Chloromethylated crosslinked polystyrene microspheres and preparation method thereof

Abstract

This application relates to the field of polymer polymerization technology, and particularly relates to a chloromethylated crosslinked polystyrene microsphere and a preparation method thereof. The preparation method includes the following steps: mixing water and a dispersant to prepare a continuous phase; mixing a styrene monomer, a divinylbenzene monomer, an unsaturated organosilane, and an oil-soluble initiator to prepare a dispersed phase; mixing the continuous phase and the dispersed phase to carry out a suspension polymerization reaction to prepare mother balls; mixing the mother balls, chloromethylsilane, and an organic solvent to carry out a chloromethylation reaction to prepare chloromethylated crosslinked polystyrene microspheres. The method for preparing chloromethylated crosslinked polystyrene microspheres has little harm to the human body and equipment, little potential safety hazard, low cost, and high chlorine loading after chloromethylation.

Description

Technical Field

[0001] This application relates to the technical field of polymer polymerization, and particularly relates to a chloromethylated crosslinked polystyrene microsphere and a preparation method thereof. Background Art

[0002] Chloromethylated crosslinked polystyrene microspheres are a chemically modified crosslinked polystyrene material, in which chloromethyl (-CH 2 Cl) groups are attached to the surface or chains of the polystyrene microspheres. This modification enhances the functionality of the material, enabling the microspheres to be used as precursors for various chemical reactions or for adsorbing specific molecules, especially in coupling reactions that require functional groups to participate. Therefore, chloromethylated polystyrene microspheres have applications in multiple fields such as adsorption separation, drug loading, and biomolecule coupling.

[0003] Currently, there are mainly two methods for preparing chloromethylated crosslinked polystyrene microspheres: One is that under the action of a Lewis acid catalyst, the crosslinked polystyrene microspheres react directly or indirectly with a chloromethylating reagent (mainly chloromethyl ether) to generate chloromethylated crosslinked polystyrene microspheres. However, most chloromethylating reagents are volatile, have strong carcinogenicity, and a large amount of hydrochloric acid is generated during the reaction, which is highly harmful to the human body and equipment. Although the volatility of some long-chain alkyl chloromethyl ethers has been improved, their carcinogenicity still exists, and there are also safety hazards, and the cost is relatively expensive; The other is to use a chloromethylated functional monomer, such as p-chloromethylstyrene (CMS), to carry out crosslinked copolymerization with styrene and divinylbenzene to generate chloromethylated crosslinked polystyrene microspheres. However, CMS is expensive and not suitable for industrial production applications. Moreover, the chlorine loading of the above methods is not high. Summary of the Invention

[0004] Based on this, the first aspect of this application provides a preparation method of a chloromethylated crosslinked polystyrene microsphere, and its technical solution is as follows:

[0005] A preparation method of a chloromethylated crosslinked polystyrene microsphere, comprising the following steps:

[0006] Mix water and a dispersant to prepare a continuous phase;

[0007] Mix a styrene monomer, a divinylbenzene monomer, an unsaturated organosilane, and an oil-soluble initiator to prepare a dispersed phase;

[0008] Mix the continuous phase and the dispersed phase, and carry out suspension polymerization to prepare mother balls;

[0009] Mix the mother balls, chloromethylsilane, and an organic solvent, and carry out chloromethylation reaction to prepare chloromethylated crosslinked polystyrene microspheres.

[0010] The second aspect of the present application provides a chloromethylated crosslinked polystyrene microsphere, which is prepared by the preparation method described above.

[0011] Compared with the traditional scheme, the present application has the following beneficial effects:

[0012] In the present application, an unsaturated organosilane is added to the dispersion phase. The unsaturated organosilane undergoes sol-gel while copolymerizing with styrene and divinylbenzene, doping silane segments and inorganic silica gel into the microspheres, providing new active sites for the crosslinked polystyrene microspheres and enriching their chemical modifiability. Subsequently, chloromethylsilane is selected as the chloromethylating reagent, which has little harm to the human body and equipment, small potential safety hazards, and low cost. At the same time, the chlorine loading is high after chloromethylation. Description of the Drawings

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application and more comprehensively understand the present application and its beneficial effects, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0014] Figure 1 It is the infrared spectrum of CMPS-1 obtained in Example 1.

