Polyamides, process for their preparation and use
Patent Information
- Application Number
- CN202311605613.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-27
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2043-11-27
AI Technical Summary
Existing methods for preparing polyamidines are usually carried out at high temperatures, which leads to the formation of byproducts and the methods are not mild enough to achieve high atom economy.
Polyamidinium with regio- and stereoregular structures is prepared by polymerization of polyacid monomers and polyamine monomers in an organic solvent under the action of an alkaline catalyst, under the protection of an inert gas atmosphere.
The method enables the efficient preparation of polyamidine under low-temperature conditions, exhibiting good solubility, processing performance, and thermal stability, with no byproduct formation, and meets the requirements of atom economy.
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Figure CN117720724B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer chemistry and materials science, specifically relating to a polyamidine, its preparation method, and its application. Background Technology
[0002] Polyamidine, also known as imine, is a class of polymers containing amidine groups in their molecular chains. Due to its potential applications in drug controlled release, heavy metal ion separation, papermaking additives, sludge dewatering agents, and flocculants, it is receiving increasing attention. Currently, there are various methods for preparing polyamidine. For example, polyamidine can be prepared by polymerizing diketene imine with a diamine in refluxed 1,4-dioxane under nitrogen protection (Journal of Polymer Science, Polymer Chemistry Edition, 1977, 15, 2163); polyamidine can also be prepared by polymerizing nitrile with an amine using aluminum trichloride catalyzed under argon protection at 200°C (Russian Chemical Bulletin, 2010, 59, 2159); polyamidine can also be prepared by reacting a diamine monomer with triethylcarboxylate at 180°C under nitrogen protection, accompanied by the production of ethanol as a byproduct (Polymer Bulletin, 1993, 31, 381; Polymer Bulletin, 1994, 33, 397; Polymer Bulletin (1995, 34, 43) reported the preparation of polyamidinium by polymerizing aryl diamine monomers and monocarboxylic acid monomers in sulfolane at 160 °C using poly(trimethylsilane phosphate) as a catalyst. The methods described above for preparing polyamidinium generally involve high temperatures and some may produce byproducts. Therefore, establishing novel polymerization reactions with high atom economy under mild conditions for the preparation of polyamidinium is of great significance. Summary of the Invention
[0003] In order to overcome the shortcomings and deficiencies of existing technologies, enrich the preparation methods of polyamidine, and realize the application value of polyamidine, the purpose of this invention is to provide a polyamidine and its preparation method and application; this invention provides a method for preparing regio- and stereoregular polyamidine based on nitrile and amine monomers, which is simple, efficient and easy to operate.
[0004] Another object of the present invention is to provide a polyamidine prepared by the above method, which has good solubility, processability, thermal stability and film-forming properties.
[0005] The objective of this invention is achieved through the following technical solution:
[0006] A method for preparing polyamidine includes the following steps:
[0007] Under the protection of an inert gas, polyacrylonitrile monomers and polyamine monomers, or monomers containing both cyano and amino groups, are subjected to a one-step polymerization reaction in an organic solvent with an alkaline catalyst to obtain polyamidine.
[0008] The polynitrile monomer contains at least two cyano groups; the polyamine monomer contains at least two amino groups; the monomer containing both cyano and amino groups contains at least one cyano group and at least one amino group.
[0009] Preferably, the polynitrile monomer is as shown in formula (Ⅲ):
[0010]
[0011] The polyamine monomers are shown in formula (IV):
[0012] H2N-R 2 -NH2 (IV);
[0013] The monomer containing both cyano and amino groups is shown in formula (V):
[0014]
[0015] The general structural formula of the polyamidine is shown in formula (I) or formula (II);
[0016]
[0017] In equations (I) to (V), n is an integer from 3 to 200, and R 1 R 2 R 3 These are the same or different organic groups.
[0018] In a further preferred embodiment, in equations (I) to (V), R 1 R 2 R 3 Each is independently selected from the following chemical structures
[0019] Any one of Equations 1 to 27;
[0020]
[0021] Where m, h, i, j, and k are each independent integers from 1 to 20; X is selected from NH, O, or S elements; * indicates the substitution position.
