Preparation method of structurally controllable polyionic liquid

Abstract

The present invention discloses a preparation method of structurally controllable polyionic liquids, belonging to the technical field of polymer materials. This method first synthesizes a series of structurally controllable cationic sequence monodisperse polymers with alkynyl end groups, and then conducts a copper-catalyzed azide-alkyne click reaction with polyepichlorohydrin modified with azide groups to complete polymer modification and realize the synthesis of polyionic liquids. The preparation method provided by the present invention has mild reaction conditions, high yield, simple post-treatment, and precisely controllable cationic side chain structure, and has potential and wide application value in the fields of biomedicine, functional materials, etc.

Description

Technical Field

[0001] The present invention relates to the field of polymer materials, and particularly to a method for preparing a structurally controllable polyionic liquid. Background Art

[0002] Polyionic liquids are a class of polymers containing cationic and anionic groups, and simultaneously possess the characteristics of both polymers and ionic compounds, with unique physical and chemical properties, and are becoming a new type of material with a wide range of application scenarios. The synthesis of polyionic liquids generally involves free radical polymerization of monomers containing ionic groups, or functionalizing non-ionic polymers to introduce ionic bonds to achieve the synthesis of polyionic liquids. Currently, polyionic liquids have a wide range of applications in the fields of electrochemistry, energy science, materials science, etc.

[0003] Polymers with precisely controllable structures have uniform molecular weights and precisely designable molecular structures, which endow them with a series of special physical, chemical, and biological properties, making them a type of polymer material with great potential in many aspects. The synthesis methods of sequence polymers mainly include step polymerization, exponential growth method, monomer insertion method, etc., and generally have problems such as cumbersome reaction steps, complex purification work, low yield and productivity. Achieving the synthesis of structurally controllable polyionic liquids remains a difficult problem. In view of the above problems, a solution is proposed below. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing a structurally controllable polyionic liquid. By means of post-modification, a polycation molecular chain with precisely controllable structure is grafted onto the side chain of azide group-modified polyepichlorohydrin to achieve the synthesis of a structurally controllable polyionic liquid.

[0005] The above technical purpose of the present invention is achieved through the following technical solutions:

[0006] A method for preparing a structurally controllable polyionic liquid, characterized by comprising the following steps: S1:

[0007] Prepare a solution of a tertiary amine compound with a concentration of 5 - 15 g / L, mix the solution with propargyl bromide, place it at 40 - 60 °C for reaction for 4 - 8 hours, and then obtain a cationic polymer G0.5 through post-treatment;

[0008] Subsequently, the cationic polymer G0.5 was prepared into a solution with a concentration of 5 - 15 g / L, and this solution was mixed with a tertiary amine - azide compound. A catalyst was added under the protection of an inert gas, and the mixture was reacted at 40 - 60 °C for 4 - 12 hours. After post - treatment, cationic polymer G1 was obtained; the molar ratio of the tertiary amine compound to propargyl bromide was 1:1.2 - 2, the molar ratio of the cationic polymer G0.5 to the tertiary amine - azide compound was 1:1.2 - 2, and the molar ratio of the cationic polymer G0.5 to the catalyst was 10 - 100:1;

[0009] S2:

[0010]

[0011] The cationic polymer G1 was prepared into a solution with a concentration of 5 - 15 g / L, and this solution was mixed with propargyl bromide. The mixture was reacted at 40 - 60 °C for 4 - 8 hours. After post - treatment, cationic polymer G1.5 was obtained, and the molar ratio of the cationic polymer G1 to propargyl bromide was 1:1.2 - 2;

[0012] S3:

[0013]

[0014] The cationic polymer G1.5 was prepared into a solution with a concentration of 5 - 15 g / L, and this solution was mixed with a tertiary amine - azide compound. A catalyst was added under the protection of an inert gas, and the mixture was reacted at 40 - 60 °C for 4 - 12 hours. After post - treatment, cationic polymer G2 was obtained, the molar ratio of the cationic polymer G1.5 to the tertiary amine - azide compound was 1:1.2 - 2, and the molar ratio of the cationic polymer G1.5 to the catalyst was 10 - 100:1;

[0015] S4:

[0016]

[0017] The cationic polymer G2 was prepared into a solution with a concentration of 5 - 15 g / L, and this solution was mixed with propargyl bromide. The mixture was reacted at 40 - 60 °C for 4 - 8 hours. After post - treatment, cationic polymer G2.5 was obtained, and the molar ratio of the cationic polymer G2 to propargyl bromide was 1:1.2 - 2;

[0018] S5: Steps S3 and S4 were repeatedly executed to obtain cationic molecular chains of different lengths;

[0019] S6:

[0020]

[0021] Prepare a solution of azide-modified polyepichlorohydrin at a concentration of 0.5 - 5 g / L, mix it with a cationic molecular chain, add a catalyst under the protection of an inert gas, place it at 40 - 60 °C and react for 4 - 12 hours, and then obtain a structurally controllable polyionic liquid through post-treatment. The molar ratio of the azide-modified polyepichlorohydrin to the cationic molecular chain is 1:0.1 - 2, and the molar ratio of the azide-modified polyepichlorohydrin to the catalyst is 10 - 100:1.

