A hydrophobic foam and a method for producing the same
Hydrophobic foam materials were prepared by copolymerizing acrylate monomers with acyl chloride polyvinyl alcohol acetal foam materials, which solved the problem of low oil-water emulsion separation efficiency due to surfactant instability and achieved efficient and reusable emulsion separation effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGCHUN INSTITUTE OF APPLIED CHEMISTRY CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2023-07-06
- Publication Date
- 2026-05-29
AI Technical Summary
Existing technologies are insufficient for efficiently separating surfactant-stabilized oil-water emulsions. Traditional methods are inefficient, energy-intensive, and pose secondary pollution problems.
Hydrophobic foam materials are prepared by copolymerizing acrylate monomers with acyl chloride polyvinyl alcohol acetal foam materials. The hydrophobic foam materials are then modified to achieve high-throughput and high-efficiency emulsion separation.
It achieves highly efficient separation of emulsions, with a separation efficiency of ≥99% and a maximum separation throughput of 4.33×10⁵ L m⁻²h⁻¹bar⁻¹, and the material is reusable.
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Figure CN116715810B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of emulsion separation materials technology, and more specifically, to a hydrophobic foam material and its preparation method. Background Technology
[0002] The textile, leather, metallurgical, and petrochemical industries discharge large amounts of oily wastewater, posing a threat to the environment and health. Therefore, how to properly treat oily wastewater is an urgent problem to be solved (Advanced Functional Materials 2011, 21(24), 4699-4704; Nature 2008, 452(7185), 301-310). Oily wastewater is mainly divided into two categories: immiscible oil-water mixtures and surfactant-stabilized oil-water emulsions. Phase-separated oil-water mixtures are easy to treat due to the incompatibility and density difference between oil and water. However, oil-water emulsions are droplets with microstructures (diameter less than 20 μm) and excellent stability, especially when stabilized by surfactants, making the separation of oil-water emulsions challenging. Generally, surfactant-stabilized emulsions are mainly classified into oil-in-water emulsions and water-in-oil emulsions (Langmuir 2014, 30(2), 496-500; Journal of Hazardous Materials 2022, 439, 129567). Traditional removal techniques such as gravity separation, filtration, centrifugation, calcination, flotation, chemical demulsifier treatment, and electrochemical methods suffer from problems such as low efficiency, high energy consumption, and secondary pollution (Advanced Functional Materials 2022, 32(24)). Therefore, in order to effectively separate surfactant-stabilized emulsions, it is necessary to develop new separation strategies, design new structures, and prepare new materials. Summary of the Invention
[0003] In view of this, the purpose of this invention is to provide a hydrophobic foam material and its preparation method. This invention uses acrylate monomers to functionalize and modify acyl chloride polyvinyl alcohol acetal foam materials containing double bonds to obtain hydrophobic foam materials. These hydrophobic foam materials can separate emulsions at high throughput and high efficiency, and can be reused.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] A hydrophobic foam material is obtained by copolymerization of acrylate monomers and acyl chloride polyvinyl alcohol acetal foam material containing double bonds;
[0006] The acyl chloride polyvinyl alcohol acetal foam material containing double bonds is obtained by reacting acyl chloride containing double bonds and polyvinyl alcohol acetal foam material.
[0007] In this invention, the polyvinyl acetal-based foam material is obtained by secondary crosslinking of a polyvinyl alcohol solution and an aldehyde-based crosslinking agent. A preferred method for preparing the polyvinyl acetal-based foam material includes: mixing a polyvinyl alcohol solution, a surfactant, an aldehyde-based crosslinking agent, and a polyvinyl acetal-based porous material under acidic conditions, and curing and crosslinking at 50–80°C to obtain the polyvinyl acetal-based foam material. A more preferred method includes: mixing a polyvinyl alcohol solution, a surfactant, and an aldehyde-based crosslinking agent under acidic conditions to obtain a mixture; placing the polyvinyl acetal-based foam material into the mixture, stirring the mixture until the liquid foam volume reaches its maximum, transferring it to a mold, and placing it in an oven for curing and crosslinking to obtain the polyvinyl acetal-based porous material. The mass concentration of the polyvinyl alcohol solution is 5%–20%. The surfactant includes anionic surfactants and / or nonionic surfactants.
