Polydisperse large-particle-size polystyrene microspheres and preparation method thereof
By adjusting the amount of dispersant and initiator, and using suspension polymerization to prepare polydispersed large-particle size polystyrene microspheres, the problem of poor dispersion in the prior art is solved, and efficient preparation suitable for industrial production is achieved.
Patent Information
- Application Number
- CN202510710455.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-29
- Publication Date
- 2025-08-12
AI Technical Summary
The prior art is difficult to prepare large-particle polystyrene microspheres, and the suspension polymerization process is complex and has poor dispersion, making it difficult to meet the needs of industrial production.
By adjusting the amount of dispersant and initiator, polydispersed large-particle size polystyrene microspheres are prepared by suspended polymerization, and microspheres with different particle size specifications are obtained by combining the screening step.
The prepared polystyrene microspheres have a large particle size and good dispersion. They are suitable for industrial production, with simple and controllable processes and high reproducibility.
Smart Images
Figure CN120464014A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of polystyrene microspheres, and particularly relates to polydisperse large-particle-size polystyrene microspheres and a preparation method thereof. Background Art
[0002] Styrene microspheres, with particle sizes ranging from submicron to millimeter, possess uniform physical and chemical properties and have shown great potential for application in numerous high-tech fields, including environmental protection, analytical chemistry, immunology, information and communications, standard metrology, carrier catalysis, liquid crystal displays, and microelectronics. Over the past 30 years, in-depth research and summary have been conducted on the preparation methods, functional modification, and applications of monodisperse microspheres.
[0003] Suspension polymerization involves the polymerization of monomers suspended in a dispersion medium as small droplets. This process involves the dispersion of monomers dissolved in an initiator in the form of droplets in a water medium, under the combined effects of the suspending agent and mechanical agitation. Each initiator-containing monomer droplet acts as a unit in bulk polymerization, and the polymerization reaction occurs within the monomer droplet. Depending on the water solubility of the polymer, suspension polymerization can be categorized as either homogeneous or heterogeneous. Dispersants are typically introduced to reduce the surface tension of the reaction system and stabilize the monomer droplets. Dispersants used are primarily water-soluble polymers, such as polyvinyl pyrrolidone, polyvinyl alcohol, gelatin, and hydroxymethyl cellulose. Initiators are typically azo compounds (azobisisobutyronitrile) or organic peroxides (benzoyl peroxide), and the polymerization temperature is 50-100°C. Porosity-forming agents can be good solvents (benzene, toluene, etc.), poor solvents (n-hexane, etc.), or mixed porogens to adjust the polymer's pore structure.
[0004] Suspension polymerization is a relatively complex polymerization system. Besides monomers and water, a variety of additives must be added. Therefore, numerous factors influence the styrene suspension polymerization process, including styrene purity, impurities in the water, polymerization temperature, reactor configuration, dispersant dosage, initiator concentration, stirring speed, and agitator position. Experimentation is required to find the optimal formulation and appropriate reaction conditions. Improper control can result in poor styrene dispersion, separation of the aqueous and oil phases, a rapid increase in system viscosity, agglomeration of the dispersed phase, and even violent polymerization, ultimately leading to polymerization failure.
[0005] Currently available synthesis processes, both domestically and internationally, are complex. The polystyrene microspheres obtained through suspension polymerization are too small, exhibit severe agglomeration, and lack the required dispersibility. While commercially available devices, such as microfluidics, can address these challenges, they are complex to operate and require expensive setup, resulting in limited production and prohibitive for large-scale industrial production. As can be seen from the foregoing, the current commercially available processes for preparing large-particle polystyrene are imperfect, prone to poor dispersibility and agglomeration, susceptible to various factors, and difficult to scale up. Summary of the Invention
[0006] In response to the above technical problems, the present invention provides polydisperse large-particle-size polystyrene microspheres and a method for their preparation. These microspheres are synthesized using a suspension polymerization method. By adjusting the amounts of dispersant and initiator, the resulting polystyrene microspheres exhibit uniform particle size after screening and high reproducibility. Despite the simple steps, this process achieves unexpected results.
