Preparation method of polymer

Abstract

The invention relates to the field of preparation of polymer materials, and discloses a preparation method of a polymer. The preparation method comprises the following steps: S1, carrying out first mixing on a polymer raw material and a good solvent to obtain a polymer dilute solution; wherein the dosage of the polymer raw material and the good solvent enables the content of the polymer in every 100mL of the polymer dilute solution to be less than or equal to 1.5 g; and S2, the polymer dilute solution and a precipitant are subjected to second mixing, the use amount of the precipitant is 1-100 times of the volume of the polymer dilute solution, and then a solid-phase material is separated from a second mixed material. According to the method, rapid condensation of the polymer can be achieved without designing special condensation forming equipment, the high-dispersion and high-specific-surface-area polymer easy to convey is obtained, operation is easy, and consumed time is short.

Description

Technical Field

[0001] This invention relates to the field of polymer material preparation, and more specifically, to a method for preparing a polymer. Background Technology

[0002] Solution polymerization is one of the main processes for producing high-end polyolefins such as cyclic olefin copolymers (COC), polyolefin elastomers (POE), and ethylene propylene diene monomer (EPDM). However, in the post-processing of solution polymerization products, not only must unreacted monomers be removed, but also a large amount of residual solvent must be removed. Currently, there are three main methods for solvent removal: volatile matter concentration, mechanical centrifugation sedimentation, and chemical coagulation. Among them, chemical coagulation is simple to operate, has low energy consumption, and can quickly remove large amounts of solvent. However, during the coagulation process, polyolefins often easily agglomerate in the coagulation container, greatly affecting the subsequent material conveying, and there is even a possibility that the agglomerates in the coagulation container cannot be removed. It also easily causes a large amount of solvent and unreacted monomers to be encapsulated by the polymer and difficult to remove.

[0003] To address this issue, a common strategy is to first form the polymer and then allow it to agglomerate. For example, CN106967189A, CN104941558B, and CN101928387A disclose methods that use spraying to disperse the adhesive solution into fine droplets, followed by further precipitation and agglomeration to prepare highly dispersed polymer particles or loose fragments. US5314923A and US4110529A propose using stirring to emulsify the polymer solution to achieve droplet formation, followed by thermally induced phase separation or the addition of a precipitant to prepare a highly dispersed polymer. However, these methods either require the design of special agglomeration vessels and spraying systems, or the addition of emulsification steps, increasing the complexity of the system and raising the difficulty of operation and industrial implementation.

[0004] Furthermore, CN1207749A proposes a method for preparing porous polymer particles by gradually cooling a multiphase solution of polyolefin containing a nucleating agent during stirring and phase separation. However, this method requires strict control of the cooling rate using temperature control equipment to achieve the preparation of crystalline polymer particles. Similarly, GB2226320A also proposes a method for preparing polyethylene fine particles by cooling and crystallizing in a solvent. However, polymers are generally predominantly amorphous, making it difficult to extend these two methods to the preparation of other high specific surface area polymer fine particles. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of poor polymer dispersion, low specific surface area, and complex processes in the prior art, and to provide a polymer preparation method that can achieve rapid polymer agglomeration without the need for specially designed agglomeration molding equipment, thereby obtaining a highly dispersed polymer with high specific surface area that is easy to transport. The method is simple to operate and has a short processing time.

[0006] To achieve the above objectives, the present invention provides a method for preparing a polymer, wherein the preparation method includes the following steps:

[0007] S1. The polymer raw material and a good solvent are mixed for the first time to obtain a dilute polymer solution; wherein the amount of polymer raw material and good solvent used is such that the polymer content in each 100 mL of the dilute polymer solution is less than or equal to 1.5 g.

[0008] S2. The polymer dilute solution and the precipitant are mixed for the second time, wherein the amount of the precipitant is 1-100 times the volume of the polymer dilute solution, and then the solid phase material is separated from the second mixture.

