Magnetic polymer as well as preparation method and application thereof

Abstract

The invention relates to the field of magnetic material preparation, in particular to a magnetic polymer and a preparation method and application thereof. The preparation method comprises the following steps: carrying out first polymerization reaction on magnetic particles, a sulfhydryl compound, a first polyol monomer and an isocyanate monomer; wherein the magnetic particles comprise oxides containing Fe < 2 + > and / or Fe < 3 + >. The first polymerization reaction can be carried out on the surfaces of the magnetic particles, the generated polymer can tightly coat the magnetic particles, and the controllability of the specific surface area and the particle size of the obtained magnetic polymer is relatively good. The magnetic polymer also has good magnetic responsiveness and can be applied to the field of magnetic response, such as biomedicine, protein purification, immunochromatography, cell labeling, cell separation and the like.

Description

Technical Field

[0001] The present invention relates to the field of preparation of magnetic materials, and particularly relates to a magnetic polymer, a preparation method thereof and an application thereof. Background Art

[0002] Magnetic-responsive polymer microspheres refer to superparamagnetic microsphere particles with a particle size in the micron or nanometer range. They have the ability to move directionally under the action of an external magnetic field, can move and aggregate under the action of an external magnetic field, and can be redispersed after removing the external magnetic field. They are mainly magnetic polymer microspheres prepared by decorating a magnetic core made of magnetic nanomaterials or magnetic nanocomposites through monolayer or multilayer assembly. Due to their rapid separation characteristics, they have broad application prospects in the fields of biomedicine, protein purification and immunochromatography, cell labeling, cell separation and bioengineering.

[0003] The complex diversity of the application fields of magnetic microspheres requires magnetic microspheres to have more excellent properties. For example, uniform particle size, strong enough magnetic responsiveness, not easy to settle, rich surface active groups that can be coupled with biochemical substances, and rapid separation from the sample to be measured under the action of an external magnetic field. Strong superparamagnetic responsiveness corresponds to a high content of superparamagnetic particles in the magnetic microspheres, and these superparamagnetic particles are generally iron oxides. The preparation of magnetic microspheres generally includes coprecipitation method, oxidation precipitation method, reduction precipitation method, complex polymerization method and physical adsorption method. Each method has its advantages and disadvantages, and its average particle size is generally between 0.2 - 20 μm. Modifying magnetic microspheres or magnetic nanoparticles finally obtains active groups such as hydroxyl, carboxyl, phenolic hydroxyl, ester, primary amine, secondary amine, urea, amide, etc., but there are problems such as low group density or iron leakage.

[0004] CN110049972A discloses a method for polymer-coated magnetic microspheres, which uses appropriate polymer monomers and crosslinking agents to perform two swelling polymerizations on polymer microspheres containing superparamagnetic crystals to coat the polymer microspheres, thereby solving the problem of leakage of superparamagnetic particles. However, the existing magnetic microsphere coating methods still have defects such as low group density and uncontrollable reaction, which limit the application direction of magnetic microspheres. Summary of the Invention

[0005] Therefore, the first technical problem to be solved by the present invention is to overcome the defects of uncontrollable particle size and small specific surface area of magnetic particles in the prior art, so as to provide a magnetic polymer, a preparation method thereof and an application thereof.

[0006] The second technical problem to be solved by the present invention is to overcome the defects of low surface group density and limited performance of magnetic particles in the prior art, so as to provide a magnetic polymer, a preparation method thereof and an application thereof.

[0007] For this reason, the present invention provides the following technical solutions.

[0008] In a first aspect, the present invention provides a method for preparing a magnetic polymer, comprising:

[0009] Performing a first polymerization reaction on magnetic particles, a mercapto compound, a first polyol monomer, and an isocyanate monomer; wherein, the magnetic particles comprise oxides containing Fe 2+ and / or Fe 3+ .

[0010] Further, the preparation method further comprises the step of adding a second polyol monomer to perform a second polymerization reaction;

[0011] Preferably, it further comprises the step of adding a polymerization monomer to perform a third polymerization reaction.

[0012] Further, the magnetic particles are nanoscale particles and / or micron-scale microspheres; and / or,

[0013] The mercapto compound comprises at least one of mercaptoethanol, mercaptoacetic acid, ammonium mercaptomethanesulfonate, and mercaptomethyl acrylate; and / or,

[0014] The mass ratio of the mercapto compound to the magnetic particles is (1 - 4):1, optionally (1 - 2):1; and / or,

[0015] The molar ratio of the mercapto compound to the first polyol monomer is (0.1 - 4):(10 -3 - 1), optionally (0.2 - 3.5):1; and / or,

[0016] The molar ratio of the mercapto compound to the isocyanate monomer is (0.05 - 2):1; and / or,

[0017] The temperature of the first polymerization reaction is 70 - 85 °C, and the time of the first polymerization reaction is 12 - 24 h.

[0018] Further, the molar ratio of the mercapto compound to the second polyol monomer is (0.05 - 0.1):1; and / or,

[0019] The temperature of the second polymerization reaction is 70 - 85 °C, and the time of the second polymerization reaction is 4 - 8 h; and / or,

[0020] The polymerization monomer comprises at least one of vinyl monomers, acrylic monomers, acrylate monomers, and acrylamide monomers; and / or,

[0021] The mass ratio of the polymerization monomer to the product of the second polymerization reaction is 1:(0.1 - 5); and / or,

[0022] The temperature of the third polymerization reaction is 60 - 80 °C, and the reaction time is 15 - 24 h; and / or,

[0023] When carrying out the third polymerization reaction, it further includes the step of adding an initiator. Optionally, the dosage of the initiator is 0.01 - 2 wt% of the polymerization monomer.

