阅读说明：本技术 一种交联型聚合物及基于其的阴离子交换膜 (Cross-linked polymer and anion exchange membrane based on same ) 是由 魏海兵 余晟 江涛 王子豪 徐赫 丁运生 于 2020-04-30 设计创作，主要内容包括：本发明公开了一种交联型聚合物及基于其的阴离子交换膜,该聚合物的功能离子基元为含有金刚烷大位阻基团的咪唑鎓盐。本发明的阴离子交换膜具有离子电导率高、抗溶胀性能好和耐碱性好等诸多优势。(The invention discloses a cross-linking type polymer and an anion exchange membrane based on the same. The anion exchange membrane has the advantages of high ionic conductivity, good swelling resistance, good alkali resistance and the like.)

1. A crosslinked polymer characterized by: the structure of the polymer is shown as the formula (1):

in the formula: the cation group in the ion-containing structural unit is an imidazolium salt containing adamantane substituent; each R⁰Each independently selected from alkylene groups having 1 to 20 carbon atoms; each R¹Each independently selected from alkylene with 1-20 carbon atoms or p-dibenzyl; the ionic structural unit and the nonionic structural unit are connected through a carbon-carbon double bond or a carbon-carbon single bond; x is 0.05-0.98; m is an integer between 10 and 1,000,000.

2. The crosslinked polymer of claim 1, wherein: the structure of the polymer is shown as formula (2), formula (3), formula (4) or formula (5):

in the formula: each R¹Each independently selected from alkylene with 1-20 carbon atoms or p-dibenzyl; r²And R³Each independently selected from alkyl with 1-20 carbon atoms, adamantyl, phenyl, 2, 6-dimethylphenyl or 2,4, 6-trimethylphenyl, and R²And R³At least one of which is adamantyl; r⁴And R⁵Each independently selected from alkyl with 1-20 carbon atoms, phenyl, 2, 6-dimethylphenyl or 2,4, 6-trimethylphenyl; counterion A^-Selected from the group consisting of halide ions; x is 0.05-0.98; m is an integer between 10 and 1,000,000.

3. A method for producing the crosslinked polymer according to claim 1 or 2, characterized in that: firstly, reacting a cycloolefin halogen end-group derivative with imidazole to obtain a cycloolefin derivative containing imidazolium salt; then dissolving the cyclic olefin derivative containing the imidazolium salt and the bicycloalkene compound in an organic solvent, adding a Grubbs catalyst, and reacting for 3-15min at room temperature by rapid stirring to obtain a solution of the crosslinking polymer.

4. The production method according to claim 3, characterized in that:

the crosslinking polymer shown in the formula (2) is obtained by reacting the cycloolefine derivative containing the imidazolium salt shown in the formula (6) with the bicycloalkene compound shown in the formula (7), wherein R is⁶Is a norbornene structure:

reacting a cyclic olefin derivative containing an imidazolium salt shown in a formula (8) with a bicycloalkene compound shown in a formula (9) to obtain a crosslinking polymer shown in a formula (3):

further hydrogenating the crosslinking type polymer shown in the formula (2) to obtain the crosslinking type polymer shown in the formula (4); and (3) further hydrogenating the crosslinking type polymer shown in the formula (3) to obtain the crosslinking type polymer shown in the formula (5).

5. The method of claim 4, wherein:

the configuration of the norbornene structure is a pure exo structure shown in formula (10), a pure endo structure shown in formula (11) or a mixture structure of exo and endo isomers shown in formula (12):

wherein R is a substituent, and is applicable to all the substituents described in formula (6) or formula (7).

6. The method of claim 4, wherein:

the cyclic olefin derivative containing the imidazolium salt shown in the formula (6) is obtained by reacting hydroxylated cyclic olefin with bis-haloalkane in alkali liquor to obtain cyclic olefin halogen end-group derivative, and then reacting the cyclic olefin halogen end-group derivative with imidazole containing adamantane substituent in chloroform, wherein the molar weight of the hydroxylated cyclic olefin is 1-5 times of that of the bis-haloalkane, and the reaction formulas are shown as a formula (13) and a formula (14):

the dicyclic olefin compound shown in the formula (7) is obtained by reacting hydroxylated cycloolefins with bis-halogenated alkyl in alkali liquor, wherein the molar weight of the hydroxylated cycloolefins is 2-10 times of that of the bis-halogenated alkyl, and the reaction formula is shown as the formula (15):

in the formula, the terminal group X is a halogen element.

