A method for preparing a gas barrier film based on microwave heating

Abstract

The present invention provides a method for preparing a gas barrier film based on microwave heating, which relates to the technical field of gas barrier films. In the present invention, a casting solution is prepared by uniformly mixing a polymerization monomer and an initiator. After degassing treatment, it is pre-polymerized at a preset temperature. When the viscosity of the casting solution reaches the preset value, the pre-polymerization is stopped and the casting solution is uniformly coated on a substrate by a doctor blade. The casting solution coated on the substrate is subjected to microwave curing treatment, so that the casting solution is cured on the substrate without coking, and a gas barrier film with a gas permeability lower than 300 cm<supgt;3< / supgt>·m<supgt;‑2< / supgt>·day<supgt;‑1< / supgt>·0.1MPa<supgt;‑1< / supgt> is prepared for gas isolation. The atomic utilization rate in the preparation process of the present invention is 100% and no emissions are generated. The process flow is green and environmentally friendly. The film preparation time is short, and the prepared gas barrier film has excellent gas barrier performance and stability, can meet the requirement of long-term gas isolation during storage and transportation, effectively avoids gas leakage, and lays a foundation for ensuring the safe transportation of gas.

Description

Technical Field

[0001] The present invention relates to the technical field of gas barrier films, and specifically relates to a method for preparing a gas barrier film based on microwave heating method. Background Art

[0002] The climate issue is a severe challenge faced by the Earth's ecosystem since the Industrial Revolution, and the energy issue is the fundamental issue for the development of human society. The world energy transition characterized by clean and low-carbon is an effective measure to solve the energy problem and address climate change. Whether it is the hydrogen energy industry characterized by clean energy or the CCUS industry committed to the "dual-carbon goal", the safe and efficient storage of gases is a key link. To obtain a higher storage capacity, high-purity gases usually need to be stored under high-pressure conditions, which also poses higher requirements for the mechanical properties and barrier properties of gas storage materials.

[0003] High-barrier film materials are widely used in various production and living fields due to their excellent barrier properties, low cost, and good transparency. Early barrier materials included ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), polyamide (PA), polyvinyl alcohol (PVA), etc. Among them, high barrier property is an important characteristic of these barrier materials, including gas barrier property, moisture barrier property, oil barrier property, and fragrance retention property. With the economic development and the improvement of people's living standards, the performance of barrier films will be further improved, and the application fields will be further expanded. Summary of the Invention

[0004] The present invention aims to solve the leakage problem during gas storage by improving the performance of the barrier film, and proposes a method for preparing a gas barrier film based on microwave heating method. Without using any solvents, the atomic utilization rate of the preparation process reaches 100% and no emissions are generated. The process flow is green and environmentally friendly, and has good industrial application prospects.

[0005] The present invention adopts the following technical solutions:

[0006] A method for preparing a gas barrier film based on microwave heating method, the gas permeation rate of the prepared gas barrier film is lower than 300 cm 3 ·m -2 ·day -1 ·0.1MPa -1 , and specifically includes the following steps:

[0007] Step 1, mix the polymerization monomer and the initiator, the mass ratio between the initiator and the polymerization monomer is 0.8% - 15%, and then use stirring and ultrasonic to mix the two evenly to prepare a casting solution, and perform degassing treatment;

[0008] Step 2: Pre-polymerize the degassed casting solution at a preset temperature, and detect the viscosity of the casting solution. When the viscosity of the casting solution is not less than 2000 mPa·s and does not exceed 10000 mPa·s, stop the pre-polymerization and evenly coat the casting solution on the substrate using a doctor blade.

[0009] Step 3: Perform microwave curing on the casting solution coated on the substrate so that the casting solution cures on the substrate without coking, to obtain a gas barrier film for gas isolation.

[0010] Preferably, the polymerization monomer is self-polymerization of the same monomer or copolymerization of different monomers;

[0011] The polymerization monomer has active groups and can undergo cross-linking reactions. The cross-linking reactions are at least one of self-polymerization reaction of epoxy groups, reaction of epoxy groups with amino groups, reaction of epoxy groups with carboxyl groups, reaction of epoxy groups with acid anhydrides, and reaction of epoxy groups with hydroxyl groups.