[0024] Furthermore, the first polyol monomer and the second polyol monomer are each independently selected from at least one of saturated polyols and unsaturated polyols; and / or,

[0025] The first polyol monomer and the second polyol monomer are each independently selected from at least one of alcohol compounds and alcohol polymers; and / or,

[0026] The first polyol monomer and the second polyol monomer are each independently selected from diols having double bonds, optionally carbon-carbon double bonds; and / or,

[0027] The first polyol monomer and the second polyol monomer are each independently selected from alcohol polymers with a weight average molecular weight less than 600 Da; and / or,

[0028] The first polyol monomer and the second polyol monomer are each independently selected from at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and alcohol polymers with a weight average molecular weight less than 600 Da; and / or,

[0029] The first polyol monomer and the second polyol monomer are each independently selected from at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, cis-2-butene-1,4-butanediol, 2,4-hexadiene-1,6-diol, 1,4-butenediol, 1,2-ethanediol, 2-pentene-1,5-diol, 2,3-dihydroxy-1-butene, 3-allyloxy-1,2-propanediol, 2-vinylpropane-1,3-diol, polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600. Optionally, they are selected from at least one of cis-2-butene-1,4-butanediol, 2,3-dihydroxy-1-butene, 3-allyloxy-1,2-propanediol, and 2-vinylpropane-1,3-diol; and / or,

[0030] The isocyanate monomer is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4-diisocyanatodicyclohexylmethane, and tetramethyl-m-xylene diisocyanate; and / or,

[0031] The isocyanate monomers are selected from at least one of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane (HMDI), and tetramethyl-m-xylylene diisocyanate (TMXDI); and / or,

[0032] The isocyanate monomers are selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.

[0033] It should be noted that both the first polyol monomer and / or the second polyol monomer can include one or more polyols. By way of example, the first polyol monomer includes at least one or two of the above specific polyols.

[0034] In the present invention, the vinyl monomers are selected from isobutene, butadiene, etc. The acrylic monomers are selected from acrylic acid, methacrylic acid, etc. The acrylate monomers are selected from (meth)acrylate, 2-hydroxyethyl (meth)acrylate, (meth)acrylate methyl ester, glycidyl (meth)acrylate, etc. The acrylamide monomers are selected from (meth)acrylamide, N,N-dimethylacrylamide, 2-hydroxyethyl acrylamide, acrylamidopropyltrimethylammonium chloride, 2-acrylamido-2-methylpropanesulfonic acid.

[0035] The initiator is selected from conventional initiators in the art, such as organic peroxide acyl peroxides (benzoyl peroxide, lauroyl peroxide), hydroperoxides (cumene hydroperoxide, tert-butyl hydroperoxide), dialkyl peroxides (di-tert-butyl peroxide, diisopropylbenzene peroxide), ester peroxides (tert-butyl peroxybenzoate, tert-butyl peroxypivalate), ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide), dicarbonate peroxides (diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate). Inorganic peroxide persulfates, such as potassium persulfate, sodium persulfate, ammonium persulfate. Azide initiators, such as azobisisoheptonitrile (ABVN), azobisisopentanenitrile, azobisisobutyronitrile, azobis(cyclohexylcarbonitrile), azoisobutyronitrileformamide, azodiisobutyramidine hydrochloride, dimethyl 2,2'-azobis(2-methylpropionate), 2,2'-azobis(2-methylimidazoline hydrochloride), azodicyanovaleric acid, etc.

[0036] It should be noted that when adding the polymerization monomers for the third polymerization reaction, it also includes the step of adding a solvent, such as water, an organic solvent, etc. The mass ratio of the solvent to the magnetic particles can be, but is not limited to, (10 - 50):1. After the third polymerization reaction, it also includes steps such as adding a solvent for washing, etc. The number of washing times can be, but is not limited to, 4 - 6 times.

[0037] It should be further noted that when performing the first polymerization reaction and / or the second polymerization reaction, it also includes the step of adding a solvent. Optionally, the solvent is an anhydrous solvent, and the water content of the anhydrous solvent < 200 ppm, optionally < 100 ppm, more optionally < 50 ppm. The anhydrous solvent refers to a solvent that does not react with isocyanate. Specifically, the water content is detected by a Mettler Toledo Karl Fischer moisture meter V10S according to the national standard GB6283-2008 "Determination of water content in chemical products - Karl Fischer method (coulometric method)". In the present invention, the solvent is selected from at least one of acetone, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether. Optionally, it is selected from dioxane and / or diethylene glycol dimethyl ether. In this step, the mass of the solvent can be, but is not limited to, 10-50 times that of the magnetic particles. After the first polymerization reaction, it may also include conventional steps such as washing.

[0038] Furthermore, the particle size of the nanoscale particles is 10-400 nm; and / or,

[0039] The oxide containing Fe 2+ and / or Fe 3+ is magnetite; and / or,

[0040] The magnetic particles are micron-sized microspheres; and / or,

[0041] The micron-sized microspheres include polymer microspheres, and the surface of the polymer microspheres includes the oxide containing Fe 2+ and / or Fe 3+ ; Preferably, the polymer microspheres include at least one of polystyrene and polyacrylate; and / or,

[0042] The particle size of the micron-sized microspheres is 1 μm - 5 μm.

