridyl, tetrahydropyrazolopyridyl, tetrahydroimidazopyridyl, tetrahydrotriazolopyridyl, and tetrahydroquinolinyl groups.Representative substituted heterocyclic groups can be pyridyl or morpholinyl groups that are mono- or more than one substituted, for example, 2-, 3-, 4-, 5- or 6-substituted or di-substituted with various substituents such as, but not limited to, those listed above.

[0091] Heteroaryl groups are aromatic ring compounds containing five or more ring members, one or more of which are heteroatoms, such as, but not limited to, N, O, S, or B. Heteroaryl groups include, but are not limited to, groups such as pyrrolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, thiophenyl, benzothiophenyl, furanyl, benzofuranyl, indolyl, azaindolyl (pyrrolopyridyl), indazolyl, benzimidazolyl, imidazopyridyl (azabenzimidazolyl), pyrazolopyridyl, triazolopyridyl, benzotriazolyl, benzoxazolyl, benzothiazolyl, benzothiadiazolyl, imidazopyridyl, isoxazolopyridyl, thianaphthalenyl, purinyl, xanthinyl, adeninyl, guaninyl, quinolinyl, isoquinolinyl, tetrahydroquinolinyl, quinoxalinyl, and quinazolinyl groups. The phrase "heteroaryl group" includes fused ring compounds such as indolyl and 2,3-dihydroindolyl, but the phrase does not include heteroaryl groups that have other groups, such as alkyl groups, attached to one of the ring members. Rather, heteroaryl groups with such substitutions are referred to as "substituted heteroaryl groups." Representative substituted heteroaryl groups may be substituted one or more times with a variety of substituents, such as those listed above.

[0092] Those skilled in the art will recognize that the compounds of the present invention may exhibit the phenomenon of tautomerism, conformational isomerism, geometric isomerism and / or optical isomerism.The drawings of formulae in this specification and claims can only represent one of the possible tautomerism, conformational isomerism, optical isomerism or geometric isomerism, therefore, it should be understood that the present invention encompasses any tautomerism, conformational isomerism, optical isomerism and / or geometric isomerism of the compounds having one or more of the utilities described herein, as well as mixtures of these various different forms.

[0093] As will be readily appreciated by one of ordinary skill in the art, a wide variety of functional groups and other structures may exhibit tautomerism, and all tautomers of the compounds described herein are within the scope of the invention.

[0094] Stereoisomers of a compound are also known as "optical isomers" and include all chiral, diastereomeric, and racemic forms of a structure unless a specific stereochemistry is explicitly indicated. Thus, the compounds used in the present invention include enriched or resolved optical isomers at any or all asymmetric atoms, as will be apparent from the depiction. Both racemic and diastereomeric mixtures, as well as individual optical isomers, can be isolated or synthesized substantially free of their enantiomeric or diastereomeric partners, and are all within the scope of the present invention.

[0095] Although the present disclosure has been described by reference to specific embodiments thereof, those skilled in the art will understand that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the present disclosure as defined by the appended claims. Moreover, many modifications may be made to adapt a particular situation, material, composition of matter, method, one or more operations to the objective, spirit and scope of the present disclosure. All such modifications are intended to be within the scope of the appended claims. In particular, although a particular method may be described with reference to certain operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or rearranged to form equivalent methods without departing from the teachings of the present disclosure. Thus, unless specifically indicated herein, the order and grouping of operations are not limitations of the present disclosure. The present invention provides, for example, the following items. (Item 1) [ka] [Wherein, two adjacent * teeth, [ka] The binding to the two asterisks in * is R 3 and R 4 and X is selected from an alkylene group, -[O]-, -[S]-, a nitrogen-containing group, and a cyclic group; Y 1 and Y 2 are independently selected from alkyl groups; R 1 、R 2 、R 3 、R 4 、R 5 , and R6 are independently a hydride group, an alkyl group, an aryl group, a heterocyclic group, a halogen group, a group containing an -O- moiety, a group containing an -O(CO)- moiety, a group containing an -O(CO)O- moiety, a group containing an -O(CO)N< moiety), a group containing an -S- moiety, a group containing a -B< moiety, -NO 2 , a group containing a -N< moiety, a group containing a -P< moiety, a group containing a -(PO)< moiety, a group containing a -CHO, a -(CO)- moiety, a group containing a -(CO)O- moiety, a group containing a -(CO)N< moiety, and a group containing a -Si≡ moiety; X 1 -[O]-, -[S]-, -[B(O)R a ]-, -[NR a ]-, -[P(O)R a ]-, -[(PO)(O)R a ]-, -[CO]-, -[CR a R b ]-, -[C(O)R a (O)R b ]-, and -[Si(O)R a (O)R b ]-, R a and R b are independently selected from a hydrido group, an alkyl group, an aryl group, and a heterocyclic group. A ladder polymer comprising a plurality of moieties each represented by: (Item 2) Y 1 =Y 2 and X 1 -[CH 2 ]- and R 1 =R 2 =R 3 =R 4 =R 5 =R 6 2. The ladder polymer according to item 1, wherein: (Item 3)

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Claims

1. 【Chemical 51】 【Chemistry 52】 [During the ceremony X is selected from an alkylene group, —[O]—, —[S]—, a nitrogen-containing group, and a cyclic group; Y １ and Y ２ are independently selected from alkyl groups; R １ , R ２ , R ３ , R ４ , R ５ , and R ６ are independently a hydride group, an alkyl group, an aryl group, a heterocyclic group, a halogen group, a group containing an —O— moiety, a group containing an —O(CO)— moiety, a group containing an —O(CO)O— moiety, a group containing an —O(CO)N< moiety), a group containing an —S— moiety, a group containing a —B< moiety, —NO ２ , a group containing a -N< moiety, a group containing a -P< moiety, a group containing a -(PO)< moiety, a group containing a -CHO, a -(CO)- moiety, a group containing a -(CO)O- moiety, a group containing a -(CO)N< moiety, and a group containing a -Si≡ moiety; X １ is -[O]-, -[S]-, -[B(O)R ａ ] -, -[NR ａ ]-,-[P(O)R ａ ]-,-[(PO)(O)R ａ ]-, -[CO]-, -[CR ａ R ｂ ]-,-[C(O)R ａ (O)R ｂ ]-, and -[Si(O)R ａ (O)R ｂ ]-, R ａ and R ｂ are independently selected from a hydrido group, an alkyl group, an aryl group, and a heterocyclic group. A ladder polymer comprising at least one unit having a structure selected from:

2. Y １ = Y ２ And X １ - [CH ２ ]-, and R １ = R ２ = R ３ = R ４ = R ５ = R ６ 2. The ladder polymer of claim 1, wherein: = a hydride group. 【Request 3】 【Chemical 53】 wherein n is an integer greater than 1.

3. The ladder polymer of claim 2, represented by: 【Request 4】 【Chemical 54】 [In the formula, A is an aromatic group; n is an integer greater than 1.

3. The ladder polymer of claim 2, represented by: 【Request 5】 【Chemical 55】 wherein n is an integer greater than 1.

3. The ladder polymer of claim 2, represented by:

6. The structure: 【Chemistry 56】 2. The ladder polymer of claim 1, comprising at least one unit having the formula:

7. The structure: 【Chemistry 57】 2. The ladder polymer of claim 1, comprising at least one unit having the formula:

8. The structure: 【Chemistry 58】 2. The ladder polymer of claim 1, comprising at least one unit having the formula:

9. A membrane for gas separation comprising the ladder polymer according to any one of claims 1 to 8.

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