[0008] In this invention, the preparation method of the polyvinyl acetal-based porous material includes:
[0009] Under acidic conditions, a polyvinyl alcohol solution, a surfactant, and an aldehyde crosslinking agent are mixed and cured and crosslinked at 50–80°C to obtain a polyvinyl alcohol acetal-based porous material; the mass concentration of the polyvinyl alcohol solution is 5%–20%; the surfactant includes anionic surfactants and / or nonionic surfactants.
[0010] Polyvinyl alcohol (PVA) is a highly hydrophilic, biocompatible, thermally stable, and environmentally friendly polymer. PVA-based foam materials contain a large number of easily modifiable functional hydroxyl groups.
[0011] The hydrophobic foam material obtained by this invention has a pore size of 18-25 μm and a porosity of 70%-80%.
[0012] The present invention also provides a method for preparing the above-mentioned hydrophobic foam material, comprising: copolymerizing acrylate monomers with acyl chloride polyvinyl alcohol acetal foam material containing double bonds in the presence of an initiator to obtain the hydrophobic foam material;
[0013] The acyl chloride polyvinyl alcohol acetal foam material containing double bonds is obtained by reacting acyl chloride containing double bonds and polyvinyl alcohol acetal foam material.
[0014] In this invention, the reaction between the acyl chloride containing double bonds and the polyvinyl alcohol acetal foam material is carried out in the presence of an acylation catalyst;
[0015] The acylation catalyst includes one or more of pyridine, 4-dimethylaminopyridine, diethylamine, or triethylamine;
[0016] The mass ratio of the acylation catalyst to the polyvinyl acetal foam material is (0.2-0.8):2.
[0017] In this invention, the polyvinyl alcohol acetal foam material is obtained by two crosslinking processes, including a polyvinyl alcohol solution and an aldehyde crosslinking agent; the time for each crosslinking process is 4 to 20 hours.
[0018] In this invention, the preparation method of the polyvinyl alcohol acetal-based foam material includes: mixing a polyvinyl alcohol solution, a surfactant, an aldehyde crosslinking agent, and a polyvinyl alcohol acetal-based porous material under acidic conditions, and curing and crosslinking at 50–80°C; the crosslinking time is 4–20 h; the mass ratio of the polyvinyl alcohol solution, surfactant, and aldehyde crosslinking agent is 100:1:(2–5); the mass concentration of the polyvinyl alcohol solution is 5%–20%, preferably 6%–10%; the surfactant includes anionic surfactants and / or... Alternatively, a nonionic surfactant may be used; the surfactant preferably includes one or more of sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dibutylnaphthalene sulfonate, polyethylene glycol octylphenyl ether, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate polyoxyethylene ether, and sorbitan monooleate; the aldehyde crosslinking agent includes one or more of formaldehyde, glyoxal, glutaraldehyde, and paraformaldehyde; the acidic conditions are preferably provided by one or more of formic acid, hydrochloric acid, phosphoric acid, and sulfuric acid.
[0019] In this invention, the preferred method for preparing the polyvinyl acetal foam material includes: mixing a polyvinyl alcohol solution, a surfactant, and an aldehyde crosslinking agent under acidic conditions to obtain a mixture; placing the polyvinyl acetal foam material into the mixture, stirring the mixture until the liquid foam volume reaches its maximum, transferring it into a mold, and placing it in an oven for curing and crosslinking.
