Method for preparing homogeneous polymer spheres by using double-dispersion system

Abstract

The invention relates to a method for preparing homogeneous polymer spheres by using a double dispersion system, which comprises the following steps: (1) mixing an oil phase with a first water phase to form oil phase liquid drops; (2) mixing the oil-phase liquid drops obtained in the step (1) with a second water phase, and carrying out polymerization reaction to obtain homogeneous polymer spheres; wherein the viscosity eta 1 of the first water phase is greater than the viscosity eta 2 of the second water phase. The homogeneity and the yield of the homogeneous polymer spheres produced by the method disclosed by the invention are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of polymer preparation technology, and specifically relates to a method for preparing uniform polymer spheres using a bidispersion system. Background Technology

[0002] Uniformly sized polymer spheres (also known as "uniform-sized polymer spheres") have been widely used in various fields such as drug delivery, catalysis, ion exchange resins, chromatographic separation, and biomedical engineering due to their unique physicochemical properties. However, polymer spheres with slightly larger particle sizes (>0.2 mm) are often difficult to prepare.

[0003] Chinese Patent CN114887574B discloses a device for synthesizing uniformly sized polymer spheres based on channel prepolymerization and its method of use. In this method, uniform oil-phase droplets can be generated through vibration-jet spraying. The oil-phase droplets undergo prepolymerization through a prepolymerization channel, which can increase the viscosity of the monomers within the oil-phase droplets to a certain extent, thereby maintaining their particle size. Finally, the oil-phase droplets enter a reactor or other device and are heated to polymerize into the product. In this "vibration-jet-prepolymerization-polymerization" process, the oil-phase droplets are generated during the spraying process. The sprayed oil-phase droplets enter a reactor (or curing reactor, solidification reactor) equipped with a stirrer through the prepolymerization channel. That is, there are two generation processes for the oil-phase droplets: one is the spraying process, and the other is the stirring process in the reactor.

[0004] In the above process, although the use of prepolymerization channels reduces the impact of stirring on oil phase droplets, in actual production, the shear force of stirring in large reactors can still cause the oil phase droplets to break up, resulting in uneven particle size.

[0005] Therefore, there is an urgent need to develop new methods for preparing uniformly sized polymer spheres in order to improve the particle size uniformity of polymer spheres or the yield of uniformly sized polymers. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method for preparing uniformly sized polymer spheres using a bidispersion system, the method comprising the following steps: (1) The oil phase is mixed with the first aqueous phase to form oil phase droplets; (2) The oil phase droplets obtained in step (1) are mixed with the second aqueous phase and polymerized to obtain uniform polymer spheres; The viscosity η1 of the first aqueous phase is greater than the viscosity η2 of the second aqueous phase.

[0007] According to an embodiment of the present invention, in step (1) of the method, the oil phase comprises a monomer and an initiator.

[0008] According to an embodiment of the present invention, the first aqueous phase comprises a first dispersant and water.

[0009] According to an embodiment of the present invention, the second aqueous phase comprises a second dispersant and water.

[0010] According to an embodiment of the present invention, step (1) is performed under vibration conditions.

[0011] According to an embodiment of the present invention, step (2) is carried out under stirring conditions.

[0012] According to an embodiment of the invention, the polymerization reaction in step (2) is carried out under heating conditions. For example, the polymerization reaction in step (2) includes a reaction at a temperature of 80 to 99°C, for example, a reaction at a temperature of 80 to 99°C for at least 1 hour.

[0013] According to an embodiment of the present invention, the method includes: under vibration conditions, injecting an oil phase into a first aqueous phase to form oil phase droplets; the oil phase droplets entering a second aqueous phase, and under stirring conditions, carrying out a polymerization reaction to obtain uniform polymer spheres; The oil phase includes a monomer and an initiator; the first aqueous phase includes a first dispersant and water, the second aqueous phase includes a second dispersant and water, and the viscosity η1 of the first aqueous phase is greater than the viscosity η2 of the second aqueous phase.

[0014] According to an embodiment of the present invention, the viscosities of η1 and η2 can be independently selected from 1 to 5 mPa·s, for example 1 mPa·s, 1.5 mPa·s, 2 mPa·s, 2.5 mPa·s, 3 mPa·s, 3.5 mPa·s, 4 mPa·s, 4.5 mPa·s or 5 mPa·s, provided that η1 > η2.

[0015] According to an embodiment of the present invention, η1 and η2 have the following relationships (1) and / or (2): (1) The value of η1-η2 is >0 mPa·s, for example, the value of η1-η2 is 0.01~3.00 mPa·s; (2) The value of η1 / η2 is greater than 1, for example, the value of η1 / η2 is 1.02~3.50.

