Sulfonated phthalazinone structure-containing polyarylether blended ultrafiltration membrane and preparation method thereof

Abstract

The invention belongs to the technical field of ultrafiltration membranes, and discloses a sulfonated polyarylether blended ultrafiltration membrane containing a phthalazinone structure and a preparation method of the sulfonated polyarylether blended ultrafiltration membrane. The preparation method comprises the following steps: taking sulfonated polyarylether resin containing the phthalazinone structure and polyarylether resin containing the phthalazinone structure as membrane materials, adding an additive and a solvent, preparing a membrane casting solution, and preparing the blended ultrafiltration membrane by adopting a non-solvent induced phase separation method. Since the main chain of the sulfonated polyarylether containing the phthalazinone structure contains a full-aromatic distorted and non-coplanar structure, the sulfonated polyarylether containing the phthalazinone structure has excellent heat resistance and chemical stability and also has good hydrophilicity, so that the blended ultrafiltration membrane prepared from the sulfonated polyarylether containing the phthalazinone structure has good permeability, selectivity, hydrophilicity and heat resistance; good application prospects are realized in the field of water treatment.

Description

Technical Field

[0001] This invention belongs to the field of ultrafiltration membrane technology and relates to sulfonated polyarylene ether blend ultrafiltration membrane containing diazanaphthone structure and its preparation method. Background Technology

[0002] Ultrafiltration (UF) is a membrane separation technology that uses porous membranes to purify, separate, or concentrate solutions. It offers advantages such as low operating pressure, high flow rate, high separation efficiency, environmental friendliness, ease of operation, and low investment costs, making it widely used in water treatment, advanced wastewater treatment and water resource recycling, electronics, food industry, chemical separation, and biopharmaceuticals. UF membranes have a molecular weight cutoff of 500-500,000 and a pore size of 0.002 µm-0.1 µm, capable of retaining large molecules, bacteria, proteins, viruses, and other substances. An ideal UF membrane should possess both high water flux and high rejection rate; the structure of the membrane material plays a crucial role in both. Currently, the main materials for UF membranes are still polyarylethersulfones, including polysulfone and polyethersulfone. Both materials exhibit good acid and alkali resistance, thermal stability, and mechanical properties. However, due to the hydrophobicity of polyarylethersulfone, the membrane is susceptible to fouling by organic pollutants and microorganisms during operation, leading to reduced membrane flux and shortened lifespan. Furthermore, its heat resistance and chemical stability still require further improvement.

[0003] Polyethersulfone containing a diazanaphthone structure is a novel type of polyarylethersulfone. Its polymer backbone contains a fully aromatic, twisted, non-coplanar structure, exhibiting high-temperature resistance, solubility, and excellent overall performance. Polyethersulfone containing a diazanaphthone structure has been used to prepare high-performance ultrafiltration membranes (CN200910220545.2, CN201711016692.9, CN202010965644.X) and composite membrane bases (Journal of Membrane Science, 679, 122537 (2024), Separation and Purification Technology, 362, 131652, (2024), Journal of Materials Science, 57, 21251-21264 (2022),) demonstrating good separation performance and high-temperature resistance.

[0004] Polyethersulfone (PES) blends containing diazanaphthone structures are used to prepare PES blend ultrafiltration membranes. By enhancing the membrane's hydrophilicity, a tightly bound water layer can be formed in aqueous media, reducing the interaction between the membrane and contaminants, hindering contaminant deposition on the membrane surface, and improving the antifouling properties of the ultrafiltration membrane. Furthermore, the sulfonic acid groups provide transport channels for water molecules within the membrane, thereby simultaneously improving the permeation performance of the ultrafiltration membrane. PES blend ultrafiltration membranes show promising application prospects in the field of water treatment. Summary of the Invention

[0005] This invention addresses the shortcomings of existing polysulfone or polyethersulfone membrane materials in terms of poor high-temperature performance by proposing a sulfonated diazanaphthone-containing polyaryl ether blend ultrafiltration membrane and its preparation method. It uses high-temperature resistant and soluble sulfonated diazanaphthone-containing polyaryl ether resin and diazanaphthone-containing polyaryl ether resin as membrane materials to prepare a blend ultrafiltration membrane with high selectivity and high temperature resistance.

[0006] The technical solution of the present invention:

[0007] A sulfonated polyarylene ether blend ultrafiltration membrane containing a diazanaphthone structure, wherein the structural formula of the polyarylene ether containing the diazanaphthone structure is as follows:

[0008]

[0009] Among them, R1, R2, R3 and R4 are hydrogen atoms, halogen atoms, methyl, aryl or sulfonic acid groups, and R1, R2, R3 and R4 may be the same or different;

[0010] Ar1 is one or more of the following structures:

[0011] , , , .

