Preparation method of organic solvent-resistant reverse osmosis membrane and organic solvent-resistant reverse osmosis membrane

Abstract

The invention discloses a preparation method of an organic solvent-resistant reverse osmosis membrane and the organic solvent-resistant reverse osmosis membrane. The preparation method of the organic-solvent-resistant reverse osmosis membrane comprises the following steps: (1) adding polyimide and hexamethylenediamine into N-methyl pyrrolidone, and stirring for a period of time after charging is completed, so as to obtain a membrane casting solution; (2) loading the membrane casting solution on a carrier, and then carrying out gel bath treatment to obtain a base membrane; (3) infiltrating the base membrane in hot water, and taking out the base membrane after infiltrating to obtain a first precursor; (4) sequentially infiltrating the first precursor into a water phase solution and an organic phase solution, and taking out after infiltrating to obtain a second precursor; wherein the water phase solution is prepared from m-phenylenediamine and piperazine; the organic phase solution comprises trimesoyl chloride and triptycene-1, 3, 6, 8-tetraacyl chloride, and the organic phase solution comprises trimesoyl chloride and triptycene-1, 3, 6, 8-tetraacyl chloride; and (5) carrying out heat treatment on the second precursor to obtain the organic solvent-resistant reverse osmosis membrane.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of reverse osmosis membranes, in particular to a preparation method of an organic solvent-resistant reverse osmosis membrane and the organic solvent-resistant reverse osmosis membrane. BACKGROUND

[0002] In the industrial production of chemical, pharmaceutical, printing and dyeing industries, organic solvents are widely used, and a large amount of organic solvent wastewater with high toxicity and difficult degradation is generated. Traditional water treatment methods such as biochemical method and adsorption method have limited treatment effect on such wastewater and are high in cost. Although reverse osmosis technology performs well in seawater desalination and water treatment, traditional polyamide reverse osmosis membranes will swell, plasticize and even chemically degrade in an organic solvent environment, resulting in a sharp decline in separation performance and a short service life, which greatly limits its application in organic solvent systems.

[0003] To solve this problem, organic solvent reverse osmosis (OSRO) technology based on polymer membranes emerged as the times require. OSRO requires that the membrane material not only can withstand chemical corrosion of organic solvents, but also can maintain stable separation precision under high operating pressure. In the prior art, polyimide is considered as one of the ideal materials for preparing OSRO membranes due to its excellent mechanical strength, thermal stability and inherent solvent resistance. However, the traditional polyimide-based OSRO membrane still has a certain swelling problem in strong polar solvents. At present, there is no OSRO membrane on the market that has high solvent resistance, high desalination rate and good flux. SUMMARY

[0004] In order to improve the organic solvent resistance on the basis of high desalination rate and good flux, the present application provides a preparation method of an organic solvent-resistant reverse osmosis membrane and the organic solvent-resistant reverse osmosis membrane, and the technical solutions are as follows:

[0005] The preparation method of the organic solvent-resistant reverse osmosis membrane comprises the following steps:

[0006] (1) polyimide and hexanediamine are added to N-methylpyrrolidone, and after the feeding is completed, the mixture is stirred for a period of time to obtain a casting solution;

[0007] (2) the casting solution is loaded on a carrier, and then subjected to gel bath treatment to obtain a base film;

[0008] (3) the base film is immersed in hot water, and after the immersion is completed, the first precursor is obtained;

[0009] (4) the first precursor is sequentially immersed in an aqueous solution and an organic phase solution, and after the immersion is completed, the second precursor is obtained; wherein the aqueous solution comprises m-phenylenediamine and piperazine; and the organic phase solution comprises trimesoyl chloride and triptycene-1,3,6,8-tetracarboxylic acid chloride;

[0010] (5) heat treating the second precursor to obtain the organic solvent resistant reverse osmosis membrane.