[0022] Preferably, the tertiary amine compound is one or more of dimethylpropylamine, dimethylbutylamine, dimethylethanolamine, and triethylamine.

[0023] Preferably, for the tertiary amine compound solution, the cationic polymer G0.5 solution, the cationic polymer G1 solution, and the azide-modified polyepichlorohydrin solution, their solvents are all one or more of N,N-dimethylformamide, dimethyl sulfoxide, and N-methylpyrrolidone.

[0024] Preferably, the tertiary amine-azide compound is one of dimethylazidoethylamine, dimethylazidopropylamine, dimethylazidobutylamine, dimethylazidopentylamine, dimethylazidohexylamine, dimethylazidoheptylamine, dimethylazidooctylamine, or a homolog with a main chain containing more methylene groups.

[0025] Preferably, the catalyst is one or more of cuprous chloride, cuprous bromide, or elemental copper.

[0026] Preferably, the post-treatment method is the precipitation method, and the precipitant is one or more of ether, ethyl acetate, acetone, or tetrahydrofuran.

[0027] Preferably, prepare the cationic molecular chain obtained in step S4 into a solution with a concentration of 10 - 50 g / L, and repeat the operations of step S2 and step S3 1 - 8 times to obtain the cationic molecular chain. The beneficial effects of the present invention are as follows:

[0028] (1) For the synthesized cationic polymer, there are multiple cations on a single side chain. Generally, for the cationic polymer synthesized by the post-modification method in the prior art, only a single cationic group can be introduced on a single side chain, which brings great limitations to the adjustment of structure and properties.

[0029] (2) Through monomer structure design, different commercial bromohydrins are selected, and the side chain structure and the cation spacing on the side chain are precisely controllable. This makes it easy to design and regulate properties such as the polarity and molecular chain flexibility of the polymer.

[0030] (3) The side chain grafting reaction is a copper-catalyzed azide-alkyne click reaction, with mild reaction conditions, high yield, simple post-treatment, and can be produced on a large scale.

[0031] (4) The end of the side chain can be designed as a reactive group, such as a hydroxyl group, an unsaturated bond, etc. This provides the possibility for further functionalization and modification of the product polymer. Description of the Drawings

[0032] Figure 1 It is the spectrum obtained by Maldi-Tof mass spectrometry after the cationic polymer G3 in Example 1 is subjected to ion exchange using lithium bis(trifluoromethanesulfonyl)imide.

[0033] Figure 2 It is the spectrum obtained by Maldi-Tof mass spectrometry after the cationic compound G5 in Example 1 is subjected to ion exchange using lithium bis(trifluoromethanesulfonyl)imide.

[0034] Figure 3 It is the aqueous gel permeation chromatography spectrum of the structure-controlled polyionic liquid obtained in Example 1. Detailed Embodiments

[0035] The following are only the preferred embodiments of the present invention, and the scope of protection is not limited to this embodiment. All technical solutions within the concept of the present invention should belong to the scope of protection of the present invention.

[0036] Example 1:

[0037] S1: In a 10-milliliter round-bottom flask, dimethylethanolamine was made into a 3-milliliter DMF solution with a concentration of 10 g / L and mixed with 0.5 grams of propargyl bromide. The mixture was stirred and reacted at 40 °C for 4 hours. The product was precipitated in 50 milliliters of ether, dissolved in 3 milliliters of DMF, and then precipitated again in 50 milliliters of ether. After drying the precipitate, the cationic polymer G0.5 was obtained. Subsequently, the above-obtained cationic polymer G0.5 was made into a 3-milliliter DMF solution, mixed with 0.5 g of dimethylazidoethylamine, and 7 milligrams of cuprous bromide was added under nitrogen protection. The mixture was stirred and reacted at 40 °C for 4 hours. The product was precipitated in 50 milliliters of ether, dissolved in 3 milliliters of DMF, and then precipitated again in 50 milliliters of ether. After drying the precipitate, the cationic polymer G1 was obtained.