[0043] Furthermore, the magnetic particles also include other metal oxides different from iron, and the other metal oxides are determined by those skilled in the art according to needs, and the present invention does not make any limiting requirements in this regard.

[0044] The preparation method of the nanoscale particles includes: adding ammonia water to a solution containing Fe 2+ and / or Fe 3+ , reacting, and adjusting the pH;

[0045] Preferably, the temperature of the reaction is 20 - 50 °C, and the time is 2 - 5 h;

[0046] Preferably, the pH value is 9 - 11;

[0047] Furthermore, the solution containing Fe 2+ and / or Fe 3+The oxide is prepared by conventional methods in the art, for example, sol-gel method, co-precipitation method, microemulsion method, thermal decomposition method and hydrothermal method. The present invention does not specifically limit the preparation method of the oxide containing Fe 2+ and / or Fe 3+ Herein, a preparation method of the oxide containing Fe 2+ and / or Fe 3+ is exemplified. For example: Add an organic solvent into a three-necked reaction kettle, introduce nitrogen and continuously stir for 30 - 40 min, then, under nitrogen protection, add an iron salt and / or a ferrous salt (when both an iron salt and a ferrous salt are included, the molar ratio of the ferrous salt to the iron salt is (3 - 6):(3 - 6)), such as ferrous sulfate tetrahydrate and ferric chloride hexahydrate, and the molar ratio of ferrous sulfate tetrahydrate to ferric chloride hexahydrate is (3 - 6):(3 - 6), which can be optionally 4:4. Continuously stir until the system becomes clear and transparent, then add ammonia water, and react at 20 - 50 °C for 2 - 5 h, keeping the pH of the system between 9 - 11. After the reaction is completed, place the obtained product on a magnet for washing, wash with water and ethanol until the supernatant is neutral, and finally place the product in a vacuum oven to dry to a constant weight to obtain nano-sized particles A. When preparing the nano-sized particles, the organic solvent can be at least one of n-butanol, cyclohexane, dodecylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether.

[0048] Herein, a preparation method of magnetic particles in the form of micron-sized microspheres is exemplified, for example, including:

[0049] (1) Prepare a monodisperse seed microsphere suspension

[0050] Wash styrene with 4 wt% sodium hydroxide solution for 2 - 5 times, then wash with water until the pH is 7 - 8, which can be optionally 7.8. Add anhydrous sodium sulfate, and carry out vacuum distillation under the conditions of 100 - 120 mBar and 50 - 60 °C, collect the middle fraction, and seal and dry at - 20 ~ - 15 °C to obtain the treated styrene. Among them, the mass ratio of styrene to anhydrous sodium sulfate is about (3 - 5):(0.3 - 0.35).

[0051] The surfactant and the solvent are mixed and placed in a reactor. Nitrogen is introduced, and then styrene monomer is added. Stirring is turned on, the rotation speed is adjusted to 240 - 260 rpm, and the temperature is raised to 80 - 90 °C. Then an initiator is added, and the reaction is carried out at 80 - 90 °C for 24 - 28 h to prepare a polystyrene monodisperse seed microsphere suspension. The average size of the polystyrene monodisperse seed microspheres is 500 - 600 nm, preferably 500 - 520 nm. Among them, the surfactant is a conventional auxiliary agent in the art, such as sodium dodecyl sulfate; the initiator is a conventional substance in the art, such as ammonium persulfate solution with a concentration of 5 - 5.2 wt%; the solvent is water. The addition amount of the surfactant is 0.2% - 1.0% of the styrene monomer, such as 0.75%; the addition amount of the initiator is 0.2% - 3% of the styrene monomer, such as 1%. The solid content of the polystyrene monodisperse seed microsphere suspension is 8 - 12%, such as 10%.

[0052] (2) Preparation of monodisperse porous polystyrene microspheres B

[0053] The polymerization monomer, initiator, and surfactant are mixed and emulsified. After emulsification, the above-mentioned polystyrene monodisperse seed microsphere suspension is added, and stirring and swelling are carried out at 30 - 35 °C for 12 - 18 h, and then polymerization reaction is carried out at 70 - 80 °C for 16 - 24 h. After the reaction, it is washed with water and acetone to extract the linear styrene seeds in the microspheres until the detected linear styrene content in the eluate is less than 100 ppm, and then dried to obtain monodisperse porous polystyrene microspheres B. Among them, the polymerization monomer includes divinylbenzene (purity 80 - 85 wt%), styrene, and toluene. The ratio of these monomers is determined according to requirements. The mass ratio of divinylbenzene, styrene, and toluene in the present invention can be but is not limited to (1.2 - 2):(0.8 - 1.2):(5 - 6.5), such as 1.68:1:5.89; the surfactant is a conventional auxiliary agent in the art, such as polyvinyl alcohol PVA 1788, sodium dodecyl sulfate solution (concentration 0.45 - 0.5 wt%). The addition amount of the surfactant in this step is 5 - 9% of the polymerization monomer, such as 7.25%; the addition amount of the initiator is 0.2 - 0.5% of the polymerization monomer, such as 0.3%. The initiator is a common initiator in the art, such as benzoyl peroxide.

[0054] The specific surface area and average pore diameter of the microspheres are measured by the BET method, and the average particle size of the microspheres is tested by the laser particle size analyzer method. The present invention can adopt but is not limited to the above methods when testing the specific surface area, average particle size, and average pore diameter of the microspheres.