[0011] The preparation method has the advantages that: (1) the introduced hexanediamine can not only react with the imide ring in the polyimide to form a more compact crosslinked network, significantly inhibiting the swelling of the base film in the solvent, but also the amine groups at both ends of the hexanediamine molecular chain are partially exposed on the surface of the base film during the film forming process, and these amine groups can react with the acyl chloride groups in the organic phase solution in the subsequent interfacial polymerization step, thereby forming a firm covalent bond between the polyimide base film and the polyamide separation layer, greatly enhancing the interfacial bonding force between the separation layer and the base film, and effectively solving the problem of easy separation layer peeling or swelling failure in harsh organic solvent environment. (2) The hot water soaking treatment of the base film can more effectively remove the residual organic solvent in the membrane pores, avoid the influence of the residual organic solvent on the subsequent interfacial polymerization reaction, and ensure the quality of the separation layer; and the process can also relax the internal stress of the polymer chain generated during the film forming process, so that the structure of the film is more stable, and the size shrinkage and solvent swelling effect are reduced. (3) The aromatic polyamide network formed by the m-phenylenediamine in the aqueous solution has high selectivity and rigidity, and the piperazine can introduce hydrophilic and flexible segments, which helps to improve the flux. (4) The trimesoyl chloride in the organic phase solution is a classic trifunctional crosslinking agent, which ensures the high crosslinking degree of the network, and the triptycene monomer is a molecule with a unique three-dimensional rigid paddle wheel structure, which can react with polyamines to form a separation layer with enhanced sub-nanometer micropores and interconnected free volume, realizing the synergistic improvement of flux and salt rejection rate. (5) The final heat treatment can promote the crosslinking reaction of the amine groups and the acyl chloride groups in the separation layer which have not been completely reacted, thereby further improving the crosslinking density and network integrity of the polyamide separation layer, which helps to obtain higher solute rejection rate and stronger anti-solvent swelling and anti-chemical degradation ability; at the same time, the heat treatment also helps to enhance the interfacial interaction between the polyamide separation layer and the polyimide base film, so that the whole composite membrane becomes a more stable and durable whole, ensuring its long-term stable operation in organic solvent separation applications.

[0012] As a further improvement of the preparation method of the above-mentioned organic solvent resistant reverse osmosis membrane: in step (1), the polyimide is first dissolved in N-methyl pyrrolidone, and then the hexanediamine is added; the mass ratio of N-methyl pyrrolidone, polyimide and hexanediamine is (75-85):(15-25):(0.75-3.75); after the feeding is completed, stirring for 12-24 hours.

[0013] As a further improvement of the preparation method of the above-mentioned organic solvent resistant reverse osmosis membrane: in step (2), polyester non-woven fabric is used as the carrier, the casting solution is loaded onto the polyester non-woven fabric, and the gel bath treatment is carried out in pure water at 20-30°C until the solidification molding is completed.

[0014] As a further improvement of the above method for preparing the organic-solvent-resistant reverse osmosis membrane, in step (3), the base membrane is soaked in hot water at 60-80℃ for 0.5-2 hours.

[0015] As a further improvement of the above method for preparing the organic-solvent-resistant reverse osmosis membrane, step (4) comprises the following steps performed in sequence:

[0016] The first precursor is soaked in the aqueous solution, and after the soaking is completed, the first precursor is taken out and the surface is blown with a compressed air knife;

[0017] Then the first precursor is soaked in the organic phase solution, and after the soaking is completed, the first precursor is taken out and the surface is flushed with n-hexane, thereby obtaining the second precursor.

[0018] As a further improvement of the above method for preparing the organic-solvent-resistant reverse osmosis membrane, in the aqueous solution, the mass fraction of m-phenylenediamine is 1.5-3.5wt%, and the mass fraction of piperazine is 0.5-2wt%; the first precursor is soaked in the aqueous solution for 60-120 seconds.

[0019] As a further improvement of the above method for preparing the organic-solvent-resistant reverse osmosis membrane, in the organic phase solution, the mass fraction of trimesoyl chloride is 0.1-0.3wt%, and the mass fraction of triptycene-1,3,6,8-tetracarboxylic acid chloride is 0.05-0.15wt%; the first precursor is soaked in the organic phase solution for 30-90 seconds.

