Styrene polymer microsphere as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to styrene polymer microspheres as well as a preparation method and application thereof. The preparation method comprises the following steps: S1, carrying out first mixing on water, an inorganic dispersant and an organic dispersant to obtain a water phase; s2, carrying out second mixing on a monomer, an initiator and a pore-foaming agent to obtain an oil phase; s3, adding the oil phase into the water phase, carrying out polymerization reaction, and carrying out cleaning and solid-liquid separation on a product to obtain styrene polymer microspheres; a suspension polymerization method is adopted, and an inorganic dispersant and an organic dispersant which have a synergistic effect are added in a water phase preparation process, so that the yield of the prepared styrene polymer microspheres is improved; when being used as a chromatography medium, the microspheres have excellent resolution.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to styrene polymer microspheres and a preparation method and application thereof. Background Art

[0002] Agarose is widely used for protein separation due to its good affinity for proteins. When agarose is used as a chromatography medium, it is a soft matrix, and the pressure drop is large during application, and the back pressure of the chromatography column is high, which is not conducive to column operation. In addition, due to the limitations of the sphering method of the agarose matrix, the sphering particle size range is wide, resulting in low resolution during separation and purification, which are all weaknesses of agarose matrices. Recently, many scholars have studied the purification of proteins based on styrene. Compared with agarose chromatography medium, the mechanical strength of cross-linked polystyrene chromatography medium is significantly improved, making the separation material reusable and improving the cycle life of the material. The existing technology generally improves the resolution by continuously reducing the particle size of the chromatography medium, but this method requires a more demanding preparation process on the one hand, and there is a problem of low yield; on the other hand, the small particle size produces a higher column pressure, and the separated material can only pass through the separation column at a lower flow rate, resulting in increased test time and more cumbersome operation. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defects of low yield and low resolution of the existing method for preparing chromatography media, thereby providing a styrene polymer microsphere and a preparation method and application thereof.

[0004] To this end, the present invention provides the following technical solutions:

[0005] The first aspect of the present invention protects a method for preparing styrene polymer microspheres, wherein the preparation method comprises the following steps:

[0006] S1, first mixing water, an inorganic dispersant, and an organic dispersant to obtain an aqueous phase;

[0007] S2, mixing the styrene monomer, the initiator and the porogen for a second time to obtain an oil phase;

[0008] S3, adding the oil phase to the water phase to carry out polymerization reaction, washing the product, and performing solid-liquid separation to obtain styrene polymer microspheres.

[0009] In the present invention, in step S1, water, an inorganic dispersant, and an organic dispersant may be added together and mixed, or water may be added first, and then the inorganic dispersant and the organic dispersant are added in sequence under stirring to make the mixing more uniform.

[0010] In the present invention, in step S2, the monomer, initiator, and porogen may be added and mixed together, or the monomer and initiator may be added first, and then the porogen may be added and mixed. In the present invention, the second mixing is performed at room temperature and can be evenly dispersed. Typically, but not limited to, the second mixing time is 10-15 minutes.

[0011] In the present invention, in step S3, cleaning the product comprises the following steps: using a cleaning agent to mix and clean a product system containing solids and liquids; on the one hand, the cleaning agent can extract the porogen in the system, and after re-treatment, the porogen can be reused; on the other hand, the cleaning agent can wash away the organic matter that is residual on the surface of the solid product and can be dissolved in the cleaning agent, so that the solid product is purer; typically, but not limitingly, the cleaning agent includes at least one of methanol, ethanol, acetone, and methylal, and the specific amount is determined according to actual conditions; in step S3, the solid product obtained after solid-liquid separation is also screened, mainly to remove unreacted reactants in the polymerization process and oligomers that have not formed microspheres.

[0012] According to the present invention, the inorganic dispersant includes a water-soluble salt; optionally, it includes at least one of calcium chloride, sodium chloride, magnesium sulfate, and sodium carbonate.