[0012] Ar2 can be one or more of the following structures:

[0013] , , ,

[0014] , , .

[0015] The structural formula of sulfonated diazanaphthone-containing polyarylene ethers is as follows:

[0016]

[0017] Ar3 can be one or more of the following structures:

[0018] , , ,

[0019] , .

[0020] A method for preparing a sulfonated diazanaphthone-containing polyaryl ether blend ultrafiltration membrane, using sulfonated diazanaphthone-containing polyaryl ether resin and diazanaphthone-containing polyaryl ether resin as membrane materials, employs a solvent-inducing phase separation method to prepare the blend ultrafiltration membrane, the steps of which are as follows:

[0021] (1) Sulfonated polyarylene ether containing diazanaphthone structure, polyarylene ether membrane material containing diazanaphthone structure, and additives are dissolved in a solvent to prepare a casting solution; the total mass fraction of sulfonated polyarylene ether containing diazanaphthone structure and polyarylene ether containing diazanaphthone structure in the casting solution is 5~30%, and the mass fraction of additives is 2~25%; the mass ratio of sulfonated polyarylene ether containing diazanaphthone structure and polyarylene ether containing diazanaphthone structure in the casting solution is 1:99~1:1, for example, 1:99, 1:80, 1:60, 1:50, 1:30, 1:20, 1:10, 1:5, 1:4, 1:2, 1:1.5 or 1:1;

[0022] (2) Pour the casting solution onto a glass plate or non-woven fabric, scrape it with a scraper to form a nascent membrane of a certain thickness, leave it in the air for 5-60 s, place it in a gel bath at 5-60 ℃, and soak it in deionized water to remove solvent and additives, thereby obtaining a sulfonated polyarylene ether blend ultrafiltration membrane containing a diazanaphthone structure.

[0023] The ion exchange capacity of the sulfonated diazonaphthone-containing polyarylether membrane material in the casting solution is [not specified]. The preferred ion exchange capacity of sulfonated polyarylether membrane materials containing diazanaphthone structure is [value missing]. .

[0024] The solvent used to prepare the casting solution is one or a mixture of two or more of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-1-pyrrolidone, with N,N-dimethylacetamide and / or N-methyl-1-pyrrolidone being preferred solvents.

[0025] The additive can be one or a mixture of two or more of the following: small organic molecules, polyvinylpyrrolidone, polyethylene glycol, lithium chloride, and lithium nitrate. The small organic molecule additive is ethylene glycol, ethylene glycol methyl ether, diethylene glycol, methanol, ethanol, propanol, butanol, acetone, butanone, propylene glycol, glycerol, diethyl ether, dioxane, tetrahydrofuran, formic acid, acetic acid, oxalic acid, or ethyl acetate. Preferred additives include ethylene glycol, ethylene glycol methyl ether, methanol, ethanol, propanol, acetone, butanone, diethyl ether, tetrahydrofuran, formic acid, or acetic acid.

[0026] In this invention, the film is left in the air for 5 to 60 seconds, preferably 5 to 15 seconds, during the film-forming process.

[0027] The gel bath used in this invention is deionized water, and the gel bath temperature is 5~60 ℃, preferably 10~30 ℃.

[0028] The blended ultrafiltration membrane is soaked in deionized water to fully remove solvents and additives.

[0029] The beneficial effects of this invention are as follows: This invention prepares a sulfonated polyarylene ether blend ultrafiltration membrane containing a diazanaphthone structure. This type of ultrafiltration membrane has the characteristics of high flux, high rejection rate, high temperature resistance, and excellent chemical stability. It can be used directly in the field of ultrafiltration separation, or it can be used as a base membrane for the preparation of composite dehumidification membranes, composite nanofiltration membranes, composite reverse osmosis membranes, and gas separation membranes, etc. Attached Figure Description

[0030] Figure 1 The image shown is a cross-sectional electron microscope image of the sulfonated polyarylene ether blend ultrafiltration membrane containing a diazanaphthone structure obtained in Example 1, with a scale of 100 μm. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0032] Comparative example:

[0033] 15% (w / w) of poly(phenylene ether sulfone) (PPESS) and 5% (w / w) of ethylene glycol methyl ether were added to N,N-dimethylacetamide as a membrane-forming solvent and stirred until completely dissolved. The solution was then filtered through a 400-mesh filter to remove impurities. After vacuum degassing, the solution was allowed to stand. The casting solution was then poured onto a glass plate and scraped with a doctor blade to form a nascent membrane. After being exposed to air for 15 seconds, the membrane was immersed in a gel bath at 25 °C to form a solid membrane. The membrane was then soaked in deionized water to completely remove residual organic solvents and additives, yielding the PPESS ultrafiltration membrane. Pre-pressurization with deionized water at 0.15 MPa for 30 min and testing at 0.1 MPa at 25 °C showed a pure water flux of [value missing]. The rejection rate for polyethylene glycol 10000 was 95.6%.

