Polymeric strong cation exchange resin and preparation method thereof

Abstract

The invention relates to the technical field of ion exchange resin, in particular to polymerized strong cation exchange resin and a preparation method thereof. The preparation method comprises the following steps: mixing hydroxyl polystyrene microspheres with a side chain S1, and carrying out condensation reaction to form the polymeric strong cation exchange resin, wherein the structural formula of the hydroxyl polystyrene microspheres is shown in the specification, n and m are respectively and independently selected from any numerical value between 1 and 00, the structural formula of the side chain S1 is shown in the specification, and p and q are respectively and independently selected from any integer between 1 and 5.

Description

Technical Field

[0001] This invention relates to the field of ion exchange resin technology, and more specifically, to polymeric strong cation exchange resins and their preparation methods. Background Technology

[0002] Since the 19th century, monodisperse small-particle chromatographic packing materials have attracted increasing attention for the separation and purification of proteins. Due to their small particle size and good rigidity, these packing materials are highly advantageous for improving column efficiency, enhancing sample recovery, and preserving the biological activity of solutes, making them particularly suitable for high-resolution separation and rapid analysis of biomolecules. Ion exchange resins are not only widely used for separating various biomolecules, but industrial chemical purification processes generally include one or more steps of ion exchange.

[0003] Traditional ion exchange chromatography typically uses polysaccharide gels as the matrix, which suffers from drawbacks such as poor mechanical strength, low pressure resistance, inability to perform rapid elution, long separation times, and a tendency to denature and inactivate biomolecules. Inorganic silica gel packing materials offer high mechanical strength, high column efficiency, and easy control over pore size and particle size, but suffer from a narrow pH range (2–8), irreversible adsorption of proteins by residual silanol groups on the silica gel surface during protein separation, resulting in low protein recovery rates and loss of biological activity. Furthermore, the coating on coated silica gel stationary phases is prone to detachment and exhibits poor stability during continuous use.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a polymeric strong cation exchange resin and its preparation method. The embodiments of this invention provide a polymeric strong cation exchange resin with advantages such as good biocompatibility, chemical stability, good hydrophilicity, and ease of derivatization. Its hydrophilicity reduces the chance of non-specific interactions between the matrix and proteins, and it can be widely used within a pH range of 1 to 12.

[0006] This invention is implemented as follows: In a first aspect, the present invention provides a method for preparing a polymeric strong cation exchange resin, comprising: mixing hydroxyl polystyrene microspheres with side chain S1 and performing a condensation reaction to form the polymeric strong cation exchange resin; The structural formula of the hydroxyl polystyrene microspheres is shown below: n and m are each independently selected from any value between 1 and 00. The structural formula of the side chain S1 is as follows: p and q are each independently selected from any integer between 1 and 5.

[0007] In an optional embodiment, the condensation reaction conditions include: the mass ratio of the hydroxyl polystyrene microspheres to the side chain S1 is 1:(2-3); and the reaction temperature is 90~100℃.

[0008] In an optional embodiment, the preparation steps of the side chain S1 are as follows: SM1, trichloroacetonitrile and Lewis acid are mixed and heated to undergo a ring-opening reaction to form SM2; wherein, SM1 is 4-[(2,3-epoxypropoxy)methyl]-2,2-dimethyl-1,3-dioxolane; SM2 and the first catalyst are mixed and hydrolyzed under acidic conditions to form SM3; The SM3 and the sulfite aqueous solution were mixed and heated under reflux to undergo a substitution reaction to form SM4; The SM4, hydrobromic acid-acetic acid solution, and second catalyst are mixed and heated to initiate a halogenation reaction to form the side chain S1.