[0055] (3) Mix the above-mentioned nanoscale particles A and monodisperse porous polystyrene microspheres B using the hybridization system NHS-0 (manufactured by Nara Machinery Co., Ltd.). The circumferential speed of its blades is 100 m / s (16,200 rpm) to obtain magnetic microspheres C. The surface of the magnetic microspheres C includes oxides containing Fe 2+ and / or Fe 3+ . It should be noted that the magnetic nanoparticles A and monodisperse porous polystyrene microspheres B can also be mixed using other instruments well-known in the art to obtain magnetic microspheres C. For example, the Lu Xiangyi high-speed centrifuge.

[0056] In a second aspect, the present invention provides a magnetic polymer, comprising magnetic particles and a first polymer matrix. The surface of the magnetic particles includes oxides containing Fe 2+ and / or Fe 3+ . The surface of the first polymer matrix contains thiourea groups, and the first polymer matrix includes polyurethane; the magnetic particles and the first polymer matrix are connected through the chelation of oxides containing Fe 2+ and / or Fe 3+ with the thiourea groups.

[0057] Furthermore, the magnetic polymer further includes a second polymer matrix grafted on the surface of the first polymer matrix. The first polymer matrix and the second polymer matrix are connected by a covalent bond.

[0058] Furthermore, the magnetic particles include at least one of nanoscale particles or micron-scale microspheres; and / or,

[0059] The second polymer matrix includes a homopolymer or copolymer formed by at least one monomer selected from acrylic monomers, vinyl monomers, acrylate monomers, and acrylamide monomers; and / or,

[0060] The magnetic particles are micron-scale microspheres; and / or,

[0061] The micron-scale microspheres include a polymer and oxides containing Fe 2+ and / or Fe 3+ . It should be noted that the polymer can be, but is not limited to, at least one of polystyrene, polyacrylic acid, and polyacrylate.

[0062] In a third aspect, the present invention provides the application of the magnetic polymer prepared by the above preparation method or the above magnetic polymer as a magnetic-responsive polymer.

[0063] The technical solution of the present invention has the following advantages:

[0064] 1. The present invention provides a method for preparing a magnetic polymer, which involves performing a first polymerization reaction on magnetic particles, a mercapto compound, a first polyol monomer, and an isocyanate monomer. Among them, the magnetic particles include oxides containing Fe 2+ and / or Fe 3+ . The reaction provided by the present invention can occur on the surface of magnetic particles including the oxides containing Fe 2+ and / or Fe 3+ . After the reaction, the mercapto compound generates a thiourea derivative, making the polymer contain thiourea groups. Due to the chelating force between the thiourea groups and the oxides containing Fe 2+ and / or Fe 3+ , the polymer formed by the polymerization reaction can tightly coat the magnetic particles, and the specific surface area and particle size controllability of the obtained magnetic polymer are relatively good. Among them, one end of the thiourea derivative is tightly connected to the oxides containing Fe 2+ and / or Fe 3 + on the magnetic particles through chelation, and the other end of the thiourea derivative is connected to the polyurethane prepared by the reaction of the first polyol and the isocyanate. The prepared polymer has controllable particle size, a smaller particle size, and a larger specific surface area. This magnetic polymer can be applied in the field of magnetic response, such as biomedicine, protein purification, immunochromatography, cell labeling, cell separation, etc.

[0065] 2. The present invention provides a method for preparing a magnetic polymer. By performing a second polymerization reaction in the present invention, functional groups such as carbon-carbon double bonds can be further introduced onto the polyurethane surface. Further, a polymerization monomer is introduced into the magnetic particles to perform a third polymerization reaction. The polymer formed by the polymerization monomer is covalently bonded to the product obtained from the first polymerization reaction or the second polymerization reaction, and further surface modification is performed on the surface of the magnetic polymer, making the magnetic polymer have a high functional group content, a high group density, enriching the surface properties of the magnetic polymer, and reducing the leakage of iron.

[0066] 3. The present invention provides a method for preparing a magnetic polymer. The specific dosages of the mercapto compound and the magnetic particles can enable the polyurethane containing thiourea groups obtained by polymerization to perform chelation coating on the surface of the magnetic particles with the oxides containing Fe 2+ and / or Fe 3+ on the surface of the magnetic particles, which can effectively avoid the leakage, aggregation, and oxidation of the magnetic particles, and bring many reactive groups to the magnetic polymer, providing space for the next reaction.

[0067] Furthermore, the present invention uses specific dosages of the mercapto compound and the first polyol to adjust the chain length of the polyurethane, and the number of reactive groups can be regulated according to the requirements of subsequent reactions to make it reach the optimal level. Specific Embodiments

[0068] The following embodiments are provided to better understand the present invention further. It is not limited to the described best mode, and does not limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with those of other prior arts falls within the protection scope of the present invention.

[0069] For those embodiments where specific experimental steps or conditions are not indicated, the operations or conditions of the conventional experimental steps described in the literature in this field can be followed. For the reagents or instruments whose manufacturers are not indicated, they are all conventional reagent products that can be obtained through commercial purchase.

[0070] The specific surface area and average pore diameter of the magnetic polymer are measured by the nitrogen adsorption method. The specific method is as follows: Weigh 1.50 g of the dried magnetic polymer and put it into a fully automatic specific surface area and porosity analyzer ASAP 2020 (Micromeritics Instrument Co.). Set the detection of the specific surface area, with the degassing temperature of 120 °C and the degassing time of 8 h. Under these conditions, detect it by the nitrogen physical adsorption method and calculate its specific surface area using the BET model.