[0009] The beneficial effects of the present invention through the above technical solution include at least the following:

[0010] This invention employs a dilute solution coagulation method to quickly and directly form polymers into highly dispersed fine particles or loose debris, avoiding the use of special coagulation and dispersion equipment, reducing equipment design and manufacturing costs, and is simple to operate and easy to implement industrially.

[0011] In this invention, the polymer is highly dispersed during the coagulation process, and the solvent and unreacted monomers therein can easily and quickly diffuse into the precipitant, avoiding the polymer from encapsulating impurities such as solvents, and greatly reducing the load of deep volatilization in post-treatment.

[0012] The prepared polymer fine particles or loose debris have a high specific surface area, which is beneficial for the implementation of subsequent processes for the removal of volatile matter and ash. Attached Figure Description

[0013] Figure 1 (A) is a photograph of the process by which a dilute COC polymer solution in Example 1 of the present invention coagulates into loose fragments;

[0014] Figure 1 (B) is a photograph of the process by which a dilute COC polymer solution condenses into microparticles in Example 3 of the present invention;

[0015] Figure 2 (A) is a photograph of the COC agglomerate polymer block formed by direct coagulation of COC adhesive in Comparative Example 1 of the present invention.

[0016] Figure 2(B) is a photograph of the COC polymer concentrated solution condensed into flocculent material in Comparative Example 2 of the present invention;

[0017] Figure 2 (C) is a photograph of loose COC polymer fragments formed by the coagulation of a dilute COC polymer solution in Example 1 of the present invention;

[0018] Figure 2 (D) is a photograph of the fine COC polymer particles formed by the coagulation of the dilute COC polymer solution in Example 2 of the present invention;

[0019] Figure 2 (E) is a photograph of COC polymer particles formed by the coagulation of a dilute COC polymer solution in Example 3 of the present invention. Detailed Implementation

[0020] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0021] This invention provides a method for preparing a polymer, wherein the preparation method includes the following steps:

[0022] S1. The polymer raw material and a good solvent are mixed for the first time to obtain a dilute polymer solution; wherein the amount of polymer raw material and good solvent used is such that the polymer content in each 100 mL of the dilute polymer solution is less than or equal to 1.5 g.

[0023] S2. The polymer dilute solution and the precipitant are mixed for the second time, wherein the amount of the precipitant is 1-100 times the volume of the polymer dilute solution, and then the solid phase material is separated from the second mixture.

[0024] Due to their unique long-chain properties, polymer molecules generally cannot disperse individually in solution like small-molecule solutions. Instead, they tend to entangle and interact with each other. When a precipitant is added, the polymers rapidly agglomerate and precipitate due to this entanglement. Therefore, traditional coagulation processes typically require forced methods such as spraying or emulsification to disperse the polymer solution into droplets before coagulation. However, the inventors discovered through in-depth research that when the polymer solution is diluted to a certain concentration and then added to a precipitant, the polymer can rapidly coagulate to form highly dispersed small-sized polymer particles or loose fragments with a high specific surface area. This method is simple to operate, time-efficient, and eliminates the need for specialized coagulation equipment to prepare highly dispersed polymers with an average particle size of 90-2000 μm and a high specific surface area.

[0025] The present invention does not particularly limit the type of polymer raw material. The method provided by the present invention is applicable to any type of polymer raw material. Preferably, the polymer raw material is selected from polyolefins, and more preferably from at least one of cyclic olefin copolymer raw materials, ethylene propylene diene monomer (EPDM) rubber raw materials and linear low-density polyethylene raw materials.

[0026] This invention does not impose any particular restrictions on the types of good solvents and precipitants. Based on the type of polymer raw materials, the basic principle of similar compatibility is used to select good solvents and precipitants. The selection of good solvents and precipitants should meet the following requirements: good solvents and precipitants can be miscible or have a large solubility. The two can form a homogeneous phase and enable the polymer to aggregate into highly dispersed small polymer particles or loose debris.

[0027] In a preferred embodiment of the present invention, the good solvent is selected from at least one of toluene, xylene, cyclohexane and hexane.

[0028] In a preferred embodiment of the present invention, the precipitant is selected from ethanol and / or acetone.