[0013] According to the present invention, the organic dispersant includes at least one of cellulose, lignin sulfonate, gelatin, and a surfactant; optionally, the organic dispersant includes at least one of carboxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, calcium lignin sulfonate, sodium lignin sulfonate, gelatin, anionic surfactants and non-ionic surfactants; further optionally, the anionic surfactants and non-ionic surfactants include at least one of sodium dodecyl sulfonate, sodium polystyrene sulfonate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium stearate, polyvinyl alcohol, polyvinyl pyrrolidone, Span 80, Span 60, Span 40, and Span 20.

[0014] According to the present invention, the mass ratio of water, inorganic dispersant and organic dispersant is (1000-2500):(30-250):(1-5).

[0015] According to the present invention, the temperature of the first mixing is 40-90° C. and the time is 6-48 hours.

[0016] According to the present invention, the styrene monomer includes at least one of styrene, divinylbenzene, ethylstyrene and p-chloromethylstyrene.

[0017] In the present invention, when the styrene monomer is divinylbenzene, it contains two double bonds, which not only participates in the polymerization reaction but also acts as a cross-linking agent to connect linear polymers to form a three-dimensional network structure, thereby further improving the mechanical properties of the polymer.

[0018] According to the present invention, the initiator includes at least one of peroxides, azo compounds, and persulfates; optionally, it includes at least one of benzoyl peroxide (BPO), tert-butyl peroxy-2-ethylhexanoate, azobisisobutyronitrile, azobisisoheptylnitrile, potassium persulfate, and ammonium persulfate.

[0019] According to the present invention, based on the weight of the monomer, the weight of the initiator is 0.5-3 wt %, and can be optionally 0.75-1.5 wt %.

[0020] According to the present invention, the porogen includes at least one of fatty alcohols, alkanes, acrylates, and fatty acids; optionally, it includes at least two of isooctyl alcohol, isobutyl alcohol, cyclohexanol, methyl isobutyl carbinol, dodecanol, isododecane, isooctane, n-heptane, toluene, butyl acetate, dibutyl phthalate, and isooctyl acid; it can be selected from a combination of isododecane and toluene, a combination of isooctyl alcohol and dibutyl phthalate, a combination of isooctyl alcohol and methyl isobutyl carbinol, and a combination of isooctyl alcohol, n-heptane, and butyl acetate.

[0021] According to the present invention, based on the weight of the monomer, the weight of the porogen is 50-260 wt %, and can be optionally 100-160 wt %.

[0022] According to the present invention, based on the mass of the water phase, the mass of the oil phase is 10-80wt%, optionally 15-25wt%.

[0023] According to the present invention, the heating rate of the polymerization reaction is 0.2-1°C / min; optionally 0.25-0.5°C / min.

[0024] In the present invention, in step S3, since the polymerization reaction is carried out by adding the oil phase into the water phase, the polymerization reaction does not start heating at room temperature, but is heated on the basis of the first mixing temperature.

[0025] According to the present invention, the polymerization reaction temperature is 65-90°C, the time is 3-12h, and the rotation speed is 80-500rpm; optionally, the polymerization reaction temperature is 65-80°C, the time is 6-10h, and the rotation speed is 300-500rpm.

[0026] The second aspect of the present invention protects styrene polymer microspheres prepared by the above-mentioned preparation method.

[0027] According to the present invention, the average particle size of the microspheres is 25-700 μm, and the uniformity coefficient of the particle size is 1.05-1.50.

[0028] According to the present invention, the average particle size of the microspheres is 50-100 μm, and the uniformity coefficient of the particle size is 1.05-1.25.

[0029] According to the present invention, the median pore size of the microspheres is 50-500 nm.

[0030] According to the present invention, the double bond content on the surface of the microsphere is 0.8-1.4 mmol / g.

[0031] The third aspect of the present invention protects a chromatography medium, wherein the chromatography medium comprises the styrene polymer microspheres prepared by the aforementioned preparation method or the aforementioned styrene polymer microspheres.

[0032] In the present invention, the chromatography medium can be prepared into affinity chromatography medium, ion exchange chromatography medium, hydrophobic chromatography medium after further chemical modification, including metal chelate chromatography medium, Q chromatography medium, DEAE chromatography medium, SP chromatography medium, CM chromatography medium, phenyl chromatography medium, butyl chromatography medium, octyl chromatography medium, etc.