[0009] In an optional embodiment, (1) the Lewis acid is a chloride of a metal salt, preferably copper chloride; (2) The conditions for initiating the ring-opening reaction by heating include: the molar ratio of the SM1, the trichloroacetonitrile and the Lewis acid is 1:(2-3):(0.1-0.3), the temperature is 25~35℃, and the time is 2~6h; (3) The first catalyst is Amberlyst-15; (4) The hydrolysis conditions include: the mass ratio of SM2 to the first catalyst is (90-110):1, the temperature is 0~30℃, and the time is more than 30h; (5) The sulfite is sodium sulfite; (6) The conditions for initiating the substitution reaction by heating and reflux include: the molar ratio of SM3 to sulfite is 1:(0.7-1.0), the reflux temperature is 80~100℃, and the time is more than 1h; (7) The second catalyst is acetic anhydride; (8) The conditions for initiating the halogenation reaction by heating include: the concentration of the hydrobromic acid-acetic acid solution is 30%~35%; the mass ratio of SM4, the hydrobromic acid-acetic acid solution and the second catalyst is 1:(2-3):(0.3-0.7); the temperature is 60~65℃; and the time is 3~6h.

[0010] In an optional embodiment, the preparation steps of the hydroxyl polystyrene microspheres are as follows: styrene, divinylbenzene and an initiator are mixed and heated to initiate a polymerization reaction to form polystyrene microspheres; The polystyrene microspheres, the third catalyst, and the halogen are mixed and a substitution reaction is carried out to form halogenated polyethylene benzene microspheres; The halogenated polyethylene benzene microspheres and the fourth catalyst were mixed and hydrolyzed under alkaline conditions to form hydroxyl polystyrene microspheres.

[0011] In an optional embodiment, the initiator is selected from peroxides, preferably benzoyl peroxide; The conditions for initiating the polymerization reaction by heating include: the mass ratio of the styrene, the divinylbenzene and the initiator is 4.3:1:(0.5-0.8), the temperature is 70~80℃, and the time is more than 4 hours.

[0012] In an optional embodiment, the third catalyst comprises a Lewis acid, preferably AlCl3; the halogen is bromine; The conditions for the substitution reaction include: the mass ratio of the polystyrene microspheres, the third catalyst, and the halogen is (45-55):1:(170-190), the temperature is -10~0℃, and the time is 0.5~1h.

[0013] In an optional embodiment, the fourth catalyst comprises an iodide, preferably copper iodide; Preferably, the hydrolysis conditions include: a mass ratio of the halogenated polyethylene benzene microspheres to the fourth catalyst of (300-500):1; a temperature of 120-140°C; and a time of 48 hours or more.

[0014] Secondly, the present invention provides a polymeric strong cation exchange resin, which is prepared by the preparation method of the polymeric strong cation exchange resin described in the foregoing embodiments.

[0015] In an optional embodiment, it is selected from polymers shown in the following structural formula: ; Preferably, the particle size of the polymeric strong cation exchange resin is 25-35 micrometers.

[0016] The present invention has the following beneficial effects: The polymeric strong cation exchange resin provided in the embodiments of the present invention belongs to a polymer matrix stationary phase, which has the advantages of good biocompatibility, chemical stability and easy derivatization. Its hydrophilicity reduces the chance of non-specific interactions between the matrix and proteins, and it can also be widely used in the pH range of 1 to 12. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1Electron microscope images of polymeric strong cation exchange resins provided in embodiments of the present invention; Figure 2 This is a graph showing the comparison results of pressure / flow characteristics provided in Test Example 1 of the present invention; Figure 3 This is a protein separation effect diagram of the polymeric strong cation exchange resin provided in Test Example 2 of the present invention; Figure 4 and Figure 5 This is a protein separation effect diagram of sodium polystyrene sulfonate resin provided in Test Example 2 of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0020] In a first aspect, embodiments of the present invention provide a method for preparing a polymeric strong cation exchange resin, comprising: S1, synthetic side chain S1; S1.1, Synthesize SM2; SM1, trichloroacetonitrile, and a Lewis acid are mixed and subjected to a ring-opening reaction to form SM2; wherein, SM1 is 4-[(2,3-epoxypropoxy)methyl]-2,2-dimethyl-1,3-dioxolane, and the Lewis acid is a chloride of a metal salt, preferably copper chloride; the molar ratio of SM1, trichloroacetonitrile, and Lewis acid is 1:(2-3):(0.1-0.3), for example, 1:3:0.2; the temperature is 25-35°C; and the time is 2-6 hours. SM1 was purchased from Shanghai Bieder Pharmaceutical Technology Co., Ltd.

