A method for preparing a polymer porous material based on high internal phase emulsion

Abstract

The application provides a method for preparing a polymer porous material based on a high internal phase emulsion. The method is performed through cross-linking and solidification of a linear copolymer high internal phase emulsion, and a polymer porous material is obtained. The method can be performed at room temperature, is beneficial to shaping according to use requirements in actual application, is simple in process, is mild in condition, and does not need special conditions and equipment. The obtained polymer porous material is high in porosity, uniform in internal pore distribution, and has good adsorption.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of polymer porous material preparation and environmental functional material preparation, and particularly relates to a preparation method of a room-temperature crosslinking type polymer porous material which can be arbitrarily shaped and can be produced and applied on a large scale, and particularly relates to a preparation method of a polymer porous material used in the fields of adsorption, oil-water separation, heat preservation, sound insulation, porous liquid injection smooth surface construction and the like. BACKGROUND

[0002] A high internal phase emulsion is an emulsion with a dispersed phase volume fraction greater than 74%, and a polymer porous material prepared by using a high internal phase emulsion template method has many advantages such as high porosity, low density and large specific surface area. In addition, the macroscopic morphology of the material can be adjusted by designing different reaction molds, and the microscopic pore morphology can be controlled by adjusting parameters such as the amount of emulsifier and the volume fraction of the internal phase. The polymer porous material prepared by the high internal phase emulsion template method not only has a simple operation, but also usually has an open structure with internal interpenetration. These characteristics make the polymer porous material prepared by the high internal phase emulsion template method very popular, and it has great application potential in many fields such as adsorption, catalysis, sensing and tissue engineering.

[0003] Although the research on the preparation of polymer porous materials by the high internal phase emulsion template method has been very extensive, most of them are still at the laboratory research stage, and there are still great challenges in large-scale industrial application. This is because the traditional process of preparing polymer porous materials by using the high internal phase emulsion template method is generally to mix a mixture containing monomers, initiators and crosslinking agents as a continuous phase, and then mix and emulsify the continuous phase with a dispersed phase under the assistance of an emulsifier to form a high internal phase emulsion. Then, it is transferred to a mold, and the monomers in the continuous phase are polymerized and crosslinked under the conditions of high temperature, radiation and the like. Finally, the dispersed phase solvent, unreacted monomers and emulsifier are further removed by extraction and the like, and the polymer porous material is finally dried to form a polymer porous material. In addition, the porous material prepared by the high internal phase template method from a thermoplastic polymer is often low in heat resistance due to the influence of the glass transition temperature and melting temperature of the polymer, which limits its application in high temperature environments.

[0004] The traditional high internal phase emulsion template method for preparing polymer porous materials still has the following problems in large-scale production and application: (1) The preparation of polymer porous materials by high internal phase emulsion template method often requires molding before polymerization and cross-linking curing, which cannot achieve arbitrary molding and limits its large-scale application; (2) High internal phase emulsion monomer polymerization usually needs to be carried out under high temperature, radiation and other conditions, which not only consumes a lot of energy, but also makes it difficult to meet the requirements of production equipment when large-size porous materials are needed; (3) During the high internal phase emulsion polymerization and curing process, the monomer conversion rate cannot reach 100%, and unreacted monomers are inevitable. Further removal processes are complicated and costly, and it is also difficult to remove unreacted monomers from large-size porous materials by extraction and other methods, which inevitably affects the performance of the products and the environment; (4) Small molecule emulsifiers will remain in the porous materials, which will affect the water resistance and mechanical properties of the porous materials.

[0005] Therefore, it is particularly important to find a method for preparing porous materials using a high internal phase emulsion template method that is energy-efficient, low-cost, simple in process, arbitrarily shaped, and industrially producible and applicable. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method for preparing porous polymer materials based on high internal phase emulsions. This method involves crosslinking and curing a linear copolymer high internal phase emulsion to obtain the porous polymer material. Crosslinking can be carried out at room temperature, facilitating shaping according to application requirements. The process is simple, the conditions are mild, and no special conditions or equipment are required. The resulting porous polymer material has high porosity, uniform internal pore distribution, and good adsorption properties, thus fulfilling the purpose of this invention.

[0007] The purpose of this invention is to provide a method for preparing porous polymer materials based on a high internal phase emulsion. The method involves crosslinking and curing a linear copolymer high internal phase emulsion to obtain the porous polymer material. The crosslinking and curing temperature is 15-40℃, preferably 18-30℃, and more preferably 20-25℃.