7. The method of claim 4, wherein:

the cyclic olefin derivative containing the imidazolium salt shown in the formula (8) is obtained by reacting hydroxylated cyclic olefin with bis-haloalkane in alkali liquor to obtain cyclic olefin halogen end-group derivative, and then reacting the cyclic olefin halogen end-group derivative with imidazole containing adamantane substituent in chloroform, wherein the molar weight of the hydroxylated cyclic olefin is 1-5 times of that of the bis-haloalkane, and the reaction formulas are shown as a formula (16) and a formula (17):

the dicyclic olefin compound shown in the formula (9) is obtained by reacting hydroxylated cycloolefins with bis-halogenated alkyl in alkali liquor, wherein the molar weight of the hydroxylated cycloolefins is 2-10 times that of the bis-halogenated alkyl, and the reaction formula is shown as the formula (18):

in the formula, the terminal group X is a halogen element.

8. A cross-linked anion exchange membrane characterized in that: is obtained by film-forming the crosslinked polymer according to any one of claims 1 or 2.

9. The cross-linked anion exchange membrane of claim 8, wherein: the anion in the anion exchange membrane is halide A^-，A^-Can be converted into other desired anions by ion exchange, including hydroxide, carbonate, bicarbonate, hexafluorophosphate, sulfate or other anions different from A^-Other halogen ions of (1).

10. The cross-linked anion exchange membrane of claim 8 or 9, wherein: coating a film on a substrate or a reinforced fabric with a solution of the crosslinking polymer shown in the formula (2) or the formula (3), and then drying the film in a drying oven at 30-200 ℃ to sufficiently remove the solvent, thereby obtaining the crosslinking anion-exchange membrane based on the crosslinking polymer shown in the formula (2) or the formula (3);

soaking a crosslinking type anion exchange membrane based on a crosslinking type polymer shown in a formula (2) or a formula (3) in a solution reaction kettle containing a Crabtree catalyst for hydrogen hydrogenation reaction, wherein the pressure of hydrogen is between 1 and 100 atmospheric pressures, the reaction temperature is between 0 and 150 ℃, and the reaction time is between 0.5 and 100 hours; and after the reaction is finished, taking the membrane out of the system, washing and drying to obtain the cross-linked anion-exchange membrane based on the cross-linked polymer shown in the formula (4) or the formula (5).

Technical Field

The invention belongs to the field of ion exchange membrane materials, and particularly relates to a cross-linked polymer and an anion exchange membrane based on the same.

Background

Anion exchange membranes serve as the core component of alkaline fuel cells, and their ability to transport ions directly determines the performance of the fuel cell. Researchers are working on improving the ionic conductivity of the polymer by regulating and controlling the Ion Exchange Capacity (IEC), the aggregation state structure of the membrane material and the hydration degree in the membrane. Among them, increasing IEC in the membrane is the most effective method for increasing the conductivity of the ionic membrane, but too high ion content causes excessive water absorption and excessive swelling of the membrane material, so that the normal mechanical properties of the membrane cannot be maintained. On the other hand, the anion exchange membrane applied to the fuel cell is also required to have better alkali stability. It has been difficult to satisfy the properties of high ionic conductivity, good dimensional stability, and excellent alkali resistance, etc., simultaneously, in the reported membrane materials.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a cross-linked polymer and an anion exchange membrane based on the same, and the technical problems to be solved are as follows: the stability of imidazole cation is improved by introducing adamantane large steric hindrance group, and the structural stability of the anion exchange membrane is improved by adding a cross-linking agent to enable the cation to be chemically cross-linked during polymerization to form a cross-linked network structure, so that the anion exchange membrane with optimized chemical stability and size stability is obtained.