[0016] According to an embodiment of the present invention, the value of η1-η2 is >0 mPa·s, for example, 0.01~3.00 mPa·s, such as 0.05~2.50 mPa·s. Examples of η1-η2 include 0.05 mPa·s, 0.10 mPa·s, 0.15 mPa·s, 0.20 mPa·s, 0.25 mPa·s, 0.30 mPa·s, 0.35 mPa·s, 0.40 mPa·s, 0.45 mPa·s, 0.50 mPa·s, 0.55 mPa·s, 0.60 mPa·s, 0.65 mPa·s, 0.70 mPa·s, 0.75 mPa·s, 0.80 mPa·s, 0.85 mPa·s, 0.90 mPa·s, 0.95 mPa·s, 1.00 mPa·s, 1.05 mPa·s, and 1.10 mPa·s. mPa·s, 1.15 mPa·s, 1.20mPa·s, 1.25 mPa·s, 1.30 mPa·s, 1.35 mPa·s, 1.40 mPa·s, 1.45 mPa·s, 1.50 mPa·s, 1.55 mPa·s, 1.60 mPa·s, 1.65 mPa·s, 1.70 mPa·s, 1.75 mPa·s, 1.80 mPa·s, 1.85 mPa·s, 1.90 mPa·s, 1.95 mPa·s, 2.00 mPa·s, 2.05 mPa·s, 2.10 mPa·s, 2.15mPa·s, 2.20 mPa·s, 2.25 mPa·s, 2.30 mPa·s, 2.35 mPa·s, 2.40 mPa·s, 2.45 mPa·s, 2.50 mPa·s, 2.55 mPa·s, 2.60 mPa·s, 2.65 mPa·s, 2.70 mPa·s, 2.75 mPa·s, 2.80 mPa·s, 2.85 mPa·s, 2.90 mPa·s, 2.95 mPa·s or 3.00 mPa·s.

[0017] According to an embodiment of the present invention, the value of η1 / η2 is >1, for example, 1.02~3.50, such as 1.05~3.00, and examples can be 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.95, 2.00, 2.05, 2.10, 2.15, 2.20, 2.25, 2.30, 2.35, 2.40, 2.45, 2.50, 2.55, 2.60, 2.65, 2.70, 2.75, 2.80, 2.85, 2.90, 2.95 or 3.00.

[0018] Not wanting to be confined to existing theories, the inventors unexpectedly discovered that when the viscosity of the first aqueous phase is greater than that of the second aqueous phase, it is particularly advantageous for the method of this invention. Specifically, when oil droplets enter the second aqueous phase from the first aqueous phase, controlling the viscosity of the second aqueous phase to be lower than that of the first aqueous phase helps maintain the droplet size of the oil phase, avoids excessive breakage of the oil phase droplets, and improves particle size uniformity. Based on this, this invention does not impose any particular limitations on the method of adjusting the viscosity of the first and second aqueous phases. Those skilled in the art should understand that selecting dispersants of different viscosities or combinations thereof, adjusting the concentration of dispersants or combinations thereof, and combinations thereof are all optional methods for adjusting the viscosity of the first and second aqueous phases, thereby achieving a viscosity of the first aqueous phase greater than that of the second aqueous phase.

[0019] According to an exemplary embodiment of the present invention, the first dispersant and the second dispersant may be the same or different, and are independently selected from one, two or more of polyvinyl alcohol, gelatin, sodium lignosulfonate, hydroxyethyl cellulose, hydroxymethyl cellulose, sodium dodecylbenzenesulfonate and sodium dodecyl sulfate.

[0020] In the context of this invention, polyvinyl alcohol can have a viscosity of 1 to 100 mPa·s under the test method in accordance with GB / T 12010.2-2010. The viscosity can be, for example, 4 to 50 mPa·s, such as 5 to 30 mPa·s. As an example, the viscosity of the polyvinyl alcohol can be 1 mPa·s, 2 mPa·s, 3 mPa·s, 4 mPa·s, 5 mPa·s, 6 mPa·s, 7 mPa·s, 8 mPa·s, 9 mPa·s, 10 mPa·s, 11 mPa·s, 12 mPa·s, 13 mPa·s, 14 mPa·s, 15 mPa·s, 16 mPa·s, 17 mPa·s, 18 mPa·s, 19 mPa·s, 20 mPa·s, 21 mPa·s, 22 mPa·s, 23 mPa·s, 24 mPa·s, 25 mPa·s, 26 mPa·s, 27 mPa·s, 28 mPa·s, 29 mPa·s, or 30 mPa·s. It should be understood that the first dispersant and the second dispersant may also be selected from polyvinyl alcohol with the same or different viscosity, or a combination of one, two or more of other dispersants (gelatin, sodium lignosulfonate, hydroxyethyl cellulose, hydroxymethyl cellulose, sodium dodecylbenzenesulfonate and sodium dodecyl sulfate).