[0020] As a further improvement of the above method for preparing the organic-solvent-resistant reverse osmosis membrane, it further comprises the following steps performed before the soaking in the aqueous solution: the first precursor is soaked in a dopamine aqueous solution with a mass fraction of 0.1-0.3wt% and a pH of 8-9 for 2-4 hours, and after the soaking is completed, the first precursor is taken out and the surface is blown with a compressed air knife. In this way, the soaking in the dopamine solution can form a polydopamine intermediate layer on the surface of the first precursor. First, the intermediate layer, like a molecular glue, greatly enhances the interfacial bonding force between the separation layer and the base membrane, significantly improving the structural stability and anti-peeling ability of the membrane. Second, the intermediate layer improves the hydrophilicity of the surface of the first precursor, allowing the subsequent interfacial polymerization reaction solution to spread uniformly, which helps to form a more compact and defect-free separation layer.

[0021] As a further improvement of the above method for preparing the organic-solvent-resistant reverse osmosis membrane, in step (5), the second precursor is placed in an oven and heated at 90-130℃ for 10-30 minutes.

[0022] The organic-solvent-resistant reverse osmosis membrane is prepared by the above method for preparing the organic-solvent-resistant reverse osmosis membrane.

[0023] In conclusion, the preparation method of the organic solvent-resistant reverse osmosis membrane has simple process and low material cost, the obtained organic solvent-resistant reverse osmosis membrane has good separation effect and high flux, and the organic solvent resistance is significantly improved, so that the organic solvent-resistant reverse osmosis membrane can continuously and stably operate at high pressure and high flux under the condition of organic solvent, and the application scene is more extensive, and the practicality is high.

[0024] The application will be further described below through specific embodiments. Additional aspects and advantages of the application will be described in the following description, some of which will become apparent to those skilled in the art from the following description, or will be learned by practice of the application. DETAILED DESCRIPTION

[0025] The application will be further described below through specific embodiments. Additional aspects and advantages of the application will be described in the following description, some of which will become apparent to those skilled in the art from the following description, or will be learned by practice of the application.

[0026] The technical solutions and technical features provided in each part of the description, including the following description, in the application can be combined with each other without conflict.

[0027] In addition, the embodiments of the application involved in the following description are generally only a part of the embodiments of the application, not all the embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments in the application without creative labor should belong to the protection scope of the application.

[0028] Regarding the terms and units in the application. The terms "include", "have" and any variations thereof in the description and claims of the application and related parts are intended to cover non-exclusive inclusion.

[0029] Example 1

[0030] The preparation method of the organic solvent-resistant reverse osmosis membrane of the embodiment comprises the following steps:

[0031] (1) P84 polyimide is dissolved in N-methyl pyrrolidone, then hexanediamine is added and stirred for 12 hours to obtain a casting solution; wherein the mass ratio of N-methyl pyrrolidone, polyimide and hexanediamine is 80:20:2.

[0032] (2) The casting solution is loaded onto the polyester non-woven fabric with a doctor blade with a knife gap of 150 microns at a moving speed of 10 m / min, and then gel bath treatment is carried out in pure water at 25 DEG C until solidification molding to obtain a base film.

[0033] (3) The base film is immersed in hot water at 60 DEG C for 1 hour to obtain a first precursor.

[0034] (4) polymeric treatment is performed on the first precursor, specifically:

[0035] Firstly, the first precursor is immersed in an aqueous solution for 90 seconds, and after the immersion is completed, the surface is blown with a compressed air knife; the aqueous solution is a mixture of m-phenylenediamine and piperazine, wherein the mass fraction of m-phenylenediamine is 2.5wt%, and the mass fraction of piperazine is 1wt%;

[0036] Subsequently, the first precursor is immersed in an organic phase solution for 60 seconds, and after the immersion is completed, the surface is washed with n-hexane, thereby obtaining a second precursor; the organic phase solution is a mixture of trimesoyl chloride and triptycene-1,3,6,8-tetracarboxylic acid chloride (the solvent is n-hexane, the same below), wherein the mass fraction of trimesoyl chloride is 0.2wt%, and the mass fraction of triptycene-1,3,6,8-tetracarboxylic acid chloride is 0.1wt%.

[0037] (5) the second precursor is placed in an oven and kept at 90℃ for 30 minutes, thereby obtaining an organic solvent-resistant reverse osmosis membrane.