[0021] S1.2, Synthesize SM3; SM2 and a first catalyst were mixed and hydrolyzed under acidic conditions to form SM3. The first catalyst was Amberlyst-15. The mass ratio of SM2 to the first catalyst was (90-110):1, for example, 100:1, at a temperature of 25-35°C for at least 30 hours. Amberlyst-15 was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0022] S1.3, Synthesize SM4; SM3 and an aqueous solution of sulfite are mixed and heated under reflux to undergo a substitution reaction to form SM4; wherein the sulfite is sodium sulfite. The molar ratio of SM3 to sulfite is 1:(0.7-1.0), for example 1:1, the reflux temperature is 80~100℃, and the time is more than 1 hour.

[0023] S1.4, Synthesize S1; A halogenation reaction is initiated by heating a mixture of SM4, a hydrobromic acid-acetic acid solution, and a second catalyst to form S1; wherein the second catalyst is acetic anhydride. The concentration of the hydrobromic acid-acetic acid solution is 30%~35%; the mass ratio of SM4, the hydrobromic acid-acetic acid solution, and the second catalyst is 1:(2-3):(0.3-0.7), for example, 1:3:0.5, the temperature is 60~65℃, and the time is 3~6h.

[0024] S2, Synthetic hydroxyl polystyrene microspheres; S2.1, Synthetic polystyrene microspheres Styrene, divinylbenzene, and an initiator are mixed and heated to initiate a polymerization reaction to form polystyrene microspheres. The initiator is selected from peroxides, such as, but not limited to, benzoyl peroxide. The molar ratio of styrene, divinylbenzene, and the initiator is 4.3:1:(0.5-0.8), for example, 4.3:1:0.76. The temperature is 70-80°C, and the reaction time is at least 4 hours. Styrene and divinylbenzene were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0025] S2.2, Synthetic halogenated polyethylene benzene microspheres; The polystyrene microspheres, a third catalyst, and a halogen are mixed and subjected to a substitution reaction to form halopolystyrene microspheres; wherein the third catalyst comprises a Lewis acid, preferably AlCl3; and the halogen is bromine. The molar ratio of the polystyrene microspheres, the third catalyst, and the halogen is (45-55):1:(170-190), for example, 50:1:184, the temperature is -10~0℃, and the time is 0.5~1h.

[0026] S2.3, Synthesis of hydroxyl polystyrene microspheres; The halogenated polyethylene benzene microspheres and a fourth catalyst are mixed and hydrolyzed under alkaline conditions to form hydroxyl polystyrene microspheres. The fourth catalyst comprises an iodide, preferably copper iodide. Alkaline conditions are achieved using a hydroxide (e.g., potassium hydroxide). The mass ratio of the halogenated polyethylene benzene microspheres to the fourth catalyst is (300-500):1, for example, 400:1; the temperature is 120-140°C; and the time is 48 hours or more.

[0027] It should be noted that hydroxyl polystyrene microspheres can be prepared by referring to the above method, or existing hydroxyl polystyrene microspheres can be purchased directly, for example, from Shanghai Yikefan Biotechnology Co., Ltd.

[0028] S3, a synthetic polymeric strong cation exchange resin; Hydroxy-coated polystyrene microspheres are mixed with side chain S1 and subjected to a condensation reaction to form the polymeric strong cation exchange resin. The structural formula of the hydroxyl polystyrene microspheres is shown below: n and m are each independently selected from any value between 1 and 00. The structural formula of the side chain S1 is as follows: p and q are each independently selected from any integer between 1 and 5, such as 1, 2, 3, 4, 5, etc., and preferably any value between 1 and 3.