In order to solve the technical problem, the invention adopts the following technical scheme:

the invention firstly provides a cross-linking type polymer with a structure shown as a formula (1):

in the formula: the cation group in the ion-containing structural unit is an imidazolium salt containing adamantane substituent; each R⁰Each independently selected from alkylene groups having 1 to 20 carbon atoms; each R¹Each independently selected from alkylene with 1-20 carbon atoms or p-dibenzyl; the ionic structural unit and the nonionic structural unit are connected through a carbon-carbon double bond or a carbon-carbon single bond; x is 0.05-0.98; m is an integer between 10 and 1,000,000.

Further, the structure of the polymer is shown as formula (2), formula (3), formula (4) or formula (5):

in the formula: each R¹Each independently selected from alkylene with 1-20 carbon atoms or p-dibenzyl; r²And R³Each independently selected from alkyl with 1-20 carbon atoms, adamantyl, phenyl, 2, 6-dimethylphenyl or 2,4, 6-trimethylphenyl, and R²And R³At least one of which is adamantyl; r⁴And R⁵Each independently selected from alkyl with 1-20 carbon atoms, phenyl, 2, 6-dimethylphenyl or 2,4, 6-trimethylphenyl; counterion A^-Selected from the group consisting of halide ions; x is 0.05-0.98; m is an integer between 10 and 1,000,000.

The invention also discloses a preparation method of the cross-linked polymer, which comprises the steps of firstly reacting the cycloolefinic halogen end-group derivative with imidazole to obtain a cycloolefinic derivative containing imidazolium salt; then, the cycloolefine derivative containing the imidazolium salt and the dicyclic olefine compound are dissolved in an organic solvent, Grubbs catalyst (the first generation, the second generation and the third generation of Grubbs catalyst can be all used) is added, and the mixture is stirred and reacted for 3-15min at room temperature, so that the solution of the crosslinking type polymer is obtained.

Further, the organic solvent used for polymerization may be independently selected from one or a mixture of dichloromethane, chloroform, carbon tetrachloride, 1, 2-tetrachloroethane, and the like.

Further, a crosslinked polymer represented by the formula (2) is obtained by reacting a cycloolefin derivative containing an imidazolium salt represented by the formula (6) with a bicycloalkene compound represented by the formula (7) wherein R is⁶Is a norbornene structure: a

Reacting a cyclic olefin derivative containing an imidazolium salt shown in a formula (8) with a bicycloalkene compound shown in a formula (9) to obtain a crosslinking polymer shown in a formula (3):

further hydrogenating the crosslinking type polymer shown in the formula (2) to obtain the crosslinking type polymer shown in the formula (4); and (3) further hydrogenating the crosslinking type polymer shown in the formula (3) to obtain the crosslinking type polymer shown in the formula (5).

Further, the configuration of the norbornene structure is a pure exo structure represented by formula (10), a pure endo structure represented by formula (11), or a mixture structure of exo and endo isomers represented by formula (12):

wherein R is a substituent, and is applicable to all the substituents described in formula (6) or formula (7).

Furthermore, the cyclic olefin derivative containing the imidazolium salt shown in the formula (6) is obtained by reacting hydroxylated cyclic olefin with bis-haloalkane in alkali liquor by taking tetrabutylammonium bromide as a phase transfer catalyst at room temperature to obtain a cyclic olefin halogenated end-group derivative, and then reacting the cyclic olefin halogenated end-group derivative with imidazole containing adamantane substituent at 40-80 ℃ in chloroform, wherein the molar weight of the hydroxylated cyclic olefin is 1-5 times that of the bis-haloalkane, and the reaction formulas are shown as a formula (13) and a formula (14):

further, the dicyclic olefin compound shown in the formula (7) is obtained by reacting hydroxylated cycloolefins with bis-halogenated alkyl in alkali liquor by taking tetrabutylammonium bromide as a phase transfer catalyst at room temperature, wherein the molar weight of the hydroxylated cycloolefins is 2-10 times of that of the bis-halogenated alkyl, and the reaction formula is shown as the formula (15):

in the formula, the terminal group X is a halogen element.

