CN104311824B - Magnetic polymer based on polymine and preparation method thereof - Google Patents

Abstract

The invention relates to a magnetic polymer based on polyethyleneimine and a preparation method thereof; a method for post-modifying and synthesizing the magnetic polymer by using linear and branched polyethyleneimine as a macromolecular reactant. The main chain type magnetic polymer with magnetic elements is synthesized by quaternizing polyethyleneimine, ion exchange, and then replacing the original anion with tetrahalide ferric anion. The molecular weight of PEI used in the polymer is 600Da～1000kDa; Fe/N is 0.25～0.85. Polyethyleneimines of different chain structures and molecular weights are reacted with methyl iodide to form quaternary ammonium salts, and after ion exchange, the quaternary ammonium salts are reacted with metal halides to synthesize polymers containing magnetic elements. The method has the advantages of low cost, simple process, mild reaction conditions and simple operation steps. The magnetic polymer has potential applications in magnetic film materials, electromagnetic devices, wave-absorbing materials, and _CO2 separation and adsorption.

Description

Magnetic polymer based on polyethyleneimine and its preparation method

technical field

The present invention relates to a class of magnetic polymers and their synthesis methods, in particular to polyethyleneimine-based magnetic polymers and their preparation methods; linear and branched polyethyleneimines (PEI) are used as macromolecular reactants for post-modification synthesis Magnetic polymer approach.

Background technique

As the macromolecule with the highest density of amino groups, polyethyleneimine (PEI) has unique physical and chemical properties, so it has attracted a lot of researchers' interest in it. Boussif et al. (Boussif et al., Proceeding of the National Academy of Sciences, 92 (16), 7297-7301.) found that PEI can be used as a gene transfection reagent. Beyth et al. (Beythetal. Biomaterials 27 (2006) 3995-4002.) mixed cross-linked quaternized PEI into medical resin to study its antibacterial effect. Hu (Huetal., The Journal of Physical Chemistry B, 2005, 109(10): 4285-4289.) et al. used PEI to modify carbon nanotubes and use them as a substrate to induce neuronal cell growth. Son et al. (Sonetal., Microporous and Mesoporous Materials, 113(1), 31-40.) implanted PEI into porous silicon materials and explored its CO2 adsorption efficiency. Vinogradov et al. (Vinogradov et al., Mendeleev Communications, 19(4), 222-223.) synthesized porous CuO-Al2O3 composites using PEI as a structure-directing agent. Today, PEI has been widely used in gene transfection, antibacterial materials, CO2 adsorption materials, porous composite materials and other fields.

However, until now, no one has used PEI to modify and synthesize magnetic materials. In recent years, magnetic polymer materials have shown unique advantages in the fields of information industry and biomedical engineering. Especially in information storage materials, magnetic separation, wave-absorbing materials, magnetic resonance imaging, and controlled release of drugs, it has attractive application prospects and is one of the hot topics in current research. The existing magnetic polymer materials are roughly divided into two categories: one is magnetic composite materials mixed with inorganic magnetic particles; the other is magnetic polymers with magnetic groups on the main side chain. The former has the problem of poor compatibility, while the latter is often complicated in process and high in cost. The synthesis method of magnetic polymer with simple preparation process, relatively low cost and controllable magnetic properties is still blank. This patent synthesizes and characterizes a PEI-based magnetic macromolecule for the first time through quaternization of PEI, ion exchange, and complex iron salt.

The documents related to this patent are: In 2004, Hyashi et al. (S.Hayashietal., Chemistry Letters, 2004, 33, 1590-1591.) of Japan synthesized and reported for the first time that it was composed of quaternary ammonium salt cation and ferric tetrachloride anion ion. magnetic ionic liquid small molecules. In 2011, Spain's etc. (M. etal., Polymer Chemistry, 2011, 2, 1275-1278.) first reported the preparation of polyionic liquids containing tetrahalide ferric anions. The polymer was quaternized and anion exchanged by post-modification methods, and then compounded with tetrahalide Iron negative ions to prepare magnetic polymers.

Contents of the invention

The object of the present invention is to provide a series of polyethyleneimine-based magnetic polymers and their preparation methods.

The technical solution adopted by the present invention to solve technical problems:

A magnetic polymer based on polyethyleneimine, which has the following general chemical structure:

The molecular weight of PEI used in the synthesis of A and B is 600Da～1000kDa; Fe/N is 0.25～0.85.