[0071] The test method for the average size (average particle diameter) of the particle size of the magnetic polymer: It is obtained by testing with a nano laser particle size analyzer (Nicomp N3000). Specifically, it includes: accurately prepare a 0.2 mg / mL sample to be tested, put it into the nano laser particle size analyzer, and run it 3 times to measure the average particle diameter.

[0072] The iron leakage amount of the magnetic polymer is detected by inductively coupled plasma-mass spectrometry (ICP-MS). The specific method is to weigh 0.2 g of the magnetic polymer, add 10 mL of 2% disodium ethylenediaminetetraacetate (EDTA) and 1% hydrogen peroxide, soak for 2 h, filter by magnetic attraction, and then measure the iron ion leakage amount of the filtrate using ICP-MS.

[0073] The iron ion content of the magnetic polymer: It is detected by inductively coupled plasma-mass spectrometry (ICP-MS). Specifically, weigh 0.5 g of the sample, add 10 g of concentrated nitric acid, soak for 12 h, then filter the residue, dilute it 100 times, and measure the iron ion content using ICP-MS. Among them, the iron ion refers to Fe 2+ and / or Fe 3+ , and the iron ion content refers to the mass ratio of Fe 2+ and / or Fe 3+ in the mass of the magnetic polymer.

[0074] Testing method for the double bond content of magnetic polymers: The magnetic polymers undergo click chemical reactions with thiols to introduce sulfur elements onto the magnetic polymers, and the double bond content is obtained through elemental analysis. Specifically, it includes: Weigh 0.2 - 0.4 g of magnetic polymers, add 10 times the weight of mercaptoethanol, 2 times the weight of azobisisobutyronitrile, and add 20 times the amount of isopropanol. Place them in a shaker at 70 °C and react for 24 h. After the reaction, use isopropanol, water, and ethanol to wash 5 - 10 times, and vacuum dry to obtain the test sample. Weigh 0.1500 - 0.3000 g of the above test sample and put it into the Vario ELⅢ elemental analyzer of Elementar Company in Germany. Select the CHNS mode, adopt the micro combustion method, and automatically measure and calculate the sulfur content. Finally, calculate the content of double bond groups based on the sulfur content of the magnetic polymers.

[0075] The carboxyl content of magnetic polymers is determined by conductometric titration using the 794Basic Titrino manufactured by Metrohm Company.

[0076] Preparation Example 1

[0077] This preparation example provides a kind of nanoparticles and its preparation method. The preparation method includes:

[0078] Add 220 mL of n-butanol, 500 mL of cyclohexane, and 150 mL of octylphenol polyoxyethylene ether - 10 (OP - 10) into a three-necked reaction kettle. After introducing nitrogen and continuously stirring for 30 min, add 52.62 g of ferrous sulfate tetrahydrate, 120.44 g of ferric chloride hexahydrate, and 250 mL of water. Continuously stir until the system becomes clear and transparent, ensuring that the whole process is under 20 °C and nitrogen environment. Then add 30 mL of ammonia water (concentration 25 - 28%), and react at 20 °C for 2 h. After the reaction, place the obtained product on a magnet for washing, wash with water and ethanol until the supernatant is neutral. Finally, place the product in a vacuum oven at 40 °C and dry to constant weight to obtain magnetic iron oxide nanoparticles A. The average particle size of magnetic iron oxide nanoparticles A is 10 nm.

[0079] Preparation Example 2

[0080] This preparation example provides a kind of magnetic microspheres and its preparation method. The preparation method includes:

[0081] (1) Wash 3 kg of styrene twice with 2 L of 4 wt% sodium hydroxide, then wash with water until the pH is 7.8. Add 300 g of anhydrous sodium sulfate, and carry out vacuum distillation under the conditions of 100 mBar and 50 °C. Collect 1.80 kg of the middle fraction, seal and dry at - 20 °C to obtain the treated styrene.

[0082] Add 12 g of sodium dodecyl sulfate to 14.4 kg of water, stir to dissolve, and filter using a 0.22 μm filter membrane. Add the filtered solution to a 20 L reactor, then purge with nitrogen for 30 min to remove oxygen. Then add 1.60 kg of the above-treated styrene, turn on the stirrer, control the rotation speed at 240 rpm, heat up to 80 °C, add 160 mL of 10 wt% ammonium persulfate solution, and react at 80 °C for 24 h to obtain a polystyrene monodisperse seed microsphere suspension. The average particle size of the polystyrene monodisperse seed microspheres is 500 nm, and the solid content of the suspension is 10%.

[0083] (2) Mix, dissolve 2.35 kg of 80% pure divinylbenzene, 1.4 kg of styrene, 8.25 kg of toluene, and 37.5 g of benzoyl peroxide, and add them to a 60 L solution containing 1 wt% polyvinyl alcohol (PVA 1788) and 0.45 wt% sodium dodecyl sulfate, and perform fine emulsification with an ultrasonic homogenizer. After emulsification, add 6 kg of the above polystyrene monodisperse seed microsphere suspension, stir and swell at 30 °C for 16 h, and then carry out a polymerization reaction at 80 °C for 20 h. After the reaction is completed, wash with water 10 times, wash with acetone 5 times, and extract the linear styrene in the microspheres with toluene until the content of linear styrene detected in the eluate is less than 100 ppm. After drying, 3.51 kg of monodisperse porous polystyrene microspheres B are obtained. The specific surface area measured by the BET method is 550 m 2 / g, the average pore diameter is 16 nm, and the average particle size detected by a laser particle size analyzer is 1086 nm.