[0020] In this invention, the preparation method of the polyvinyl acetal-based porous material includes:
[0021] Under acidic conditions, a polyvinyl alcohol solution, a surfactant, and an aldehyde-based crosslinking agent are mixed and cured and crosslinked at 50–80°C to obtain a polyvinyl alcohol acetal-based porous material; the crosslinking time is 4–20 h; the mass ratio of the polyvinyl alcohol solution, surfactant, and aldehyde-based crosslinking agent is 100:1:(2–5); the mass concentration of the polyvinyl alcohol solution is 5%–20%, preferably 6%–10%; the surfactant includes anionic surfactants and / or nonionic surfactants; the surfactant preferably includes one or more of sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dibutylnaphthalene sulfonate, polyethylene glycol octylphenyl ether, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate polyoxyethylene ether, and sorbitan monooleate; the aldehyde-based crosslinking agent includes one or more of formaldehyde, glyoxal, glutaraldehyde, and paraformaldehyde; the acidic conditions are preferably provided by one or more of formic acid, hydrochloric acid, phosphoric acid, and sulfuric acid.
[0022] In this invention, the copolymerization temperature is 50–100°C, preferably 50–80°C; the copolymerization time is 4–8 hours.
[0023] In this invention, the mass ratio of the acrylate monomer to the acyl chloride polyvinyl alcohol acetal foam material containing double bonds is 1:(1-5), more preferably 1:(2-5), and even more preferably 1:2 or 1:5.
[0024] In this invention, the mass ratio of the initiator to the acyl chloride polyvinyl alcohol acetal foam material containing double bonds is 1:(100-1000), more preferably 1:(200-500); the initiator includes organic peroxide initiators and / or azo initiators; the initiator includes one or more of benzoyl peroxide, dodecyl peroxide, azobisisobutyronitrile, and azobisisoheptanenitrile.
[0025] In this invention, the acrylate monomers include one or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and hexyl methacrylate.
[0026] In this invention, the copolymerization is preferably carried out in the presence of an organic solvent; the organic solvent is one or more of toluene, methanol, dimethyl sulfoxide, dimethylformamide, acetonitrile and N-methylpyrrolidone, preferably toluene, methanol, dimethyl sulfoxide or acetonitrile; the volume ratio of the organic solvent to the mass of the polyvinyl acetal foam material is (8-15) mL:1 g.
[0027] In this invention, after the copolymerization is completed, the system is dried; the drying is preferably carried out under vacuum conditions.
[0028] This invention uses polyvinyl alcohol as a raw material to prepare polyvinyl alcohol formal (PVF) foam with a macroporous structure as a base material; then, secondary crosslinking of PVA solution is performed to manufacture PVF / PVA foam materials with an interpenetrating network structure and smaller pore size. First, active unsaturated olefin double bond groups are introduced into the PVF / PVA foam matrix through an acylation reaction to obtain methacryloyl chloride-functionalized PVF / PVA-Mac foam materials. Then, methacrylate monomers are copolymerized and grafted onto PVF / PVA-Mac to obtain a series of PVF / PVA-Mac-PXMA foam materials, and their wettability, mechanical properties, continuous emulsion separation performance, demulsification performance, recyclability, and long-term stability are characterized. Attached Figure Description
[0029] Figure 1 This is a flowchart of the preparation process of hydrophobic foam material in Embodiment 1 of the present invention. Detailed Implementation
[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0031] To further illustrate the present invention, the following embodiments are provided for detailed description. All raw materials used in the following embodiments of the present invention are commercially available products.
[0032] The emulsion separation performance test of the present invention includes: accurately weighing a certain amount of the foam material obtained above and filling it into a self-made emulsion separation test device to conduct an emulsion separation performance test experiment, wherein the emulsion used is a Span-80 stabilized water / dichloromethane emulsion (V 水 / V 二氯甲烷 =1 / 99), collect the effluent, and measure the dichloromethane content in the effluent by gas chromatography headspace method.
[0033] The polyvinyl alcohol solution used in this embodiment of the invention is prepared by the following steps:
[0034] Polyvinyl alcohol powder was dissolved in deionized water to prepare a polyvinyl alcohol aqueous solution with a mass fraction of 6% to 10%; the degree of polymerization of the polyvinyl alcohol powder was 1700 and the molecular weight was 75000.