[0007] In a first aspect, the present invention provides a method for preparing polydisperse large-particle-size polystyrene microspheres, comprising the following steps:
[0008] Step S1: adding a dispersant to a reaction vessel under stirring conditions, then adding a reaction solvent to react at room temperature, stirring for a predetermined time, and then adding a monomer, a crosslinking agent, an initiator, a porogen and an electrolyte.
[0009] Step S2, heating to 60°C to 80°C and refluxing for a predetermined time, centrifuging, washing, and drying the product to obtain dry large-size polystyrene microspheres.
[0010] Furthermore, the monomer is styrene, the dispersant is polyvinyl pyrrolidone, and the mass ratio of the dispersant to the monomer is 0.02 to 0.1: 1. If the dispersant is too little, the polystyrene microspheres cannot be guaranteed not to agglomerate, and if the dispersant is too much, the polystyrene microspheres may become sticky.
[0011] Furthermore, the reaction solvent in step S1 is any one of deionized water, ethanol or a mixed solution of ethanol and water, and the mass ratio of the reaction solvent to the monomer is (18-22):1.
[0012] Furthermore, the cross-linking agent is divinylbenzene, and the mass ratio of the cross-linking agent to the monomer is (0.1-0.3):1.
[0013] Furthermore, the initiator is any one of azobisisobutyronitrile and benzoyl peroxide or a combination thereof, and the mass ratio of the crosslinking agent to the monomer is (0.02-0.06):1.
[0014] Furthermore, the porogen is any one or more of toluene, dibutyl phthalate, n-heptane or cyclohexanol, and the mass ratio of the porogen to the monomer is (0.2-0.4):1.
[0015] Furthermore, the electrolyte is any one or more of sodium chloride, potassium chloride, sodium carbonate or potassium carbonate, and the mass ratio of the electrolyte to the monomer is (0.01-0.03):1.
[0016] Furthermore, in step S1, the monomers and ratios of styrene, initiator, cross-linking agent, etc. must all meet the specified ranges in order to prepare large-particle polystyrene microspheres that meet application requirements; otherwise, the prepared microspheres will have poor dispersibility.
[0017] The present invention fully disperses a dispersant in a reaction solvent, adds a polymer monomer, an initiator, a cross-linking agent, a porogen, and an electrolyte, and obtains polydisperse large-particle-size polystyrene microspheres after sufficient reaction. The microspheres are sieved through sieves of different mesh sizes to obtain monodisperse large-particle-size polystyrene microspheres of different particle sizes.
[0018] Compared with the prior art, the present invention has at least the following beneficial effects:
[0019] The present invention uses monomers, dispersants, initiators, porogens, and electrolytes to directly produce polydisperse large-particle polystyrene microspheres through a one-step suspension polymerization process. The prepared polystyrene microspheres have a large particle size, meeting production requirements and being highly suitable for industrial production.
[0020] The present invention adopts a suspension polymerization method and regulates the dispersion effect of the entire system by changing the amount of the dispersant and the initiator, thereby improving the dispersibility of the polystyrene microsphere particle size and avoiding agglomeration.
[0021] The preparation process of the invention is simple, the process is controllable, the stability and reproducibility are good, and it is easy to produce on a large scale, and can be widely used in the production of polystyrene microspheres with various particle sizes.
[0022] The raw materials of the invention are widely available, cheap and easily available, the reaction conditions are mild, the reaction rate is fast, the reaction efficiency is high, the repeatability is high, and the method is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a scanning electron microscope image of the large-particle polystyrene microspheres in Example 1 of the present invention. DETAILED DESCRIPTION
[0024] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.
[0025] Unless otherwise specified, the raw materials and materials used in the examples of the present invention were purchased through general commercial channels.
[0026] The sources of the raw materials, materials and instruments involved in the following examples or comparative examples are as follows:
[0027] Polyvinylpyrrolidone, CAS number: 9003-39-8;
[0028] Styrene, CAS number: 100-42-5;
[0029] Divinylbenzene, CAS number: 1321-74-0;
[0030] Azobisisobutyronitrile, CAS number: 78-67-1;
[0031] Toluene, CAS number: 108-88-3;
[0032] Ethanol (95%), CAS No.: 64-17-5;
[0033] Scanning electron microscope, Hitachi Regulus8100;
[0034] Laser particle size analyzer, Malvern Mastersizer 2000.