[0033] The technical solution of the present invention has the following advantages:

[0034] 1. The present invention provides a method for preparing styrene polymer microspheres, wherein the preparation method comprises the following steps: S1, first mixing water, an inorganic dispersant, and an organic dispersant to obtain an aqueous phase; S2, second mixing a monomer, an initiator, and a porogen to obtain an oil phase; S3, adding the oil phase to the aqueous phase, performing a polymerization reaction, washing the product, and performing solid-liquid separation to obtain styrene polymer microspheres; the present invention adopts a suspension polymerization method, and adds a synergistic inorganic dispersant and an organic dispersant during the preparation of the aqueous phase, thereby improving the yield of the obtained styrene polymer microspheres; when the microspheres are used as chromatography media, it has long been recognized that the smaller the size of the microspheres, the higher the resolution, so technicians have been studying how to reduce the size of the microspheres to below 10 μm, but the inventors unexpectedly discovered during the experiment that although the average particle size of the microspheres prepared by this method is greater than 10 μm, they can still show excellent resolution when used as chromatography media. Compared with the preparation method of microspheres with an average particle size of less than 10 μm, the preparation method of the present invention is simple, the conditions are milder, and the process flow and energy consumption are reduced. At the same time, in the actual separation process, compared with microspheres with an average particle size of less than 10 μm, the flow rate of the separated material in the separation column is higher, which shortens the test time and improves the separation efficiency.

[0035] 2. The specific inorganic dispersants and organic dispersants of the present invention have low toxicity. When the chromatographic medium is used to separate substances such as proteins, it will not contaminate the separated substances and has good biocompatibility.

[0036] 3. The specific amount and type of the porogen, the polymerization reaction conditions, and the amount of the initiator in the present invention have a synergistic effect, which can further make the prepared styrene polymer microspheres have an appropriate average pore size, successfully separate the target object, and have high compressive strength, and can be reused.

[0037] 4. The specific monomer types in the present invention make the surface of the prepared polymer microspheres have a large number of double bonds, which provide reaction sites and can form new functional groups, so that the microspheres can be specifically adsorbed.

[0038] 5. The present invention provides a styrene polymer microsphere, wherein the average particle size of the microsphere is 25-700 μm, and the uniformity coefficient of the particle size is 1.05-1.50; although the average particle size of the microsphere in the present invention is greater than 10 μm, when it meets the specific particle size and the uniformity coefficient of the specific particle size, the two work synergistically and can exhibit excellent resolution when used as a chromatographic medium.

[0039] 6. The median pore size of the microspheres in the present invention has a large fluctuation range, and can separate targets of different molecular weights. In addition, when the microspheres are used as chromatography media, they have excellent compressive strength, thereby improving the recycling rate of the chromatography media.

[0040] 7. The specific double bond content in the microspheres of the present invention enables the microspheres to have multiple reaction sites, which can be connected to new functional groups and prepared into different chromatographic media, so that the treated microspheres can be specifically adsorbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 is a pore size distribution diagram of styrene polymer microspheres prepared in Example 1;

[0043] Figure 2 This is the pore size distribution diagram of the styrene polymer microspheres prepared in Example 4. DETAILED DESCRIPTION

[0044] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to 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 other prior arts shall fall within the protection scope of the present invention.

[0045] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0046] Commercially available divinylbenzene includes 63 wt% divinylbenzene and 37 wt% ethylstyrene;

[0047] The weight average molecular weight of polyvinyl alcohol is 75000 g / mol;

[0048] The weight average molecular weight of sodium polystyrene sulfonate is 65000 g / mol;

[0049] The weight average molecular weight of polyvinyl pyrrolidone K90 is 1200000 g / mol;

[0050] The weight average molecular weight of hydroxyethyl methylcellulose is 70000 g / mol.

[0051] The specific steps of screening in the embodiment and comparative example include: laying a nylon sieve with a pore size of 20 μm on the screening frame, adding the microspheres to be screened, controlling the flow rate to 10 L / h, the ultrasonic power to 300 W, and the stirring speed to 30 rpm to collect the microspheres on the sieve.