[0035] Example 1
[0036] The preparation process of the hydrophobic foam material in this embodiment is as follows: Figure 1 As shown, the preparation method specifically includes the following steps:
[0037] (1) Mix 1000 mL of 8.0% (w / w) polyvinyl alcohol aqueous solution, 10 g of sodium dodecyl sulfate, and 500 mL of 10.0% (w / w) sulfuric acid aqueous solution, stir for 2 h, and then add 50 g of formaldehyde aqueous solution. Continue stirring for 30 min until the liquid foam volume reaches its maximum, then cure and crosslink in a 50℃ oven for 12 h. Remove, wash, and dry to constant weight to obtain polyvinyl alcohol acetal-based porous material. The average pore size of the obtained material is 60 μm, and the porosity is 80%.
[0038] (2) Preparation of PVF / PVA: Mix 500 mL of 6.0% (w / w) polyvinyl alcohol aqueous solution, 5 g of sodium dodecyl sulfate, and 500 mL of 10.0% (w / w) sulfuric acid aqueous solution, stir for 1 h, and add 20 g of formaldehyde aqueous solution. Continue stirring for 30 min, immerse 50 g of polyvinyl alcohol acetal foam in the mixture, and after reaching saturation absorption, cure and crosslink in an oven at 50 °C for 12 h. Remove, wash, and dry to constant weight to obtain secondary crosslinked polyvinyl alcohol acetal foam material.
[0039] (3) Preparation of PVF / PVA-Mac: 50g of secondary cross-linked polyvinyl alcohol acetal foam material, 0.1mol of pyridine and 1mL of methacryloyl chloride were added to 500mL of acetonitrile solution and reacted at 30℃ for 4h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain acyl chloride polyvinyl alcohol acetal foam material.
[0040] (4) Preparation of PVF / PVA-Mac-PMMA: 50g of acyl chloride polyvinyl alcohol acetal foam material, 0.1mol of methyl methacrylate and 0.1g of benzoyl peroxide were added to 500mL of toluene solution and reacted at 50℃ under a nitrogen atmosphere for 6h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain hydrophobic polyvinyl alcohol acetal foam material. The average pore size of the obtained material was 25μm and the porosity was 75%.
[0041] (5) Emulsion separation performance test: The emulsion separation efficiency of the foam material obtained in this embodiment is ≥99%, and the maximum separation flux can reach 4.29×10⁻⁶. 5 L m -2 h -1 bar -1 After ten cycles, the separation flux remained at 4.00 × 10⁻⁶. 5 Lm -2 h -1 bar -1 All of the above separation efficiencies are ≥99%.
[0042] Example 2
[0043] (1) Mix 2000 mL of a 6.0% (w / w) polyvinyl alcohol aqueous solution, 20 g of sodium dodecyl sulfonate, and 500 mL of a 20.0% (w / w) sulfuric acid aqueous solution, stir for 1 h, and then add 40 g of glutaraldehyde aqueous solution. Continue stirring for 30 min until the liquid foam volume reaches its maximum, then cure and crosslink in a 60℃ oven for 8 h. Remove, wash, and dry to constant weight to obtain a polyvinyl alcohol acetal-based porous material. The average pore size of the obtained material is 70 μm, and the porosity is 85%.
[0044] (2) Mix 1000 mL of a 10.0% (w / w) polyvinyl alcohol aqueous solution, 5 g of sodium dodecyl sulfonate, and 500 mL of a 20.0% (w / w) hydrochloric acid aqueous solution, stir for 1 h, and add 40 g of glutaraldehyde aqueous solution. Continue stirring for 30 min, immerse 100 g of polyvinyl alcohol acetal foam in the mixture, and after reaching saturation absorption, cure and crosslink in a 60℃ oven for 8 h. Remove, wash, and dry to constant weight to obtain a secondary crosslinked polyvinyl alcohol acetal foam material.
[0045] (3) 100g of secondary cross-linked polyvinyl alcohol acetal foam material, 0.5mol of triethylamine and 5mL of methacryloyl chloride were added to 1000mL of acetone solution and reacted at 50℃ for 6h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain acyl chloride polyvinyl alcohol acetal foam material.