[0038] The methanol flux of the fresh organic solvent-resistant reverse osmosis membrane obtained by testing is 19.3L / (m 2 ·h), and the sodium chloride desalination rate is 97.5%. After the membrane is immersed in N,N-dimethylformamide for 7 days, the methanol flux is 18.8L / (m 2 ·h), the sodium chloride desalination rate is 95.2%, the flux retention rate after continuous operation for 100 hours is 96.2%, and the sodium chloride desalination rate retention rate is 97.9%.

[0039] Example 2

[0040] Compared with Example 1, the difference between the preparation method of the organic solvent-resistant reverse osmosis membrane of the present embodiment is that the mass ratio of N-methylpyrrolidone, polyimide and hexanediamine is 75:15:0.75.

[0041] The methanol flux of the fresh organic solvent-resistant reverse osmosis membrane obtained by testing is 20.5L / (m 2 ·h), and the sodium chloride desalination rate is 96.5%. After the membrane is immersed in N,N-dimethylformamide for 7 days, the methanol flux is 20L / (m 2 ·h), the sodium chloride desalination rate is 94.5%, the flux retention rate after continuous operation for 100 hours is 95.6%, and the sodium chloride desalination rate retention rate is 96.8%.

[0042] Example 3

[0043] Compared with Example 1, the difference between the preparation method of the organic solvent-resistant reverse osmosis membrane of the present embodiment is that the mass ratio of N-methylpyrrolidone, polyimide and hexanediamine is 85:25:3.75.

[0044] The methanol flux of the fresh organic-solvent-resistant reverse osmosis membrane was 18.6 L / (m 2 ·h), and the sodium chloride desalination rate was 97.2%. After the membrane was immersed in N,N-dimethylformamide for 7 days, the methanol flux was 18.2 L / (m 2 ·h), the sodium chloride desalination rate was 95.1%, the flux retention rate after continuous operation for 100 hours was 96.5%, and the sodium chloride desalination rate retention rate was 97.3%.

[0045] Example 4

[0046] Compared with Example 1, the difference of the preparation method of the organic-solvent-resistant reverse osmosis membrane in the present example is that in step (3), the base membrane is immersed in hot water at 80°C for 1 hour.

[0047] The methanol flux of the fresh organic-solvent-resistant reverse osmosis membrane was 19.1 L / (m 2 ·h), and the sodium chloride desalination rate was 97.6%. After the membrane was immersed in N,N-dimethylformamide for 7 days, the methanol flux was 18.4 L / (m 2 ·h), the sodium chloride desalination rate was 95.7%, the flux retention rate after continuous operation for 100 hours was 95.7%, and the sodium chloride desalination rate retention rate was 97.4%.

[0048] Example 5

[0049] Compared with Example 1, the difference of the preparation method of the organic-solvent-resistant reverse osmosis membrane in the present example is that the mass fraction of m-phenylenediamine is 1.5 wt%, and the mass fraction of piperazine is 2 wt%.

[0050] The methanol flux of the fresh organic-solvent-resistant reverse osmosis membrane was 21.4 L / (m 2 ·h), and the sodium chloride desalination rate was 96.3%. After the membrane was immersed in N,N-dimethylformamide for 7 days, the methanol flux was 20.7 L / (m 2 ·h), the sodium chloride desalination rate was 93.6%, the flux retention rate after continuous operation for 100 hours was 94.7%, and the sodium chloride desalination rate retention rate was 96.7%.

[0051] Example 6

[0052] Compared with Example 1, the difference of the preparation method of the organic-solvent-resistant reverse osmosis membrane in the present example is that the mass fraction of m-phenylenediamine is 3.5 wt%, and the mass fraction of piperazine is 0.5 wt%.

[0053] The methanol flux of the fresh organic-solvent-resistant reverse osmosis membrane was 17.9 L / (m 2• h), the sodium chloride desalination rate was 98.3%. The methanol flux of the membrane after static immersion in N,N-dimethylformamide for 7 days was 17.4 L / (m 2 • h), the sodium chloride desalination rate was 96.1%, the flux retention rate after continuous operation for 100 hours was 95.7%, and the sodium chloride desalination rate retention rate was 96.7%.