[0035] <Example 1>
[0036] Turn on the mechanical stirring at 500 rpm, add 0.6 g of polyvinyl pyrrolidone to a 500 mL three-necked flask, add 200 mL of a mixed solution of deionized water and ethanol (deionized water: ethanol = 9:1) to the reaction vessel for reaction, stir for 30 minutes, add 10 g of monomer styrene, 2 g of cross-linking agent divinylbenzene, 0.4 g of initiator azobisisobutyronitrile, 3 g of porogen toluene and 0.2 g of electrolyte sodium chloride, turn on the condensation water, raise the temperature to 70 ° C, react for 24, and then centrifuge and wash the product with ethanol and deionized water three times each. The drying temperature is 60 ° C and the drying time is 6 to 20 hours to obtain dry large-particle polystyrene microspheres.
[0037] The large-size polystyrene spheres were sieved using stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh to obtain polystyrene microspheres of different particle size ranges. In this embodiment, the particle size corresponding to 400 mesh is 38 μm.
[0038] <Example 2>
[0039] Turn on the mechanical stirring at 500 rpm, add 0.2 g of polyvinyl pyrrolidone to a 500 mL three-necked flask, add 200 mL of a mixed solution of deionized water and ethanol (deionized water: ethanol = 9:1) to the reaction vessel for reaction, stir for 30 minutes, add 10 g of monomer styrene, 2 g of cross-linking agent divinylbenzene, 0.4 g of initiator azobisisobutyronitrile, 3 g of porogen toluene and 0.2 g of electrolyte sodium chloride, turn on the condensation water, raise the temperature to 70 ° C, react for 24, and then centrifuge and wash the product with ethanol and deionized water three times each. The drying temperature is 60 ° C and the drying time is 6 to 20 hours to obtain dry large-particle polystyrene microspheres.
[0040] The large-particle polystyrene balls were sieved with stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh to obtain polystyrene microspheres with different particle size ranges.
[0041] <Example 3>
[0042] Turn on the mechanical stirring at 500 rpm, add 1 g of polyvinyl pyrrolidone to a 500 mL three-necked flask, add 200 mL of a mixed solution of deionized water and ethanol (deionized water: ethanol = 9:1) to the reaction vessel for reaction, stir for 30 minutes, then add 10 g of monomer styrene, 2 g of cross-linking agent divinylbenzene, 0.4 g of initiator azobisisobutyronitrile, 3 g of porogen toluene and 0.2 g of electrolyte sodium chloride, turn on the condensation water, raise the temperature to 70 ° C, react for 24, and then centrifuge and wash the product with ethanol and deionized water three times each. The drying temperature is 60 ° C and the drying time is 6 to 20 hours to obtain dry large-particle polystyrene microspheres.
[0043] The large-particle polystyrene balls were sieved with stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh to obtain polystyrene microspheres with different particle size ranges.
[0044] <Example 4>
[0045] Turn on the mechanical stirring at 500 rpm, add 0.6 g of polyvinyl pyrrolidone to a 500 mL three-necked flask, add 200 mL of a mixed solution of deionized water and ethanol (deionized water: ethanol = 9:1) to the reaction vessel for reaction, stir for 30 minutes, add 10 g of monomer styrene, 2 g of cross-linking agent divinylbenzene, 0.2 g of initiator azobisisobutyronitrile, 3 g of porogen toluene and 0.2 g of electrolyte sodium chloride, turn on the condensation water, raise the temperature to 70 ° C, react for 24, and then centrifuge and wash the product with ethanol and deionized water three times each. The drying temperature is 60 ° C and the drying time is 6 to 20 hours to obtain dry large-particle polystyrene microspheres.
[0046] The large-particle polystyrene balls were sieved with stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh to obtain polystyrene microspheres with different particle size ranges.
[0047] <Example 5>
[0048] Turn on the mechanical stirring at 500 rpm, add 0.6 g of polyvinyl pyrrolidone to a 500 mL three-necked flask, add 200 mL of a mixed solution of deionized water and ethanol (deionized water: ethanol = 9:1) to the reaction vessel for reaction, stir for 30 minutes, add 10 g of monomer styrene, 2 g of cross-linking agent divinylbenzene, 0.6 g of initiator azobisisobutyronitrile, 3 g of porogen toluene and 0.2 g of electrolyte sodium chloride, turn on the condensation water, raise the temperature to 70 ° C, react for 24, and then centrifuge and wash the product with ethanol and deionized water three times each. The drying temperature is 60 ° C and the drying time is 6 to 20 hours to obtain dry large-particle polystyrene microspheres.