[0015] Figure 2 It is the particle size distribution diagram of CMPS-1 obtained in Example 1. Detailed Embodiments

[0016] The following further details the present application with specific embodiments. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present application more thorough and comprehensive.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0018] Terms

[0019] Unless otherwise stated or there are contradictions, the terms or phrases used herein have the following meanings:

[0020] In the present application, when referring to "multiple", "multiple types", "multiple times", "multiple elements", etc., unless otherwise specified, it means greater than 2 or equal to 2 in quantity. For example, "one or more" means one or greater than or equal to two.

[0021] In this application, the terms "optionally", "optional", and "option" mean that something is either present or absent, that is, it refers to either one of two alternative scenarios: "present" or "absent". If the term "option" appears multiple times in a technical solution, and there is no special instruction, no contradiction, or no mutual restraint relationship, then each "option" is independent of the others.

[0022] In this application, in the terms "first aspect", "second aspect", "third aspect", "fourth aspect", etc., the terms "first", "second", "third", "fourth", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or quantity, nor can they be construed as implicitly indicating the importance or quantity of the technical features being indicated. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumerative description and should be understood not to constitute a closed limitation on quantity.

[0023] In this application, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the optional numerical values are considered continuous within the above numerical interval and include the two numerical endpoints of the numerical range (i.e., the minimum value and the maximum value), as well as each numerical value between these two numerical endpoints.

[0024] The temperature parameter in this application, unless otherwise specified, allows for both constant temperature treatment and variation within a certain temperature range. It should be understood that the so-called constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within ranges such as ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0025] In this application, when it comes to percentage content, unless otherwise specified, for solid-liquid mixtures and solid-solid mixtures, it refers to mass percentage, and for liquid-liquid mixtures, it refers to volume percentage.

[0026] In this application, when it comes to percentage concentration, unless otherwise specified, it refers to the final concentration. The so-called final concentration refers to the proportion of the added component in the system after adding this component.

[0027] In this application, %(w / w) and wt% both represent weight percentage, %(v / v) represents volume percentage, and %(w / v) represents mass-volume percentage.

[0028] The first aspect of this application provides a method for preparing chloromethylated crosslinked polystyrene microspheres. In some embodiments, the method for preparing chloromethylated crosslinked polystyrene microspheres includes the following steps:

[0029] S10. Mix water and a dispersant to prepare a continuous phase.

[0030] Optionally, the dispersant includes a first dispersed phase and a second dispersed phase. The first dispersed phase is selected from at least one of gelatin, polyvinyl alcohol, and polyethylene glycol. The second dispersed phase is selected from at least one of sodium dodecylbenzenesulfonate and sodium dodecyl sulfate.

[0031] Optionally, the mass ratio of the first dispersed phase to the second dispersed phase is (1.5 - 4):1. For example, the mass ratio of the first dispersed phase to the second dispersed phase is 1.5:1, 2:1, 3:1, 4:1.

[0032] Optionally, the mass ratio of the dispersant to water is 1:(50 - 100). For example, the mass ratio of the dispersant to water is 1:50, 1:60, 1:70, 1:80, 1:90, 1:100.

[0033] S20. Mix styrene monomer, divinylbenzene monomer, unsaturated organosilane, and oil-soluble initiator to prepare a dispersed phase.

[0034] Optionally, the divinylbenzene monomer is provided by a divinylbenzene solution, and the concentration of the divinylbenzene monomer in the divinylbenzene solution is 55% - 80%. For example, the concentration of the divinylbenzene monomer in the divinylbenzene solution is 55%, 63%, 80%.