[0029] Furthermore, the mass ratio of the hydroxyl polystyrene microspheres to the side chain S1 is 1:(2-3), for example, 1:2.6; the reaction temperature is 90~100℃.

[0030] Then, the polymeric strong cation exchange resin with the desired particle size is obtained by sieving.

[0031] It should be noted that the hydroxyl polystyrene microspheres can be sieved to select the desired particle size before the condensation reaction with side chain S1. Furthermore, sieving the particle size before the condensation reaction can further reduce production costs.

[0032] This invention takes the synthesis of the following polymeric strong cation exchange resin as an example, and the synthesis is carried out according to the following synthetic route:

[0033] Synthetic pathway of side chain S1:

[0034] Secondly, the present invention provides a polymeric strong cation exchange resin, which is prepared by the preparation method of the polymeric strong cation exchange resin described in the foregoing embodiments.

[0035] In an optional embodiment, it is selected from any of the polymers shown in the following structural formulas: ; The particle size of polymeric strong cation exchange resin is 25-35 micrometers.

[0036] The polymeric strong cation exchange resin provided in this embodiment of the invention has the following characteristics: (1) Uniform particle size: Polymerized strong cation exchange resins are composed of uniformly sized microspheres (e.g., 30 μm) that can form a tightly packed, well-ordered bed. This shortens the diffusion path of solutes (proteins) within the particles, accelerates the mass transfer rate, avoids uneven flow rate of the mobile phase caused by the mixing of particles of different sizes, reduces solute peak broadening, and improves column efficiency and peak symmetry.

[0037] (2) The side chains are highly hydrophilic: Polymerized strong cation exchange resins have side chains rich in multiple hydrophilic groups such as hydroxyl (-OH), which easily form a hydration layer during purification, shielding hydrophobic interactions and reducing the non-selective adsorption of proteins by hydrophobic forces on the hydrophobic surface of the resin, thereby reducing the loss of target proteins and co-adsorption of impurities.

[0038] Furthermore, the polymeric strong cation exchange resin provided in this embodiment of the invention has a rigid porous network structure, and its surface is covalently modified with sulfonic acid groups (-SO3). - ), forming fixed sites with permanent negative charges, and binding exchangeable cations (such as Na+). + H + Maintaining charge balance. The core of the purification mechanism is electrostatically driven ion exchange, a process that relies on the reversible binding between the protein surface charge and the resin functional groups. Specifically: (1) Protein binding: When a positively charged protein approaches a sulfonic acid microsphere, it is adsorbed onto the resin surface by Coulomb attraction. The positively charged groups of the protein react with the counterions (such as Na+) on the resin. + Displacement occurs: Protein-NH3 + + Resin-SO3 - Na + → Resin-SO3 - ··· + H3N-Protein + Na + Negatively charged (pH>pI) or neutral proteins flow directly through the microspheres due to electrostatic repulsion / no attraction, while target proteins are retained within the microsphere channels due to strong electrostatic attraction. (2) Protein dissociation: By altering the buffer conditions to reduce electrostatic attraction, linearly increasing [NaCl] (0 → 1 M) causes weakly bound proteins to elute first, followed by strongly bound proteins. High concentrations of cations (such as NaCl) reduce electrostatic attraction. + Competitive binding sites for sulfonic acid groups: Resin-SO3 - ··· + H3N-Protein + Na +→ Resin-SO3 - Na + + Protein-NH3 + This allows for the dissociation of the target protein.

[0039] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0040] Example 1 This embodiment provides a method for preparing a polymeric strong cation exchange resin, including: S1. Synthesis of polystyrene microspheres.

[0041] (1) Preparation of aqueous phase: Add 70g of water to the reactor, then add 7g of sodium chloride and wait for it to dissolve completely. Add 0.02g of methylene blue, 0.5g of gelatin, 0.35g of trisodium phosphate, 1.3g of disodium hydrogen phosphate, and 0.1g of lignin. Stir and mix thoroughly, and heat to 75℃ to obtain the aqueous phase for later use.