[0029] In a preferred embodiment of the present invention, when the polymer raw material is a cyclic olefin copolymer raw material, the good solvent is selected from toluene and / or xylene, and the precipitant is selected from ethanol and / or acetone; when the polymer raw material is ethylene propylene diene monomer (EPDM) rubber raw material, the good solvent is cyclohexane, and the precipitant is ethanol; when the polymer raw material is linear low-density polyethylene raw material, the good solvent is hexane, and the precipitant is acetone.

[0030] The inventors have discovered that the method provided by this invention, when using preferred solvents and precipitants, exhibits better performance than other types of polymer raw materials, including cyclic olefin copolymers, ethylene propylene diene monomer (EPDM) rubber, and linear low-density polyethylene (LLDPE). The resulting polymer products possess superior dispersibility and specific surface area. The method provided by this invention is particularly effective for cyclic olefin copolymer raw materials.

[0031] In a preferred embodiment of the present invention, the cyclic olefin copolymer (COC) raw material has a weight-average molecular weight of 20,000-150,000 g / mol, a molecular weight distribution coefficient of 1.2-3, a glass transition temperature of 50-200℃, and a molar content of structural units derived from norbornene in the cyclic olefin copolymer (COC) of 30-80%. The method provided by the present invention has better effects on cyclic olefin copolymer raw materials that meet these conditions, and the resulting polymer product has superior dispersibility and specific surface area.

[0032] To obtain a cyclic olefin copolymer raw material that meets the aforementioned conditions, in a preferred embodiment of the present invention, the preparation method of the cyclic olefin copolymer raw material includes: mixing ethylene and norbornene in the presence of a catalyst, a co-catalyst, and a solvent for a polymerization reaction; wherein the catalyst is a metallocene catalyst (rac-[Et(Ind)2]ZrCl2 catalyst), the co-catalyst is methylaluminoxane, and the solvent is toluene. When preparing the cyclic olefin copolymer raw material, the molar ratio of ethylene to norbornene is 1:(8-12), and the weight ratio of norbornene to toluene is 1:(7-11); the polymerization reaction temperature is 50-150℃, the pressure is 1-3 MPaG, and the time is 25-40 min; based on a volume of 1 L of the obtained mixture, the catalyst content is (5-7) × 10⁻⁶. -5 mol; the amount of catalyst is calculated as Zr, the amount of co-catalyst is calculated as Al, and the molar ratio of co-catalyst to catalyst is (1000-2000):1.

[0033] To accelerate the formation of a stable dilute solution from the polymer, in a preferred embodiment, in S1, the first mixing is carried out under heating conditions, and the temperature of the first mixing should be less than or equal to the boiling point of the good solvent under the same pressure. Preferably, the temperature of the first mixing is 40-110°C.

[0034] To promote a more thorough formation of a stable dilute solution from the polymer, preferably, in S1, the first mixing is carried out under stirring conditions, which can be done by magnetic stirring or mechanical stirring, with a stirring speed of 50-1000 rpm and a stirring time of 0.5-10 h.

[0035] In S2, the present invention does not have any particular restrictions on the second mixing method. The polymer dilute solution can be poured directly into the precipitant all at once, or the polymer dilute solution can be added drop by drop to the precipitant, or the precipitant can be poured into the polymer dilute solution.

[0036] In step S2, in order to further improve the solvent removal efficiency, in a preferred case, the temperature of the second mixing in step S2 is less than or equal to the boiling point of the precipitant under the same pressure. Preferably, the temperature of the second mixing is 20-50°C.

[0037] To further promote the polymer to aggregate more quickly into highly dispersed fine particles or loose debris with a high specific surface area, the second mixing is preferably carried out under stirring conditions, which can be mechanical stirring or magnetic stirring, with a stirring speed of less than or equal to 1000 rpm, preferably 100-600 rpm; and a stirring time of less than or equal to 60 min, preferably 1-30 min.