[0022] Preferably, the inert gas is nitrogen or a rare gas (such as argon).
[0023] Preferably, the organic solvent is at least one selected from tetrahydrofuran, dichloromethane, chloroform, toluene, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylacetamide, and N,N-dimethylformamide;
[0024] More preferably, the organic solvent is dimethyl sulfoxide; the resulting polyamidine has a higher molecular weight and better solubility, making it easier to apply in the next step.
[0025] Preferably, the alkaline catalyst is at least one selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, potassium carbonate, cesium carbonate, sodium carbonate, sodium methoxide, sodium tert-butoxide, potassium tert-butoxide, lithium tert-butoxide, potassium hydride, sodium hydride, phosphononitrile base, triethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and 4-dimethylaminopyridine (DMAP);
[0026] More preferably, the alkaline catalyst is at least one selected from sodium tert-butoxide, potassium tert-butoxide, lithium tert-butoxide, potassium hydride, and sodium hydride;
[0027] Preferably, the amount of the alkaline catalyst is 5 to 500% of the molar amount of cyano groups in the polynitrile monomer; the amount of the alkaline catalyst is 5 to 500% of the molar amount of nitrile groups in a monomer that contains both cyano and amino groups.
[0028] More preferably, the amount of the alkaline catalyst is 150-250% of the molar amount of cyano groups in the polynitrile monomer; the amount of the alkaline catalyst is 150-250% of the molar amount of cyano groups in a monomer that contains both cyano and amino groups.
[0029] Preferably, the molar ratio of the cyano group in the polynitrile monomer to the amino group in the polyamine monomer is (0.5-3):1;
[0030] More preferably, the molar ratio of the nitrile group in the polynitrile monomer to the amino group in the polyamine monomer is 1:1;
[0031] Preferably, the concentration of the polynitrile monomer is 0.05–5 mol / L; the concentration of the monomer containing both cyano and amino groups is 0.05–5 mol / L.
[0032] More preferably, the concentration of the polynitrile monomer is 0.4–0.6 mol / L; the concentration of the monomer containing both cyano and amino groups is 0.8–1.2 mol / L.
[0033] Preferably, the polymerization reaction temperature is 0–180°C; more preferably, the temperature is 0–50°C. Even more preferably, the polymerization reaction temperature is 10–35°C.
[0034] Preferably, the polymerization reaction takes 5 minutes to 36 hours. Alternatively, the polymerization reaction takes 6 hours to 30 hours.
[0035] Preferably, the polymerization reaction is carried out at a rotation speed of 20-800 rpm.
[0036] Preferably, after the polymerization reaction is completed, the crude product is dissolved in organic solvent 1, then a precipitant is added for precipitation, the precipitate is collected, and dried to constant weight;
[0037] More preferably, the precipitant is at least one of water, methanol, ethanol, acetone, ethyl acetate, dichloromethane, and tetrahydrofuran; the organic solvent 1 is at least one of dimethyl sulfoxide, N,N-dimethylacetamide, and N,N-dimethylformamide; the ratio of the organic solvent 1 to the polynitrile monomer is (5-10) mL: (0.1-5) mol; and the drying is vacuum drying at a temperature of 25-80°C.
[0038] The above-described preparation method yields polyamidine. This polyamidine exhibits good thermal stability and excellent processability, showing promising application prospects.
[0039] The above-mentioned polyamidines have applications as optical materials, in metal ion detection, and in the preparation of bioimaging reagents.
[0040] Compared with the prior art, the present invention has the following advantages:
[0041] (1) The preparation method of the present invention directly uses polynitrile monomers and polyamine monomers to carry out polymerization reaction at a lower temperature to prepare polyamidine, which is innovative and of great significance.
[0042] (2) The reaction raw materials of the present invention are readily available and can be purchased directly or prepared through a simple reaction; the polymerization conditions are mild, the process is simple, the polymerization efficiency is high, and the product has a high molecular weight.