[0042] (2) Preparation of organic phase: 28.3g of styrene (purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) and 6.6g of divinylbenzene (purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) were added to the mixing tank, followed by 35g of isobutanol and finally 5kg of benzoyl peroxide. The mixture was stirred evenly to obtain the organic phase for later use.

[0043] (3) Polymerization operation: The prepared organic phase is added to the aqueous phase. The mass ratio of organic phase to aqueous phase is 1:1. Stirring is started, and the temperature is raised to 80°C to initiate the polymerization reaction. After the temperature inside the reactor reaches 80°C, it is kept at this temperature for 0.5 hours. Then, the temperature is raised to 82°C and kept at this temperature for 4 hours. Isobutanol is distilled. The whole process takes 4 hours. When the temperature inside the reactor reaches 100°C, the distillation is completed. The temperature inside the reactor is lowered to 65°C and the material is ready to be discharged to obtain 30g of polystyrene microspheres.

[0044] S2, Synthesis of brominated polystyrene.

[0045] (1) Add 450g of dichloroethane and 30g of polystyrene microspheres prepared by S1 to a 2L five-necked flask, and purge with nitrogen gas at a constant speed for protection. Heat to 35°C and stir. After all the polystyrene microspheres have dissolved, cool the system to below 0°C, add 1.5g of titanium tetrachloride, and stir for 30min to treat the polystyrene.

[0046] (2) Cool the raw material mixture obtained in step (1) to below 0°C and pass in an inert gas for protection; dissolve 0.7g of catalyst AlCl3 in 150g of dichloroethane and place it in a 500ml jacketed dropping funnel, and then place 129g of bromine in another 500ml jacketed dropping funnel. After the temperature of both is lowered to below 0°C, start to add them to the raw material mixture simultaneously to carry out the substitution reaction. Add both at the same time. The addition time is 0.5h. The reaction temperature of the system is controlled at around -10°C. After the addition is completed, keep the temperature below 0°C for 0.5h.

[0047] (3) After the heat preservation is completed, 1% hydrazine hydrate aqueous solution is added dropwise as a quencher to quench the residual bromine and catalyst. The system changes from reddish-brown to colorless and the pH value becomes alkaline. During the dropwise addition process, the system temperature is kept below 5℃. The organic phase is washed with 10% NaOH aqueous solution 3 to 4 times and then separated. The aqueous phase is treated and discharged. 0.9g of reducing agent sodium telluride is dissolved in 10% NaOH aqueous solution and added to the organic phase. Then 0.03g of triethylbenzylammonium chloride is added and heated to 50℃ and stirred for 2.5h. After the reaction is completed, the mixture is allowed to stand and separate into layers. The organic phase is treated and discharged. The organic phase is a crude solution of brominated polystyrene.

[0048] (4) The crude brominated polystyrene solution was washed and separated with 10% NaOH aqueous solution. The aqueous phase was discharged. The organic phase brominated polystyrene solution was then added dropwise to 6L of boiling water containing 6g sodium dodecylbenzenesulfonate. The volatilized components were separated in an oil-water separator. The dichloroethane in the lower layer was recovered and reused. The rotation speed was controlled at 120 rpm. A grayish-white slurry was obtained in boiling water azeotrope. After vacuum filtration, the mother liquor was discharged. The solid was placed in a vacuum drying oven and dried at 120℃ to constant weight to obtain 92g of off-white powder of brominated polystyrene microspheres. The yield was 95.5% and the bromine content was 70.1%.

[0049] Synthesis of S3-hydroxyl polystyrene microspheres.

[0050] Add 80g of the brominated polystyrene microspheres prepared by S2 to a 500mL reaction flask, then add 1000mL of DMSO and 100mL of water, followed by 0.2g of copper iodide and 10g of potassium hydroxide. Stir well, heat to 130℃, and react for 48 hours. After the reaction is complete, drop the reaction solution into 100L of water at a speed of 500rpm.