[0008] Another objective of this invention is to provide a polymer porous material prepared by a method for preparing polymer porous materials based on high internal phase emulsion. Its average pore size is 1-24 μm, preferably 2-18 μm, more preferably 4-12 μm; and its porosity is 80-99%, preferably 85-97.5%, more preferably 90-96%.

[0009] The method for preparing polymer porous materials based on high internal phase emulsion provided by this invention has the following beneficial effects:

[0010] (1) The method for preparing polymer porous materials based on high internal phase emulsion provided by the present invention utilizes linear copolymers to form stable high internal phase emulsions, and crosslinks and cures them at room temperature. The crosslinking and curing conditions are mild and do not require special conditions or special equipment, and the process conditions are easy to control.

[0011] (2) In the method described, room temperature crosslinking and curing are carried out using a high internal phase emulsion, which can be arbitrarily shaped, making it convenient to carry out in actual production and meet the requirements of different application environments.

[0012] (3) The method for preparing polymer porous materials based on high internal phase emulsion provided by the present invention has a simple process and no unreacted monomers remain in the product during the preparation of polymer porous materials. There is no need to remove unreacted monomers, which further simplifies the process and avoids affecting the performance of the product.

[0013] (4) The polymer porous material prepared by the method of the present invention has high porosity, uniform internal pore distribution, and good adsorption, which greatly broadens the application direction. Attached Figure Description

[0014] Figure 1 A digital photograph of the room-temperature shaped polymer porous material A obtained in Example 1 of the present invention is shown;

[0015] Figure 2 This shows a scanning electron microscope image of the polymer porous material A obtained in Example 1 of the present invention;

[0016] Figure 3 This shows a scanning electron microscope image of the polymer porous material B obtained in Example 2 of the present invention;

[0017] Figure 4 The diagram shows the self-cleaning performance of the porous liquid injection smooth surface constructed from polymer porous material B obtained in Example 2 of the present invention.

[0018] Figure 5 This shows a scanning electron microscope image of the polymer porous material C obtained in Example 3 of the present invention;

[0019] Figure 6 This shows a scanning electron microscope image of the polymer porous material D obtained in Example 4 of the present invention;

[0020] Figure 7 The thermogravimetric curve of the polymer porous material D obtained in Example 4 of the present invention is shown. Detailed Implementation

[0021] The present invention will now be described in detail through specific embodiments, and the features and advantages of the present invention will become clearer and more explicit with these descriptions.

[0022] This invention provides a method for preparing polymer porous materials based on high internal phase emulsions. The method involves crosslinking and curing a linear copolymer high internal phase emulsion to obtain a polymer porous material.

[0023] The crosslinking and curing temperature is 15-40℃, preferably 18-30℃, and more preferably 20-25℃. The high internal phase emulsion of this invention can be crosslinked and cured at 15-40℃, especially at room temperature. At this temperature, it is easier to coat or fill the high internal phase emulsion into molds, and it is more conducive to shaping into various shapes. No additional conditions are required, the shaping conditions are simple and easy to control, no special equipment is needed, and the preparation method is simple, which is beneficial to meeting the needs of actual production and application.

[0024] The linear copolymer comprises hydrophobic segments, hydrophilic segments, and crosslinked segments, and is prepared by copolymerization of hydrophobic monomers, hydrophilic monomers, and crosslinked monomers.

[0025] The hydrophobic monomer is selected from one or more of unsaturated alkylbenzenes and acrylates, preferably from one or more of alkenylbenzenes, acrylates, and methacrylates, and more preferably from one or more of styrene, methyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, and hydroxyethyl methacrylate, such as styrene, butyl acrylate, and methyl methacrylate. The dispersed phase of the water-in-oil high internal phase emulsion is water, which is low-cost, economical, and environmentally friendly. Furthermore, the porous material formed after curing is hydrophobic and has good water resistance. Therefore, this invention preferentially selects to prepare water-in-oil high internal phase emulsions. However, the continuous phase of the water-in-oil high internal phase emulsion needs to have sufficient hydrophobicity to enhance the wettability difference between the continuous phase and the dispersed phase, avoiding a decrease in emulsion stability due to mutual solubility. In this invention, a linear copolymer is used as the continuous phase, therefore, it needs to ensure sufficient hydrophobicity.

[0026] This invention uses unsaturated hydrocarbon benzene and acrylate monomers as hydrophobic monomers for linear copolymers, ensuring that the resulting linear copolymers possess sufficient hydrophobicity. In particular, the use of styrene, butyl acrylate, and methyl methacrylate as hydrophobic monomers to construct linear copolymers results in suitable hydrophobicity, enabling the formation of stable, high-internal-phase emulsions with appropriate viscosity that can be molded at 15-40°C, such as at room temperature.