[0043] (3) The preparation method of the present invention has excellent regioselectivity and stereoselectivity, and no by-products are generated during the polymerization process. It is a green polymerization that meets the requirements of atom economy. Attached Figure Description
[0044] Figure 1 The infrared spectra of polyamidine P1, the model small molecule compound, and their corresponding monomers prepared in Example 1 are shown below; where A is the spectrum of monomer 1a, B is the spectrum of monomer 2a, C is the spectrum of model compound M1, and D is the spectrum of polyamidine P1 prepared in Example 1.
[0045] Figure 2The images show the 1H NMR spectra of polyamidine P1, the model small molecule compound, and their corresponding monomers prepared in Example 1 in deuterated DMSO; where A is the spectrum of monomer 1a, B is the spectrum of monomer 2a, C is the spectrum of model compound M1, and D is the spectrum of polyamidine P1 prepared in Example 1.
[0046] Figure 3 This is a single-crystal diagram of the model compound M2;
[0047] Figure 4 The thermogravimetric curve of polyamidine P1 prepared in Example 1 is shown. Detailed Implementation
[0048] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. However, the implementation of the present invention is not limited thereto. For process parameters not specifically noted, conventional techniques can be referred to.
[0049] In the following examples, the room temperature is 10–35°C.
[0050] Example 1
[0051] In this embodiment, monomer 1a is terephthalonitrile, and its structural formula is: 2a is 4,4'-diaminodiphenylmethane, and its structural formula is: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0052] This invention systematically explores the polymerization reaction conditions of monomers 1a and 2a, specifically including the polymerization solvent, monomer concentration, polymerization reaction time, catalyst dosage, reaction temperature, and catalyst type. The polymerization reaction results are shown in Table 1 (where monomer concentration refers to the concentration of monomer 1a, and the concentrations of monomers 1a and 2a are the same; rt refers to room temperature; parameters and processes not given are the same as the optimal preparation method described below).
[0053] Table 1. Optimization of polymerization reaction conditions for monomers 1a and 2a
[0054]
[0055] An optimal preparation method for polyamidine (P1) comprises the following steps:
[0056] (1) Add a magnetic magnet, monomer 1a (64.0 mg, 0.5 mmol), monomer 2a (99.0 mg, 0.5 mmol), and sodium hydride (40.0 mg, 1 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide with a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0057] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P1.
[0058] Analysis showed that the yield of polyamidine P1 was 99%, the weight-average molecular weight was 20,700, and the molecular weight distribution was 1.50.
[0059] Model compounds The preparation method is similar to that of polymers.
[0060] The infrared spectra of the polyamidinium, its corresponding monomers, and model compounds are as follows: Figure 1 (Where A is the spectrum of monomer 1a, B is the spectrum of monomer 2a, C is the spectrum of model compound M1, and D is the spectrum of polyamidinium). From Figure 1 The polymer can be preliminarily identified as polymidine, and monomer 1a is measured at a wavenumber of 2239 cm⁻¹. -1 The stretching vibration peak of the cyano group (C≡N) disappeared in the spectra of model compound M1 and polymer P1, and the characteristic infrared peaks of the amino group (-NH2) and carbon-nitrogen double bond (C=N) of amidine were formed at 3354 and 1588 cm⁻¹, respectively. -1 Appear.
[0061] The 1H NMR spectra of the polyamidinium, its corresponding monomer, and model compounds are shown below. Figure 2 (Where A is the spectrum of monomer 1a, B is the spectrum of monomer 2a, C is the spectrum of model compound M1, and D is the spectrum of polyamidinium). From Figure 2 The polymer can be identified as polyamidine, and the monomer 2a ( Figure 2 The -NH2 at a chemical shift of 4.79 ppm in the model compound (B) Figure 2 It disappears in C and in polyamidine ( Figure 2 The concentration of -NH2 on the amidine formed by the reaction of model compound M1 with polyamidinium is very weak. The presence of a single peak at a chemical shift of 6.26 ppm indicates that the polymerization reaction has proceeded successfully. Furthermore, the single-crystal structure of model compound M2 (…) Figure 3The carbon-nitrogen double bond of amidine is shown to be in E-type structure, further demonstrating that the polymerization reaction has excellent regioselectivity and stereoselectivity.