[0051] After the addition was complete, stirring was continued for 2 hours. The mixture was then filtered, washed several times with water, and dried to obtain 30g of hydroxyl polystyrene microspheres.

[0052] S4, particle size sieving of hydroxyl polystyrene microspheres.

[0053] (1) Add 30g of hydroxyl polystyrene microspheres prepared by S3 to 1L of water and stir evenly. Then add the mixture to a wet centrifugal sieve separator for multiple separations and collect the microspheres with a particle size of 30 µm.

[0054] (2) Microspheres of other particle sizes were combined and dissolved in dichloroethane, azeotropically in water, with a rotation speed of 500 rpm. After cooling to 25~35°C, the mixture was filtered, water was added and stirred evenly, and then added to a wet centrifugal sieve separator for multiple separations. Microspheres with a particle size of 30 µm were collected.

[0055] (3) Repeat operation (2) multiple times to obtain 15.3g of hydroxyl polystyrene microspheres with a single particle size of 30 µm.

[0056] Synthesis of S5 and side chain S1.

[0057] (1) Under nitrogen protection, 188.2 g SM1 (purchased from Shanghai Bid Pharmaceutical Technology Co., Ltd.), 26.9 g copper chloride, 1882 mL DMF / water mixture (volume ratio 99:1), and 433.2 g trichloroacetonitrile were added to the reaction flask. After stirring at 30°C for 3 hours, 1882 mL of water was added to the mixture. The aqueous layer was extracted with ethyl acetate (500 mL × 3). The organic layers were combined, washed with water (150 mL × 2), dried over 200 g anhydrous sodium sulfate, filtered, and concentrated under reduced pressure at 40°C to obtain 231.3 g of SM2 concentrate.

[0058] (2) Add 231.3g of SM2 and 2.3L of anhydrous ethanol to the reaction flask and stir until dissolved. Then add 2.31g of Amberlyst-15 (purchased from Shanghai Maclean Biochemical Technology Co., Ltd.) and react at 25~35°C for 38h. After the reaction is complete, concentrate under reduced pressure at 40°C to obtain 190.2g of SM3 concentrate.

[0059] (3) Add 190.2g of SM3 and 433g of 30% sodium sulfite aqueous solution to the reaction flask and stir until homogeneous. Heat to 96℃ and start reflux. Continue to keep the temperature for 2h. After the reaction is completed, concentrate under reduced pressure to dryness. Add 900mL of methanol to the concentrated residue and stir for 30min. Solid precipitates out. After filtration and drying, 126.3g of SM4 solid powder is obtained.

[0060] (4) Add 126.3g of SM4 and 378.9g of 30% hydrobromic acid-acetic acid solution to the reaction flask and stir for 10min. Then add 63.2g of acetic anhydride and heat to 63℃ and keep the temperature for 5h. After the reaction is complete, concentrate under reduced pressure to dryness, add methanol and slurry three times, 300mL each time. After slurrying, filter and dry to obtain 61.5g of side chain S1.

[0061] Synthesis of S6 and WST-30.

[0062] 15.0 g of hydroxyl polystyrene microspheres prepared by S4 were added to a high-pressure reactor. Under nitrogen protection, sodium hydroxide (50%, 12.8 g) and 16.3 g of water were added. The solution was stirred at 25–35°C for 30 minutes to form sodium salt, and then reacted with 39 g of side chain S1 prepared by S5 under vacuum conditions <-20°C for 1 hour. The reactor was then heated to 95–100°C and maintained for 4 hours to complete the reaction. The reactor was cooled to 25–35°C, filtered, and then washed three times with 100 mL of purified water each time to remove excess side chain S1. After drying, 24.9 g of the desired polymeric strong cation exchange resin (hereinafter also referred to as WST-30) was obtained.

[0063] The structural formula of this polymeric strong cation exchange resin is shown below: Its particle size is 30 micrometers.