[0027] The hydrophilic monomer is selected from one or more of alkenyl monocarboxylic acids, alkenyl dicarboxylic acids, and alkenyl anhydrides, preferably from one or more of alkenyl monocarboxylic acids, alkenyl dicarboxylic acids, and alkenyl anhydrides with C3-C4 carbon atoms, and more preferably from one or more of acrylic acid, methacrylic acid, maleic acid, and maleic anhydride, such as acrylic acid. When preparing a high internal phase emulsion, the linear copolymer containing crosslinking groups exists in the continuous phase (oil phase), while the crosslinking agent exists in the dispersed phase (aqueous phase). If the linear copolymer is too hydrophobic, it will affect the later crosslinking effect. Therefore, a small amount of hydrophilic monomer is added to give the linear copolymer a certain degree of hydrophilicity, thereby increasing the contact opportunity between the hydrophobic copolymer and the hydrophilic crosslinking agent.

[0028] In this invention, alkenyl monocarboxylic acid, alkenyl dicarboxylic acid, and alkenyl anhydride are used as hydrophilic monomers, especially acrylic acid, methacrylic acid, maleic acid, and maleic anhydride, which can give the high internal phase emulsion a certain degree of hydrophilicity. At 15-40℃, it can react with the crosslinking agent in the aqueous dispersion phase to complete the crosslinking and curing process.

[0029] The crosslinking monomer is a monomer containing room-temperature crosslinking groups, preferably selected from one or more of diacetone acrylamide, ethyl acetoacetate methacrylate, and methyl vinyl ketone, and more preferably diacetone acrylamide. Directly preparing a high internal phase emulsion from a linear copolymer and then curing it to obtain a porous material results in poor heat resistance, solvent resistance, and mechanical properties because a crosslinking network is not formed between the polymers. Therefore, introducing crosslinking groups into the molecular chain of the linear copolymer enhances the material's various properties by forming a crosslinking network. In this invention, a crosslinking monomer that can crosslink at room temperature is used to achieve room-temperature shaping of the linear copolymer. In particular, using diacetone acrylamide as a crosslinking agent not only improves the mechanical properties of the polymer porous material but also allows for crosslinking and shaping at room temperature, which is beneficial for the application of polymer porous materials.

[0030] In the linear copolymer, the mass ratio of crosslinking monomer, hydrophilic monomer, and hydrophobic monomer is 1:(0.1-1.9):(6-30), preferably 1:(0.2-1.6):(8-25), and more preferably 1:(0.3-1.3):(10-20). The amount of crosslinking monomer affects the number of crosslinkable groups in the system, thereby affecting the crosslinking effect and mechanical properties of the material. The ratio of hydrophobic monomer to hydrophilic monomer affects the stability of the high internal phase emulsion. Within the above ratio range, a higher proportion of hydrophobic monomer is more conducive to the formation of a stable high internal phase emulsion. If the proportion of hydrophobic monomer is too high and the proportion of hydrophilic monomer is too low, it will affect the hydrophilicity of the linear copolymer, thereby affecting the crosslinking process.

[0031] The linear copolymer has a molecular weight of (0.1-4.0)×10⁻⁶. 5g / mol, preferably (0.2-3.0)×10 5 g / mol, more preferably (0.3-2.0)×10 5 g / mol. The performance of the polymer porous material prepared based on high internal phase emulsion is limited by molecular weight. If its molecular weight is too low, below 0.1 × 10⁻⁶ g / mol, it will be affected. 5 The prepared material has poor mechanical properties due to its high molecular weight (g / mol). Increasing the molecular weight can improve the mechanical strength of the polymer porous material. However, if the molecular weight is too high, exceeding 4.0 × 10⁻⁶ g / mol, the mechanical properties will be poor. 5 The high molecular weight (g / mol) results in excessively high polymer viscosity due to severe entanglement between molecular chains, which in turn degrades the performance of the porous polymer material. Furthermore, in this patent, an excessively high molecular weight of the copolymer reduces its solubility in dichloromethane, making it difficult to use as a continuous phase in the preparation of high internal phase emulsions. Therefore, it is necessary to rationally control the molecular weight of the copolymer.

[0032] The linear copolymer high internal phase emulsion is a stable emulsion obtained by adding a dispersed phase dropwise to a continuous phase and mixing them evenly.

[0033] The continuous phase is a mixture obtained by dispersing and dissolving the linear copolymer in a solvent.