[0062] Figure 4 The thermogravimetric analysis (TGA) of polyamidine P1 shows a thermal decomposition temperature (the temperature corresponding to a 5% weight loss) of 273℃, indicating that the prepared polyamidine has excellent thermal stability. Furthermore, this polyamidine compound is readily soluble in common organic solvents such as dimethyl sulfoxide, dimethylformamide, and dimethylacetamide at room temperature, demonstrating excellent solubility and processability.
[0063] The structural formula of polyamidine P1 is:
[0064]
[0065] Example 2
[0066] In this embodiment, monomer 1a is terephthalonitrile, and its structural formula is: 2b is a 4,4'-diaminodiphenyl ether, with the following structural formula: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0067] A method for preparing polyamidine (P2) includes the following steps:
[0068] (1) Add a magnetic magnet, monomer 1a (64.0 mg, 0.5 mmol), monomer 2b (100.0 mg, 0.5 mmol), and sodium hydride (40.0 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide with a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0069] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 24 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P2.
[0070] Analysis revealed that the yield of polyamidine P2 was 99%, with a weight-average molecular weight of 13,000 and a molecular weight distribution of 1.28. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0071] The polyamidine P2 has the following structural formula:
[0072]
[0073] Example 3
[0074] In this embodiment, monomer 1a is terephthalonitrile, and its structural formula is: 2c is 4,4'-methylenebis(2,6-diethylaniline), with the following structural formula: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0075] A method for preparing polyamidine (P3) includes the following steps:
[0076] (1) Add a magnetic magnet, monomer 1a (64.0 mg, 0.5 mmol), monomer 2c (155.0 mg, 0.5 mmol), and sodium hydride (40 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide with a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0077] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 24 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P3.
[0078] Analysis revealed that the yield of polyamidine P3 was 99%, with a weight-average molecular weight of 6900 and a molecular weight distribution of 1.08. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0079] The polyamidine P3 has the following structural formula:
[0080]
[0081] Example 4
[0082] In this embodiment, monomer 1a is terephthalonitrile, and its structural formula is: 2d is 4,4'-diaminodiphenyl sulfone, and its structural formula is: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0083] A method for preparing polyamidine (P4) includes the following steps:
[0084] (1) Add a magnetic magnet, monomer 1a (60.0 mg, 0.5 mmol), monomer 2d (124 mg, 0.5 mmol), and sodium hydride (40 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide with a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0085] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P4.
[0086] Analysis revealed that the yield of polyamidine P4 was 99%, with a weight-average molecular weight of 10,900 and a molecular weight distribution of 1.14. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0087] The polyamidinium P4 has the following structural formula:
[0088]
[0089] Example 5
[0090] In this embodiment, monomer 1a is terephthalonitrile, and its structural formula is: 2e is 4,4'-diamino-3,3'-dimethylbiphenyl, with the following structural formula: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0091] A method for preparing polyamidine (P5) includes the following steps:
[0092] (1) Add a magnetic magnet, monomer 1a (60.0 mg, 0.5 mmol), monomer 2e (106 mg, 0.5 mmol), and sodium hydride (40 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide with a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0093] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P5.
[0094] Analysis revealed that the yield of polyamidine P5 was 95%, with a weight-average molecular weight of 11,500 and a molecular weight distribution of 1.30. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0095] The polyamidine P5 has the following structural formula:
[0096]
[0097] Example 6
[0098] In this embodiment, monomer 1b is isophthalonitrile, and its structural formula is as follows: 2a is 4,4'-diaminodiphenylmethane, and its structural formula is: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0099] A method for preparing polyamidine (P6) includes the following steps:
[0100] (1) Add a magnetic magnet, monomer 1b (60.0 mg, 0.5 mmol), monomer 2a (79.2 mg, 0.5 mmol), and sodium hydride (40 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide using a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0101] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P6.