[0084] Referring to CN110049972A, mix 20 g of magnetic iron oxide nanoparticles A and 20 g of monodisperse porous polystyrene microspheres B using a hybridization system NHS-0 (manufactured by Nara Machinery Co., Ltd.), and the circumferential speed of its blades is 100 m / s (16200 rpm) to obtain magnetic microspheres C. The average particle size of the microspheres is 1100 nm.

[0085] Example 1

[0086] This example provides a method for preparing a magnetic polymer, including:

[0087] Weigh 10 g of ferromagnetic iron oxide magnetic nanoparticles A, add 300 g of anhydrous solvent diethylene glycol dimethyl ether, disperse evenly by ultrasonic stirring. At 25 °C, keep purging nitrogen for 30 min, then add 10 g of mercaptoethanol and continue stirring for 30 min. Add anhydrous cis-2-butene-1,4-diol (CAS: 6117-80-2) (the molar ratio of mercaptoethanol to anhydrous cis-2-butene-1,4-diol is 0.56:1) and diphenylmethane diisocyanate (MDI) (the molar ratio of mercaptoethanol to MDI is 0.64:1). Heat up to 80 °C and keep purging nitrogen for reaction for 20 h. Then add anhydrous cis-2-butene-1,4-diol (the molar ratio of mercaptoethanol to anhydrous cis-2-butene-1,4-diol is 0.07:1), heat up to 80 °C and react for 4 h. After the reaction is completed, cool down to 25 °C, recover the product by a magnet, wash the product with diethylene glycol dimethyl ether and acetone successively for 5 times, and perform vacuum drying to constant weight to obtain magnetic polymer-1.

[0088] Example 2

[0089] This example provides a method for preparing a magnetic polymer, including:

[0090] Weigh 10 g of magnetic microspheres C, add 300 g of anhydrous solvent diethylene glycol dimethyl ether, disperse evenly by ultrasonic stirring. At 25 °C, keep purging nitrogen for 30 min, then add 10 g of mercaptoethanol and continue stirring for 30 min. Add anhydrous cis-2-butene-1,4-diol (the molar ratio of mercaptoethanol to anhydrous cis-2-butene-1,4-diol is 0.56:1) and diphenylmethane diisocyanate (MDI) (the molar ratio of mercaptoethanol to MDI is 0.64:1). Heat up to 80 °C and keep purging nitrogen for reaction for 20 h. Then add anhydrous cis-2-butene-1,4-diol (the molar ratio of mercaptoethanol to anhydrous cis-2-butene-1,4-diol is 0.07:1), heat up to 80 °C and react for 4 h. After the reaction is completed, cool down to 25 °C, recover the product by a magnet, wash the product with diethylene glycol dimethyl ether and acetone successively for 5 times, and perform vacuum drying to constant weight to obtain magnetic polymer-2.

[0091] Example 3

[0092] This example provides a method for preparing a magnetic polymer, which is basically the same as Example 2. The difference from Example 2 is that: in this example, the addition amount of mercaptoethanol is 20 g, and the mass ratio of mercaptoethanol to magnetic microspheres C is 2:1, and magnetic polymer-3 is prepared.

[0093] Example 4

[0094] This example provides a method for preparing a magnetic polymer, which is basically the same as Example 2. The difference from Example 2 is that the first polymerization reaction temperature and the second polymerization reaction time are different. In this example, the first polymerization reaction temperature is 85 °C and the second polymerization reaction time is 8 h, obtaining magnetic polymer-4.

[0095] Example 5

[0096] This example provides a method for preparing a magnetic polymer, which is basically the same as Example 2. The amount of anhydrous cis-2-butene-1,4-diol added is adjusted. The difference from Example 2 is that in this example, when carrying out the first polymerization reaction, the molar ratio of mercaptoethanol to anhydrous cis-2-butene-1,4-diol is 0.28:1, obtaining magnetic polymer-5.

[0097] Example 6

[0098] This example provides a method for preparing a magnetic polymer, including:

[0099] Weigh 10 g of magnetic microspheres C, add 300 g of anhydrous solvent diethylene glycol dimethyl ether, disperse them evenly by ultrasonic stirring. At 25 °C, after purging with nitrogen for 30 min, add 10 g of mercaptoethanol and continue stirring for 30 min. Then add 1,2-ethylene glycol (CAS: 1571-60-4) (the molar ratio of mercaptoethanol to 1,2-ethylene glycol is 2.6:1) and diphenylmethane diisocyanate (MDI) (the molar ratio of mercaptoethanol to MDI is 0.64:1), heat up to 80 °C and continue the nitrogen purge reaction for 20 h; then add 1,2-ethylene glycol (the molar ratio of mercaptoethanol to 1,2-ethylene glycol is 0.07:1), heat up to 80 °C and react for 4 h. After the reaction is completed, cool down to 25 °C, recover the product by a magnet, wash the product with diethylene glycol dimethyl ether and acetone 5 times in sequence, and carry out vacuum drying to constant weight, obtaining magnetic polymer-6.