Furthermore, the cyclic olefin derivative containing the imidazolium salt shown in the formula (8) is obtained by reacting hydroxylated cyclic olefin with bis-haloalkane in alkali liquor by taking tetrabutylammonium bromide as a phase transfer catalyst at room temperature to obtain a cyclic olefin halogenated end-group derivative, and then reacting the cyclic olefin halogenated end-group derivative with imidazole containing adamantane substituent at 40-80 ℃ in chloroform, wherein the molar weight of the hydroxylated cyclic olefin is 1-5 times that of the bis-haloalkane, and the reaction formulas are shown as a formula (16) and a formula (17):

the dicyclic olefin compound shown in the formula (9) is obtained by reacting hydroxylated cycloolefins with bis-halogenated alkyl in alkali liquor by taking tetrabutylammonium bromide as a phase transfer catalyst at room temperature, wherein the molar weight of the hydroxylated cycloolefins is 2-10 times that of the bis-halogenated alkyl, and the reaction formula is shown as the formula (18):

in the formula, the terminal group X is a halogen element.

The invention further discloses a cross-linked anion exchange membrane which is obtained by forming a membrane from the cross-linked polymer. The anion in the anion exchange membrane is halide A^-，A^-Can be converted into other desired anions by ion exchange, including hydroxide, carbonate, bicarbonate, hexafluorophosphate, sulfate or other anions different from A^-Other halogen ions of (1). During the specific operation, the film is only required to be placed in a solution containing corresponding ions (such as NaOH solution, KOH solution and Na solution with the concentration of 0.01-10 mol/L)₂CO₃Solution, K₂CO₃Solution, NaHCO₃Solution, KHCO₃Solution, NaPF₆Solution, KPF₆Solution, etc.) for a sufficient time, and then thoroughly washed with deionized water. For example: soaking the anion exchange membrane with the anions as halogen ions in NaOH aqueous solution with the concentration of 0.01-10mol/L or NaOH aqueous solution with the concentration of 0.01-10mol/LTo obtain an anion exchange membrane with hydroxide ions as anions (i.e. A in the structural formula of the crosslinked anion exchange membrane based on the adamantane imidazolium salt)^-Conversion to OH^-)。

Furthermore, the thickness of the anion exchange membrane is 0.001-5mm, and when the counter ion is hydroxide, the ionic conductivity is not lower than 5 mS/cm.

Further, a solution of the cross-linked polymer represented by formula (2) or formula (3) is coated on a substrate or a reinforcing fabric, and then transferred to a drying oven at 30-200 ℃ for drying, so as to sufficiently remove the solvent, thereby obtaining a cross-linked anion-exchange membrane based on the cross-linked polymer represented by formula (2) or formula (3);

further, soaking a crosslinking type anion exchange membrane based on the crosslinking type polymer shown in the formula (2) or the formula (3) in a solution reaction kettle containing a Crabtree catalyst for hydrogen hydrogenation reaction, wherein the pressure of hydrogen is between 1 and 100 atmospheric pressures, the reaction temperature is between 0 and 150 ℃, and the reaction time is between 0.5 and 100 hours; and after the reaction is finished, taking the membrane out of the system, washing and drying to obtain the cross-linked anion-exchange membrane based on the cross-linked polymer shown in the formula (4) or the formula (5).

Further: the substrate is selected from a culture dish, a glass plate or a polytetrafluoroethylene plate; the reinforced fabric is selected from polyethylene cloth, polypropylene cloth, polyester cloth, nylon cloth or polyvinyl chloride cloth; the coating method can be solution casting film forming, rotary coating, film scraping, casting or dipping.

Compared with the prior art, the invention has the beneficial effects that:

the anion exchange membrane prepared from the cross-linked ionomer can be applied to the field of various diaphragms, has good mechanical property and chemical stability under the condition of ensuring certain ionic conductivity, has good application prospect, and is particularly suitable for the anion exchange membrane of an alkaline fuel cell.

Drawings

FIG. 1 is a graph of water absorption versus temperature for the anion exchange membrane prepared in example 1;

FIG. 2 is a graph of conductivity versus temperature for the anion exchange membrane prepared in example 1.

Detailed Description

The invention is described in further detail below with reference to the figures and examples.