[0049] The large-particle polystyrene balls were sieved with stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh to obtain polystyrene microspheres with different particle size ranges.
[0050] Comparative Example 1
[0051] Turn on the mechanical stirring at 500 rpm, add 0.6 g of polyvinyl pyrrolidone to a 500 mL three-necked flask, add 200 mL of a mixed solution of deionized water and ethanol (deionized water: ethanol = 9:1) to the reaction vessel for reaction, stir for 30 minutes, add 10 g of monomer styrene, 2 g of cross-linking agent divinylbenzene, 0.4 g of initiator azobisisobutyronitrile, 3 g of porogen toluene and 0.2 g of electrolyte sodium chloride, turn on the condensation water, raise the temperature to 60 ° C, react for 24, and then centrifuge and wash the product with ethanol and deionized water three times each. The drying temperature is 60 ° C and the drying time is 6 to 20 hours to obtain dry large-particle polystyrene microspheres.
[0052] The large-particle polystyrene balls were sieved with stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh to obtain polystyrene microspheres with different particle size ranges.
[0053] Comparative Example 2
[0054] Turn on the mechanical stirring at 500 rpm, add 0.6 g of polyvinyl pyrrolidone to a 500 mL three-necked flask, add 200 mL of a mixed solution of deionized water and ethanol (deionized water: ethanol = 9:1) to the reaction vessel for reaction, stir for 30 minutes, add 10 g of monomer styrene, 2 g of cross-linking agent divinylbenzene, 0.4 g of initiator azobisisobutyronitrile, 3 g of porogen toluene and 0.2 g of electrolyte sodium chloride, turn on the condensation water, raise the temperature to 65 ° C, react for 24, and then centrifuge and wash the product with ethanol and deionized water three times each. The drying temperature is 60 ° C and the drying time is 6 to 20 hours to obtain dry large-particle polystyrene microspheres.
[0055] The large-particle polystyrene balls were sieved with stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh to obtain polystyrene microspheres with different particle size ranges.
[0056] Comparative Example 3
[0057] Turn on the mechanical stirring at 500 rpm, add 0.6 g of polyvinyl pyrrolidone to a 500 mL three-necked flask, add 200 mL of a mixed solution of deionized water and ethanol (deionized water: ethanol = 9:1) to the reaction vessel for reaction, stir for 30 minutes, add 10 g of monomer styrene, 2 g of cross-linking agent divinylbenzene, 0.4 g of initiator azobisisobutyronitrile, 3 g of porogen toluene and 0.2 g of electrolyte sodium chloride, turn on the condensation water, raise the temperature to 75 ° C, react for 24, and then centrifuge and wash the product with ethanol and deionized water three times each. The drying temperature is 60 ° C and the drying time is 6 to 20 hours to obtain dry large-particle polystyrene microspheres.
[0058] The large-particle polystyrene balls were sieved with stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh to obtain polystyrene microspheres with different particle size ranges.
[0059] Comparative Example 4
[0060] Turn on the mechanical stirring at 500 rpm, add 0.6 g of polyvinyl pyrrolidone to a 500 mL three-necked flask, add 200 mL of a mixed solution of deionized water and ethanol (deionized water: ethanol = 9:1) to the reaction vessel for reaction, stir for 30 minutes, add 10 g of monomer styrene, 2 g of cross-linking agent divinylbenzene, 0.4 g of initiator azobisisobutyronitrile, 3 g of porogen toluene and 0.2 g of electrolyte sodium chloride, turn on the condensation water, raise the temperature to 80 ° C, react for 24, and then centrifuge and wash the product with ethanol and deionized water three times each. The drying temperature is 60 ° C and the drying time is 6 to 20 hours to obtain dry large-particle polystyrene microspheres.
[0061] The large-particle polystyrene balls were sieved with stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh to obtain polystyrene microspheres with different particle size ranges.