[0100] Example 7

[0101] This example provides a method for preparing a magnetic polymer, including:

[0102] Add 15 g of magnetic polymer-1 and 300 g of isopropanol to a 1 L reactor, purge with nitrogen to remove oxygen at 25 °C, stir for 30 min, then add 30 g of acrylic acid and 0.6 g of azobisisobutyronitrile (AIBN) and continue stirring for 30 min. Heat up to 75 °C and continue the nitrogen purge for polymerization reaction for 20 h. After the reaction is completed, cool down to 25 °C, recover the product by a magnet, and wash the product with isopropanol and water 5 times each, obtaining magnetic polymer-7.

[0103] Example 8

[0104] This embodiment provides a method for preparing a magnetic polymer, including:

[0105] Add 15 g of magnetic polymer-2 to a 1 L reactor, add 300 g of isopropanol, purge with nitrogen to remove oxygen at 25 °C. After stirring for 30 min, add 30 g of acrylic acid and 0.6 g of azobisisobutyronitrile (AIBN), and continue stirring for 30 min. Then raise the temperature to 75 °C and continuously purge with nitrogen for the third polymerization reaction for 20 h. After the reaction is completed, cool down to 25 °C, recover the product with a magnet, and wash the particles 5 times each with isopropanol and water to obtain magnetic polymer-8.

[0106] Example 9

[0107] This embodiment provides a method for preparing a magnetic polymer, including:

[0108] Weigh 10 g of magnetic microspheres C, add 300 g of anhydrous solvent diethylene glycol dimethyl ether, disperse evenly by ultrasonic stirring. At 25 °C, after purging with nitrogen for 30 min, add 10 g of mercaptoethanol and continue stirring for 30 min. Add anhydrous cis-2-butene-1,4-diol (the molar ratio of mercaptoethanol to anhydrous cis-2-butene-1,4-diol is 0.06:1) and diphenylmethane diisocyanate (MDI) (the molar ratio of mercaptoethanol to MDI is 0.64:1), raise the temperature to 80 °C and continuously purge with nitrogen for 20 h. After the reaction is completed, cool down to 25 °C, recover the product with a magnet, wash the product 5 times successively with diethylene glycol dimethyl ether and acetone, and perform vacuum drying to constant weight to obtain magnetic polymer-9.

[0109] Comparative Example 1

[0110] This comparative example provides a method for preparing a polymer, which is basically the same as that in Example 2, except that mercaptoethanol is not added, and magnetic polymer-D1 is obtained.

[0111] Comparative Example 2

[0112] This comparative example provides a method for preparing a magnetic polymer, including:

[0113] Put 333 parts by mass of 0.5 wt% sodium dodecylbenzenesulfonate aqueous solution into a 1 L separable flask. Next, put 13.3 parts by mass of magnetic microspheres C, disperse and heat to 60 °C. Dropwise add the first pre-emulsion to the above flask. The first pre-emulsion includes 100 parts by mass of sodium dodecylbenzenesulfonate aqueous solution (concentration 0.5 wt%), 18 parts by mass of MMA, 2 parts by mass of TMP, 0.4 parts by mass of PEROYL. The dropping time of the pre-emulsion is 2 h to form a first polymer layer on the surface of magnetic microspheres C.

[0114] After the addition of the pre-emulsion was completed, the mixture was kept at 60 °C with stirring for 1 h. A second pre-emulsion was added dropwise to the product. The second pre-emulsion included 50 parts by mass of an aqueous solution of sodium dodecylbenzenesulfonate (concentration: 0.5 wt%), 8.75 parts by mass of glycidyl methacrylate, 1.25 parts by mass of TMP, and 0.2 parts by mass of PEROYL. The dropping time was 80 min. After the addition was completed, the temperature was raised to 75 °C and polymerization was continued for 2 h. After the reaction was completed, a second polymer layer was formed on the first polymer layer. The particles in the above product were separated by magnetic separation and washed with distilled water to obtain polymer particles D2 with glycidyl groups (particle size: 2231 nm).

[0115] To the obtained magnetic polymer microspheres D2 (1.0 part by mass) was added 10 parts by mass of a 1 wt% aqueous sulfuric acid solution, and ultrasonic waves were irradiated for 5 min to disperse the particles. Next, the mixture was stirred at 60 °C for 5 h. Next, the magnetic particles were separated from the obtained liquid by magnetic separation, dispersed in pure water, and subjected to magnetic separation for washing. The above operation was repeated 5 times to obtain OH group-containing magnetic polymer microspheres - D3.

[0116] After washing the 1.0 part by mass of magnetic microspheres D3 with 1,3-dioxolane 3 times, it was dispersed in 10 parts by mass of 1,3-dioxolane, and a solution in which 1 part by mass of succinic anhydride and 0.15 part by mass of triethylamine were dissolved was added, and the mixture was stirred at 25 °C for 4 h to introduce carboxyl groups. After the reaction was completed, the obtained particles were separated by magnetic separation, washed with 1,3-dioxolane 3 times, and then washed with distilled water 4 times to obtain carboxyl group-containing magnetic microspheres D4. The polymer D4 was placed in an aqueous solution with a pH of 7 containing 0.01 wt% 2-methyl-4-isothiazolin-3-one (the pH of this aqueous solution was adjusted with ProClin950 manufactured by Aldrich) to obtain a dispersion, and the content of polymer D4 in the dispersion was 10 wt%. The results of each example and comparative example are shown in the following table.

[0117] Table 1 Test Results

[0118]

[0119] Note: " / " in the table indicates that the value does not exist.

[0120] From the above results, it can be seen that the magnetic polymer provided by the present invention has advantages such as small particle size and large specific surface area. The magnetic polymer has a small iron leakage amount, a high iron content, and a high magnetic responsiveness.