[0046] (4) 100g of acyl chloride polyvinyl alcohol acetal foam material, 0.2mol of methyl methacrylate and 0.2g of dodecyl peroxide were added to 1000mL of toluene solution and reacted at 60℃ under a nitrogen atmosphere for 8h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain hydrophobic polyvinyl alcohol acetal foam material. The average pore size of the obtained material was 22μm and the porosity was 76%.
[0047] (5) Emulsion separation performance test: The emulsion separation efficiency of the foam material obtained in this embodiment is ≥99%, and the maximum separation flux can reach 4.25×10⁻⁶. 5 L m -2 h -1 bar -1 After ten cycles, the separation flux remained at 4.00 × 10⁻⁶. 5 L m - 2 h -1 bar -1 All of the above separation efficiencies are ≥99%.
[0048] Example 3
[0049] (1) Mix 800 mL of 8.0% (w / w) polyvinyl alcohol aqueous solution, 8 g of polyethylene glycol octylphenyl ether, and 800 mL of 30.0% (w / w) phosphoric acid aqueous solution, stir for 1 h, and then add 30 g of glyoxal aqueous solution. Continue stirring for 30 min until the liquid foam volume reaches its maximum, then cure and crosslink in an oven at 80℃ for 4 h. Remove, wash, and dry to constant weight to obtain polyvinyl alcohol acetal-based porous material. The average pore size of the obtained material is 74 μm, and the porosity is 78%.
[0050] (2) Mix 800 mL of 8.0% (w / w) polyvinyl alcohol aqueous solution, 8 g of polyethylene glycol octylphenyl ether, and 800 mL of 30.0% (w / w) phosphoric acid aqueous solution, stir for 1 h, and add 30 g of glyoxal aqueous solution. Continue stirring for 30 min, immerse 80 g of polyvinyl alcohol acetal foam in the mixture, and after reaching saturation absorption, cure and crosslink in an oven at 80 °C for 4 h. Remove, wash, and dry to constant weight to obtain secondary crosslinked polyvinyl alcohol acetal foam material.
[0051] (3) 80g of secondary cross-linked polyvinyl alcohol acetal foam material, 0.3mol of 4-dimethylaminopyridine and 10mL of methacryloyl chloride were added to 800mL of toluene solution and reacted at 50℃ for 8h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain acyl chloride polyvinyl alcohol acetal foam material.
[0052] (4) 80g of acyl chloride polyvinyl alcohol acetal foam material, 0.4mol of propyl methacrylate and 0.3g of azobisisobutyronitrile were added to 800mL of methanol solution and reacted at 80℃ under a nitrogen atmosphere for 4h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain hydrophobic polyvinyl alcohol acetal foam material. The average pore size of the obtained material was 18μm and the porosity was 78%.
[0053] (5) Emulsion separation performance test: The emulsion separation efficiency of the foam material obtained in this embodiment is ≥99%, and the maximum separation flux can reach 4.33×10⁻⁶. 5 L m -2 h -1 bar -1 After ten cycles, the separation flux remained at 4.00 × 10⁻⁶. 5 L m - 2 h -1 bar -1 All of the above separation efficiencies are ≥99%.
[0054] Example 4
[0055] (1) Mix 1000 mL of a 10.0% (w / w) polyvinyl alcohol aqueous solution, 10 g of sorbitan monolaurate, and 1000 mL of a 40.0% (w / w) sulfuric acid aqueous solution, stir for 1 h, and then add 40 g of formaldehyde aqueous solution. Continue stirring for 30 min until the liquid foam volume reaches its maximum, then cure and crosslink in an oven at 80 °C for 6 h. Remove, wash, and dry to constant weight to obtain a polyvinyl alcohol acetal-based porous material. The average pore size of the obtained material is 70 μm, and the porosity is 82%.