[0034] The solvent is selected from one or more of halogenated hydrocarbon solvents, aromatic solvents, and ketone solvents, preferably one or more of chloroalkane solvents with C1-C3 carbon atoms, alkylbenzene solvents, and alkyl ketone solvents with C2-C5 carbon atoms, more preferably one or more of dichloromethane, toluene, xylene, and acetone, such as dichloromethane. The solvents used in this invention can dissolve the linear copolymers in this invention to form high internal phase emulsions, especially dichloromethane, which has a boiling point of 39.8°C and the ability to evaporate at room temperature. Using dichloromethane as the continuous phase solvent to prepare high internal phase emulsions eliminates the need for a solvent removal step because of its self-evaporation.

[0035] In the continuous phase, the mass concentration of the linear copolymer is 0.02-0.24 g / mL, preferably 0.03-0.18 g / mL, and more preferably 0.04-0.12 g / mL. The linear copolymer, as the continuous phase of the high internal phase emulsion, forms the skeletal structure of the polymer porous material after curing. If the concentration of the linear copolymer is too low, with a constant total volume, there is less copolymer, resulting in high porosity and poor mechanical properties in the porous material formed by the copolymer. If the concentration of the linear copolymer is too high, the resulting porous material skeletal structure is more compact, leading to better mechanical properties, but it also results in excessively low porosity and pore size.

[0036] Preferably, a stabilizer is also added to the continuous phase. The stabilizer is selected from one or more inorganic nanoparticles, preferably from one or more of nano-zinc oxide, nano-silica, and nano-hydroxyapatite, and more preferably nano-zinc oxide. The average particle size of the stabilizer is 10-100 nm, preferably 20-60 nm, and more preferably 25-35 nm. Using inorganic nanoparticles as a stabilizer can, on the one hand, reduce the oil-water interfacial tension, keeping the emulsion stable; on the other hand, inorganic nanoparticles can also act as fillers in porous polymer materials, enhancing the mechanical properties and heat resistance of the porous materials.

[0037] The mass ratio of the stabilizer to the linear copolymer is (0.05-1.0):1, preferably (0.08-0.8):1, and more preferably (0.1-0.6):1. Increasing the amount of stabilizer enables the stabilization of a larger oil-water interface, thereby dispersing the dispersed phase into smaller droplets, resulting in a smaller pore size in the obtained polymer porous material.

[0038] Nanoparticles can also enhance the mechanical properties of materials. Rigid nanoparticles can transfer stress from the polymer porous material matrix to the nanoparticles themselves when subjected to force. Therefore, appropriately increasing the amount of stabilizer improves the mechanical properties of the polymer porous material.

[0039] Preferably, an organic base, selected from one or more organic amines, is added to the continuous phase, more preferably from one or more alkylamines, and even more preferably triethylamine. By introducing an organic base, such as triethylamine, the pH of the high internal phase emulsion is adjusted to alkaline, thereby enhancing the storage stability of the high internal phase emulsion.

[0040] In the method for preparing polymer porous materials based on high internal phase emulsion, the linear copolymer is added to a solvent to dissolve, and then a stabilizer and / or organic base are added and stirred to obtain a continuous phase.

[0041] The stirring speed is 500-24000 r / min, preferably 1000-22000 r / min, and more preferably 1500-20000 r / min. The stirring time is 1-40 min, preferably 3-30 min, and more preferably 4-20 min. At the above stirring speeds, it is beneficial to disperse the dispersed phase solvent into droplets with smaller diameters and more uniform dispersion, thus resulting in a porous material with smaller pore size and more uniform distribution.

[0042] The mass-to-volume ratio of the linear copolymer to the organic base is (6-25) g:1 mL, preferably (9-22) g:1 mL, and more preferably (12-19) g:1 mL.

[0043] The dispersed phase is a solution obtained by dissolving a crosslinking agent in water. Preferably, the water is distilled water, deionized water, or ultrapure water.

[0044] The crosslinking agent is selected from one or more of diacylhydrazides and diamine compounds, preferably one or more of adipate diacylhydrazide, oxalate diacylhydrazide, maleic anhydride diacylhydrazide, hydrazine carbonate, m-phenylenediamine, 1,6-hexanediamine and 1,2-cyclohexanediamine, and more preferably adipate diacylhydrazide.

[0045] In the dispersed phase, the concentration of the crosslinking agent is 0.1-2.4 g / L, preferably 0.2-1.8 g / L, and more preferably 0.3-1.2 g / L.

[0046] The molar ratio of the crosslinking agent to the crosslinking monomer is (0.2-1.8):1, preferably (0.4-1.2):1, and more preferably (0.5-0.8):1. In the method, the dispersed phase is added dropwise to the continuous phase and stirred to emulsify, thereby obtaining a stable high internal phase emulsion.