[0035] Optionally, the mass ratio of the divinylbenzene solution to the styrene monomer is 1:(1 - 100). For example, the mass ratio of the divinylbenzene solution to the styrene monomer is 1:1, 1:20, 1:50, 1:80, 1:100.

[0036] The unsaturated organosilane can be selected from silane coupling agents with a rich variety and affordable price. Optionally, the unsaturated organosilane is selected from at least one of γ-methacryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane, and acryloxythrimethylsilane.

[0037] Optionally, the mass ratio of the unsaturated organosilane to the styrene monomer is 1:(1 - 4). For example, the mass ratio of the unsaturated organosilane to the styrene monomer is 1:1, 1:2, 1:3, 1:4.

[0038] Optionally, the oil-soluble initiator is selected from at least one of benzoyl peroxide and azobisisobutyronitrile.

[0039] Optionally, the mass ratio of the oil-soluble initiator to the total amount of the unsaturated organosilane and styrene is 1:(50 - 100). For example, the mass ratio of the oil-soluble initiator to the total amount of the unsaturated organosilane and styrene is 1:50, 1:60, 1:70, 1:80, 1:90, 1:100.

[0040] S30. Mix the continuous phase and the dispersed phase, and carry out suspension polymerization reaction to prepare mother balls.

[0041] Optionally, the volume ratio of the dispersed phase to the continuous phase is 1:(3 - 10). For example, the volume ratio of the dispersed phase to the continuous phase is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10.

[0042] Optionally, the reaction temperature of the suspension polymerization reaction is 70°C to 85°C. For example, the reaction temperature of the suspension polymerization reaction is 70°C, 75°C, 80°C, 85°C.

[0043] Optionally, the reaction time of the suspension polymerization reaction is 8h to 16h. For example, the reaction time of the suspension polymerization reaction is 8h, 12h, 16h.

[0044] Optionally, the stirring speed of the suspension polymerization reaction is 300 rpm to 700 rpm.

[0045] Taking the unsaturated organosilane KH570 (γ-methacryloxypropyltrimethoxysilane) as an example, the reaction formula of suspension polymerization is as follows:

[0046]

[0047] During the suspension polymerization process, KH570 copolymerizes with styrene and divinylbenzene while undergoing sol-gel, doping silane segments and inorganic silica gel into the microspheres, providing new active sites for the cross-linked polystyrene microspheres and enriching their chemical modifiability.

[0048] S40. Mix the mother balls, chloromethylsilane and organic solvent, and carry out chloromethylation reaction to prepare chloromethylated cross-linked polystyrene microspheres.

[0049] Optionally, the chloromethylsilane has the structure shown in Formula I: Formula I, wherein R 1 , R 2 and R 3 are each independently selected from one of hydrogen group, methoxy group, ethoxy group and chloro group, and at least two of R 1 , R 2 and R 3 are the same, selected from chloro group, methoxy group or ethoxy group. The chloromethylation reagent selects chloromethylsilane, which has little harm to the human body and equipment, small safety hazards, low cost, and high chlorine loading after chloromethylation.

[0050] Optionally, the mass ratio of the chloromethylsilane to the mother balls is 1:(1 - 3). For example, the mass ratio of the chloromethylsilane to the mother balls is 1:1, 1:2, 1:3.

[0051] Optionally, the organic solvent is selected from at least one of toluene, xylene, dichloromethane, and dichloroethane.

[0052] Optionally, the mass-volume ratio of the mother balls to the organic solvent is 1 g:(3 - 7) mL.

[0053] Optionally, the reaction temperature of the chloromethylation reaction is 50°C to 70°C. For example, the reaction temperature of the chloromethylation reaction is 50°C, 60°C, or 70°C.

[0054] Optionally, the reaction time of the chloromethylation reaction is 3 h to 8 h. For example, the reaction time of the chloromethylation reaction is 3 h, 5 h, or 8 h.