[0021] According to a preferred embodiment of the present invention, the first dispersant may be selected from one, two or more of polyvinyl alcohol, gelatin, sodium lignosulfonate, hydroxyethyl cellulose, hydroxymethyl cellulose, sodium dodecylbenzenesulfonate and sodium dodecyl sulfate.

[0022] According to a preferred embodiment of the present invention, based on the total mass of the first aqueous phase, the mass percentage content of each dispersant in the first dispersant can be greater than 0% and not more than 3%, for example, it can be 0.001% to 3%, such as 0.001% to 2.5%, and examples are 0.001% to 0.05%, 0.01% to 0.1%, 0.01% to 2.5%, 0.05% to 2.3%, or 0.1% to 2%.

[0023] Preferably, based on the total mass of the first aqueous phase, the total mass percentage content of the first dispersant can be 0.1% to 2.5%, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4%, or 2.5%.

[0024] According to an exemplary embodiment of the present invention, the first dispersant comprises a dispersant combination 1 consisting of a mandatory first primary dispersant, an optional first secondary dispersant, and an optional second secondary dispersant: Combination 1

[0025] According to an exemplary embodiment of the present invention, the first dispersant comprises a dispersant combination 2 consisting of a first primary dispersant, an optional first secondary dispersant, and an optional second secondary dispersant: Combination 2

[0026] According to an exemplary embodiment of the present invention, the first dispersant comprises a dispersant combination 3 consisting of a first primary dispersant, an optional first secondary dispersant, and an optional second secondary dispersant: Combination 3

[0027] According to a preferred embodiment of the present invention, the second dispersant may be polyvinyl alcohol. The mass concentration of the second dispersant is 0.1% to 1%, for example, 0.1%, 0.2%, 0.3%, 0.5%, 0.7%, 0.8%, or 1%.

[0028] In some specific embodiments of the present invention, the combination of the first dispersant and the second dispersant may be selected from one of the following: (a) The first dispersant contains polyvinyl alcohol (viscosity 6 mPa·s), and the second dispersant contains polyvinyl alcohol (viscosity 25 mPa·s). (b) The first dispersant contains polyvinyl alcohol (viscosity 22 mPa·s), and the second dispersant contains polyvinyl alcohol (viscosity 25 mPa·s); (c) The first dispersant contains polyvinyl alcohol (viscosity 6 mPa·s) and the second dispersant contains polyvinyl alcohol (viscosity 22 mPa·s). (d) The first dispersant contains hydroxyethyl cellulose and the second dispersant contains polyvinyl alcohol (viscosity 6 mPa·s). (e) The first dispersant contains hydroxyethyl cellulose and the second dispersant contains polyvinyl alcohol (viscosity 22 mPa·s). (f) The first dispersant contains hydroxymethyl cellulose and the second dispersant contains polyvinyl alcohol (viscosity 22 mPa·s).

[0029] In some preferred embodiments of the present invention, in any of the above-described (a) to (c), the first aqueous phase may further comprise one or more of gelatin, hydroxyethyl cellulose and sodium lignosulfonate, with an exemplary mass percentage content of 0.01% to 2% based on the total mass of the first aqueous phase.

[0030] Alternatively, in some preferred embodiments of the present invention, in any of the schemes (d) to (f) above, the first aqueous phase may further comprise polyvinyl alcohol, with an exemplary mass percentage content of 0.01% to 0.1% based on the total mass of the first aqueous phase.

[0031] Alternatively, in some preferred embodiments of the present invention, in any of the schemes (a) to (f) above, the first aqueous phase may further comprise one or both selected from sodium dodecylbenzenesulfonate and sodium dodecyl sulfate, with an exemplary mass percentage content of 0.001% to 0.05% based on the total mass of the first aqueous phase.

[0032] According to an embodiment of the present invention, the monomer is selected from one or more of styrene, divinylbenzene, methyl acrylate, methyl methacrylate, glycidyl methacrylate, triallyl isocyanurate, and divinylpropyl itaconic acid.

[0033] According to an embodiment of the present invention, the initiator is selected from one or both of benzoyl peroxide and azobisisobutyronitrile, and its exemplary amount is 0.1% to 5% of the monomer mass.

[0034] According to an embodiment of the present invention, the method for preparing uniform polymer spheres using a bidispersive system can be carried out in a channel-based prepolymerization uniform polymer sphere synthesis apparatus, for example, based on the channel-based prepolymerization uniform polymer sphere synthesis apparatus disclosed in Chinese Patent Specification No. CN114887574B.