[0056] (2) Mix 1000 mL of a 10.0% (w / w) polyvinyl alcohol aqueous solution, 10 g of sorbitan monolaurate, and 1000 mL of a 40.0% (w / w) sulfuric acid aqueous solution, stir for 1 h, and add 40 g of formaldehyde aqueous solution. Continue stirring for 30 min, then immerse 100 g of polyvinyl alcohol acetal foam in the mixture. After reaching saturation absorption, cure and crosslink in an oven at 80 °C for 6 h. Remove, wash, and dry to constant weight to obtain a secondary crosslinked polyvinyl alcohol acetal foam material.
[0057] (3) 100g of secondary cross-linked polyvinyl alcohol acetal foam material, 0.5mol of pyridine and 10mL of methacryloyl chloride were added to 1000mL of N,N-dimethylformamide solution and reacted at 60℃ for 8h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain acyl chloride polyvinyl alcohol acetal foam material.
[0058] (4) 100g of acyl chloride polyvinyl alcohol acetal foam material, 0.5mol of butyl methacrylate and 0.4g of azobisisobutyronitrile were added to 1000mL of methanol solution and reacted at 70℃ under a nitrogen atmosphere for 6h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain hydrophobic polyvinyl alcohol acetal foam material. The average pore size of the obtained material was 22μm and the porosity was 78%.
[0059] (5) Emulsion separation performance test: In this embodiment, the emulsion separation efficiency of the foam material is ≥99%, and the maximum separation flux can reach 4.19×10⁻⁶. 5 L m -2 h -1 bar -1 After ten cycles, the separation flux remained at 4.00 × 10⁻⁶. 5 L m - 2 h -1 bar -1 All of the above separation efficiencies are ≥99%.
[0060] Example 5
[0061] (1) Mix 1000 mL of a 6.0% (w / w) polyvinyl alcohol aqueous solution, 10 g of sorbitan monopalmitate, and 1000 mL of a 40.0% (w / w) phosphoric acid aqueous solution, stir for 1 h, and then add 30 g of formaldehyde aqueous solution. Continue stirring for 30 min until the liquid foam volume reaches its maximum, then cure and crosslink in a 60℃ oven for 10 h. Remove, wash, and dry to constant weight to obtain a polyvinyl alcohol acetal-based porous material. The average pore size of the obtained material is 72 μm, and the porosity is 80%.
[0062] (2) Mix 1000 mL of a 6.0% (w / w) polyvinyl alcohol aqueous solution, 10 g of sorbitan monopalmitate, and 1000 mL of a 40.0% (w / w) phosphoric acid aqueous solution, stir for 1 h, and add 30 g of formaldehyde aqueous solution. Continue stirring for 30 min, immerse 100 g of polyvinyl alcohol acetal foam in the mixture, and after reaching saturation absorption, cure and crosslink in a 60℃ oven for 10 h. Remove, wash, and dry to constant weight to obtain a secondary crosslinked polyvinyl alcohol acetal foam material.
[0063] (3) 100g of secondary cross-linked polyvinyl alcohol acetal foam material, 0.5mol of pyridine and 10mL of methacryloyl chloride were added to 1000mL of N-methyl-2-pyrrolidone solution and reacted at 60℃ for 8h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain acyl chloride polyvinyl alcohol acetal foam material.
[0064] (4) 100g of acyl chloride polyvinyl alcohol acetal foam material, 0.5mol of hexyl methacrylate and 0.2g of azobisisobutyronitrile were added to 1000mL of methanol solution and reacted at 80℃ under a nitrogen atmosphere for 6h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain hydrophobic polyvinyl alcohol acetal foam material. The average pore size of the obtained material was 21μm and the porosity was 74%.
[0065] (5) Emulsion separation performance test: In this embodiment, the emulsion separation efficiency of the foam material is ≥99%, and the maximum separation flux can reach 4.19×10⁻⁶. 5 L m -2 h -1 bar -1 After ten cycles, the separation flux remained at 4.00 × 10⁻⁶. 5 L m - 2 h -1 bar -1 All of the above separation efficiencies are ≥99%.