[0064] The polymeric strong cation exchange resin prepared in Example 1 was characterized using electron microscopy. The results are shown in [reference needed]. Figure 1 .according to Figure 1 It can be seen that the polymeric strong cation exchange resin provided in the embodiments of the present invention has uniform size and is free of fine powder, fragments and broken 30um beads.

[0065] Test Example 1 Test sample: A: The WST-30 polymeric strong cation exchange resin with a single particle size of 30 μm prepared in Example 1 of this invention; B: Sodium polystyrene sulfonate resin of type CT-9 with a particle size of 30um was purchased from Tianjin Xijinna Environmental Protection Materials Technology Co., Ltd. C: Sodium polystyrene sulfonate resin of type CT-9 with a particle size of 50um was purchased from Tianjin Xijinna Environmental Protection Materials Technology Co., Ltd.

[0066] The pressure / flow characteristics of the different resins were tested. The pressure / flow data were obtained in a column with an inner diameter of 100 mm and a bed height of 10 cm. The specific method is as follows: Inlet connection method: Inlet feed pump → Pressure gauge → Packing column → Outlet Measurement method: Adjust the flow rate of the feed pump (cm / h), observe and record the pressure count value (bar) to obtain the pressure / flow characteristics of the different resins.

[0067] See results Figure 2 ,according to Figure 2It is known that the WST-30 polymeric strong cation exchange resin with a single particle size of 30 μm provided in the embodiments of the present invention can form a stable bed, has excellent flow properties, and its back pressure is much lower than that of other resins in the same particle size range.

[0068] Test Example 2 Protein separation effect Separate sample: a mixture of 1 gram whey protein, 1 gram β-lactoglobulin and 1 gram amylase. Column size: 10 mm inner diameter × 60 mm (5 mL); Resins: WST-30, a polymeric strong cation exchange resin provided in Example 1 of this invention; sodium polystyrene sulfonate resin with an average particle size of 50 μm (purchased from Tianjin Xijinna Environmental Protection Materials Technology Co., Ltd., CT-9 type); sodium polystyrene sulfonate resin with an average particle size of 30 μm (purchased from Tianjin Xijinna Environmental Protection Materials Technology Co., Ltd., CT-9 type); The structural formula of sodium polystyrene sulfonate resin is shown below:

[0069] Elution buffer: Phase A (0.5 mol / L sodium chloride), Phase B (20 mmol / L bis(tris(hydroxymethyl)aminomethane)propane); Elution gradient: 0 - 100% elution buffer, 30 column volumes, gradient as follows:

[0070] pH value: 7.0; Flow rate: 1000 cm / hour.

[0071] See test results Figure 3 , Figure 4 and Figure 5 ,in Figure 3 Corresponding to the WST-30 separation effect diagram, Figure 4 The separation effect of sodium polystyrene sulfonate resin with an average particle size of 50 μm is shown in the figure. Figure 5 The separation effect of sodium polystyrene sulfonate resin with an average particle size of 30 μm is shown in the figure.

[0072] according to Figure 4 and Figure 5 It is known that the smaller the average particle size of polymeric strong cation exchange resins, the better the separation and purification of proteins; according to Figure 3 and Figure 5 It can be seen that, at high flow rates, the polymeric strong cation exchange resin WST-30 provided in Example 1 of this invention has a better ability to separate and purify proteins than sodium polystyrene sulfonate resin with the same average particle size of 30 μm, and WST-30 has a better effect on the separation and purification of proteins.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a polymeric strong cation exchange resin, characterized in that, include: Hydroxy-coated polystyrene microspheres are mixed with side chain S1 and subjected to a condensation reaction to form the polymeric strong cation exchange resin. The structural formula of the hydroxyl polystyrene microspheres is shown below: n and m are each independently selected from any value between 1 and 00. The structural formula of the side chain S1 is as follows: p and q are each independently selected from any integer between 1 and 5.

2. The preparation method according to claim 1, characterized in that, The conditions for the condensation reaction include: the mass ratio of the hydroxyl polystyrene microspheres to the side chain S1 is 1:(2-3); and the reaction temperature is 90~100℃.