[0052] Example 1

[0053] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0054] S1, add 2500mL of water to a 5000mL three-necked flask, set the stirring speed to 150rpm, add 25g of dispersant calcium chloride to dissolve, then add 25g of dispersant polyvinyl alcohol, raise the temperature to 50℃ and keep warm for 16h to obtain an aqueous phase;

[0055] S2, add 158.7g of commercially available divinylbenzene, 41.3g of styrene, and 2g of BPO into a 2000mL beaker, stir to dissolve, then add 186.7g of porogen isododecane and 93.3g of porogen toluene, continue stirring for 10min to make the dispersion more uniform, to obtain an oil phase;

[0056] S3, adding the oil phase to the water phase in the three-necked flask, the mass of the oil phase is 18.9wt% based on the mass of the water phase, and carrying out a polymerization reaction, heating to 80°C at a heating rate of 0.25°C / min, keeping warm for 12 hours, with a rotation speed of 500rpm, and cooling to room temperature after the reaction is completed; washing the product with methanol, separating the solid and the liquid, and sieving to obtain styrene polymer microspheres.

[0057] Example 2

[0058] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0059] The method of Example 1 is the same, except that "2 g of BPO" is changed to "3 g of BPO".

[0060] Example 3

[0061] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0062] S1, according to the method of S1 in Example 1;

[0063] S2, add 95.2g of commercially available divinylbenzene, 104.8g of styrene, and 2g of BPO into a 2000mL beaker, stir to dissolve, then add 200g of porogen n-heptane and 100g of porogen methyl isobutyl carbinol, continue stirring for 10min to make the dispersion more uniform, and obtain an oil phase;

[0064] S3, according to the method of S3 in Example 1.

[0065] Example 4

[0066] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0067] S1, add 2500mL of water to a 5000mL three-necked flask, set the stirring speed to 150rpm, add 25g of calcium chloride to dissolve, then add 15g of dispersant polyvinyl alcohol and 10g of dispersant sodium polystyrene sulfonate, raise the temperature to 50°C and keep warm for 16h to obtain an aqueous phase;

[0068] S2, add 95.2g of commercially available divinylbenzene, 104.8g of styrene, and 2g of BPO into a 2000mL beaker, stir to dissolve, then add 200g of porogen isooctyl alcohol and 100g of porogen methyl isobutyl carbinol, continue stirring for 10min to make the dispersion more uniform, to obtain an oil phase;

[0069] S3, according to the method of S3 in Example 1.

[0070] Example 5

[0071] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0072] S1, add 2500mL of water to a 5000mL three-necked flask, set the stirring speed to 150rpm, add 25g of dispersant calcium chloride to dissolve, then add 15g of dispersant polyvinyl alcohol and 10g of dispersant sodium polystyrene sulfonate, raise the temperature to 50°C and keep warm for 16h to obtain an aqueous phase;

[0073] S2, add 95.2g of commercially available divinylbenzene, 104.8g of styrene, and 2g of BPO into a 2000mL beaker, stir to dissolve, then add 200g of porogen n-heptane and 100g of porogen methyl isobutyl carbinol, continue stirring for 10min to make the dispersion more uniform, and obtain an oil phase;

[0074] S3, adding the oil phase to the water phase in the three-necked flask, the mass of the oil phase is 19.7wt% based on the mass of the water phase, and carrying out a polymerization reaction, heating to 80°C at a heating rate of 0.25°C / min, keeping warm for 12 hours, with a rotation speed of 500rpm, and cooling to room temperature after the reaction is completed; washing the product with acetone, separating the solid and the liquid, and sieving to obtain styrene polymer microspheres.