[0035] For example, the method includes the following steps: (S1) Prepare the oil phase and inject it into the jet oil phase tank; prepare the first aqueous phase and load it into the prepolymerization channel; after the first aqueous phase fills the prepolymerization channel, prepare the second aqueous phase in the reactor. (S2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to obtain uniform oil phase droplets that meet the size requirements. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise and enter the reactor, where they come into contact with the second aqueous phase and gradually disperse in the second aqueous phase. (S3) After the oil phase is sprayed, close the bottom valve of the reactor to isolate the first aqueous phase and the second aqueous phase from contact, and carry out the polymerization reaction under heating conditions.

[0036] According to an embodiment of the present invention, in step (S3), the reaction is carried out at a temperature of 80-99°C for at least 1 hour. As an example, in step (S3), the polymerization reaction is carried out under one, two, three, or four conditions selected from (i) to (iv): (i) Raise the temperature of the reactor to 90~92℃ and maintain it for 1.5~5 hours; (ii) Lower the temperature to 80~82℃ and maintain it for 1~2 hours; (iii) Raise the temperature to 90~92℃ and maintain it for 2~3 hours; (iv) Raise the temperature to 95~98℃ and maintain it for 2~4 hours.

[0037] The present invention also provides polymer products prepared by the method described above for preparing uniform polymer spheres using a bidispersion system.

[0038] The present invention also provides the use of the polymer product in pharmaceuticals, catalysis, ion exchange resins, chromatographic separation, and biomedicine.

[0039] Beneficial effects This invention provides a method for preparing uniform polymer spheres using a bidispersion system, wherein the bidispersion system refers to the use of two dispersed phases (two aqueous phases) with different properties; wherein, the first aqueous phase is used in the vibration jetting process, that is, the jetted oil phase droplets directly contact the first aqueous phase, and enter the second aqueous phase through the first aqueous phase, and finally polymerize into uniform polymer spherical particles in the second aqueous phase.

[0040] This invention employs different dispersion systems. By changing the viscosity, the dispersion performance of the dispersed phase is optimized. A first aqueous phase is mixed with sprayed oil droplets to disperse the oil droplets. During the polymerization reaction under stirring conditions, a second aqueous phase is used to disperse the oil droplets. The viscosity of the second aqueous phase is lower than that of the first aqueous phase. Therefore, when the oil droplets enter the second aqueous phase from the first, they maintain their particle size, preventing excessive breakage and ensuring uniform polymer sphere size. Compared to using a single dispersion system (single aqueous phase), under the same operating conditions, the uniformity and yield of the homogeneous polymer spheres produced by this invention are significantly improved. The polymer spheres prepared by this invention have more uniform particle size, resolving the contradiction that a single dispersion system has different effects on the spraying and stirring processes. This allows for the scale-up production of homogeneous polymer spheres and is suitable for the development and production of homogeneous ion exchange resins.

[0041] Terminology Definitions and Explanations Unless otherwise stated, the terms "comprising," "including," and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or apparatus. Furthermore, unless otherwise stated, the numbering of the method steps is merely a convenient tool for identifying the method steps and is not intended to limit the order of the method steps or to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, shall also be considered within the scope of the invention.

[0042] Unless otherwise stated, the terms "first" and "second" used in this invention, and "primary" and "secondary" used in the description of dispersants, are intended to distinguish the objects described and should not be construed as limiting a specific order, sequence, or whether they exist simultaneously. It should be understood that the technical features described in this way can be applied according to the description in this specification so that the applied technical solution can be implemented without departing from the spirit of this invention.

[0043] Unless otherwise stated, the viscosity determination method in this invention shall comply with the requirements of GB / T 12010.2-2010. Detailed Implementation

[0044] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0045] Unless otherwise specified in the following embodiments, all process equipment or apparatus used are conventional equipment or apparatus in the art.

[0046] It should be noted that the following embodiments and comparative examples all use the channel-based prepolymer homogeneous polymer sphere synthesis apparatus disclosed in Chinese Patent CN114887574B, only to facilitate the demonstration of the advantages and effects of the present invention under comparable conditions, but not intended to limit the method of the present invention to operation on this apparatus. It should be understood that the method of the present invention can be used in other apparatuses with similar functions, as long as they can achieve a bidisperse system in the prepolymerization and polymerization stages, such as the apparatus disclosed in Chinese Patent CN214261908U.

[0047] An oil phase is sprayed into a first aqueous phase using a vibratory jetting method, forming oil droplets. These droplets rise in the first aqueous phase and enter a reactor containing a second aqueous phase. Once all the oil droplets have entered the reactor, the valve connecting the reactor to the second aqueous phase is closed, raising the temperature inside the reactor. This causes the oil droplets to polymerize into particles at a higher temperature. After cleaning, the product is obtained. The following details the specifics of each embodiment and comparative example.