[0038] After a second mixing of the polymer dilute solution and the precipitant, the solid phase material can be separated from the second mixture to obtain a polymer product with high dispersibility and high specific surface area. This invention does not particularly limit the method for separating the solid phase material from the second mixture; conventional solid-liquid separation methods in the art can be used. Preferably, the separation method includes: filtering and drying the second mixture. Filtration can be performed using centrifugal filtration, positive pressure filtration, or vacuum negative pressure filtration; drying can be performed using vacuum heating drying. In a preferred embodiment, the heating drying temperature is 40-100℃, and the time is 5-72 hours.

[0039] The present invention will be described in detail below through examples and comparative examples. Unless otherwise specified, the methods used in the following examples are conventional; the reagents and materials used are commercially available unless otherwise specified.

[0040] Unless otherwise specified, in the following examples and comparative examples, the commercial COC granules were purchased from Polyplastics Co., Ltd., grade 6013F-04, with a weight-average molecular weight of 50,000 g / mol, a molar content of structural units from norbornene of 48%, a molecular weight distribution coefficient of 2, and a glass transition temperature of 135°C.

[0041] Example 1

[0042] Preparation of the toluene reaction solution for cyclic olefin polymer (COC): 10g of norbornene was dissolved in 90g of purified toluene and added to a polymerization reactor. The reactor temperature was raised to 60℃, and then high-purity ethylene (dehydrated and deoxygenated) was introduced into the reactor. The molar ratio of ethylene to norbornene was 1:10. After the pressure inside the reactor reached 1MPa, rac-[Et(Ind)2]ZrCl2 catalyst and methylaluminoxane (MAO) co-catalyst were added. The catalyst dosage was 6 × 10⁻⁶ based on a total volume of 1L for norbornene, ethylene, toluene, catalyst, and co-catalyst. -5 The amount of catalyst used was calculated as Zr, and the amount of co-catalyst used was calculated as Al. The molar ratio of co-catalyst to catalyst was 2000:1. After reacting for 30 min, a COC toluene reaction solution was obtained. Ethanol precipitation revealed a COC content of 8 g per 100 mL of the solution. Using trichlorobenzene as a solvent, high-temperature GPC analysis showed that the weight-average molecular weight of the obtained COC was 70,000 g / mol, and the molecular weight distribution coefficient was 1.9. NMR analysis showed that the molar content of structural units from norbornene was 50%. Differential scanning calorimetry determined the glass transition temperature to be 145 °C.

[0043] Take 5 mL of the gel solution and add 35 mL of toluene. Dilute the gel solution at 500 rpm until the COC content in 100 mL of diluted gel solution is 1 g. Stir at 45 °C under normal pressure for 30 min. After cooling the diluted gel solution to room temperature, pour it into 200 mL of ethanol and continue stirring for 30 min. Filter under negative pressure and dry at 60 °C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. The average particle size of the loose solid COC fragments obtained by optical microscopy was 1021 μm.

[0044] Figure 1 (A) is a photograph of the process by which a dilute COC polymer solution coagulates into loose debris. Figure 1 (A) It can be seen that the system is emulsion-like due to the small particle size.

[0045] Figure 2 (C) is a photograph of loose fragments of COC polymer formed by the coagulation of a dilute COC polymer solution.

[0046] Example 2

[0047] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 min to obtain a diluted solution, resulting in a COC content of 0.8 g per 100 mL of the diluted solution. 40 mL of the diluted solution, cooled to room temperature, was poured into 400 mL of ethanol and stirred at 500 rpm for 30 min. The solution was then filtered under negative pressure and vacuum dried at 60°C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. Optical microscopy analysis showed that the average particle size of the solid COC fine particles was 500 μm.

[0048] Figure 2 (D) is a photograph of fine COC polymer particles formed by the aggregation of a dilute COC polymer solution.

[0049] Example 3

[0050] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 min to obtain a diluted solution, resulting in a COC content of 0.5 g per 100 mL of diluted solution. 40 mL of the diluted solution was poured into 400 mL of acetone and stirred at 400 rpm for 30 min at 25°C. The solution was then filtered under negative pressure and dried at 60°C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. Optical microscopy analysis showed that the average particle size of the solid COC particles was 95 μm.