[0038] S2: The above cationic polymer G1 was dissolved in 3 milliliters of DMF, mixed with 0.5 grams of propargyl bromide, and stirred and reacted at 40 °C for 4 hours. The product was precipitated in 50 milliliters of ether, dissolved in 3 milliliters of DMF, and then precipitated again in 50 milliliters of ether. After drying the precipitate, the cationic polymer G1.5 was obtained.

[0039] S3: Subsequently, dissolve the cationic polymer G1.5 in 3 mL of DMF, mix it with 0.5 g of dimethylazidoethylamine, add 10 mg of cuprous bromide under nitrogen protection, stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, dissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G2 is obtained.

[0040] S4: Dissolve the above-mentioned cationic polymer G2 in 3 mL of DMF, mix it with 0.5 g of propargyl bromide, stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, dissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G2.5 is obtained.

[0041] S5: Repeat steps S3 and S4 three times to obtain the cationic polymer G5.5 containing six cations.

[0042] S6: Dissolve 0.5 g of azide-modified polyepichlorohydrin in 3 mL of DMF, mix it with the above-obtained cationic polymer G5.5, add 20 mg of cuprous bromide under nitrogen protection, stir and react at 40 °C for 6 hours. The product is precipitated in 50 mL of diethyl ether, dissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the structurally controllable polyionic liquid is obtained.

[0043] Example 2

[0044] S1: Prepare a 3 mL DMF solution with a concentration of 10 g / L of triethylamine in a 10 mL round-bottom flask, mix it with 0.5 g of propargyl bromide, and stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, dissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G0.5 is obtained. Subsequently, dissolve the above-obtained cationic polymer G0.5 in 3 mL of DMF, mix it with 0.5 g of dimethylazidopropylamine, add 7 mg of cuprous bromide under nitrogen protection, and stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, dissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G1 is obtained.

[0045] S2: Dissolve the above-mentioned cationic polymer G1 in 3 mL of DMF, mix it with 0.5 g of propargyl bromide, stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, dissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G1.5 is obtained.

[0046] S3: Subsequently, dissolve the cationic polymer G1.5 in 3 mL of DMF, mix it with 0.5 g of dimethylazidopropylamine, add 10 mg of cuprous bromide under nitrogen protection, stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, redissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G2 is obtained.

[0047] S4: Dissolve the above cationic polymer G2 in 3 mL of DMF, mix it with 0.5 g of propargyl bromide, stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, redissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G2.5 is obtained.

[0048] S5: Repeat steps S3 and S4 twice to obtain the cationic polymer G5.5 containing 5 cations.

[0049] S6: Dissolve 0.5 g of azide-modified polyepichlorohydrin in 3 mL of DMF, mix it with the above-obtained cationic polymer G5.5, add 20 mg of cuprous bromide under nitrogen protection, stir and react at 40 °C for 6 hours. The product is precipitated in 50 mL of diethyl ether, redissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the structurally controllable polyionic liquid is obtained.

[0050] Example 3

[0051] S1: In a 10 mL round-bottom flask, prepare a 3 mL DMF solution of dimethylethanolamine with a concentration of 10 g / L, mix it with 0.5 g of propargyl bromide, and stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, redissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G0.5 is obtained. Subsequently, dissolve the above-obtained cationic polymer G0.5 in 3 mL of DMF, mix it with 0.5 g of dimethylazidooctylamine, add 7 mg of cuprous bromide under nitrogen protection, and stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, redissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G1 is obtained.

[0052] S2: Dissolve the above cationic polymer G1 in 3 mL of DMF, mix it with 0.5 g of propargyl bromide, stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, redissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G1.5 is obtained.

[0053] S3: Subsequently, dissolve the cationic polymer G1.5 in 3 mL of DMF, mix it with 0.5 g of dimethyl azidoethylamine, add 10 mg of cuprous bromide under nitrogen protection, stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, dissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G2 is obtained.

[0054] S4: Dissolve the above-mentioned cationic polymer G2 in 3 mL of DMF, mix it with 0.5 g of propargyl bromide, stir and react at 40 °C for 4 hours. The product is precipitated in 50 mL of diethyl ether, dissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the cationic polymer G2.5 is obtained.

[0055] S5: Repeat steps S3 and S4 4 times to obtain the cationic polymer G5.5 containing 7 cations.

[0056] S6: Dissolve 0.5 g of azide-modified polyepichlorohydrin in 3 mL of DMF, mix it with the above-obtained cationic polymer G5.5, add 20 mg of cuprous bromide under nitrogen protection, stir and react at 40 °C for 6 hours. The product is precipitated in 50 mL of diethyl ether, dissolved in 3 mL of DMF and then precipitated again in 50 mL of diethyl ether. After drying the precipitate, the structurally controllable polyionic liquid is obtained.