[0034]

[0035] PPESS chemical structure

[0036] Example 1:

[0037] The ion exchange capacity of vacuum drying is Sulfonated naphthalene-biphenyl coether sulfone (SPPBES) was dissolved at 1% by mass in N,N-dimethylacetamide membrane solvent. Then, 14% by mass of bisphenol S-type naphthalene-biphenyl coether sulfone (PPESS) and 5% by mass of ethylene glycol methyl ether were added. After complete dissolution, the solution was filtered through a 400-mesh filter to remove impurities. After vacuum degassing, the solution was allowed to stand. The casting solution was then poured onto a glass plate and scraped with a doctor blade to form a nascent membrane. After holding in air for 15 seconds, the membrane was immersed in a gel bath at 25 °C to form a solid membrane. The membrane was then soaked in deionized water to completely remove residual organic solvents and additives, resulting in a blended ultrafiltration membrane. Its structure and performance were then determined. The membrane was pre-pressurized with deionized water at 0.15 MPa for 30 min and tested at 0.1 MPa at 25 °C. The pure water flux of the membrane was [value missing]. The rejection rate for polyethylene glycol 10000 was 94.8%.

[0038]

[0039] SPPBES chemical structure

[0040] By comparing the performance of the comparative example and Example 1, it can be seen that the water flux of the sulfonated diazonyl ketone polyarylene blend ultrafiltration membrane is higher than that of the diazonyl ketone polyarylene ultrafiltration membrane, while the rejection rate of polyethylene glycol 10000 is comparable. This indicates that compared with the diazonyl ketone polyarylene ultrafiltration membrane, the sulfonated diazonyl ketone polyarylene blend ultrafiltration membrane has both good selectivity and high permeability.

[0041] Example 2:

[0042] The ion exchange capacity of vacuum drying is Sulfonated naphthalene-biphenyl coether sulfone (SPPBES) was dissolved at 2% by mass in N,N-dimethylacetamide membrane solvent. Then, 14% by mass of naphthalene-biphenyl coether sulfone (PPESS) and 5% by mass of ethylene glycol methyl ether were added. After complete dissolution, the solution was filtered through a 400-mesh filter to remove impurities. After vacuum degassing, the solution was allowed to stand. The casting solution was then poured onto a glass plate and scraped with a doctor blade to form a nascent membrane. After holding in air for 15 seconds, the membrane was immersed in a gel bath at 25 °C to form a solid membrane. The membrane was then soaked in deionized water to thoroughly remove residual organic solvents and additives, resulting in a blended ultrafiltration membrane. Pre-pressurized with deionized water at 0.15 MPa for 30 min, and tested at 0.1 MPa at 25 °C, the pure water flux of the membrane was [value missing]. The rejection rate for polyethylene glycol 10000 was 92.9%.

[0043] Example 3:

[0044] The ion exchange capacity of vacuum drying is Sulfonated naphthalene-biphenyl coether sulfone (SPPBES) was dissolved at 4% by mass in N,N-dimethylacetamide membrane solvent. Then, 12% by mass of naphthalene-biphenyl coether sulfone (PPESS) and 5% by mass of ethylene glycol methyl ether were added. After complete dissolution, the solution was filtered through a 400-mesh filter to remove impurities. After vacuum degassing, the solution was allowed to stand. The casting solution was then poured onto a glass plate and scraped with a doctor blade to form a nascent membrane. After holding in air for 15 seconds, the membrane was immersed in a gel bath at 25°C to form a solid membrane. The membrane was then soaked in deionized water to thoroughly remove residual organic solvents and additives, yielding an alloy ultrafiltration membrane. Pre-pressurized with deionized water at 0.15 MPa for 30 min, and tested at 0.1 MPa at 25°C, the pure water flux of the membrane was [value missing]. The rejection rate for polyethylene glycol 10000 was 90.3%.