[0102] Analysis revealed that the yield of polyamidine P6 was 99%, with a weight-average molecular weight of 20,700 and a molecular weight distribution of 1.50. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0103] The structural formula of polyamidine P6 is:
[0104]
[0105] Example 7
[0106] In this embodiment, monomer 1b is isophthalonitrile, and its structural formula is as follows: 2b is a 4,4'-diaminodiphenyl ether, with the following structural formula: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0107] A method for preparing polyamidine (P7) includes the following steps:
[0108] (1) Add a magnetic magnet, monomer 1b (60.0 mg, 0.5 mmol), monomer 2b (80.0 mg, 0.5 mmol), and sodium hydride (40 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide using a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0109] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P7.
[0110] Analysis revealed that the yield of polyamidine P7 was 98%, with a weight-average molecular weight of 11,600 and a molecular weight distribution of 1.21. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0111] The polyamidinium P7 has the following structural formula:
[0112]
[0113] Example 8
[0114] In this embodiment, monomer 1b is isophthalonitrile, and its structural formula is as follows: 2c is 4,4'-methylenebis(2,6-diethylaniline), with the following structural formula: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0115] A method for preparing polyamidine (P8) includes the following steps:
[0116] (1) Add a magnetic magnet, monomer 1b (60.0 mg, 0.5 mmol), monomer 2c (155.0 mg, 0.5 mmol), and 60% sodium hydride (40 mg, 1.0 mmol) to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper. Then, evacuate the tube and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide using a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is complete, dilute the reaction solution to 5 mL with dimethyl sulfoxide.
[0117] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P8.
[0118] Analysis revealed that the yield of polyamidine P8 was 78%, with a weight-average molecular weight of 5800 and a molecular weight distribution of 1.04. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0119] The polyamidine P8 has the following structural formula:
[0120]
[0121] Example 9
[0122] In this embodiment, monomer 1b is isophthalonitrile, and its structural formula is as follows: 2d is 4,4'-diaminodiphenyl sulfone, and its structural formula is: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0123] A method for preparing polyamidine (P9) includes the following steps:
[0124] (1) Add a magnetic magnet, monomer 1b (60.0 mg, 0.5 mmol), monomer 2d (124 mg, 0.5 mmol), and sodium hydride (40 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide with a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0125] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P9.
[0126] Analysis revealed that the yield of polyamidine P9 was 99%, with a weight-average molecular weight of 9100 and a molecular weight distribution of 1.10. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0127] The polyamidine P9 has the following structural formula:
[0128]
[0129] Example 10
[0130] In this embodiment, monomer 1b is isophthalonitrile, and its structural formula is as follows: 2e is 4,4'-diamino-3,3'-dimethylbiphenyl, with the following structural formula: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0131] A method for preparing polyamidine (P10) includes the following steps:
[0132] (1) Add a magnetic magnet, monomer 1b (60.0 mg, 0.5 mmol), monomer 2e (106 mg, 0.5 mmol), and sodium hydride (40 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide with a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0133] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P10.
[0134] Analysis revealed that the yield of polyamidine P10 was 95%, with a weight-average molecular weight of 11,500 and a molecular weight distribution of 1.30. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0135] The polyamidine P10 has the following structural formula:
[0136]
[0137] Example 11
[0138] In this embodiment, monomer 1a is terephthalonitrile, and its structural formula is: 2f is p-phenylenediamine, and its structural formula is: All of these are commercially available and inexpensive; in this example, they were purchased from Anaiji Chemical.
[0139] A method for preparing polyamidine (P11) includes the following steps:
[0140] (1) Add a magnetic magnet, monomer 1a (60.0 mg, 0.5 mmol), monomer 2f (68.0 mg, 0.5 mmol), and sodium hydride (40 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide using a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0141] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P11.
[0142] Analysis revealed that the yield of polyamidine P11 was 33%, with a weight-average molecular weight of 5300 and a molecular weight distribution of 1.10. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0143] The polyamidine P11 has the following structural formula:
[0144]
[0145] Example 12
[0146] In this embodiment, monomer 3a is m-aminobenzonitrile, and its structural formula is: It is commercially available at a low price; in this example, it was purchased from Energie Chemicals.