[0047] The high internal phase emulsion is cross-linked and cured at 15-40°C, preferably 18-30°C, and more preferably 20-25°C to obtain a polymer porous material.

[0048] The present invention also provides a polymer porous material prepared by the method for preparing polymer porous materials based on high internal phase emulsion, wherein the average pore size is 1-24 μm, preferably 2-18 μm, more preferably 4-12 μm; and the porosity is 80-99%, preferably 85-97.5%, more preferably 90-96%.

[0049] This invention provides a method for preparing porous polymer materials based on high internal phase emulsions, enabling crosslinking and curing in an emulsion state at room temperature to complete the shaping process of the porous polymer material. First, a linear copolymer containing hydrophobic and hydrophilic components and room-temperature crosslinking side groups is prepared through molecular design and emulsion polymerization. Using a solution containing the linear copolymer as the continuous phase, a water-in-oil high internal phase emulsion is prepared under the action of an inorganic particle stabilizer. This creamy high internal phase emulsion can be arbitrarily shaped on or inside various object surfaces. During natural drying at room temperature, the polymer and crosslinking agent undergo a room-temperature crosslinking reaction, ultimately forming a porous polymer material with a three-dimensional network crosslinked structure.

[0050] The preparation conditions are mild, requiring no special heating, radiation, or other special equipment. The shaping process is easy to control, allowing for arbitrary molding. Energy consumption is low, and there is no need to remove unconverted monomers. The process is simple, and the resulting polymer porous material has high porosity, uniform internal pore distribution, and good adsorption properties. It can be applied to fields such as wastewater purification. This provides a method for preparing polymer porous materials that can be mass-produced using a high internal phase emulsion template method.

[0051] Example

[0052] Example 1

[0053] A linear copolymer was prepared by emulsion polymerization using diacetone acrylamide, acrylic acid, methyl methacrylate, butyl acrylate, and styrene as monomers and ammonium persulfate as initiator, through a pre-emulsification process. The preparation process is as follows:

[0054] Pre-emulsification: Weigh 50g of deionized water, 1g of sodium dodecyl sulfate, and 0.5g of nonylphenol polyoxyethylene ether, and add them to a 500mL three-necked flask. Stir for 15min at 25℃ and 1000r / min. Then weigh 5g of diacetone acrylamide, 3g of acrylic acid, 5g of methyl methacrylate, 10g of butyl acrylate, 77g of styrene, and 0.15g of chain transfer agent n-dodecyl mercaptan into a beaker. Add the mixture dropwise to a four-necked flask using a constant pressure funnel over a period of 40min. After the addition is complete, continue stirring for 30min to complete the pre-emulsification.

[0055] Emulsion polymerization: After pre-emulsification, 80g of deionized water, 0.6g of sodium dodecyl sulfate, 0.4g of nonylphenol polyoxyethylene ether, and 0.2g of sodium bicarbonate were added to a 500mL four-necked flask. The mixture was stirred at 150r / min for 15min at 80℃ under a nitrogen atmosphere. Then, 15g of the pre-emulsion was added. After 5min, 0.2g of ammonium persulfate dissolved in 10g of deionized water was added to the reaction flask. After 5min, an initiator solution prepared from 0.4g of ammonium persulfate and 10g of deionized water was added dropwise, while the remaining pre-emulsion was added dropwise using a constant pressure funnel. The addition was completed in approximately 4 hours. The temperature was then raised to 82℃ and maintained for 1 hour. Heating was then stopped, and the mixture was cooled. The emulsion was filtered through a 200-mesh filter cloth to obtain a copolymer emulsion with a solid content of approximately 40%.

[0056] Copolymer separation and purification: The obtained emulsion was added dropwise to a 5% hot sodium chloride solution to break the emulsion (emulsion:sodium chloride solution = 1:5). The broken emulsion was filtered using a vacuum pump, and the resulting powdered product was washed 3-5 times with warm water to remove residual surfactants and sodium chloride, followed by washing with anhydrous ethanol to remove unreacted monomers. Finally, the product was dried in a forced-air drying oven at 50°C for 12 hours to obtain a random linear copolymer (poly(diacetone acrylamide-co-polyacrylic acid-co-polymethyl methacrylate-co-butyl acrylate-co-polystyrene), with a number average molecular weight of 5 × 10⁻⁶. 4 g / mol.