[0051] Figure 1 (B) is a photograph of the process by which a dilute COC polymer solution condenses into microparticles. Figure 1(B) It can be seen that the system is emulsion-like due to the small particle size.

[0052] Figure 2 (E) is a photograph of COC polymer particles formed by the aggregation of a dilute COC polymer solution.

[0053] Example 4

[0054] Commercially available COC granules were added to xylene and heated at 105°C and stirred at 800 rpm for 60 min to obtain a diluted solution, resulting in a COC content of 0.5 g per 100 mL of diluted solution. 40 mL of the diluted solution was poured into 400 mL of acetone and stirred at 500 rpm for 30 min at 25°C. The solution was then filtered under negative pressure and dried at 60°C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. Optical microscopy analysis showed that the average particle size of the solid COC particles was 97 μm.

[0055] Photographic results of the process of COC polymer dilute solution coagulating into microparticles and Figure 1 (B) Similarly, the photographic results of COC polymer particles condensed from dilute COC polymer solutions are similar to... Figure 2 (E) Similarly, the attached figure is not shown.

[0056] Example 5

[0057] Commercially available COC granules were added to xylene and heated at 105°C and stirred at 800 rpm for 60 min to obtain a diluted solution, resulting in a COC content of 0.5 g per 100 mL of diluted solution. 40 mL of the diluted solution was poured into 400 mL of ethanol and stirred at 500 rpm for 0.5 min at 25°C. The solution was then filtered under negative pressure and dried at 60°C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. Optical microscopy analysis showed that the average particle size of the solid COC particles was 101 μm.

[0058] Photographic results of the process of COC polymer dilute solution coagulating into microparticles and Figure 1 (B) Similarly, the photographic results of COC polymer particles condensed from dilute COC polymer solutions are similar to... Figure 2 (E) Similarly, the attached figure is not shown.

[0059] Example 6

[0060] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 min to obtain a diluted solution, resulting in a COC content of 0.5 g per 100 mL of diluted solution. 40 mL of the diluted solution was poured into 400 mL of ethanol, filtered directly under negative pressure without stirring, and dried at 60°C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. Optical microscopy analysis showed that the average particle size of the solid COC particles was 108 μm.

[0061] Photographic results of the process of COC polymer dilute solution coagulating into microparticles and Figure 1 (B) Similarly, the photographic results of COC polymer particles condensed from dilute COC polymer solutions are similar to... Figure 2 (E) Similarly, the attached figure is not shown.

[0062] Example 7

[0063] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 minutes to obtain a diluted solution with a COC content of 0.5 g per 100 mL of diluted solution. 400 mL of acetone was added to 40 mL of the diluted solution, and the mixture was filtered directly under negative pressure without stirring. After drying at 60°C for 72 hours, a highly dispersed COC polymer with a high specific surface area was obtained. Optical microscopy analysis showed that the average particle size of the solid COC particles was 100 μm.

[0064] Photographic results of the process of COC polymer dilute solution coagulating into microparticles and Figure 1 (B) Similarly, the photographic results of COC polymer particles condensed from dilute COC polymer solutions are similar to... Figure 2 (E) Similarly, the attached figure is not shown.

[0065] Example 8

[0066] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 min to obtain a diluted solution, resulting in a COC content of 0.5 g per 100 mL of diluted solution. 40 mL of the diluted solution was poured into 40 mL of ethanol, filtered directly under negative pressure without stirring, and dried at 60°C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. Optical microscopy analysis showed that the average particle size of the solid COC particles was 115 μm.

[0067] Photographic results of the process of COC polymer dilute solution coagulating into microparticles and Figure 1 (B) Similarly, the photographic results of COC polymer particles condensed from dilute COC polymer solutions are similar to... Figure 2 (E) Similarly, the attached figure is not shown.