[0012] Preferably, in step 1, both the polymerization monomer and the initiator are in liquid state;

[0013] The polymerization monomer is glycerol triglycidyl ether, a mixture of glycerol triglycidyl ether and polyethyleneimine, or a mixture of glycerol triglycidyl ether and ethylenediamine;

[0014] The initiator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0015] Preferably, the degassing treatment is at least one of vacuum degassing, ultrasonic degassing, and centrifugal degassing.

[0016] Preferably, in step 2, the preset temperature is 0 to 30 °C, and the pre-polymerization duration is 1 to 12 h; the height of the doctor blade is set to 50 to 400 μm.

[0017] Preferably, the degassed casting solution is pre-polymerized at room temperature or in an ice-water bath.

[0018] Preferably, the substrate is at least one of non-woven fabric, plastic sheet, and steel.

[0019] Preferably, in step 3, during the microwave curing treatment, the power of the microwave is set to 400 to 800 W, and the microwave curing treatment duration does not exceed 5 min.

[0020] Preferably, the gas isolated by the gas barrier film is at least one of H2, O2, N2, CO2, and CH4.

[0021] The mechanism of the present invention is:

[0022] The present invention uniformly mixes a low-viscosity polymerizable monomer and an initiator to form a homogeneous phase, and pre-polymerizes at a relatively low temperature to form a prepolymer having a viscosity of not less than 2000 mPa·s and not more than 10000 mPa·s. This prepolymer has both fluidity and viscosity and will not ooze or spread when scrape-coated on a substrate. By curing the prepolymer on the substrate under a microwave environment, the remaining reactive groups of the monomer are rapidly cross-linked to obtain a gas barrier film for isolating gases, which is used to isolate H2, O2, N2, CO2, and CH4.

[0023] The beneficial effects of the present invention are as follows:

[0024] The method for preparing a gas barrier film based on the microwave heating method proposed by the present invention has an atomic utilization rate of 100% during the preparation process of the gas barrier film and does not use any solvents, without generating any emissions, and the process is green and environmentally friendly. At the same time, the preparation cycle of the gas barrier film is relatively short, the film-forming time is less than 5 minutes, and the prepared gas barrier film has excellent gas barrier performance and stability, and the gas permeation rate is less than 300 cm 3 ·m -2 ·day -1 ·0.1MPa -1 , which can meet the requirements of long-term operation, effectively avoid gas leakage, and provide technical support for ensuring the safety of gas storage and transportation. Description of the Drawings

[0025] Figure 1 It is a diagram of the permeation stability performance of the gas barrier film prepared in Example 1.

[0026] Figure 2 It is a diagram of the permeation stability performance of the gas barrier film prepared in Example 2.

[0027] Figure 3 It is a diagram of the permeation stability performance of the gas barrier film prepared in Example 3.

[0028] Figure 4 It is a diagram of the permeation stability performance of the gas barrier film prepared in Example 4. Detailed Embodiments

[0029] The present invention will be specifically described below in conjunction with the drawings and embodiments:

[0030] The present invention proposes a method for preparing a gas barrier film based on the microwave heating method, and the gas permeation rate of the prepared gas barrier film is less than 300 cm 3 ·m -2 ·day -1 ·0.1MPa -1 , which is used to isolate H2, O2, N2, CO2, and CH4, effectively avoiding gas leakage during gas storage, and specifically includes the following steps:

[0031] Step 1: Mix the polymerization monomer and the initiator. The mass ratio of the initiator to the polymerization monomer is 0.8% - 15%. Then, use stirring and ultrasonic treatment to uniformly mix the two to prepare a casting solution, and perform degassing treatment.

[0032] The polymerization monomer is the self - polymerization of the same monomer or the copolymerization of different monomers; the polymerization monomer has active groups and can undergo cross - linking reactions. The cross - linking reactions include at least one of the self - polymerization reaction of epoxy groups, the reaction of epoxy groups with amino groups, the reaction of epoxy groups with carboxyl groups, the reaction of epoxy groups with acid anhydrides, and the reaction of epoxy groups with hydroxyl groups.

[0033] Step 2: Pre - polymerize the degassed casting solution at a temperature of 0 - 30°C for 1 - 12 h, and detect the viscosity of the casting solution. When the viscosity of the casting solution is not less than 2000 mPa·s and does not exceed 10000 mPa·s, stop the pre - polymerization and use a scraper to uniformly coat the casting solution on the substrate.

[0034] The substrate has a certain mechanical strength, specifically at least one of non - woven fabric, plastic sheet, and steel.

[0035] The pre - polymerization temperature of the casting solution cannot be too high. For polymerization monomers with high reaction activity, it is advisable to pre - polymerize in an ice - water bath.