[0057] At room temperature, 25.0 g of random linear copolymer (poly(diacetone acrylamide-co-polyacrylic acid-co-polymethyl methacrylate-co-polybutyl acrylate-co-polystyrene)) was dissolved in 250 mL of dichloromethane, and 7.5 g of nano zinc oxide (Beijing Honghu United Chemical Products Co., Ltd., particle size 30±10 nm) and 1.7 mL of triethylamine were added and mixed evenly to form a continuous phase for later use.

[0058] Dissolve 0.8 g of adipic acid dihydrazide in 750 mL of deionized water as the dispersed phase.

[0059] First, the continuous phase was stirred at 1500 r / min for 30 s. Then, the dispersed phase was added dropwise over 8 min. After the addition was complete, the mixture was stirred for another 10 min to further emulsify it, resulting in a stable emulsion with a high internal phase.

[0060] The high internal phase emulsion was applied to bricks using a scraper and left at room temperature for 10 days to allow solvent evaporation and cross-linking curing, resulting in a room-temperature shaped porous polymer material A. Its digital photograph is shown below. Figure 1 As shown.

[0061] The microstructure of the polymer porous material A was observed using scanning electron microscopy (SEM), and its SEM image is shown below. Figure 2 As shown. Randomly selected SEM images ( Figure 2 The 50 internal pores in the sample have an average diameter of 4.2 ± 1.3 μm, as calculated.

[0062] The porosity of polymer porous material A was calculated using the density of the high internal phase emulsion and the density of the porous material formed after drying. Density can be calculated using the mass-to-volume ratio. Porosity was calculated using the following formula:

[0063]

[0064] Where P is porosity, %; ρ1 is density of the high internal phase emulsion, g / cm³. 3 ρ2 is the density of the polymer porous material A, in g / cm³. 3 .

[0065] The calculated porosity is 92.9%.

[0066] The polymer porous material A prepared in this embodiment was placed in a mixture of peanut oil and water (the mass ratio of peanut oil to water was 1:1). The peanut oil was adsorbed by the porous structure and oleophilicity of the material itself. After a period of time, the water became clear and transparent. It can be seen that the polymer porous material A can be used to achieve oil-water separation and water purification.

[0067] Example 2

[0068] 0.6 g of the random linear copolymer (poly(diacetone acrylamide-co-polyacrylic acid-co-polymethyl methacrylate-co-polybutyl acrylate-co-polystyrene) prepared in Example 1 was dissolved in 12 mL of dichloromethane, and 0.36 g of nano zinc oxide and 34.7 μL of triethylamine were added. After mixing evenly, a continuous phase was formed for later use.

[0069] Dissolve 19 mg of adipic acid dihydrazide in 48 mL of deionized water as the dispersed phase.

[0070] First, the continuous phase was stirred at 19000 r / min for 10 s. Then, the dispersed phase was added dropwise over 3 min. After the addition was complete, the mixture was stirred for another 2 min to further emulsify it, resulting in a stable high internal phase emulsion. This high internal phase emulsion was then piped into a piping bag and extruded to set its shape. It was then left at room temperature for 7 days to allow the solvent to evaporate and the material to crosslink and solidify, resulting in a room-temperature shaped porous polymer material B.

[0071] The microstructure of the porous polymer material B was observed using scanning electron microscopy (SEM), and its SEM image is shown below. Figure 3 As shown. Calculated according to Example 1, its average pore size is 11.6 ± 4.1 μm, and its porosity is 94.7%.

[0072] The polymer porous material B is immersed in low surface energy silicone oil for 12 hours to allow the silicone oil to fully penetrate into the surface and interior of the porous material. After removal, the oil adhering to the sample surface is wiped off with lint-free paper to prepare a porous liquid-filled smooth surface.

[0073] 10 μL of water, ink, an acidic hydrochloric acid solution with a pH of 1, and a sodium hydroxide solution with a pH of 13 were respectively added to the smooth surface of the polymer porous material with a diameter of 20 mm and a height of 8 mm. All of these liquid contaminants could slide off the smooth surface of the liquid within 1 second without leaving any stains. Figure 4 To assess the self-cleaning properties of the prepared porous fluid-filled smooth surface, based on Figure 4 It is known that porous liquid injection smooth surfaces have good self-cleaning properties against liquid contaminants such as water, ink, acid, and alkali.

[0074] Example 3

[0075] 1.2 g of the random linear copolymer (poly(diacetone acrylamide-co-polyacrylic acid-co-polymethyl methacrylate-co-polybutyl acrylate-co-polystyrene) prepared in Example 1 was dissolved in 12 mL of dichloromethane, and 0.36 g of nano zinc oxide and 69.4 μL of triethylamine were added as a continuous phase for later use.