[0068] Example 9

[0069] Linear low-density polyethylene (LLDPE) granules (weight-average molecular weight 90,000 g / mol, molecular weight distribution coefficient 3.1, melting point 122℃) were added to hexane and heated at 60℃ for 60 min with stirring at 800 rpm to obtain a diluted solution, ensuring that each 100 mL of the diluted solution contained 0.5 g of LLDPE. 40 mL of the diluted solution was poured into 400 mL of acetone and stirred at 500 rpm for 30 min at 25℃. The solution was then filtered under negative pressure and dried at 60℃ for 72 h to obtain highly dispersed LLDPE with a high specific surface area. Optical microscopy analysis showed that the average particle size of the solid LLDPE particles was 285 μm.

[0070] Photographic results of the process of linear low-density polyethylene dilute solution coagulating into microparticles and Figure 1 (B) Similarly, the photographic results of linear low-density polyethylene polymer particles agglomerated from a dilute solution of linear low-density polyethylene are similar to... Figure 2 (E) Similarly, the attached figure is not shown.

[0071] Example 10

[0072] Isotactic polypropylene granules (weight-average molecular weight 344,000 g / mol, molecular weight distribution coefficient 5.4, isotacticity 96.2%, melt flow index 3.74 g / 10 min) were added to cyclohexane and heated at 800 rpm and 60°C for 60 min to obtain a diluted solution, resulting in an isotactic polypropylene content of 0.5 g per 100 mL of the diluted solution. 40 mL of the diluted solution was poured into 400 mL of acetone and stirred at 500 rpm at 25°C for 30 min. The solution was then filtered under negative pressure and dried at 60°C for 72 h to obtain highly dispersed isotactic polypropylene with a high specific surface area. Optical microscopy analysis showed that the average particle size of the loose solid isotactic polypropylene fragments was 831 μm.

[0073] Photographs of the process by which dilute isotactic polypropylene solution agglomerates into loose fragments and Figure 1 (A) Similarly, the photographic results of isotactic polypropylene loose debris formed by the aggregation of dilute solutions of isotactic polypropylene polymer are similar to... Figure 2 (C) Similarly, the attached figure is not shown.

[0074] Example 11

[0075] Poly(N,N-dimethylaminoethyl methacrylate) (number-average molecular weight 15,000 g / mol, molecular weight distribution coefficient 1.44) was added to an acidic aqueous solution with pH 4 and dissolved at 800 rpm and 25°C for 60 min to obtain a diluted gel solution, such that the content of poly(N,N-dimethylaminoethyl methacrylate) in 100 mL of the diluted gel solution was 0.5 g. 40 mL of the diluted gel solution was poured into 400 mL of an alkaline aqueous solution with pH 12, stirred for another 30 min, filtered under negative pressure, and dried at 60°C for 72 h to obtain highly dispersed poly(N,N-dimethylaminoethyl methacrylate) with a high specific surface area. Optical microscopy analysis showed that the average particle size of the loose solid poly(N,N-dimethylaminoethyl methacrylate) fragments was 1534 μm.

[0076] Photographic results of the process of poly(N,N-dimethylaminoethyl methacrylate) solution coagulating into loose debris and Figure 1 (A) Similarly, photographic results of loose fragments of poly(N,N-dimethylaminoethyl methacrylate) formed by the coagulation of a dilute solution of poly(N,N-dimethylaminoethyl methacrylate) are similar to... Figure 2 (C) Similarly, the attached figure is not shown.

[0077] Example 12

[0078] COC granules (purchased from Mitsui Chemicals, grade APL6509T) with a weight-average molecular weight of 80,000 g / mol, a molar content of 20% from norbornene structural units, a molecular weight distribution coefficient of 2.52, and a glass transition temperature of 80 °C were added to xylene and dissolved by heating at 1000 rpm and 105 °C for 180 min to obtain a diluted gel solution, such that the COC content in each 100 mL of the diluted gel solution was 0.5 g. 40 mL of the diluted gel solution was poured into 400 mL of ethanol, and stirred at 500 rpm for 30 min at 25 °C. The mixture was then filtered under negative pressure and dried at 60 °C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. Optical microscopy analysis showed that the average particle size of the solid COC microparticles was 180 μm.