[0055] The reaction formula of the chloromethylation reaction is as follows:

[0056]

[0057] In this application, unsaturated organosilanes are added to the dispersion phase. While copolymerizing with styrene and divinylbenzene, the unsaturated organosilanes undergo sol-gel, doping silane segments and inorganic silica gel into the microspheres, providing new active sites for the cross-linked polystyrene microspheres and enriching their chemical modifiability. Subsequently, chloromethylsilane is selected as the chloromethylation reagent, which has little harm to the human body and equipment, small potential safety hazards, and low cost. At the same time, the chlorine loading after chloromethylation is high.

[0058] The above preparation method has simple raw materials, rich raw material sources, low cost, is economical and environmentally friendly, has mild reactions, and is harmless to the human body; the preparation process is simple, the by-product methanol is non-corrosive and has little impact on the equipment; the reaction has good stability and reproducibility and is suitable for industrial production; the chlorine loading of the cross-linked polystyrene microspheres can be adjusted by adjusting the contents of the unsaturated organosilane and chloromethylsilane.

[0059] The second aspect of this application provides a chloromethylated cross-linked polystyrene microsphere, which is prepared by the preparation method described above.

[0060] Optionally, the particle size of the chloromethylated cross-linked polystyrene microsphere is between 75 μm and 500 μm.

[0061] Optionally, the chlorine loading of the chloromethylated cross-linked polystyrene microsphere is 12 wt% to 20 wt%. With a high chlorine loading, the product has good applicability.

[0062] The following is a further description in combination with specific examples and comparative examples. For the raw materials involved in the following specific examples and comparative examples, unless otherwise specified, they can all be obtained commercially. For the instruments used, unless otherwise specified, they can all be obtained commercially. For the processes involved, unless otherwise specified, they are all conventional selections of those skilled in the art.

[0063] Example 1

[0064] This example provides a chloromethylated crosslinked polystyrene microsphere and its preparation method, and the steps are as follows:

[0065] Add 150 mL of deionized water, 0.9 g of gelatin and 0.6 g of sodium dodecyl sulfate into a 250 mL three-necked flask, stir at 40 °C and 200 rpm until the solution is clear and transparent to obtain the continuous phase. Take another beaker, weigh 20 g of styrene, 5 g of γ-methacryloyloxypropyltrimethoxysilane, 5 g of 63% divinylbenzene and 0.3 g of benzoyl peroxide, mix them evenly to obtain the dispersed phase. Pour the dispersed phase into the continuous phase according to a volume ratio of 1:5, stir at 300 rpm, heat up to 80 °C, and react for 12 h. After the reaction is completed, cool down to 60 °C, filter by suction, and wash twice with water and ethanol respectively to obtain the mother balls.

[0066] Add 10 g of the dried mother balls and 50 mL of toluene into a 150 mL three-necked flask, stir to disperse the mother balls evenly. Add 5 g of chloromethyltrimethoxysilane into the three-necked flask, heat up to 60 °C under the condition of 200 rpm, and react for 5 h. After the reaction is completed, separate and wash with ethanol to obtain the chloromethylated crosslinked polystyrene microspheres, denoted as CMPS-1.

[0067] Example 2

[0068] This example provides a chloromethylated crosslinked polystyrene microsphere and its preparation method, and the steps are as follows:

[0069] Add 150 mL of deionized water, 0.9 g of gelatin and 0.6 g of sodium dodecyl sulfate into a 250 mL three-necked flask, stir at 40 °C and 200 rpm until the solution is clear and transparent to obtain the continuous phase. Take another beaker, weigh 15 g of styrene, 10 g of γ-methacryloyloxypropyltrimethoxysilane, 5 g of 63% divinylbenzene and 0.3 g of benzoyl peroxide, mix them evenly to obtain the dispersed phase. Pour the dispersed phase into the continuous phase according to a volume ratio of 1:5, stir at 500 rpm, heat up to 80 °C, and react for 12 h. After the reaction is completed, cool down to 60 °C, filter by suction, and wash twice with water and ethanol respectively to obtain the mother balls.