[0076] Dissolve 37 mg of adipic acid dihydrazide in 48 mL of deionized water as the dispersed phase.

[0077] First, the continuous phase was stirred at 19000 r / min for 10 s. Then, the dispersed phase was added dropwise over 3 min. After the addition was complete, the mixture was stirred for another 2 min to further emulsify it, resulting in a stable high internal phase emulsion. This high internal phase emulsion was poured into a silicone mold and placed at room temperature for 7 days to allow the solvent to evaporate and the material to crosslink and solidify, yielding a room-temperature shaped porous polymer material C.

[0078] The microstructure of the polymer porous material C was observed by scanning electron microscopy, and its scanning electron microscopy image is shown below. Figure 5 As shown. According to the test calculation method of Example 1, its average pore size is 7.7±3.1μm and its porosity is 94.0%.

[0079] The polymer porous material C prepared in this embodiment was placed in hexane, petroleum ether, anhydrous ethanol, peanut oil, lubricating oil, and silicone oil, respectively. The samples were removed periodically, and the organic solvents or oils adhering to the sample surface were wiped clean with lint-free paper. The mass change of the sample before and after oil adsorption was used to characterize the adsorption capacity of the sample. The calculated adsorption capacities of polymer porous material C for hexane, petroleum ether, anhydrous ethanol, peanut oil, lubricating oil, and silicone oil were 4.3, 4.9, 8.2, 6.3, 7.2, and 11.7 g / g, respectively.

[0080] Example 4

[0081] 1.2 g of the random linear copolymer (poly(diacetone acrylamide-co-polyacrylic acid-co-polymethyl methacrylate-co-polybutyl acrylate-co-polystyrene) prepared in Example 1 was dissolved in 12 mL of dichloromethane, and 0.6 g of nano zinc oxide and 69.4 μL of triethylamine were added as a continuous phase for later use.

[0082] Dissolve 37 mg of adipic acid dihydrazide in 48 mL of deionized water as the dispersed phase.

[0083] First, the continuous phase was stirred at 19000 r / min for 10 s. Then, the dispersed phase was added dropwise over 3 min. After the addition was complete, the mixture was stirred for another 2 min to further emulsify it, resulting in a stable high internal phase emulsion. This high internal phase emulsion was then spread onto a polytetrafluoroethylene (PTFE) plate using a scraper and left at room temperature for 7 days to allow the solvent to evaporate and the material to crosslink and cure, yielding a room-temperature shaped porous polymer material D.

[0084] The microstructure of the polymer porous material D was observed by scanning electron microscopy, and its scanning electron microscopy image is shown below. Figure 6As shown. Following the testing and calculation methods in Example 1, the average pore size of the polymer porous material D is 3.8 ± 1.4 μm, and the porosity is 90.9%.

[0085] The thermal stability of the polymer porous material D was characterized by thermogravimetric analysis (TGA) and compared with the thermal stability of the random linear copolymer prepared in Example 1. The TGA curves are shown below. Figure 7 As shown. Tests showed that the random linear polymer prepared in Example 1 completely decomposed at 450°C, while the porous polymer material D did not completely decompose at the same temperature, and even at 600°C, it retained 28% of its mass, indicating that the thermal stability of the porous polymer material D was improved.

[0086] The present invention has been described in detail above with reference to specific embodiments and / or exemplary examples, as well as the accompanying drawings. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. A method for preparing porous polymer materials based on high internal phase emulsions, wherein the method obtains porous polymer materials by crosslinking and curing a linear copolymer high internal phase emulsion, wherein the crosslinking and curing temperature is 15-40℃. The linear copolymer comprises hydrophobic segments, hydrophilic segments, and crosslinked segments, and is prepared by copolymerization of hydrophobic monomers, hydrophilic monomers, and crosslinked monomers. The hydrophobic monomer is selected from one or more of unsaturated hydrocarbon benzene and acrylate; The hydrophilic monomer is selected from one or more of alkenyl monocarboxylic acids, alkenyl dicarboxylic acids, and alkenyl dicarboxylic anhydrides; The crosslinking monomer is a monomer containing room temperature crosslinking groups; The linear copolymer high internal phase emulsion is a stable emulsion obtained by adding a dispersed phase dropwise to a continuous phase and mixing them evenly. The continuous phase is a mixture obtained by dispersing and dissolving the linear copolymer in a solvent; The dispersed phase is a solution obtained by dissolving a crosslinking agent in water.