[0079] Photographic results of the process of COC polymer dilute solution coagulating into microparticles and Figure 1 (B) Similarly, the photographic results of COC polymer microparticles formed by the aggregation of dilute COC polymer solutions are similar to... Figure 2 (E) Similarly, the attached figure is not shown.

[0080] Example 13

[0081] Commercially available COC granules were added to naphtha and heated at 105°C and stirred at 800 rpm for 180 min to obtain a diluted solution, resulting in a COC content of 0.5 g per 100 mL of the diluted solution. 40 mL of the diluted solution was poured into 400 mL of methyl ethyl ketone and stirred at 500 rpm for 30 min at 25°C. The mixture was then filtered under negative pressure and dried at 60°C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. Optical microscopy analysis showed that the average particle size of the loose solid COC fragments was 1704 μm.

[0082] Photographic results of the process of COC polymer dilute solution coagulating into loose debris and Figure 1 (A) Similarly, the photographic results of COC polymer loose debris formed by the coagulation of dilute COC polymer solution are similar to... Figure 2 (C) Similarly, the attached figure is not shown.

[0083] Example 14

[0084] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 min to obtain a diluted solution, resulting in a COC content of 0.5 g per 100 mL of the diluted solution. 40 mL of the diluted solution was poured into 400 mL of acetone cooled to 4°C, and stirred at 400 rpm for 30 min at 4°C. The solution was then filtered under negative pressure and dried at 60°C for 72 h to obtain a highly dispersed COC polymer with a high specific surface area. Optical microscopy analysis showed that the average particle size of the loose solid COC fragments was 1540 μm.

[0085] Photographic results of the process of COC polymer dilute solution coagulating into loose debris and Figure 1 (A) Similarly, the photographic results of COC polymer loose debris formed by the coagulation of dilute COC polymer solution are similar to... Figure 2 (C) Similarly, the attached figure is not shown.

[0086] Comparative Example 1

[0087] 40 mL of the gel solution prepared in Example 1 was directly poured into 400 mL of ethanol, stirred at 500 rpm for 30 min, filtered under negative pressure, and dried at 60 °C for 72 h to obtain COC that had clumped together.

[0088] Figure 2 (A) is a photograph of COC agglomerates formed by the direct coagulation of COC colloid.

[0089] Comparative Example 2

[0090] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 min to obtain a diluted solution, resulting in a COC content of 4 g per 100 mL of diluted solution. 40 mL of the diluted solution, cooled to room temperature, was poured into 400 mL of ethanol and stirred at 500 rpm for 30 min. The solution was then filtered under negative pressure and dried at 60°C for 72 h to obtain COC precipitated into flocculent precipitates. The average length of these precipitates was directly measured to be 1.8 cm.

[0091] Figure 2 (B) is a photograph of a concentrated COC polymer solution condensed into flocculent material.

[0092] Comparative Example 3

[0093] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 minutes to obtain a diluted gel solution, resulting in a COC content of 20 g per 100 mL of diluted gel solution. 40 mL of the diluted gel solution, cooled to room temperature, was poured into 400 mL of ethanol and stirred at 500 rpm for 30 minutes. The COC was found to be dispersed in clumps in the ethanol. After negative pressure filtration, a gel-like solid was obtained. Upon forceful compression, the solid broke apart, revealing an unconsolidated COC solution containing a large amount of toluene.

[0094] Comparative Example 4

[0095] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 minutes to obtain a diluted solution, ensuring that each 100 mL of the diluted solution contained 1 g of COC. 40 mL of the diluted solution was poured into 400 mL of naphtha, and after stirring for another 30 minutes, no COC solid precipitation was observed.

[0096] Comparative Example 5

[0097] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 minutes to obtain a diluted solution, ensuring that each 100 mL of the diluted solution contained 1 g of COC. 40 mL of the diluted solution was poured into 400 mL of water, and stirring was continued for 30 minutes. The two phases separated, and no COC particles were observed to precipitate.