The synthetic method of polymer of the present invention, step is as follows:

(1) Dissolve polyethyleneimine with a molecular weight of 600Da to 1000kDa in absolute ethanol, and add it dropwise to methyl iodide at a molar ratio of N atom to methyl iodide of 1:0.6 to 10; stir the reaction at 20 to 50°C to complete , centrifuged to obtain a solid that was dissolved in water, precipitated in ethanol, centrifuged, and vacuum-dried to obtain an intermediate product a;

(2) Dissolving the intermediate product a in water, adding an excessive amount of chlorine ion exchange resin relative to the N atoms to the reaction system, stirring the reaction to complete, filtering, rotating the filtrate, and vacuum drying to obtain the intermediate product b;

(3) Dissolve solid b in methanol, add FeCl ₃ 6H ₂ O equivalent to the quaternization unit, stir and react, spin evaporate, wash and precipitate the product in ether, centrifuge, and vacuum dry to obtain the target product magnetic polymer.

The synthesis method of the magnetic polymer of the present invention utilizes linear and branched polyethyleneimine as a macromolecular reactant, and post-modifies the method for synthesizing the magnetic polymer. Its preparation is through the quaternization of polyethyleneimine, ion exchange, and then replacing the original anion with tetrahalide ferric anion to synthesize a main chain type magnetic polymer with magnetic elements. Polyethyleneimines of different chain structures and molecular weights are reacted with methyl iodide to form quaternary ammonium salts, and after ion exchange, the quaternary ammonium salts react with metal halides to synthesize polymers containing magnetic elements. Main chain type magnetic polymers with different molecular weights with linear and branched structures were prepared by this method. A novel, feasible and efficient method for synthesizing magnetic polymers is provided, and the method has the characteristics of simple process, low cost and mild reaction conditions. The obtained magnetic polymer can be used as a magnetic film material, a wave absorbing material, and a CO ₂ separation and adsorption material. Compared with the previous materials, it has the characteristics of low cost, high magnetism, and strong stability.

Description of drawings

The nuclear magnetic spectrum of Fig. 1 embodiment 1 polymer 1b;

The Raman spectrum of Fig. 2 embodiment 1 magnetic polymer A ₁ ;

The superconducting quantum interference spectrum of Fig. 3 embodiment 1 magnetic polymer A ₁ ;

Fig. 4 is the superconducting quantum interference spectrum of magnetic polymer A ₂ in Example 2.

Fig. 5 is the superconducting quantum interference spectrum of magnetic polymer A ₃ in Example 3.

Fig. 6 is the superconducting quantum interference spectrum of magnetic polymer B ₁ in Example 4.

Fig. 7 is the superconducting quantum interference spectrum of magnetic polymer B ₂ in Example 5.

Fig. 8 is the superconducting quantum interference spectrum of the magnetic polymer _B3 in Example 6.

detailed description

The following examples help to further understand the present invention, but do not limit the present invention.

Example 1

Synthesis _of Magnetic Polymer A1:

(1) Dissolve linear PEI (270.8 mg, 6.3 mmol) with a molecular weight of 600 Da in 5 ml of absolute ethanol, and add dropwise into iodomethane (4 ml, 64.2 mmol). Stir at 42° C. for 60 h, centrifuge after the reaction to obtain a yellow solid which is dissolved in water, precipitate in ethanol, centrifuge, and vacuum-dry to obtain the intermediate product 1a.

(2) Dissolve 1a (146.0 mg, 1.0 mmol) in water, add 4 g of chloride ion exchange resin to the system and stir for 8 h. After filtration, the filtrate was rotary evaporated and dried in vacuo to obtain light yellow solid 1b. According to the elemental analysis in Table 1, the quaternization conversion rate was 66%. As shown in Figure 1, the H NMR spectrum of 1b, ¹ HNMR (500Hz, D ₂ O) chemical shift δ: 3.2-3.6 (multiple peaks, -CH ₂ -, -CH ₃ connected to the quaternization unit), 2.7 -3.2 (Multiplet, _-CH2- attached to PEI unit).

(3) Dissolve 1b (83.2mg, 1.0mmol) and FeCl ₃ 6H ₂ O (170.4mg, 0.633mmol) equivalent to the quaternization unit in 5ml of methanol, stir for 16h, suspend and steam, and distill the product with anhydrous ether Washing, centrifugation to obtain a brown solid, and vacuum drying to obtain Magnetic Polymer A ₁ . Figure ₂ shows the Raman spectrum of magnetic polymer A1. The Raman spectrum at 334cm ^-1 is the absorption peak of Fe-Cl in FeCl ₄ ^-ion , which is consistent with the literature (S. Hayashi et al., Chemistry Letters, 2004, 33, 1590-1591.). As shown in Figure ₃ , the superconducting quantum interference spectrum of magnetic polymer A1 is a straight line passing through the origin, indicating that it has paramagnetism.