[0066] Example 6
[0067] (1) Mix 1000 mL of a 6.0% (w / w) polyvinyl alcohol aqueous solution, 10 g of sorbitan monostearate, and 1000 mL of a 40.0% (w / w) formic acid aqueous solution, stir for 1 h, and then add 40 g of formaldehyde aqueous solution. Continue stirring for 30 min until the liquid foam volume reaches its maximum, then cure and crosslink in an oven at 80 °C for 8 h. Remove, wash, and dry to constant weight to obtain a polyvinyl alcohol acetal-based porous material. The average pore size of the obtained material is 74 μm, and the porosity is 82%.
[0068] (2) Mix 1000 mL of a 6.0% (w / w) polyvinyl alcohol aqueous solution, 10 g of sorbitan monostearate, and 1000 mL of a 40.0% (w / w) formic acid aqueous solution, stir for 1 h, and add 40 g of formaldehyde aqueous solution. Continue stirring for 30 min, then immerse 100 g of polyvinyl alcohol acetal foam in the mixture. After reaching saturation absorption, cure and crosslink in an oven at 80 °C for 8 h. Remove, wash, and dry to constant weight to obtain a secondary crosslinked polyvinyl alcohol acetal foam material.
[0069] (3) 100g of secondary cross-linked polyvinyl alcohol acetal foam material, 0.5mol of triethylamine and 10mL of methacryloyl chloride were added to 1000mL of dimethyl sulfoxide solution and reacted at 60℃ for 8h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain acyl chloride polyvinyl alcohol acetal foam material.
[0070] (4) 100g of acyl chloride polyvinyl alcohol acetal foam material, 0.5mol of methyl methacrylate and 0.1g of azobisisobutyronitrile were added to 1000mL of acetonitrile solution and reacted at 80℃ under a nitrogen atmosphere for 6h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain hydrophobic polyvinyl alcohol acetal foam material. The average pore size of the obtained material was 24μm and the porosity was 76%.
[0071] (5) Emulsion separation performance test: The emulsion separation efficiency of the foam material obtained in this embodiment is ≥99%, and the maximum separation flux can reach 4.25×10⁻⁶. 5 L m -2 h -1 bar -1 After ten cycles, the separation flux remained at 4.00 × 10⁻⁶. 5 L m - 2 h -1 bar -1 All of the above separation efficiencies are ≥99%.
[0072] Example 7
[0073] (1) Mix 1000 mL of a 6.0% (w / w) polyvinyl alcohol aqueous solution, 10 g of sorbitan monooleate polyoxyethylene ether, and 1000 mL of a 30.0% (w / w) formic acid aqueous solution, stir for 1 h, and then add 40 g of glutaraldehyde aqueous solution. Continue stirring for 30 min until the liquid foam volume reaches its maximum, then cure and crosslink in an oven at 80 °C for 8 h. Remove, wash, and dry to constant weight to obtain a polyvinyl alcohol acetal-based porous material. The average pore size of the obtained material is 75 μm, and the porosity is 80%.
[0074] (2) Mix 1000 mL of a 6.0% (w / w) polyvinyl alcohol aqueous solution, 10 g of sorbitan monooleate polyoxyethylene ether, and 1000 mL of a 30.0% (w / w) acetic acid aqueous solution, stir for 1 h, and add 40 g of glutaraldehyde aqueous solution. Continue stirring for 30 min, immerse 100 g of polyvinyl alcohol acetal foam in the mixture, and after reaching saturation absorption, cure and crosslink in an oven at 80 °C for 8 h. Remove, wash, and dry to constant weight to obtain a secondary crosslinked polyvinyl alcohol acetal foam material.
[0075] (3) 100g of secondary cross-linked polyvinyl alcohol acetal foam material, 0.5mol of 4-dimethylaminopyridine and 10mL of methacryloyl chloride were added to 1000mL of acetonitrile solution and reacted at 60℃ for 8h. After the sample was taken out, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain acyl chloride polyvinyl alcohol acetal foam material.