[0070] Add 10 g of the dried mother balls and 50 mL of toluene into a 150 mL three-necked flask, stir to disperse the mother balls evenly. Add 5 g of chloromethyltrimethoxysilane into the three-necked flask, heat up to 60 °C under the condition of 200 rpm, and react for 5 h. After the reaction is completed, separate and wash with ethanol to obtain the chloromethylated crosslinked polystyrene mother balls, denoted as CMPS-2.

[0071] Example 3

[0072] This example provides a chloromethylated crosslinked polystyrene microsphere and a preparation method thereof, and the steps are as follows:

[0073] Add 150 mL of deionized water, 0.9 g of gelatin and 0.6 g of sodium dodecyl sulfate into a 250 mL three-necked flask, stir at 40 °C and 200 rpm until the solution is clear and transparent to obtain a continuous phase. Take another beaker, weigh 15 g of styrene, 10 g of γ-methacryloxypropyltrimethoxysilane, 5 g of 63% divinylbenzene and 0.3 g of benzoyl peroxide, mix them evenly to obtain a dispersed phase. Pour the dispersed phase into the continuous phase according to a volume ratio of 1:5, stir at 300 rpm, heat up to 80 °C, and react for 12 h. After the reaction is completed, cool down to 60 °C, filter by suction, and wash twice with water and ethanol respectively to obtain mother balls.

[0074] Add 10 g of the dried mother balls and 50 mL of toluene into a 150 mL three-necked flask, stir to disperse the mother balls evenly. Add 10 g of chloromethyltrimethoxysilane into the three-necked flask, heat up to 60 °C under the condition of 200 rpm, and react for 5 h. After the reaction is completed, separate and wash with ethanol to obtain chloromethylated crosslinked polystyrene mother balls, denoted as CMPS-3.

[0075] Example 4

[0076] This example provides a chloromethylated crosslinked polystyrene microsphere and a preparation method thereof, and the steps are as follows:

[0077] Add 150 mL of deionized water, 0.9 g of gelatin and 0.6 g of sodium dodecyl sulfate into a 250 mL three-necked flask, stir at 40 °C and 200 rpm until the solution is clear and transparent to obtain a continuous phase. Take another beaker, weigh 15 g of styrene, 10 g of γ-methacryloxypropyltrimethoxysilane, 5 g of 63% divinylbenzene and 0.3 g of benzoyl peroxide, mix them evenly to obtain a dispersed phase. Pour the dispersed phase into the continuous phase according to a volume ratio of 1:5, stir at 300 rpm, heat up to 80 °C, and react for 12 h. After the reaction is completed, cool down to 60 °C, filter by suction, and wash twice with water and ethanol respectively to obtain mother balls.

[0078] Add 10 g of the dried mother balls and 50 mL of toluene into a 150 mL three-necked flask, stir to disperse the mother balls evenly. Add 10 g of chloromethyltrichlorosilane into the three-necked flask, heat up to 60 °C under the condition of 200 rpm, and react for 5 h. After the reaction is completed, separate and wash with ethanol to obtain chloromethylated crosslinked polystyrene mother balls, denoted as CMPS-4.

[0079] Comparative Example 1

[0080] This comparative example provides a chloromethylated cross-linked polystyrene microsphere and a preparation method thereof, and the steps are as follows:

[0081] Add 150 mL of deionized water, 0.9 g of gelatin, and 0.6 g of sodium dodecyl sulfate into a 250 mL three-necked flask, stir at 40 °C and 200 rpm until the solution is clear and transparent to obtain a continuous phase. Take another beaker, weigh 20 g of styrene, 5 g of 63% divinylbenzene, and 0.3 g of benzoyl peroxide, mix them evenly to obtain a dispersed phase. Pour the dispersed phase into the continuous phase according to a volume ratio of 1:5, stir at 300 rpm, heat up to 80 °C, and react for 12 h. After the reaction is completed, cool down to 60 °C, perform suction filtration, and wash twice with water and ethanol respectively to obtain mother balls.