[0054] Example 7

[0055] Compared with Example 1, the difference of the preparation method of the organic solvent resistant reverse osmosis membrane in this embodiment is that the mass fraction of trimesoyl chloride is 0.1 wt%, and the mass fraction of triptycene-1,3,6,8-tetracarboxylic acid chloride is 0.15 wt%.

[0056] The test obtained the methanol flux of the fresh organic solvent resistant reverse osmosis membrane as 20.8 L / (m 2 • h), the sodium chloride desalination rate was 96.4%. The methanol flux of the membrane after static immersion in N,N-dimethylformamide for 7 days was 20 L / (m 2 • h), the sodium chloride desalination rate was 93.3%, the flux retention rate after continuous operation for 100 hours was 95.1%, and the sodium chloride desalination rate retention rate was 96.3%.

[0057] Example 8

[0058] Compared with Example 1, the difference of the preparation method of the organic solvent resistant reverse osmosis membrane in this embodiment is that the mass fraction of trimesoyl chloride is 0.3 wt%, and the mass fraction of triptycene-1,3,6,8-tetracarboxylic acid chloride is 0.05 wt%.

[0059] The test obtained the methanol flux of the fresh organic solvent resistant reverse osmosis membrane as 17.8 L / (m 2 • h), the sodium chloride desalination rate was 98.5%. The methanol flux of the membrane after static immersion in N,N-dimethylformamide for 7 days was 17.4 L / (m 2 • h), the sodium chloride desalination rate was 96.1%, the flux retention rate after continuous operation for 100 hours was 95.2%, and the sodium chloride desalination rate retention rate was 96.2%.

[0060] Example 9

[0061] Compared with Example 1, the difference of the preparation method of the organic solvent resistant reverse osmosis membrane in this embodiment is that in step (5), the second precursor is placed in an oven and kept at 130°C for 10 minutes.

[0062] The test obtained the methanol flux of the fresh organic solvent resistant reverse osmosis membrane as 17.6 L / (m 2• h), the sodium chloride desalination rate was 98.8%. The methanol flux of the membrane after static immersion in N,N-dimethylformamide for 7 days was 17.2 L / (m 2 • h), the sodium chloride desalination rate was 97.1%, the flux retention rate after continuous operation for 100 hours was 97.1%, and the sodium chloride desalination rate retention rate was 98.2%.

[0063] Example 10

[0064] Compared with Example 1, the difference between the preparation method of the organic solvent-resistant reverse osmosis membrane of the present example is that the first precursor is immersed in a dopamine aqueous solution with a mass fraction of 0.2 wt% and a pH of 8.5 for 3 hours before the aqueous phase solution is immersed, and the surface is blown off after the immersion is completed.

[0065] The test obtained the methanol flux of the fresh organic solvent-resistant reverse osmosis membrane as 18.2 L / (m 2 • h), the sodium chloride desalination rate was 98.7%. The methanol flux of the membrane after static immersion in N,N-dimethylformamide for 7 days was 17.9 L / (m 2 • h), the sodium chloride desalination rate was 97.6%, the flux retention rate after continuous operation for 100 hours was 97.3%, and the sodium chloride desalination rate retention rate was 98.3%.

[0066] Comparative Example 1

[0067] Compared with Example 1, the difference between the preparation method of the reverse osmosis membrane of the present comparative example is that step (3) is not performed.

[0068] The test obtained the methanol flux of the fresh reverse osmosis membrane as 21.2 L / (m 2 • h), the sodium chloride desalination rate was 95.5%. The methanol flux of the membrane after static immersion in N,N-dimethylformamide for 7 days was 19.7 L / (m 2 • h), the sodium chloride desalination rate was 90.2%, the flux retention rate after continuous operation for 100 hours was 91.2%, and the sodium chloride desalination rate retention rate was 91.3%.

[0069] Comparative Example 2

[0070] Compared with Example 1, the difference between the preparation method of the reverse osmosis membrane of the present comparative example is that the aqueous phase solution does not contain piperazine.

[0071] The test obtained the methanol flux of the fresh reverse osmosis membrane as 22.3 L / (m 2 • h), the sodium chloride desalination rate was 94.7%. The methanol flux of the membrane after static immersion in N,N-dimethylformamide for 7 days was 20.6 L / (m 2·h), the sodium chloride desalination rate was 88.6%, the flux retention rate was 91.3% after 100 hours of continuous operation, and the sodium chloride desalination rate retention rate was 92.6%.