[0121] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom still fall within the protection scope of the present invention.

Claims

1. A method for preparing a magnetic polymer, characterized in that: include: The magnetic particles, the mercapto compound, the first polyol monomer and the isocyanate monomer are subjected to a first polymerization reaction; wherein the magnetic particles include Fe 2+ and / or Fe 3+ of oxides.

2. The preparation method according to claim 1, characterized in that: Also includes the step of adding a second polyol monomer to conduct a second polymerization reaction; Preferably, the method further comprises the step of adding a polymerization monomer to carry out a third polymerization reaction.

3. The preparation method according to claim 1 or 2, characterized in that: The magnetic particles include nano-sized particles and / or micro-sized microspheres; and / or, The mercapto compound includes at least one of mercaptoethanol, thioglycolic acid, ammonium mercaptomethylsulfate, and mercaptomethacrylate; and / or, The mass ratio of the thiol compound to the magnetic particles is (1-4):1, and can be (1-2):1; and / or, The molar ratio of the mercapto compound to the isocyanate monomer is (0.05-2):1; and / or, The temperature of the first polymerization reaction is 70-85° C., and the time of the first polymerization reaction is 12-24 hours.

4. The preparation method according to any one of claims 2 to 3, characterized in that: The molar ratio of the mercapto compound to the second polyol monomer is (0.05-0.1):1; and / or, The temperature of the second polymerization reaction is 70-85° C., and the time of the second polymerization reaction is 4-8 hours; and / or, The polymerizable monomer includes at least one of a vinyl monomer, an acrylic monomer, an acrylate monomer, and an acrylamide monomer; and / or, The mass ratio of the polymerizable monomer to the product of the second polymerization reaction is 1:(0.1-5); and / or, The temperature of the third polymerization reaction is 60-80° C., and the reaction time is 15-24 hours; and / or, When the third polymerization reaction is carried out, the step of adding an initiator is also included. Optionally, the amount of the initiator is 0.01-2 wt % of the polymerization monomer.

5. The preparation method according to any one of claims 2 to 4, characterized in that: The first polyol monomer and the second polyol monomer are each independently selected from at least one of a saturated polyol and an unsaturated polyol; and / or, The first polyol monomer and the second polyol monomer are each independently selected from at least one of an alcohol compound and an alcohol polymer; and / or, The first polyol monomer and the second polyol monomer are each independently selected from diols having double bonds; and / or, The first polyol monomer and the second polyol monomer are each independently selected from alcohol polymers having a weight average molecular weight of less than 600 Da; and / or, The first polyol monomer and the second polyol monomer are each independently selected from at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and an alcohol polymer having a weight average molecular weight of less than 600 Da; and / or, The first polyol monomer and the second polyol monomer are each independently selected from at least one of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, cis-2-butene-1,4-butanediol, 2,4-hexadiene-1,6-diol, 1,4-butenediol, 1,2-ethylene glycol, 2-pentene-1,5-diol, 2,3-dihydroxy-1-butene, 3-allyloxy-1,2-propylene glycol, 2-vinylpropane-1,3-diol, polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600, and optionally, at least one of cis-2-butene-1,4-butanediol, 2,3-dihydroxy-1-butene, 3-allyloxy-1,2-propylene glycol, and 2-vinylpropane-1,3-diol; and / or, The isocyanate monomer is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4-diisocyanate dicyclohexylmethane, and tetramethyl-m-xylylene diisocyanate; and / or, The isocyanate monomer is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate and hexamethylene diisocyanate.

6. The preparation method according to any one of claims 3 to 5, characterized in that: The particle size of the nano-scale particles is 10nm-400nm; and / or, The Fe-containing 2+ and / or Fe 3+ The oxide is ferroferric oxide; and / or, The magnetic particles are micron-sized microspheres; and / or, The micron-sized microspheres include polymer microspheres, the surface of which includes the Fe-containing 2+ and / or Fe 3+ Oxide; preferably, the polymer microspheres further include at least one of polystyrene, polyacrylic acid, and polyacrylate; and / or, The particle size of the micron-sized microspheres is 1 μm-5 μm.

7. A magnetic polymer, characterized in that: It comprises magnetic particles and a first polymer matrix, wherein the surface of the magnetic particles comprises a Fe-containing 2+ and / or Fe 3+ The first polymer matrix contains thiourea groups on its surface, and the first polymer matrix includes polyurethane; the magnetic particles and the first polymer matrix are connected by Fe 2+ and / or Fe 3+ The oxide is connected by chelation with the thiourea group.

8. The magnetic polymer according to claim 7, characterized in that: The magnetic polymer further comprises a second polymer matrix, and the second polymer matrix is ​​connected to the surface of the first polymer matrix through a covalent bond.

9. The magnetic polymer according to claim 7 or 8, characterized in that: The magnetic particles include at least one of nano-sized particles or micro-sized microspheres; and / or, The second polymer matrix includes a homopolymer or a copolymer formed by at least one monomer selected from acrylic monomers, vinyl monomers, acrylate monomers, and acrylamide monomers. The magnetic particles are micron-sized microspheres; The micron-sized microspheres include a polymer and a Fe-containing 2+ and / or Fe 3+ of oxides.

10. Use of the magnetic polymer obtained by the preparation method according to any one of claims 1 to 6 or the magnetic polymer according to any one of claims 7 to 9 as a magnetic responsive polymer.

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