[0048] In the following examples, the viscosity determination methods all follow GB / T 12010.2-2010.

[0049] Example 1 (1) Using styrene and divinylbenzene in a mass ratio of 9:1 as monomers, and benzoyl peroxide as an initiator, with the initiator amount being 3% of the monomer mass, an oil phase was prepared and injected into a jet oil phase tank; polyvinyl alcohol (viscosity 25 mPa·s) and gelatin were added to water at mass concentrations of 0.2% and 0.01% respectively to prepare a first aqueous phase, which was then loaded into a prepolymer channel; polyvinyl alcohol (viscosity 6 mPa·s) was added to a reaction vessel containing water at a mass concentration of 0.1% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (that is, isolate the contact between the first aqueous phase and the second aqueous phase), raise the reactor temperature to 90°C, maintain the temperature for 1.5 hours, lower the temperature to 80°C, maintain the temperature for 1 hour, raise the temperature to 90°C again, maintain the temperature for 2 hours, raise the temperature to 95°C, maintain the temperature for 2 hours, and finally maintain the temperature at 97°C for 2 hours to obtain polymer balls.

[0050] Example 2 It is basically the same as Example 1, except that no gelatin was added to the first aqueous phase.

[0051] Example 3 The process is basically the same as in Example 1, except that: (3) after the oil phase is sprayed, the bottom valve of the reactor is closed (i.e., the contact between the first and second aqueous phases is isolated), the reactor temperature is raised to 90°C, and the temperature is maintained for 4.5 hours. Then the temperature is raised to 95°C and maintained for 2 hours. Finally, the temperature is raised to 97°C and maintained for 2 hours to obtain polymer balls.

[0052] Example 4 (1) Using methyl acrylate and divinylbenzene in a mass ratio of 10:1 as monomers and azobisisobutyronitrile as initiator, with the initiator amount being 3% of the monomer mass, an oil phase was prepared and injected into a jet oil phase tank; polyvinyl alcohol (viscosity 6 mPa·s) and gelatin were added to water at mass concentrations of 0.1% and 2% respectively to prepare a first aqueous phase, which was then loaded into a prepolymer channel; polyvinyl alcohol (viscosity 6 mPa·s) was added to a reaction vessel containing water at a mass concentration of 1% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (i.e., isolate the contact between the first aqueous phase and the second aqueous phase), raise the temperature of the reactor to 90°C, maintain the temperature for 2.5 hours, lower the temperature to 80°C, maintain the temperature for 2 hours, raise the temperature to 90°C again, maintain the temperature for 3 hours, raise the temperature to 98°C, maintain the temperature for 3 hours, and obtain polymer balls.

[0053] Example 5 (1) Using methyl methacrylate and divinylbenzene in a mass ratio of 10:1 as monomers, and benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:1 as initiators, with the amount of initiator being 3% of the monomer mass, an oil phase was prepared and injected into a jet oil phase tank; polyvinyl alcohol (viscosity 25 mPa·s) and sodium dodecylbenzenesulfonate were added to water at mass concentrations of 1% and 0.05% respectively to prepare a first aqueous phase, which was then loaded into a prepolymer channel; polyvinyl alcohol (viscosity 22 mPa·s) was added to a reaction vessel containing water at a mass concentration of 0.5% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (i.e., isolate the contact between the first and second aqueous phases), raise the reactor temperature to 90°C, maintain the temperature for 2 hours, lower the temperature to 80°C, maintain the temperature for 1.5 hours, raise the temperature to 90°C again, maintain the temperature for 2.5 hours, raise the temperature to 95°C, maintain the temperature for 2.5 hours, and obtain polymer balls.

[0054] Example 6 (1) Using methyl acrylate and triallyl isocyanurate in a mass ratio of 1:1 as monomers, and benzoyl peroxide as an initiator, with the initiator amount being 3% of the monomer mass, an oil phase was prepared and injected into a jet oil phase tank; sodium lignosulfonate and hydroxyethyl cellulose were added to water at mass concentrations of 1.5% and 0.5%, respectively, to prepare a first aqueous phase, which was then loaded into a prepolymer channel; polyvinyl alcohol (viscosity 6 mPa·s) was added to a reaction vessel containing water at a mass concentration of 0.3% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (that is, isolate the contact between the first aqueous phase and the second aqueous phase), raise the temperature of the reactor to 90°C, maintain the temperature for 2 hours, lower the temperature to 80°C, maintain the temperature for 2 hours, raise the temperature to 90°C again, maintain the temperature for 3 hours, raise the temperature to 96°C, maintain the temperature for 3 hours, and obtain polymer balls.