Example 2

Synthesis of Magnetic Polymer A2 _:

(1) Dissolve linear PEI (268.7 mg, 6.2 mmol) with a molecular weight of 1000 kDa in 5 ml of absolute ethanol, and add dropwise into iodomethane (3.9 ml, 62.6 mmol). Stir at 50° C. for 100 h, centrifuge after the reaction to obtain a yellow solid which is dissolved in water, precipitate in ethanol, centrifuge, and vacuum-dry to obtain the intermediate product 2a.

(2) Dissolve 2a (175.6mg, 1.0mmol) in water, add 4g of chloride ion exchange resin to the system and stir for 12h. After filtration, the filtrate was rotary evaporated and dried in vacuo to obtain light yellow solid 2b. According to the elemental analysis in Table 1, the quaternization conversion rate was 85%.

(3) Dissolve 2b (83.2mg, 1.0mmol) and FeCl ₃ 6H ₂ O (170.4mg, 0.633mmol) equivalent to the quaternization unit in 5ml of methanol, stir for 24h, and steam the product with anhydrous ether Wash and centrifuge to obtain a brown solid, and dry in vacuum to obtain Magnetic Polymer A ₂ . As shown in Figure 4, the superconducting quantum interference spectrum of the magnetic polymer A ₂ is a straight line passing through the origin, indicating that it has paramagnetism.

Example 3

Synthesis _of Magnetic Polymer A3:

(1) Linear PEI (268.7mg, 6.2mmol) with a molecular weight of 10kDa was dissolved in 5ml of absolute ethanol, and added dropwise to iodomethane (0.23ml, 0.37mmol). Stirring at 20° C. for 1 h, after the reaction was completed, centrifuged to obtain a yellow solid which was dissolved in water, precipitated in ethanol, centrifuged, and dried in vacuo to obtain the intermediate product 3a.

(2) Dissolve 3a (82.1mg, 1.0mmol) in water, add 4g of chloride ion exchange resin to the system and stir for 12h. After filtration, the filtrate was rotary evaporated and dried in vacuo to obtain light yellow solid 3b. According to the elemental analysis in Table 1, the quaternization conversion rate was 25%.

(3) Dissolve 3b (59.1mg, 1.0mmol) and FeCl ₃ 6H ₂ O (170.4mg, 0.633mmol) equivalent to the quaternization unit in 5ml of methanol, stir for 24h, suspend and steam, and the product is distilled with anhydrous diethyl ether Washing, centrifugation to obtain a brown solid, and vacuum drying to obtain magnetic polymer A ₃ . As shown in Figure ₅ , the superconducting quantum interference spectrum of the magnetic polymer A3 is a straight line passing through the origin, indicating that it has paramagnetism.

Example 4

Synthesis _of Magnetic Polymer B1:

(1) Dissolve branched-chain PEI (344.3 mg, 8.0 mmol) with a molecular weight of 0.18 kDa in 5 ml of absolute ethanol, and slowly dropwise add it into iodomethane (2.5 ml, 40.1 mmol). Stirring at 40° C. for 48 h, after the reaction was completed, centrifuged to obtain a yellow solid which was dissolved in water, precipitated in ethanol, centrifuged, and dried in vacuum to obtain the intermediate product 4a.

(2) Dissolve 4a (114.8mg, 1.0mmol) in water, add 4g of chloride ion exchange resin to the system and stir for 12h. After filtration, the solution was rotary evaporated, and vacuum dried to obtain light yellow solid 4b. According to the elemental analysis in Table 1, the quaternization conversion rate was 46%. (3) Dissolve 4b (72.2mg, 1.0mmol) and FeCl ₃ 6H ₂ O (124.4mg, 0.46mmol) equivalent to the quaternization unit in 5ml of methanol, stir for 16h, suspend and steam, and the product is distilled with anhydrous ether The precipitate was washed to obtain a tan solid, which was dried in vacuo to obtain Magnetic Polymer B ₁ . As shown in Figure 6, the enlarged superconducting quantum interference spectrum of magnetic polymer B ₁ has a hysteresis loop, indicating that it has ferromagnetism.