[0057] The specific embodiments described above further elaborate on the technical problems solved, technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a structurally controllable polyionic liquid, characterized in that It includes the following steps: S1: Prepare a solution of a tertiary amine compound with a concentration of 5 - 15 g / L, mix the solution with propargyl bromide, place it at 40 - 60 °C for reaction for 4 - 8 hours, and then obtain cationic polymer G0.5 through post-treatment; Subsequently, prepare a solution of cationic polymer G0.5 with a concentration of 5 - 15 g / L, mix the solution with a tertiary amine - azide compound, add a catalyst under inert gas protection, place it at 40 - 60 °C for reaction for 4 - 12 hours, and then obtain cationic polymer G1 through post-treatment; The molar ratio of the tertiary amine compound to propargyl bromide is 1:1.2 - 2, the molar ratio of cationic polymer G0.5 to the tertiary amine - azide compound is 1:1.2 - 2, and the molar ratio of cationic polymer G0.5 to the catalyst is 10 - 100:1; S2: Prepare a solution of cationic polymer G1 with a concentration of 5 - 15 g / L, mix the solution with propargyl bromide, place it at 40 - 60 °C for reaction for 4 - 8 hours, and then obtain cationic polymer G1.5 through post-treatment. The molar ratio of cationic polymer G1 to propargyl bromide is 1:1.2 - 2; S3: Prepare a solution of cationic polymer G1.5 with a concentration of 5 - 15 g / L, mix the solution with a tertiary amine - azide compound, add a catalyst under inert gas protection, place it at 40 - 60 °C for reaction for 4 - 12 hours, and then obtain cationic polymer G2 through post-treatment. The molar ratio of cationic polymer G1.5 to the tertiary amine - azide compound is 1:1.2 - 2, and the molar ratio of cationic polymer G1.5 to the catalyst is 10 - 100:1; S4: Prepare a solution of cationic polymer G2 with a concentration of 5 - 15 g / L, mix the solution with propargyl bromide, place it at 40 - 60 °C for reaction for 4 - 8 hours, and then obtain cationic polymer G2.5 through post-treatment. The molar ratio of cationic polymer G2 to propargyl bromide is 1:1.2 - 2; S5: Repeat step S3 and step S4 to obtain cationic molecular chains with different lengths; S6: Prepare a solution of azide - modified polyepichlorohydrin with a concentration of 0.5 - 5 g / L, mix it with the cationic molecular chain, add a catalyst under inert gas protection, place it at ④0 - 60 °C for reaction for 4 - 12 hours, and then obtain structurally controllable polyionic liquid through post-treatment. The molar ratio of azide - modified polyepichlorohydrin to the cationic molecular chain is 1:0.1 - 2, and the molar ratio of azide - modified polyepichlorohydrin to the catalyst is 10 - 100:

1.

2. The preparation method of a structurally controllable polyionic liquid according to claim 1, characterized in that, The tertiary amine compound is one or more of dimethylpropylamine, dimethylbutylamine, dimethylethanolamine, and triethylamine.

3. The preparation method of a structurally controllable polyionic liquid according to claim 1, characterized in that, For the tertiary amine compound solution, cationic polymer G0.5 solution, cationic polymer G1 solution, and azide - modified polyepichlorohydrin solution, their solvents are one or more of N,N - dimethylformamide, dimethyl sulfoxide, and N - methylpyrrolidone.

4. The preparation method of a structurally controllable polyionic liquid according to claim 1, characterized in that, The tertiary amine-azide compound is dimethyl azidoethylamine, dimethyl azidopropylamine, dimethyl azidobutylamine, dimethyl azidopentylamine, dimethyl azidohexylamine, dimethyl azidoheptylamine, dimethyl azidooctylamine or a homolog with a main chain containing more methylene groups.

5. The preparation method of a structurally controllable polyionic liquid according to claim 1, characterized in that, The catalyst is one or more of cuprous chloride, cuprous bromide or elemental copper.

6. The preparation method of a structurally controllable polyionic liquid according to claim 1, characterized in that The post-treatment method is the precipitation method, and the precipitant is one or more of ether, ethyl acetate, acetone or tetrahydrofuran.

7. The preparation method of a structurally controllable polyionic liquid according to claim 6, characterized in that, The cationic molecular chain obtained in step S4 is prepared into a solution with a concentration of 10-50 g / l, and the operations of step S3 to step S4 are repeated 1-8 times to obtain the cationic molecular chain.

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