[0098] Comparative Example 6

[0099] Commercially available COC granules were added to toluene and heated at 105°C and stirred at 800 rpm for 60 minutes to obtain a diluted solution, ensuring that each 100 mL of the diluted solution contained 1 g of COC. 40 mL of the diluted solution was then poured into 2 mL of ethanol and stirred for another 30 minutes; no COC particles were observed to precipitate.

[0100] Comparative Example 7

[0101] When 400 mL of ethanol was added to 40 mL of the gel prepared in Example 1, it was observed that COC directly agglomerated into clumps and could not be dispersed. The average length of the clumps was measured to be 10 cm.

[0102] The results of the above examples and comparative examples show that the method of the present invention used in Examples 1-14 can prepare highly dispersed polymers with high specific surface area. In Comparative Example 1, the prepared adhesive solution was directly poured into ethanol and stirred, then filtered under negative pressure; in Comparative Examples 2 and 3, the COC content in the diluted adhesive solution was too high; in Comparative Examples 4-6, unsuitable precipitants were used; in Comparative Example 7, the prepared adhesive solution was added to ethanol without stirring, and the COC directly agglomerated, failing to yield highly dispersed polymers.

[0103] Furthermore, Examples 9-12 changed the types of polymer raw materials, Example 13 changed the types of good solvent and precipitant, and Example 14 changed the precipitation temperature after adding the precipitant. With the polymer content in the diluted solution always at 0.5g, the average particle size of the polymers obtained in Examples 9-14 increased, but they still exhibited high dispersion. This demonstrates that when the types of polymer raw materials, good solvent and precipitant, and precipitation conditions meet preferred criteria, the average particle size of the polymer can be further reduced, resulting in a polymer solid with a larger specific surface area.

[0104] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a polymer, characterized in that, The preparation method includes the following steps: S1. The polymer raw material and a good solvent are mixed for the first time to obtain a dilute polymer solution; wherein the amount of polymer raw material and good solvent used is such that the polymer content in each 100 mL of the dilute polymer solution is less than or equal to 1.5 g. S2. The polymer dilute solution and the precipitant are mixed for the second time, wherein the amount of the precipitant is 1-100 times the volume of the polymer dilute solution, and then the solid phase material is separated from the second mixture.

2. The preparation method according to claim 1, characterized in that, The polymer raw material is selected from polyolefins, preferably from at least one of cyclic olefin copolymer raw materials, ethylene propylene diene monomer (EPDM) rubber raw materials, and linear low-density polyethylene raw materials.

3. The preparation method according to claim 1 or 2, characterized in that, The good solvent is selected from at least one of toluene, xylene, cyclohexane, and hexane.

4. The preparation method according to any one of claims 1-3, characterized in that, The precipitant is selected from ethanol and / or acetone.

5. The preparation method according to any one of claims 1-4, characterized in that, The polymer raw material is a cyclic olefin copolymer raw material, the good solvent is selected from toluene and / or xylene, and the precipitant is selected from ethanol and / or acetone; And / or, the polymer raw material is EPDM rubber raw material, the good solvent is cyclohexane, and the precipitant is ethanol; And / or, the polymer raw material is linear low-density polyethylene raw material, the good solvent is hexane, and the precipitant is acetone.

6. The method according to any one of claims 1-5, characterized in that, In S1, the temperature of the first mixture is less than or equal to the boiling point of the good solvent under the same pressure, preferably 40-110°C.

7. The method according to any one of claims 1-6, characterized in that, In S1, the first mixing is carried out under stirring conditions, with a stirring speed of 50-1000 rpm and a stirring time of 0.5-10 h.

8. The method according to any one of claims 1-7, characterized in that, In S2, the temperature of the second mixture is less than or equal to the boiling point of the precipitant under the same pressure, preferably 20-50°C.

9. The method according to any one of claims 1-8, characterized in that, The second mixing is carried out under stirring conditions, with a stirring speed of less than or equal to 1000 rpm, preferably 100-600 rpm; and a stirring time of less than or equal to 60 min, preferably 1-30 min.

10. The method according to any one of claims 1-9, characterized in that, In S2, the separation method includes filtering and drying the second mixture; wherein the drying temperature is 40-100℃ and the time is 5-72h.

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