[0062] <Test Example 1>
[0063] This test example uses a scanning electron microscope - Hitachi Regulus8100 to test the 100-120 mesh large particle size polystyrene microspheres in Example 1. The results are shown in Figure 1 Different mesh sizes have corresponding particle sizes, for example, 100 mesh corresponds to a particle size of 150 μm.
[0064] from Figure 1 It can be seen that the electron microscope image shows that the microspheres are spherical.
[0065] <Test Example 2>
[0066] In this test example, a laser particle size analyzer, Malvern Mastersizer 2000, was used to test polystyrene microspheres of different mesh sizes. The results are shown in Table 1.
[0067] Table 1 shows the particle size of the polydisperse large-particle polystyrene microspheres of Example 1.
[0068] Table 1 Particle size of polydisperse large-particle polystyrene microspheres in Example 1
[0069]
[0070]
[0071] The applicant declares that the above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and disclosure scope of the present invention.
Claims
1. A method for preparing polydisperse large-particle polystyrene microspheres, characterized in that: The steps include: Step S1: adding a dispersant to a reaction vessel under stirring conditions, then adding a reaction solvent to react at room temperature, stirring for a predetermined time, and then adding a monomer, a cross-linking agent, an initiator, a porogen and an electrolyte. Step S2, heating to 60°C to 80°C and reflux for a predetermined time, centrifuging, washing, and drying the product to obtain dry large-size polystyrene microspheres; Wherein, the monomer is styrene, the dispersant is polyvinyl pyrrolidone, and the mass ratio of the dispersant to the monomer is (0.02-0.1):1; The reaction solvent in step S1 is any one of water, ethanol, or a mixture of the two, and the mass ratio of the reaction solvent to the monomer is (18-22):1; The cross-linking agent is divinylbenzene, and the mass ratio of the cross-linking agent to the monomer is (0.1-0.3):1; The initiator is any one of azobisisobutyronitrile and benzoyl peroxide or a combination thereof, and the mass ratio of the crosslinking agent to the monomer is (0.02-0.06):1; The porogen is any one or more of toluene, dibutyl phthalate, n-heptane or cyclohexanol, and the mass ratio of the porogen to the monomer is (0.2-0.4):1; The electrolyte is any one or more of sodium chloride, potassium chloride, sodium carbonate or potassium carbonate, and the mass ratio of the electrolyte to the monomer is (0.01-0.03):
1.
2. The method for preparing polydisperse large-particle-size polystyrene microspheres according to claim 1, wherein: The particle size of the large-particle polystyrene microspheres ranges from 40 μm to 300 μm.
3. The method for preparing polydisperse large-particle-size polystyrene microspheres according to claim 2, wherein: In step S2, after obtaining dried large-particle-size polystyrene microspheres, they are sieved using stainless steel sieves of different mesh sizes to obtain polystyrene microspheres of uniform particle size.
4. The method for preparing polydisperse large-size polystyrene microspheres according to claim 3, wherein: In step S2, the dried large-size polystyrene balls are sieved using stainless steel sieves of 50 mesh, 80 mesh, 100 mesh, 120 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, and 400 mesh.
5. The method for preparing polydisperse large-particle-size polystyrene microspheres according to claim 1, wherein: In step S1, mechanical stirring is started at 300 to 600 rpm, the dispersant is added to the reaction container, and then the reaction solvent is added to react at room temperature and stirred for 30 minutes.
6. The method for preparing polydisperse large-size polystyrene microspheres according to claim 1, wherein: In step S2, the temperature is raised to 60° C. to 80° C., and after reacting for 24 hours, the product is centrifugally washed three times with ethanol and three times with deionized water, and the drying temperature is 60° C. and the drying time is 6 hours to 20 hours to obtain the dried large-particle-size polystyrene microspheres.
7. The method for preparing polydisperse large-size polystyrene microspheres according to claim 1, wherein: In step S1, the reaction solvent is a mixed solution of deionized water and ethanol, and the mass ratio of the deionized water to the ethanol is 9:
1.
8. A polydisperse large-particle-size polystyrene microsphere, characterized in that: The polystyrene microspheres are prepared by the method for preparing polydisperse large-particle polystyrene microspheres according to any one of claims 1 to 7.
9. The polydisperse large-particle-size polystyrene microspheres according to claim 8, wherein: The particle size of the large-particle polystyrene microspheres ranges from 40 μm to 300 μm.