[0076] (4) 100g of acyl chloride polyvinyl alcohol acetal foam material, 0.5mol of ethyl methacrylate and 0.1g of benzoyl peroxide were added to 1000mL of acetonitrile solution and reacted at 80℃ under a nitrogen atmosphere for 6h. After the sample was removed, it was washed with acetonitrile and dried in a vacuum oven to constant weight to obtain hydrophobic polyvinyl alcohol acetal foam material. The average pore size of the obtained material was 20μm and the porosity was 74%.
[0077] (5) Emulsion separation performance test: The emulsion separation efficiency of the foam material obtained in this embodiment is ≥99%, and the maximum separation flux can reach 4.33×10⁻⁶. 5 L m -2 h -1 bar -1 After ten cycles, the separation flux remained at 4.00 × 10⁻⁶. 5 L m - 2 h -1 bar -1 All of the above separation efficiencies are ≥99%.
[0078] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A hydrophobic foam material, characterized in that, It is obtained by copolymerization of acrylate monomers and acyl chloride polyvinyl alcohol acetal foam materials containing double bonds; the acrylate monomers include one or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and hexyl methacrylate. The acyl chloride polyvinyl alcohol acetal foam material containing double bonds is obtained by reacting acyl chloride containing double bonds and polyvinyl alcohol acetal foam material. The preparation method of the polyvinyl acetal-based foam material includes: Under acidic conditions, a polyvinyl alcohol solution, a surfactant, an aldehyde crosslinking agent, and a polyvinyl alcohol acetal porous material are mixed and cured and crosslinked at 50~80℃ to obtain a polyvinyl alcohol acetal foam material. The preparation method of the polyvinyl acetal-based porous material includes: Under acidic conditions, a polyvinyl alcohol solution, a surfactant, and an aldehyde-based crosslinking agent are mixed and cured and crosslinked at 50-80°C to obtain a polyvinyl alcohol acetal-based porous material.
2. The hydrophobic foam material according to claim 1, characterized in that, The hydrophobic foam material has a pore size of 18-25 μm and a porosity of 70%-80%.
3. A method for preparing a hydrophobic foam material, characterized in that, include: In the presence of an initiator, acrylate monomers are copolymerized with acyl chloride polyvinyl alcohol acetal foam materials containing double bonds to obtain hydrophobic foam materials; the acrylate monomers include one or more of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and hexyl methacrylate. The acyl chloride polyvinyl alcohol acetal foam material containing double bonds is obtained by reacting acyl chloride containing double bonds and polyvinyl alcohol acetal foam material. The preparation method of the polyvinyl acetal-based foam material includes: Under acidic conditions, a polyvinyl alcohol solution, a surfactant, an aldehyde crosslinking agent, and a polyvinyl alcohol acetal porous material are mixed and cured and crosslinked at 50~80℃ to obtain a polyvinyl alcohol acetal foam material. The preparation method of the polyvinyl acetal-based porous material includes: Under acidic conditions, a polyvinyl alcohol solution, a surfactant, and an aldehyde-based crosslinking agent are mixed and cured and crosslinked at 50-80°C to obtain a polyvinyl alcohol acetal-based porous material.
4. The method for preparing the hydrophobic foam material according to claim 3, characterized in that, The reaction of the acyl chloride containing double bonds and the polyvinyl alcohol acetal foam material is carried out in the presence of an acylation catalyst. The acylation catalyst includes one or more of pyridine, 4-dimethylaminopyridine, diethylamine, or triethylamine.
5. The method for preparing the hydrophobic foam material according to claim 3, characterized in that, The mass concentration of the polyvinyl alcohol solution is 5%~20%; The surfactants include anionic surfactants and / or nonionic surfactants; The aldehyde-based crosslinking agent includes one or more of formaldehyde, glyoxal, glutaraldehyde, and paraformaldehyde.
6. The method for preparing the hydrophobic foam material according to claim 3, characterized in that, The mass ratio of the acrylate monomer to the acyl chloride polyvinyl alcohol acetal foam material containing double bonds is 1:(1~5).
7. The method for preparing the hydrophobic foam material according to claim 3, characterized in that, The copolymerization temperature is 50~100℃; the copolymerization time is 6~8h.