[0072] Compare with Example 3

[0073] Compared with Example 1, the difference in the preparation method of the reverse osmosis membrane in this comparative example is that the organic phase solution does not contain triterpenoid-1,3,6,8-tetraacyl chloride.

[0074] The methanol flux of the fresh reverse osmosis membrane was measured to be 22.5 L / (m²). 2 The sodium chloride desalination rate was 94.6%. After statically immersing the membrane in N,N-dimethylformamide for 7 days, the methanol flux was 20.8 L / (m³). 2 ·h), the sodium chloride desalination rate was 89.2%, the flux retention rate was 91.5% after 100 hours of continuous operation, and the sodium chloride desalination rate retention rate was 92.4%.

[0075] Compare with Example 4

[0076] Compared with Example 1, the difference in the preparation method of the reverse osmosis membrane in this comparative example is that in step (5), the second precursor is placed in an oven and kept at 80°C for 30 minutes.

[0077] The methanol flux of the fresh reverse osmosis membrane was measured to be 19.8 L / (m²). 2 The sodium chloride desalination rate was 97.5%. After statically immersing the membrane in N,N-dimethylformamide for 7 days, the methanol flux was 18.8 L / (m³). 2 ·h), the sodium chloride desalination rate was 93.7%, the flux retention rate after 100 hours of continuous operation was 94.3%, and the sodium chloride desalination rate retention rate was 94.8%.

[0078] Compare with Example 5

[0079] Compared with Example 9, the difference in the preparation method of the reverse osmosis membrane in this comparative example is that in step (5), the second precursor is placed in an oven and kept at 140°C for 10 minutes.

[0080] The methanol flux of the fresh reverse osmosis membrane was measured to be 16.2 L / (m²). 2 The sodium chloride desalination rate was 98.4%. After statically immersing the membrane in N,N-dimethylformamide for 7 days, the methanol flux was 15.6 L / (m³). 2 ·h), the sodium chloride desalination rate is 94.9%, and the flux after 100 hours of continuous operation is 95.5%, with a sodium chloride desalination rate of 95.9%.

[0081] The pure water flux and sodium chloride desalination rate of the reverse osmosis membranes in the above examples and control examples were tested according to the "Test Methods for Reverse Osmosis Membranes" (GB / T 32373-2015), as follows:

[0082] 1. Take several (no fewer than 4) samples. The samples should be free of obvious defects such as wrinkles and damage. The size of the samples should meet the requirements of completely covering the sealing ring of the evaluation cell. The effective membrane area of ​​the samples in the evaluation cell should not be less than 2.5 × 10⁻⁶. -3 m 2 Prepare a 5000 ppm sodium chloride methanol solution and adjust the pH to 7.5 ± 0.5 (i.e., the stock solution).

[0083] 2. Immerse the sample in deionized water or distilled water for 30 minutes;

[0084] 3. Methanol flux and sodium chloride desalination rate test: Take fresh samples or samples that have been statically soaked in N,N-dimethylformamide for 7 days and place them in the evaluation cell. Turn on the water supply pump to provide the stock solution, and slowly adjust the operating pressure to 40 bar for cross-flow filtration. Maintain the temperature at 25℃±0.5℃. After stabilizing for 30 minutes, collect the permeate produced after passing through the sample using a measuring cup (no less than 30 ml per sample). Calculate the time required using a stopwatch to obtain the methanol flux. After stabilizing for 30 minutes and after stabilizing under constant pressure for 100 hours, determine the total dissolved solids (TDS) content of the stock solution and permeate according to GB / T 5750.4.

[0085] 4. After the test is completed, slowly reduce the operating pressure to below 0.05MPa and turn off the booster pump or water supply pump.

[0086] The pure water flux is calculated using the following formula:

[0087]

[0088] In the formula, J is the pure water flux, with units of L / (m³). 2 ﹒ h); V is the volume of the graduated cylinder sample, in L; T is the sampling time, in h; A is the effective area of ​​the sample, in m². 2 .