Example 5

Synthesis of Magnetic Polymer B2 _:

(1) Dissolve branched PEI (258.1 mg, 6.0 mmol) with a molecular weight of 10 kDa in 5 ml of absolute ethanol, and slowly dropwise add it into iodomethane (3.0 ml, 60.0 mmol). Stir at 40° C. for 60 h, centrifuge after the reaction to obtain a yellow solid which is dissolved in water, precipitate in ethanol, centrifuge, and vacuum-dry to obtain intermediate product 5a.

(2) Dissolve 5a (139.8mg, 1.0mmol) in water, add 5g of chloride ion exchange resin to the system and stir for 12h. After filtration, the solution was rotary evaporated, and dried in vacuum to obtain light yellow solid 5b. According to the elemental analysis in Table 1, the quaternization conversion rate was 62%.

(3) Dissolve 5b (83.0mg, 1.0mmol) and FeCl ₃ 6H ₂ O (124.4mg, 0.46mmol) equivalent to the quaternization unit in 5ml of methanol, stir for 16h, suspend and steam, and the product is distilled with anhydrous ether The precipitate was washed to obtain a tan solid, which was dried in vacuum to obtain the magnetic polymer B ₂ . As shown in Figure 7, the superconducting quantum interference spectrum of magnetic polymer B ₂ has a hysteresis loop after zooming in, indicating that it has ferromagnetism.

Example 6

Synthesis of Magnetic Polymer _B3 :

(1) Dissolve branched PEI (266.5 mg, 6.2 mmol) with a molecular weight of 100 kDa in 5 ml of absolute ethanol, and slowly dropwise add it into iodomethane (2.5 ml, 40.1 mmol). Stir at 50° C. for 72 h, centrifuge after the reaction to obtain a yellow solid which is dissolved in water, precipitate in ethanol, centrifuge, and dry in vacuo to obtain intermediate product 6a.

(2) Dissolve 6a (153.7mg, 1.0mmol) in water, add 4g of chloride ion exchange resin to the system and stir for 12h. After filtration, the solution was rotary evaporated, and vacuum dried to obtain a light yellow solid 6b. According to the elemental analysis in Table 1, the quaternization conversion rate was 71%.

(3) Dissolve 6b (88.8mg, 1.0mmol) and FeCl ₃ 6H ₂ O (124.4mg, 0.46mmol) equivalent to the quaternization unit in 5ml of methanol, stir for 16h, suspend and distill the product with anhydrous diethyl ether The precipitate was washed to obtain a tan solid, which was dried in vacuo to obtain the magnetic polymer B ₃ . As shown in Figure 8, the superconducting quantum interference spectrum of magnetic polymer _B3 has a hysteresis loop after zooming in, indicating that it has ferromagnetism.

Table 1

The above is an exemplary description of the present invention, which is not restrictive. The present invention is not limited to the technology described in the embodiments, and the authority is defined by the claims, based on the changes, reorganizations, etc. The technologies related to the present invention obtained by the method are all within the protection scope of the present invention.

Claims (3)

1. A magnetic polymer based on polyethyleneimine, characterized in that the magnetic polymer has the following general chemical structure: The molecular weight of the polyethyleneimine used in the synthesis of A and B is 600Da-1000kDa; the molar ratio of Fe/N is 0.25-0.85. 2. the synthetic method of the polymkeric substance of claim 1 is characterized in that step is as follows: (1) Dissolve polyethyleneimine with a molecular weight of 600Da to 1000kDa in absolute ethanol, and add it dropwise to methyl iodide at a molar ratio of N atom to methyl iodide of 1:0.6 to 10; stir the reaction at 20 to 50°C to complete , centrifuged to obtain a solid that was dissolved in water, precipitated in ethanol, centrifuged, and vacuum-dried to obtain an intermediate product a; (2) Dissolving the intermediate product a in water, adding an excessive amount of chlorine ion exchange resin relative to the N atoms to the reaction system, stirring the reaction to complete, filtering, rotating the filtrate, and vacuum drying to obtain the intermediate product b; (3) Dissolve solid b in methanol, add FeCl ₃ 6H ₂ O equivalent to the quaternization unit, stir and react, spin evaporate, wash and precipitate the product in ether, centrifuge, and vacuum dry to obtain the target product magnetic polymer. 3. the magnetic polymer of polyethylenimine described in claim 1 is preparing magnetic film material, electromagnetic device, wave-absorbing material and _CO separation material and _CO sorption material aspect application.