[0036] Step 3: Perform microwave curing treatment on the casting solution coated on the substrate. The power of the microwave is set to 400 - 800 W, and the duration of the microwave curing treatment does not exceed 5 min, so that the casting solution is cured on the substrate without coking, to obtain a gas - barrier film for gas isolation, which is used to isolate H2, O2, N2, CO2, and CH4.

[0037] The gas - barrier film prepared by the method of the present invention has a green and environmentally friendly preparation process and a short preparation cycle. It can operate for a long time while ensuring that the gas permeation rate is lower than 300 cm 3 ·m -2 ·day -1 ·0.1MPa -1 , providing a material basis for avoiding gas leakage during storage and transportation, and effectively improving the safety of gas transportation.

[0038] Example 1

[0039] This example uses the method for preparing a gas - barrier film based on microwave heating proposed by the present invention to prepare a gas - barrier film, which specifically includes the following steps:

[0040] Step 1: Mix 5 g of polymerization monomer with 0.1 g of initiator. In this example, the initiator is 2,4,6-tris(dimethylaminomethyl)phenol (DMP30). Then, stir and ultrasonicate for 30 min at a stirring rate of 500 rpm to uniformly mix the two to obtain a homogeneous casting solution. Perform vacuum degassing for 30 min to remove the dissolved bubbles in the casting solution.

[0041] Step 2: Pre-polymerize the degassed casting solution at 25 °C for 5 h. Detect the viscosity of the casting solution. When the viscosity of the casting solution is not less than 2000 mPa·s and does not exceed 10000 mPa·s, stop the pre-polymerization and uniformly coat the casting solution on the non-woven fabric substrate using a doctor blade with a height of 200 μm.

[0042] Step 3: Perform microwave curing on the casting solution coated on the substrate. Set the power of the microwave to 600 W and perform microwave curing for 4 min to cure the casting solution on the substrate without coking, thereby obtaining a gas barrier film for gas isolation.

[0043] Perform H2 permeation rate test, N2 permeation rate test, CO2 permeation rate test, and CH4 permeation rate test on the prepared gas barrier film respectively. The test results are shown in Table 1.

[0044] Table 1 Summary table of gas permeation rates of gas barrier films

[0045]

[0046] As can be seen from Table 1, the gas permeation rates of the gas barrier film for the five gases are all less than 300 cm 3 ·m -2 ·day -1 ·0.1 MPa -1 ; By performing the H2 permeation stability test on the gas barrier film and plotting the permeation stability performance graph of the gas barrier film, as Figure 1 shown, it is analyzed that the H2 permeation rate does not show a significant increase during the test process, thereby verifying that the gas barrier film prepared by the method of the present invention has excellent stability and can be used for long-term gas isolation.

[0047] Example 2

[0048] This example uses the method for preparing a gas barrier film based on microwave heating proposed by the present invention to prepare a gas barrier film, which specifically includes the following steps:

[0049] Step 1: Mix 7.5 g of polymerization monomer with 0.2 g of initiator. In this example, the polymerization monomer is composed of a mixture of 5 g of glycerol triglycidyl ether (GTE) and 2.5 g of polyethyleneimine (molecular weight of 300), and the initiator is 2,4,6-tris(dimethylaminomethyl)phenol (DMP30). Stir and ultrasonicate for 30 min under the condition of a stirring rate of 500 rpm to uniformly mix the two to prepare a homogeneous casting solution, and perform vacuum degassing treatment for 30 min to remove the dissolved bubbles in the casting solution.

[0050] Step 2: Pre-polymerize the degassed casting solution at a temperature of 25 °C for 2 h, and detect the viscosity of the casting solution. When the viscosity of the casting solution is not less than 2000 mPa·s and does not exceed 10000 mPa·s, stop the pre-polymerization and uniformly coat the casting solution on the non-woven fabric substrate using a doctor blade with a height of 150 μm.

[0051] Step 3: Perform microwave curing treatment on the casting solution coated on the substrate. Set the power of the microwave to 700 W and perform microwave curing treatment for 1 min to cure the casting solution on the substrate without coking, thereby obtaining a gas barrier film for gas isolation.

[0052] Perform H2 permeation rate test, N2 permeation rate test, CO2 permeation rate test, and CH4 permeation rate test on the prepared gas barrier film respectively. The test results are shown in Table 2.