[0045] Example 4:

[0046] The ion exchange capacity of vacuum drying is Sulfonated naphthalene-biphenyl coether sulfone (SPPBES) was dissolved at 2% by mass in N,N-dimethylacetamide membrane solvent. Then, 14% by mass of naphthalene-biphenyl coether sulfone (PPBES) and 5% by mass of ethylene glycol methyl ether were added. After complete dissolution, the solution was filtered through a 400-mesh filter to remove impurities. After vacuum degassing, the solution was allowed to stand. The casting solution was then poured onto a glass plate and scraped with a doctor blade to form a nascent membrane. After holding in air for 15 seconds, the membrane was immersed in a gel bath at 25 °C to form a solid membrane. The membrane was then soaked in deionized water to thoroughly remove residual organic solvents and additives, resulting in a blended ultrafiltration membrane. Pre-pressurized with deionized water at 0.15 MPa for 30 min, and tested at 0.1 MPa at 25 °C, the pure water flux of the membrane was [value missing]. The rejection rate for polyethylene glycol 10000 was 93.5%.

[0047]

[0048] PPBES chemical structure

[0049] Example 5:

[0050] The ion exchange capacity of vacuum drying is Sulfonated naphthalene-biphenyl coether sulfone (SPPEK-P) was dissolved at 1.0% by mass in N,N-dimethylacetamide as a membrane-forming solvent. Then, 15.0% by mass of naphthalene-biphenyl coether sulfone ketone (PPESK) and 9% by mass of ethylene glycol were added. After complete dissolution, the solution was filtered through a 400-mesh filter cloth to remove impurities. After vacuum degassing, the solution was allowed to stand. The casting solution was then poured onto a glass plate and scraped with a doctor blade to form a nascent membrane. After being exposed to air for 15 seconds, the membrane was immersed in a gel bath at 25 °C to form a solid membrane. The membrane was then soaked in deionized water to completely remove residual organic solvents and additives, yielding a blended ultrafiltration membrane. Its structure and performance were then determined. The membrane was pre-pressurized with deionized water at 0.15 MPa for 30 min and tested at 0.1 MPa at 25 °C. The pure water flux of the membrane was [value missing]. The rejection rate for polyethylene glycol 10000 was 90.5%.

[0051]

[0052] SPPEK-P chemical structure

[0053]

[0054] PPESK chemical structure.

Claims

1. A sulfonated phthalazinone-structure-containing polyarylether blended ultrafiltration membrane, characterized by, The sulfonated diazanaphthone-structured polyarylene blend ultrafiltration membrane includes diazanaphthone-structured polyarylene ether and sulfonated diazanaphthone-structured polyarylene ether. The structural formula of polyarylene ethers containing a diazanaphthone structure is as follows: Among them, R1, R2, R3 and R4 are hydrogen atoms, halogen atoms, methyl, aryl or sulfonic acid groups, and R1, R2, R3 and R4 may be the same or different; Ar1 is one or more of the following structures: 、 、 、 ； Ar2 can be one or more of the following structures: 、 、 、 、 、 ； The structural formula of sulfonated diazanaphthone-containing polyarylene ethers is as follows: Ar3 can be one or more of the following structures: 、 、 、 、 。 2. A method for preparing a sulfonated polyarylene ether blend ultrafiltration membrane containing a diazanaphthone structure, characterized in that, Using sulfonated polyarylene ether resin containing a diazapinene structure and polyarylene ether resin containing a diazapinene structure as membrane materials, a blended ultrafiltration membrane was prepared by a solvent-inducible phase separation method, as follows: (1) Sulfonated polyarylene ether containing diazanaphthone structure, polyarylene ether membrane material containing diazanaphthone structure, and additives are dissolved in a solvent to prepare a casting solution; the total mass fraction of sulfonated polyarylene ether containing diazanaphthone structure and polyarylene ether containing diazanaphthone structure in the casting solution is 5~30%, and the mass fraction of additives is 2~25%; the mass ratio of sulfonated polyarylene ether containing diazanaphthone structure and polyarylene ether containing diazanaphthone structure in the casting solution is 1:99~1:1; (2) Pour the casting solution onto a glass plate or non-woven fabric, scrape it with a scraper to form a nascent membrane of a certain thickness, leave it in the air for 5-60 s, place it in a gel bath at 5-60 ℃, and soak it in deionized water to remove solvent and additives, thereby obtaining a sulfonated polyarylene ether blend ultrafiltration membrane containing a diazanaphthone structure.

3. The preparation method according to claim 2, characterized in that, The solvent used to prepare the casting solution is one or a mixture of two or more of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-1-pyrrolidone.

4. The preparation method according to claim 2, characterized in that, The additive is one or more of the following: small organic molecules, polyvinylpyrrolidone, polyethylene glycol, lithium chloride, and lithium nitrate; wherein the small organic molecule additive is ethylene glycol, ethylene glycol methyl ether, diethylene glycol, methanol, ethanol, propanol, butanol, acetone, butanone, propylene glycol, glycerol, diethyl ether, dioxane, tetrahydrofuran, formic acid, acetic acid, oxalic acid, or ethyl acetate.

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