[0075] Example 6

[0076] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0077] S1, add 2500 mL of water to a 5000 mL three-necked flask, set the stirring speed to 150 rpm, add 125 g of dispersant sodium chloride to dissolve, then add 20 g of polyvinyl pyrrolidone K90, 2.5 g of sodium polystyrene sulfonate, and 2.5 g of hydroxyethyl methylcellulose, raise the temperature to 50 ° C and keep it for 6 hours to obtain an aqueous phase;

[0078] S2, add 25.4g of commercially available divinylbenzene, 174.6g of styrene, and 2g of BPO into a 2000mL beaker, stir to dissolve, then add 256g of porogen isooctyl alcohol and 64g of porogen methyl isobutyl carbinol, continue stirring for 10min to make the dispersion more uniform, to obtain an oil phase;

[0079] S3, adding the oil phase to the water phase in the three-necked flask, the mass of the oil phase is 20.5wt% based on the mass of the water phase, and carrying out a polymerization reaction, heating to 80°C at a heating rate of 0.6°C / min, keeping warm for 12 hours, with a rotation speed of 500rpm, and cooling to room temperature after the reaction is completed; washing the product with methanol, separating the solid and the liquid, and sieving to obtain styrene polymer microspheres.

[0080] Example 7

[0081] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0082] The method of Example 1 is followed, except that "186.7 g of porogen isododecane and 93.3 g of porogen toluene" are replaced with "100 g of porogen isooctyl alcohol and 50 g of porogen cyclohexanol".

[0083] Example 8

[0084] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0085] The method of Example 1 is followed, except that “heating to 80°C at a heating rate of 0.25°C / min, keeping warm for 12 hours, and rotating at 500 rpm” is changed to “heating to 82°C at a heating rate of 0.5°C / min, keeping warm for 6 hours, and rotating at 400 rpm”.

[0086] Example 9

[0087] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0088] The method of Example 5 is followed, except that “adding 200 g of porogen n-heptane and 100 g of porogen methyl isobutyl carbinol” is changed to “adding 300 g of porogen n-heptane”.

[0089] Example 10

[0090] This embodiment provides a styrene polymer microsphere, and the specific preparation method includes the following steps:

[0091] The method of Example 1 is followed, except that “heating to 80°C at a heating rate of 0.25°C / min, keeping warm for 12 hours, and rotating at 500 rpm” is changed to “heating to 82°C at a heating rate of 1°C / min, keeping warm for 5 hours, and rotating at 400 rpm”.

[0092] Comparative Example 1

[0093] This comparative example provides a styrene polymer microsphere, and the specific preparation method comprises the following steps:

[0094] The method of Example 5 is followed, except that “add 25 g of dispersant calcium chloride to dissolve, then add 15 g of dispersant polyvinyl alcohol, and then add 10 g of dispersant sodium polystyrene sulfonate” is changed to “add 50 g of dispersant calcium chloride”.

[0095] Comparative Example 2

[0096] This comparative example provides a styrene polymer microsphere, and the specific preparation method comprises the following steps:

[0097] The method of Example 5 is followed, except that “add 25 g of dispersant calcium chloride to dissolve, then add 15 g of dispersant polyvinyl alcohol, and then add 10 g of dispersant sodium polystyrene sulfonate” is changed to “add 50 g of dispersant polyvinyl alcohol”.

[0098] Test Case

[0099] (1) The yield is calculated as follows: the styrene polymer microspheres obtained by screening in the examples and comparative examples are vacuum filtered using a G2 sand core funnel at 0.1 MPa for 30 min, and then the mass m1 is weighed and the sum of the mass of all oil phases added in the polymerization reaction m2 (styrene monomer, porogen and initiator) is weighed. The yield = m1 / m2×100%;

[0100] The average particle size and the uniformity coefficient of the particle size were detected by Malvern laser particle size analyzer. The specific setting parameters were as follows: the stirrer speed was 700 rpm, the pump speed was 1750 rpm, the ultrasonic power was 80%, the refractive index was 1.54, the absorptivity was 1.0, the shading degree was 15%, the background measurement time was 10.0 s, the sample measurement time was 12.0 s each time, and the average value was taken after 3 measurements. The average particle size and the uniformity coefficient of the particle size can be directly read.