[0055] Example 7 (1) Using methyl acrylate and diethylene propylene itaconic acid in a mass ratio of 4:1 as monomers, and azobisisobutyronitrile as initiator, with the amount of initiator being 3% of the monomer mass, an oil phase was prepared and injected into a jet oil phase tank; hydroxymethyl cellulose and sodium dodecyl sulfate were added to water at mass concentrations of 0.5% and 0.001%, respectively, to prepare a first aqueous phase, which was then loaded into a prepolymer channel; polyvinyl alcohol (viscosity 22 mPa·s) was added to a reaction vessel containing water at a mass concentration of 0.8% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (that is, isolate the contact between the first aqueous phase and the second aqueous phase), raise the reactor temperature to 90°C, maintain the temperature for 1.5 hours, lower the temperature to 80°C, maintain the temperature for 1 hour, raise the temperature to 90°C again, maintain the temperature for 2 hours, raise the temperature to 95°C, maintain the temperature for 2 hours, and obtain polymer balls.

[0056] Example 8 (1) Using glycidyl methacrylate and divinylbenzene in a mass ratio of 3:1 as monomers, and benzoyl peroxide as an initiator, with the initiator amount being 3% of the monomer mass, an oil phase was prepared and injected into a jet oil phase tank; hydroxyethyl cellulose and sodium lignosulfonate were added to water at mass concentrations of 1.8% and 1% respectively to prepare a first aqueous phase, which was then loaded into a prepolymer channel; polyvinyl alcohol (viscosity 22 mPa·s) was added to a reaction vessel containing water at a mass concentration of 0.2% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (i.e., isolate the contact between the first aqueous phase and the second aqueous phase), raise the temperature of the reactor to 90°C, maintain the temperature for 2.5 hours, lower the temperature to 80°C, maintain the temperature for 2 hours, raise the temperature to 90°C again, maintain the temperature for 3 hours, raise the temperature to 98°C, maintain the temperature for 3 hours, and obtain polymer balls.

[0057] Example 9 (1) Using divinylbenzene as monomer and azobisisobutyronitrile as initiator, with the initiator amount being 3% of the monomer mass, an oil phase is prepared and injected into a jet oil phase tank; polyvinyl alcohol (viscosity 22 mPa·s) and hydroxyethyl cellulose are added to water at mass concentrations of 2% and 1.5% respectively to prepare a first aqueous phase, which is then loaded into a prepolymer channel; polyvinyl alcohol (viscosity 6 mPa·s) is added to a reaction vessel containing water at a mass concentration of 0.1% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (i.e., isolate the contact between the first and second aqueous phases), raise the reactor temperature to 90°C, maintain the temperature for 2 hours, lower the temperature to 80°C, maintain the temperature for 1.5 hours, raise the temperature to 90°C again, maintain the temperature for 2.5 hours, raise the temperature to 95°C, maintain the temperature for 2.5 hours, and obtain polymer balls.

[0058] Example 10 (1) Using methyl acrylate and divinylbenzene in a mass ratio of 2:1 as monomers, and benzoyl peroxide as an initiator, with the initiator amount being 3% of the monomer mass, an oil phase was prepared and injected into a jet oil phase tank; gelatin was added to water at a mass concentration of 1.2% to prepare a first aqueous phase, and the first aqueous phase was loaded into a prepolymer channel; polyvinyl alcohol (viscosity 22 mPa·s) was added to a reaction vessel containing water at a mass concentration of 0.7% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (that is, isolate the contact between the first aqueous phase and the second aqueous phase), raise the temperature of the reactor to 90°C, maintain the temperature for 2 hours, lower the temperature to 80°C, maintain the temperature for 1 hour, raise the temperature to 90°C again, maintain the temperature for 3 hours, raise the temperature to 97°C, maintain the temperature for 2.5 hours, and obtain polymer balls.

[0059] Example 11 (1) Using glycidyl methacrylate and divinylbenzene in a mass ratio of 5:1 as monomers, and azobisisobutyronitrile as initiator, with the initiator amount being 3% of the monomer mass, an oil phase was prepared and injected into a jet oil phase tank; hydroxyethyl cellulose, sodium lignosulfonate and sodium dodecylbenzenesulfonate were added to water at mass concentrations of 0.7%, 0.01% and 0.03% respectively to prepare a first aqueous phase, which was then loaded into a prepolymer channel; polyvinyl alcohol (viscosity 6 mPa·s) was added to a reaction vessel containing water at a mass concentration of 0.5% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (that is, isolate the contact between the first aqueous phase and the second aqueous phase), raise the reactor temperature to 90°C, maintain the temperature for 1.5 hours, lower the temperature to 80°C, maintain the temperature for 1 hour, raise the temperature to 90°C again, maintain the temperature for 2 hours, raise the temperature to 95°C, maintain the temperature for 2 hours, and obtain polymer balls.