3. The preparation method according to claim 1, characterized in that, The preparation steps of the side chain S1 are as follows: SM1, trichloroacetonitrile and Lewis acid are mixed and heated to undergo a ring-opening reaction to form SM2; wherein, SM1 is 4-[(2,3-epoxypropoxy)methyl]-2,2-dimethyl-1,3-dioxolane; The SM2 and the first catalyst are mixed and hydrolyzed under acidic conditions to form SM3; The SM3 and the sulfite aqueous solution were mixed and heated under reflux to undergo a substitution reaction to form SM4; The SM4, hydrobromic acid-acetic acid solution, and second catalyst are mixed and heated to initiate a halogenation reaction to form the side chain S1.

4. The preparation method according to claim 3, characterized in that, The conditions and process for preparing the side chain S1 shall meet at least one of the following requirements: (1) the Lewis acid is a chloride of a metal salt, preferably copper chloride; (2) The conditions for initiating the ring-opening reaction by heating include: the molar ratio of the SM1, the trichloroacetonitrile and the Lewis acid is 1:(2-3):(0.1-0.3), the temperature is 25~35℃, and the time is 2~6h; (3) The first catalyst is Amberlyst-15; (4) The hydrolysis conditions include: the mass ratio of SM2 to the first catalyst is (90-110):1, the temperature is 0~30℃, and the time is more than 30h; (5) The sulfite is sodium sulfite; (6) The conditions for initiating the substitution reaction by heating and reflux include: the molar ratio of SM3 to sulfite is 1:(0.7-1.0), the reflux temperature is 80~100℃, and the time is more than 1h; (7) The second catalyst is acetic anhydride; (8) The conditions for initiating the halogenation reaction by heating include: the concentration of the hydrobromic acid-acetic acid solution is 30%~35%; the mass ratio of SM4, the hydrobromic acid-acetic acid solution and the second catalyst is 1:(2-3):(0.3-0.7); the temperature is 60~65℃; and the time is 3~6h.

5. The preparation method according to claim 1, characterized in that, The preparation steps of the hydroxyl polystyrene microspheres are as follows: styrene, divinylbenzene and an initiator are mixed and heated to initiate a polymerization reaction to form polystyrene microspheres; The polystyrene microspheres, the third catalyst, and the halogen are mixed and a substitution reaction is carried out to form halogenated polyethylene benzene microspheres; The halogenated polyethylene benzene microspheres and the fourth catalyst were mixed and hydrolyzed under alkaline conditions to form hydroxyl polystyrene microspheres.

6. The preparation method according to claim 5, characterized in that, The initiator is selected from peroxides, preferably benzoyl peroxide; The conditions for initiating the polymerization reaction by heating include: the mass ratio of the styrene, the divinylbenzene and the initiator is 4.3:1:(0.5-0.8), the temperature is 70~80℃, and the time is more than 4 hours.

7. The preparation method according to claim 5, characterized in that, The third catalyst comprises a Lewis acid, preferably AlCl3; the halogen is bromine. The conditions for the substitution reaction include: the mass ratio of the polystyrene microspheres, the third catalyst, and the halogen is (45-55):1:(170-190), the temperature is -10~0℃, and the time is 0.5~1h.

8. The preparation method according to claim 5, characterized in that, The fourth catalyst includes an iodide, preferably copper iodide; Preferably, the hydrolysis conditions include: a mass ratio of the halogenated polyethylene benzene microspheres to the fourth catalyst of (300-500):1; a temperature of 120-140°C; and a time of 48 hours or more.

9. A polymeric strong cation exchange resin, characterized in that, It is prepared by the method for preparing polymeric strong cation exchange resin as described in claim 1.

10. The polymeric strong cation exchange resin according to claim 9, characterized in that, It is selected from polymers shown in the following structural formulas: ； Preferably, the particle size of the polymeric strong cation exchange resin is 25-35 micrometers.

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