[0101] The median pore size is detected by mercury intrusion instrument. Pore size distribution: Based on the working principle of capillary pressure, mercury enters the solid pores under the action of external pressure by taking advantage of the non-wetting property of mercury on solid samples. According to the Washburn equation, the pore volume of the corresponding pore radius can be known by measuring the volume of mercury injected under different pressures, so that the pore size distribution curve (porosity) of the porous material can be obtained, from which the median pore size can be read and the read value can be converted. The specific conversion relationship is:

[0102] Test method for double bond content: According to GB / T 601-2002 and GB 1676-81, the principle is the iodine titration in organic analysis. The double bond content in the sample is determined by titration. The specific method is: accurately weigh 1g of polymer microspheres into a 250mL ground-mouth conical flask, add 25mL of n-hexane, soak at room temperature for 2h, add 10mL of iodine bromide reagent with a pipette, shake well and place in a dark place for 1h, then add 5mL of 10wt% potassium iodide solution, shake well again, titrate with 0.1mol / L sodium thiosulfate standard solution until the solution turns yellow, add 5mL of 0.5% starch indicator, continue titrating until the blue disappears, and do a blank experiment at the same time;

[0103] Double bond value = (V1-V0) × CB / m

[0104] V1—Volume of sodium thiosulfate used for titration of sample, mL;

[0105] V0—volume of sodium thiosulfate used in blank experiment, mL;

[0106] C B —Concentration of sodium thiosulfate standard solution, mol / L;

[0107] m—sample mass, g;

[0108] The specific test results are shown in Table 1;

[0109] Table 1

[0110]

[0111] It can be seen from the data in Table 1 that the microspheres in the present invention have a smaller average particle size and a smaller uniformity coefficient of particle size, and have better resolution when used as a chromatography medium.

[0112] The pore size distribution of the styrene polymer microspheres prepared in Example 1 is as follows: Figure 1 As shown in the figure, it can be seen that the pore size is normally distributed, mainly distributed in 77-110nm, the median pore size is 86nm, and the pore size distribution is uniform; and it can be seen that the amount of mercury inflow per unit mass of microspheres under unit pore size is uniformly distributed, showing a normal distribution. It can be seen from the figure that the pore size distribution range of the microspheres is narrow and the pore size of the microspheres is uniform; the pore size distribution of the styrene polymer microspheres prepared in Example 4 is as follows Figure 2 As shown, it can be seen from the figure that the pore size is normally distributed, mainly distributed in 98-300nm, the median pore size is 258nm, the pore size distribution is uniform, and it can be seen that the amount of mercury inflow per unit mass of microspheres under unit pore size is uniformly distributed and normally distributed. It can be seen from the figure that the pore size distribution range of the microspheres is narrow and the pore size of the microspheres is uniform; and from the median pore size of Example 1 and Example 4, it can be seen that the median pore size fluctuation range between different embodiments is large, and targets of different molecular weights can be separated, and when the microspheres are used as chromatographic media, they have excellent compressive strength, which improves the recycling rate of the chromatographic media.

[0113] (2) Test method of linear flow rate: The styrene polymer microspheres prepared in the examples and comparative examples were loaded into a column (column inner diameter of 26 mm, column length of 300 mm, column loading pressure of 0.225 MPa, column loading flow rate of 38 mL / min), the volume flow rate was increased at a rate gradient of 5 mL / min at the initial volume flow rate, the linear flow rate change and column pressure change were detected, and the linear flow rate at a pressure of 0.3 MPa was recorded, which is the linear flow rate in Table 2;

[0114] The test method for compressive strength is as follows: The test method is consistent with the linear flow rate test method, and the column pressure when the volume flow rate is 60 mL / min is recorded, which is the compressive strength in Table 2;

[0115] The specific test results are shown in Table 2;

[0116] Table 2

[0117]

[0118]

[0119] By comparing the embodiment with the comparative example, it can be seen that when the embodiment of the present invention uses styrene polymer microspheres prepared by both inorganic dispersion and organic dispersant as the chromatography medium, it has a higher linear flow rate and compressive strength. When used, it can ensure that a faster flow rate is maintained under a higher pressure, saving test time and improving chromatography efficiency.