[0082] Add 10 g of the dried mother balls and 50 mL of toluene into a 150 mL three-necked flask, stir to disperse the mother balls evenly. Add 5 g of chloromethyltrimethoxysilane into the three-necked flask, heat up to 60 °C under the condition of 200 rpm, and react for 5 h. After the reaction is completed, separate and wash with ethanol to obtain chloromethylated cross-linked polystyrene microspheres, denoted as CMPS-5.

[0083] Test Example 1

[0084] Put the dried CMPS-1 of Example 1 and potassium bromide into a mortar and grind them evenly according to a mass ratio of 1:100, then put them into a tablet press and press for 1 min to form a slightly transparent thin film, and perform a scanning test using an infrared spectrometer. The infrared spectrum is as Figure 1 shown. Figure 2 It can be seen that there are stretching vibration peaks of carbonyl at 1722 cm -1 and characteristic absorption peaks of Si-O of the Si-O-Si bond at 1080 cm -1 . It indicates that γ-methacryloyloxypropyltrimethoxysilane has copolymerized with styrene and divinylbenzene; at the same time, the absorption peaks at 1270 cm -1 and 670 cm -1 belong to the bending vibration of -CH 2 Cl and the stretching vibration of C-Cl respectively, indicating that the chloromethylsilane coupling agent has been successfully grafted onto the PS microspheres.

[0085] Test Example 2

[0086] Test the particle size distribution of the dried CMPS-1 of Example 1, and the results are shown in Figure 2 . Figure 2 It shows that the particle size distribution of CMPS-1 is between 75 μm and 500 μm.

[0087] Test Example 3

[0088] The chlorine loading of the chloromethylated cross-linked polystyrene microspheres prepared in Examples 1 to 4 and Comparative Example 1 was tested by Mohr titration. The specific steps are as follows:

[0089] S1 Sample preparation: Take dry CMPS1 - CMPS5, wash with hot water 4 - 5 times until there is no Cl in the filtrate - (AgNO 3 titration test), filter by suction, dry at 60 °C to constant weight and record the weight.

[0090] S2 Sample decomposition: Take the CMPS1 - CMPS5 processed in step S1 and place them in crucibles respectively. Heat the muffle furnace at a heating rate of 5 °C / min to 700 °C, calcine for 6 h, and cool to room temperature.

[0091] S3 Sample titration: Collect the calcined powder in the crucible, add 10 mL of 50% HNO 3 solution to completely dissolve the powder. Adjust the pH of the solution to 7.5 with NaHCO 3 , add 1 mL of 10% K 2 CrO 4 indicator solution, dilute to 50 mL with deionized water, and titrate with 1 mol / L AgNO 3 standard solution. The titration end point is determined when the yellow solution turns orange and does not change color within 15 s.

[0092] The chlorine content calculation formula is:

[0093] Where: Cl%: chlorine content, %;

[0094] C AgNO3 : concentration of the standard silver nitrate solution, mol / L;

[0095] V AgNO3 : volume of the standard silver nitrate solution consumed, L;

[0096] M CMPS : mass of CMPS, g.

[0097] The chlorine loading data of CMPS is shown in Table 1.

[0098] Table 1

[0099]

[0100] As can be seen from Table 1, comparing Example 1 and Example 2, as the proportion of unsaturated silane in the dispersed phase increases, the chlorine loading of the sample relatively increases; similarly, comparing Example 2 and Example 3, as the dosage of chloromethylsilane reagent increases, the chlorine loading of the sample also increases. Thus, it can be seen that by increasing or decreasing the dosages of unsaturated silane and chloromethylsilane, the chlorine loading of CMPS can be regulated. Comparing Example 3 and Example 4, after modifying the mother balls with highly active chloromethyltrichlorosilane, the chlorine loading of the mother balls is further increased, up to 19.69% at most.