[0060] Example 12 (1) Using styrene and triallyl isocyanurate in a mass ratio of 2:1 as monomers, and benzoyl peroxide and azobisisobutyronitrile in a mass ratio of 2:1 as initiators, with the amount of initiator being 3% of the monomer mass, an oil phase was prepared and injected into a jet oil phase tank; hydroxymethyl cellulose and sodium dodecyl sulfate were added to water at mass concentrations of 2% and 0.05% respectively to prepare a first aqueous phase, which was then loaded into a prepolymer channel; polyvinyl alcohol (viscosity 22 mPa·s) was added to a reaction vessel containing water at a mass concentration of 1% to prepare a second aqueous phase; (2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to 100Hz and 0.02mm respectively. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise into the reactor, come into contact with the second aqueous phase, and gradually disperse in the second aqueous phase. (3) After the oil phase is sprayed, close the bottom valve of the reactor (i.e., isolate the contact between the first aqueous phase and the second aqueous phase), raise the temperature of the reactor to 90°C, maintain the temperature for 2.5 hours, lower the temperature to 80°C, maintain the temperature for 2 hours, raise the temperature to 90°C again, maintain the temperature for 3 hours, raise the temperature to 98°C, maintain the temperature for 3 hours, and obtain polymer balls.

[0061] Comparative Example 1 The process is basically the same as in Example 1, except that polyvinyl alcohol (viscosity 25 mPa·s) and gelatin are added to water at a mass concentration of 0.2% and 0.01% respectively to obtain an aqueous phase. A portion of the aqueous phase is used as the first aqueous phase, and the remaining aqueous phase is used as the second aqueous phase.

[0062] The viscosity of the aqueous phase in the above embodiments and comparative examples of the present invention is shown in Table 1.

[0063] Table 1. Viscosity test results of aqueous phase in the examples and comparative examples (unit: mPa·s)

[0064] It should be noted that the viscosity of polyvinyl alcohol in the examples is the product specification viscosity (provided by the manufacturer in the instruction manual), and its viscosity was measured according to the national standard GB / T 12010.2-2010. The viscosity in Table 1 refers to the specific aqueous phase, which was prepared according to the concentration and type actually used in the examples. Its viscosity was measured using the rotational viscometry method, calculated by measuring the resistance encountered by the rotor when rotating in the liquid.

[0065] The particle size of the samples prepared in the above examples and comparative examples was determined. The product yield was calculated as the percentage of the mass of the polymer spheres that met the uniformity coefficient requirement to the total mass of the obtained solids (using sieves of different aperture sizes). The effective particle size and uniformity coefficient were determined using the national standard method "Determination of Particle Size, Effective Particle Size and Uniformity Coefficient of Ion Exchange Resins" (GB / T 5758-2023), and the data obtained are shown in Table 2.

[0066] Table 2. Product yield and effective particle size under different uniformity (uniformity coefficient) conditions

[0067] As can be seen from Table 2, in Comparative Example 1, the yield of polymer balls with a uniformity coefficient lower than 1.2 was only 48.1%, and the yield of polymer balls with a uniformity coefficient lower than 1.1 was only 21.3%. In contrast, in Example 1, which used a second aqueous phase with a viscosity lower than that of the first aqueous phase, the yield of polymer balls with a uniformity coefficient lower than 1.2 reached 76.7%, and the yield of polymer balls with a uniformity coefficient lower than 1.1 reached 43.0%. This indicates that the present invention significantly improves the uniformity of polymer ball size by adjusting the viscosity of the aqueous phase.

[0068] In Example 2, no gelatin was added to the first aqueous phase. The yield of polymer balls with a uniformity coefficient lower than 1.2 was 65.5%, and the yield of polymer balls with a uniformity coefficient lower than 1.1 was 33.3%. Both yields were lower than the yields of polymer balls with the corresponding uniformity coefficients prepared by adding gelatin to the first aqueous phase in Example 1 of this invention. This indicates that adding a first secondary dispersant to the first aqueous phase based on the first primary dispersant can further improve the uniformity of the polymer ball particle size.

[0069] Compared with the gradual heating regime of Example 3, the polymer spheres prepared by the heating regime of Example 1 of the present invention, which first reacts at 90°C, then cools down to 80°C for further reaction, and then gradually increases the temperature, have higher uniformity.