[0089] The sodium chloride desalination rate is calculated using the following formula:

[0090]

[0091] In the formula, R is the sodium chloride desalination rate, in units of %; C P The total dissolved solids (TDS) of the permeate is expressed in mg / L; C f The TDS of the stock solution is expressed in mg / L.

[0092] The foregoing has described the relevant content of the present invention. Those skilled in the art will be able to implement the present invention based on these descriptions. All other embodiments obtained by those skilled in the art based on the above description of the present invention without inventive effort should fall within the scope of protection of the present invention.

Claims

1. A method for preparing an organic solvent-resistant reverse osmosis membrane, characterized in that: Includes the following steps: (1) Add polyimide and hexamethylenediamine to N-methylpyrrolidone, and stir for a period of time after the addition is completed to obtain casting solution; (2) The casting solution is loaded onto the carrier and then subjected to a gel bath treatment to obtain the base film; (3) Immerse the base membrane in hot water, and remove it after immersion to obtain the first precursor; (4) The first precursor is sequentially immersed in an aqueous solution and an organic solution, and after immersion, it is removed to obtain the second precursor; wherein the aqueous solution includes m-phenylenediamine and piperazine; the organic solution includes pyromellitic trimethylol chloride and triphenylene-1,3,6,8-tetraacyl chloride; (5) Heat treatment of the second precursor yields an organic solvent-resistant reverse osmosis membrane.

2. The method for preparing an organic solvent-resistant reverse osmosis membrane as described in claim 1, characterized in that: In step (1), polyimide is first dissolved in N-methylpyrrolidone, and then hexamethylenediamine is added; the mass ratio of N-methylpyrrolidone, polyimide and hexamethylenediamine is (75-85):(15-25):(0.75-3.75); after the addition is completed, the mixture is stirred for 12-24 hours.

3. The method for preparing an organic solvent-resistant reverse osmosis membrane as described in claim 1, characterized in that: In step (2), polyester nonwoven fabric is used as a carrier to load the casting solution onto the polyester nonwoven fabric, and gel bath treatment is carried out in pure water at 20-30°C until solidification.

4. The method for preparing an organic solvent-resistant reverse osmosis membrane as described in claim 1, characterized in that: In step (3), the base film is immersed in hot water at 60-80°C for 0.5-2 hours.

5. The method for preparing an organic solvent-resistant reverse osmosis membrane as described in claim 1, characterized in that: Step (4) includes the following steps performed sequentially: The first precursor was immersed in an aqueous solution. After immersion, it was removed and its surface was cleaned with compressed air. The first precursor is then immersed in an organic phase solution. After immersion, it is removed and the surface is rinsed with n-hexane to obtain the second precursor.

6. The method for preparing an organic solvent-resistant reverse osmosis membrane as described in claim 5, characterized in that: In the aqueous solution, the mass fraction of m-phenylenediamine is 1.5–3.5 wt%, and the mass fraction of piperazine is 0.5–2 wt%; the first precursor is immersed in the aqueous solution for 60–120 seconds.

7. The method for preparing an organic solvent-resistant reverse osmosis membrane as described in claim 5, characterized in that: In the organic phase solution, the mass fraction of pyromellitic trimethylol chloride is 0.1-0.3 wt%, and the mass fraction of triphenylene-1,3,6,8-tetraacyl chloride is 0.05-0.15 wt%; the first precursor is immersed in the organic phase solution for 30-90 seconds.

8. The method for preparing an organic solvent-resistant reverse osmosis membrane as described in claim 5, characterized in that: It also includes immersing the first precursor in a dopamine aqueous solution with a mass fraction of 0.1-0.3 wt% and a pH of 8-9 for 2-4 hours before immersing it in the aqueous solution, and then removing it and blowing the surface with a compressed air knife after immersion.

9. The method for preparing an organic solvent-resistant reverse osmosis membrane as described in claim 1, characterized in that: In step (5), the second precursor is placed in an oven and kept at 90-130°C for 10-30 minutes.

10. An organic solvent-resistant reverse osmosis membrane, characterized in that: It is prepared by the method for preparing an organic solvent-resistant reverse osmosis membrane according to any one of claims 1-9.

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