2. The method according to claim 1, characterized in that, The crosslinking and curing temperature is 18-30℃.

3. The method according to claim 2, characterized in that, The crosslinking and curing temperature is 20-25℃.

4. The method according to claim 1, characterized in that, The hydrophobic monomer is selected from one or more of alkenylbenzene, acrylate and methacrylate; The hydrophilic monomer is selected from one or more of the following: alkenyl monocarboxylic acids with C3-C4 carbon atoms, alkenyl dicarboxylic acids with C4 carbon atoms, and alkenyl dicarboxylic anhydrides with C4 carbon atoms. The crosslinking monomer is selected from one or more of diacetone acrylamide, ethyl acetoacetate methacrylate, and methyl vinyl ketone.

5. The method according to claim 4, characterized in that, The hydrophobic monomer is one or more of styrene, methyl acrylate, butyl acrylate, methyl methacrylate and ethyl methacrylate; The hydrophilic monomer is one or more of acrylic acid, methacrylic acid, maleic acid and maleic anhydride; The crosslinking monomer is diacetone acrylamide.

6. The method according to claim 1, characterized in that, In the linear copolymer, the mass ratio of crosslinking monomer, hydrophilic monomer, and hydrophobic monomer is 1:(0.1-1.9):(6-30); The linear copolymer has a molecular weight of (0.1-4.0)×10⁻⁶. 5 g / mol.

7. The method according to claim 6, characterized in that, In the linear copolymer, the mass ratio of crosslinking monomer, hydrophilic monomer, and hydrophobic monomer is 1:(0.2-1.6):(8-25); The linear copolymer has a molecular weight of (0.2-3.0)×10⁻⁶. 5 g / mol.

8. The method according to claim 7, characterized in that, In the linear copolymer, the mass ratio of crosslinking monomer, hydrophilic monomer, and hydrophobic monomer is 1:(0.3-1.3):(10-20); The linear copolymer has a molecular weight of (0.3-2.0)×10⁻⁶. 5 g / mol.

9. The method according to claim 1, characterized in that, The solvent is selected from one or more of the following: halogenated hydrocarbon solvents, aromatic solvents, and ketone solvents; In the continuous phase, the mass concentration of the linear copolymer is 0.02-0.24 g / mL.

10. The method according to claim 9, characterized in that, The solvent is one or more of the following: chloroalkanes with a carbon number of C1-C3, alkylbenzenes, and alkyl ketones with a carbon number of C3-C5. In the continuous phase, the mass concentration of the linear copolymer is 0.03-0.18 g / mL.

11. The method according to claim 10, characterized in that, The solvent is one or more of dichloromethane, toluene, xylene, and acetone; In the continuous phase, the mass concentration of the linear copolymer is 0.04-0.12 g / mL.

12. The method according to claim 1, characterized in that, A stabilizer is also added to the continuous phase, and the stabilizer is selected from one or more inorganic nanoparticles. An organic base, selected from one or more organic amines, is also added to the continuous phase.

13. The method according to claim 12, characterized in that, The stabilizer is selected from one or more of nano zinc oxide, nano silica and nano hydroxyapatite; The organic base is selected from one or more alkylamines.

14. The method according to claim 13, characterized in that, The stabilizer is nano zinc oxide; The organic base is triethylamine.

15. The method according to claim 1, characterized in that, The crosslinking agent is selected from one or more of dihydrazide compounds and diamine compounds; In the dispersed phase, the concentration of the crosslinking agent is 0.1-2.4 g / L; The molar ratio of the crosslinking agent to the crosslinking monomer is (0.2-1.8):

1.

16. The method according to claim 15, characterized in that, The crosslinking agent is selected from one or more of the following: oxalic acid dihydrazide, oxalic acid dihydrazide, maleic acid dihydrazide, hydrazine carbonate, m-phenylenediamine, 1,6-hexanediamine, and 1,2-cyclohexanediamine; In the dispersed phase, the concentration of the crosslinking agent is 0.2-1.8 g / L; The molar ratio of the crosslinking agent to the crosslinking monomer is (0.4-1.2):

1.

17. The method according to claim 16, characterized in that, The crosslinking agent is adipate dihydrazide; In the dispersed phase, the concentration of the crosslinking agent is 0.3-1.2 g / L; The molar ratio of the crosslinking agent to the crosslinking monomer is (0.5-0.8):

1.

18. A polymer porous material prepared by the method according to any one of claims 1 to 17, characterized in that, Its average pore size is 1-24 μm; its porosity is 80-99%.

19. The polymer porous material according to claim 18, characterized in that, Its average pore size is 2-18 μm; its porosity is 85-97.5%.

20. The polymer porous material according to claim 19, characterized in that, Its average pore size is 4-12 μm; its porosity is 90-96%.

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