[0070] As can be seen from Table 2, when using divinylbenzene, methyl acrylate, methyl methacrylate, glycidyl methacrylate, triallyl isocyanurate and divinylpropyl itaconic acid monomers in Examples 4-12, polymer spheres with uniform particle size can also be obtained using the method of the present invention, indicating that the method of the present invention has universality.

Claims

1. A method for preparing uniformly sized polymer spheres using a bidispersion system, characterized in that, The method includes the following steps: (1) The oil phase is mixed with the first aqueous phase to form oil phase droplets; (2) The oil phase droplets obtained in step (1) are mixed with the second aqueous phase and polymerized to obtain uniform polymer spheres; The viscosity η1 of the first aqueous phase is greater than the viscosity η2 of the second aqueous phase.

2. The method according to claim 1, characterized in that: The viscosities of η1 and η2 are independently selected from 1 to 5 mPa·s; Preferably, η1 and η2 have the following relationships (1) and / or (2): (1) The value of η1-η2 is >0 mPa·s, for example, the value of η1-η2 is 0.01~3.00 mPa·s; (2) The value of η1 / η2 is greater than 1, for example, the value of η1 / η2 is 1.02~3.

50.

3. The method according to claim 2, characterized in that: η1 and η2 have the following relationships (1) and / or (2): (1) The value of η1-η2 is 0.05~2.50 mPa·s; (2) The value of η1 / η2 is 1.05~3.

00.

4. The method according to any one of claims 1-3, characterized in that: The first aqueous phase comprises a first dispersant and water; The second aqueous phase comprises a second dispersant and water; The first dispersant and the second dispersant may be the same or different, and are independently selected from one, two or more of polyvinyl alcohol, gelatin, sodium lignosulfonate, hydroxyethyl cellulose, hydroxymethyl cellulose, sodium dodecylbenzene sulfonate and sodium dodecyl sulfate; For example, the first dispersant and the second dispersant are selected from polyvinyl alcohol with the same or different viscosity, or a combination of the first, second or more of gelatin, sodium lignosulfonate, hydroxyethyl cellulose, hydroxymethyl cellulose, sodium dodecylbenzenesulfonate and sodium dodecyl sulfate.

5. The method according to claim 4, characterized in that: The first dispersant comprises a dispersant combination 1 consisting of a mandatory first primary dispersant, an optional first secondary dispersant, and an optional second secondary dispersant: Combination 1 Alternatively, the first dispersant comprises a dispersant combination 2 consisting of a first primary dispersant, an optional first secondary dispersant, and an optional second secondary dispersant: Combination 2 Alternatively, the first dispersant comprises a dispersant combination 3 consisting of a first primary dispersant, an optional first secondary dispersant, and an optional second secondary dispersant: Combination 3 。 6. The method according to claim 4 or 5, characterized in that: The second dispersant is polyvinyl alcohol.

7. The method according to any one of claims 1-6, characterized in that, The oil phase includes monomers and initiators.

8. The method according to claim 7, characterized in that, The monomer is selected from one or more of styrene, divinylbenzene, methyl acrylate, methyl methacrylate, glycidyl methacrylate, triallyl isocyanurate, and divinylpropyl itaconic acid. Preferably, the initiator is selected from one or both of benzoyl peroxide and azobisisobutyronitrile; Preferably, step (1) is carried out under vibration conditions; and / or, step (2) is carried out under stirring conditions; and / or, the polymerization reaction in step (2) is carried out under heating conditions.

9. The method according to any one of claims 1-8, characterized in that, The method includes the following steps: under vibration conditions, an oil phase is injected into a first aqueous phase to form oil phase droplets; the oil phase droplets enter a second aqueous phase, and under stirring conditions, a polymerization reaction is carried out to obtain uniform polymer spheres.

10. The method according to any one of claims 1-9, characterized in that, The method includes the following steps: (S1) Prepare the oil phase and inject it into the jet oil phase tank; prepare the first aqueous phase and load it into the prepolymerization channel; after the first aqueous phase fills the prepolymerization channel, prepare the second aqueous phase in the reactor. (S2) Turn on the jet pump. When the oil phase is ejected from the jet microporous plate, turn on the vibrator switch and adjust its frequency and amplitude to obtain uniform oil phase droplets that meet the size requirements. When the oil phase droplets are ejected from the jet microporous plate, they come into contact with the first aqueous phase and disperse in the first aqueous phase. The oil phase droplets dispersed in the first aqueous phase gradually rise and enter the reactor, where they come into contact with the second aqueous phase and gradually disperse in the second aqueous phase. (S3) After the oil phase is sprayed, close the bottom valve of the reactor to isolate the first aqueous phase and the second aqueous phase from contact, and carry out the polymerization reaction under heating conditions.

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