[0101] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0102] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for preparing chloromethylated cross-linked polystyrene microspheres, characterized in that: The following steps are involved: Mixing water and a dispersant to prepare a continuous phase; Mixing styrene monomer, divinylbenzene monomer, unsaturated organosilane and oil-soluble initiator to prepare dispersed phase; Mixing the continuous phase and the dispersed phase to carry out suspension polymerization to prepare mother balls; The mother ball, chloromethylsilane and an organic solvent are mixed to carry out a chloromethylation reaction to prepare chloromethylated cross-linked polystyrene microspheres; The unsaturated organosilane is selected from at least one of γ-methacryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane and acryloxytrimethylsilane; The chloromethylsilane has a structure as shown in Formula I: Formula I, wherein R1, R2 and R3 are each independently selected from one of hydrogen, methoxy, ethoxy and chloro, and at least two of R1, R2 and R3 are the same and selected from chloro, methoxy or ethoxy.

2. The method for preparing chloromethylated cross-linked polystyrene microspheres according to claim 1, characterized in that: The mass ratio of the unsaturated organic silane to the styrene monomer is 1:(1-4).

3. The method for preparing chloromethylated cross-linked polystyrene microspheres according to claim 1, characterized in that: The mass ratio of the chloromethylsilane to the mother ball is 1:(1-3).

4. The method for preparing chloromethylated cross-linked polystyrene microspheres according to any one of claims 1 to 3, wherein the divinylbenzene monomer is provided by a divinylbenzene solution, the concentration of the divinylbenzene monomer in the divinylbenzene solution is 55% to 80%, and the mass ratio of the divinylbenzene solution to the styrene monomer is 1:(1 to 100).

5. The method for preparing chloromethylated cross-linked polystyrene microspheres according to any one of claims 1 to 3, characterized in that: Includes at least one of the following features: (1) The dispersant comprises a first dispersed phase and a second dispersed phase, wherein the first dispersed phase is selected from at least one of gelatin, polyvinyl alcohol, and polyethylene glycol, and the second dispersed phase is selected from at least one of sodium dodecylbenzene sulfonate and sodium dodecyl sulfate; (2) The mass ratio of the first dispersed phase to the second dispersed phase is (1.5-4):1; (3) The mass ratio of the dispersant to water is 1:(50~100).

6. The method for preparing chloromethylated cross-linked polystyrene microspheres according to any one of claims 1 to 3, characterized in that: Includes at least one of the following features: (1) The oil-soluble initiator is at least one selected from benzoyl peroxide and azobisisobutyronitrile; (2) The mass ratio of the oil-soluble initiator to the total amount of the unsaturated organic silane and styrene is 1:(50-100).

7. The method for preparing chloromethylated cross-linked polystyrene microspheres according to any one of claims 1 to 3, characterized in that: Includes at least one of the following features: (1) The volume ratio of the dispersed phase to the continuous phase is 1:(3-10); (2) The reaction temperature of the suspension polymerization reaction is 70°C to 85°C; (3) The reaction time of the suspension polymerization reaction is 8h~16h; (4) The stirring speed of the suspension polymerization reaction is 300 rpm to 700 rpm.

8. The method for preparing chloromethylated cross-linked polystyrene microspheres according to any one of claims 1 to 3, characterized in that: Includes at least one of the following features: (1) The organic solvent is at least one selected from toluene, xylene, dichloromethane and dichloroethane; (2) The reaction temperature of the chloromethylation reaction is 50°C to 70°C; (3) The reaction time of the chloromethylation reaction is 3h~8h.

9. A chloromethylated cross-linked polystyrene microsphere, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 8.

10. The chloromethylated cross-linked polystyrene microspheres according to claim 9, satisfying at least one of the following conditions: (1) The particle size of the chloromethylated cross-linked polystyrene microspheres is between 75 μm and 500 μm; (2) The chlorine loading of the chloromethylated cross-linked polystyrene microspheres is 12 wt% to 20 wt%.

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