[0147] A method for preparing polyamidine (P12) includes the following steps:
[0148] (1) Add a magnetic magnet, monomer 3a (118 mg, 1.0 mmol) and sodium hydride (40 mg, 1.0 mmol) with a mass fraction of 60% to a 25 mL polymerization tube with a branch end. Seal the polymerization tube with a rubber stopper, then evacuate and replace the nitrogen gas three times. Inject 1.0 mL of dimethyl sulfoxide with a syringe. Place the polymerization tube at room temperature and stir for 24 hours (400 rpm). After the reaction is completed, dilute the reaction solution with dimethyl sulfoxide to 5 mL.
[0149] (2) Under stirring conditions (600 rpm), the polymer solution was added dropwise to water, then allowed to stand (standing time was 12 h), filtered, and vacuum dried to constant weight (drying temperature was 50 °C) to obtain polyamidine P12.
[0150] Analysis revealed that the yield of polyamidine P12 was 33%, with a weight-average molecular weight of 4100 and a molecular weight distribution of 1.12. Furthermore, this polyamidine is readily soluble in common organic solvents such as DMF, DMSO, and DMAc at room temperature, indicating excellent solubility and processability.
[0151] The polyamidine P12 has the following structural formula:
[0152]
[0153] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A method for preparing polyamidine, characterized in that, Includes the following steps: Polyamidinium is obtained by polymerizing diaromatic nitrile monomers and diaromatic amine monomers, or monomers containing both cyano and amino groups, in an organic solvent under the action of an alkaline catalyst under the protection of an inert gas. The alkaline catalyst is at least one of sodium tert-butoxide, potassium tert-butoxide, lithium tert-butoxide, potassium hydride, and sodium hydride. The amount of the alkaline catalyst used is 150-250% of the molar amount of cyano groups in the binary aromatic nitrile monomer; the amount of the alkaline catalyst used is 150-250% of the molar amount of cyano groups in monomers containing both cyano and amino groups. The polymerization reaction is carried out at a temperature of 10~35℃; The binary aromatic nitrile monomers are shown in formula (Ⅲ): （Ⅲ）； The aforementioned diaromatic amine monomers are shown in formula (IV): (IV); The monomer containing both cyano and amino groups is shown in formula (V): （V）； The general structural formula of the polyamidine is shown in formula (I) or formula (II); （I）； (II); In equations (I) to (V), n is an integer from 3 to 200, and R 1 R 2 R 3 These are the same or different organic groups.
2. The preparation method according to claim 1, characterized in that, In equations (I) to (V), R 1 R 2 R 3 Each is independently selected from any one of the following chemical structural formulas 1 to 22; Where m, h, i, and j are each independent integers from 1 to 20; X is selected from elements NH, O, or S. Indicates a replacement position.
3. The preparation method according to claim 1, characterized in that, The organic solvent is at least one selected from tetrahydrofuran, dichloromethane, chloroform, toluene, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylacetamide, and N,N-dimethylformamide.
4. The preparation method according to claim 1, characterized in that, The molar ratio of the cyano group in the binary aromatic nitrile monomer to the amino group in the binary aromatic amine monomer is (0.5~3):1; The concentration of the binary aromatic nitrile monomer is 0.05~5 mol / L; the concentration of the monomer containing both cyano and amino groups is 0.05~5 mol / L.
5. The preparation method according to claim 4, characterized in that, The molar ratio of the cyano group in the binary aromatic nitrile monomer to the amino group in the binary aromatic amine monomer is 1:1; The concentration of the binary aromatic nitrile monomer is 0.4~0.6 M; The concentration of the monomer containing both cyano and amino groups is 0.8~1.2 M; The polymerization reaction takes 6 h to 30 h.
6. The preparation method according to claim 1, characterized in that, After the polymerization reaction is completed, the crude product is dissolved in organic solvent 1, and then a precipitant is added to precipitate the product. The precipitate is collected and dried to constant weight. The precipitant is at least one of water, methanol, ethanol, acetone, ethyl acetate, dichloromethane, and tetrahydrofuran; the organic solvent 1 is at least one of dimethyl sulfoxide, N,N-dimethylacetamide, and N,N-dimethylformamide; the ratio of organic solvent 1 to the diaromatic nitrile monomer is (5~10) mL: (0.1~5) mol; the drying is vacuum drying at a temperature of 25~80 ℃.