[0120] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A method for preparing styrene polymer microspheres, characterized in that: The preparation method comprises the following steps: S1, first mixing water, an inorganic dispersant, and an organic dispersant to obtain an aqueous phase; S2, mixing the styrene monomer, the initiator and the porogen for a second time to obtain an oil phase; S3, adding the oil phase to the water phase to carry out polymerization reaction, washing the product, and performing solid-liquid separation to obtain styrene polymer microspheres.

2. The preparation method according to claim 1, characterized in that: The inorganic dispersant includes a water-soluble salt; optionally, includes at least one of calcium chloride, sodium chloride, magnesium sulfate, and sodium carbonate; And / or, the organic dispersant includes at least one of cellulose, lignin sulfonate, gelatin, and a surfactant; optionally, the organic dispersant includes at least one of carboxymethyl cellulose, hydroxyethyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, calcium lignin sulfonate, sodium lignin sulfonate, gelatin, anionic surfactants, and nonionic surfactants; further optionally, the anionic surfactants and nonionic surfactants include at least one of sodium dodecyl sulfonate, sodium polystyrene sulfonate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, sodium stearate, polyvinyl alcohol, polyvinyl pyrrolidone, Span 80, Span 60, Span 40, and Span 20; And / or, the mass ratio of water, inorganic dispersant and organic dispersant is (1000-2500):(30-250):(1-5).

3. The preparation method according to claim 1 or 2, characterized in that: The temperature of the first mixing is 40-90° C. and the time is 6-48 hours.

4. The preparation method according to any one of claims 1 to 3, characterized in that: The styrene monomer includes at least one of styrene, divinylbenzene, ethylstyrene and p-chloromethylstyrene; And / or, the initiator comprises at least one of peroxide, azo compound and persulfate; Optionally, the initiator includes at least one of benzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, azobisisobutyronitrile, azobisisoheptanenitrile, potassium persulfate, and ammonium persulfate; and / or, based on the weight of the monomer, the weight of the initiator is 0.5-3 wt%, optionally 0.75-1.5 wt%; And / or, the porogen includes at least one of fatty alcohol, alkane, acrylate, and fatty acid; optionally, includes at least two of isooctyl alcohol, isobutyl alcohol, cyclohexanol, methyl isobutyl carbinol, dodecanol, isododecane, isooctane, n-heptane, toluene, butyl acetate, dibutyl phthalate, and isooctyl acid; optionally, it may be a combination of isododecane and toluene, a combination of isooctyl alcohol and dibutyl phthalate, a combination of isooctyl alcohol and methyl isobutyl carbinol, or a combination of isooctyl alcohol, n-heptane, and butyl acetate; And / or, based on the weight of the monomer, the weight of the porogen is 50-260 wt %, and optionally 100-160 wt %.

5. The preparation method according to any one of claims 1 to 4, characterized in that: Based on the mass of the water phase, the mass of the oil phase is 10-80wt%, and can be optionally 15-25wt%.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The heating rate of the polymerization reaction is 0.2-1°C / min; optionally 0.25-0.5°C / min; And / or, the polymerization reaction temperature is 65-90°C, the time is 3-12h, and the rotation speed is 80-500rpm; optionally, the polymerization reaction temperature is 65-80°C, the time is 6-10h, and the rotation speed is 300-500rpm.

7. Styrene polymer microspheres prepared by the preparation method according to any one of claims 1 to 6.

8. The styrene polymer microspheres according to claim 7, characterized in that: The average particle size of the microspheres is 25-700 μm, and the uniformity coefficient of the particle size is 1.05-1.50; Optionally, the average particle size of the microspheres is 50-100 μm, and the uniformity coefficient of the particle size is 1.05-1.

25.

9. The styrene polymer microspheres according to claim 7 or 8, characterized in that: The median pore size of the microspheres is 50-500 nm; And / or, the double bond content on the surface of the microsphere is 0.8-1.4 mmol / g.

10. A chromatography medium, characterized in that The chromatography medium comprises styrene polymer microspheres prepared by the preparation method according to any one of claims 1 to 6 or styrene polymer microspheres according to any one of claims 7 to 9.

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