[0053] Table 2 Summary table of gas permeation rates of gas barrier films

[0054]

[0055] As can be seen from Table 2, the gas permeation rates of the gas barrier film for the five gases are all less than 300 cm 3 ·m -2 ·day -1 ·0.1 MPa -1 ; By performing an H2 permeation stability test on the gas barrier film and plotting the permeation stability performance graph of the gas barrier film, as Figure 2 shown, it is analyzed that the H2 permeation rate does not show an obvious increase during the test process, thereby verifying that the gas barrier film prepared by the method of the present invention has excellent stability and can be used for long-term gas isolation.

[0056] Example 3

[0057] This example uses the method for preparing a gas barrier film based on microwave heating proposed by the present invention to prepare a gas barrier film, which specifically includes the following steps:

[0058] Step 1: Mix 6.2 g of polymerization monomer with 0.0496 g of initiator. In this embodiment, the polymerization monomer is composed of 5 g of glycerol triglycidyl ether (GTE) and 1.2 g of ethylenediamine, and the initiator is 2,4,6-tris(dimethylaminomethyl)phenol (DMP30). Stir and ultrasonicate for 30 min under the condition of a stirring rate of 500 rpm to mix the two evenly to prepare a homogeneous casting solution, and perform vacuum degassing treatment for 30 min to remove the dissolved bubbles in the casting solution.

[0059] Step 2: Pre-polymerize the degassed casting solution in an ice-water bath for 1 h, and detect the viscosity of the casting solution. When the viscosity of the casting solution is not less than 2000 mPa·s and does not exceed 10000 mPa·s, stop the pre-polymerization and evenly coat the casting solution on the non-woven fabric substrate using a doctor blade with a height of 100 μm.

[0060] Step 3: Perform microwave curing treatment on the casting solution coated on the substrate. Set the power of the microwave to 700 W and perform microwave curing treatment for 2 min to cure the casting solution on the substrate without coking, thereby obtaining a gas barrier film for gas isolation.

[0061] Perform H2 permeation rate test, N2 permeation rate test, CO2 permeation rate test, and CH4 permeation rate test on the prepared gas barrier films respectively. The test results are shown in Table 3.

[0062] Table 3 Summary table of gas permeation rates of gas barrier films

[0063]

[0064] As can be seen from Table 3, the gas permeation rates of the gas barrier film for the five gases are all less than 300 cm 3 ·m -2 ·day -1 ·0.1 MPa -1 ; By performing H2 permeation stability test on the gas barrier film, draw the permeation stability performance diagram of the gas barrier film, as shown in Figure 3 shown. It is analyzed that the H2 permeation rate does not show an obvious increase during the test process, thereby verifying that the gas barrier film prepared by the method of the present invention has excellent stability and can be used for long-term gas isolation.

[0065] Example 4

[0066] In this embodiment, a gas barrier film is prepared by using the method for preparing a gas barrier film based on microwave heating proposed by the present invention, which specifically includes the following steps:

[0067] Step 1: Mix 5 g of polymerizable monomer with 0.75 g of initiator. In this example, the polymerizable monomer is glycerol triglycidyl ether (GTE), and the initiator is 2,4,6-tris(dimethylaminomethyl)phenol (DMP30). Stir and ultrasonicate for 30 min at a stirring rate of 500 rpm to uniformly mix the two and prepare a homogeneous casting solution. Then perform vacuum degassing for 30 min to remove the dissolved bubbles in the casting solution.

[0068] Step 2: Pre-polymerize the degassed casting solution in an ice-water bath for 1 h, and measure the viscosity of the casting solution. When the viscosity of the casting solution is not less than 2000 mPa·s and does not exceed 10000 mPa·s, stop the pre-polymerization and uniformly coat the casting solution on the non-woven fabric substrate using a doctor blade with a height of 100 μm.

[0069] Step 3: Perform microwave curing treatment on the casting solution coated on the substrate. Set the power of the microwave to 800 W and perform microwave curing treatment for 5 min to cure the casting solution on the substrate without coking, thereby obtaining a gas barrier film for gas isolation.

[0070] Perform H2 permeation rate test, N2 permeation rate test, CO2 permeation rate test, and CH4 permeation rate test on the prepared gas barrier film respectively. The test results are shown in Table 4.

[0071] Table 4 Summary of gas permeation rates of the gas barrier film

[0072]

[0073] As can be seen from Table 4, the gas permeation rates of the gas barrier film for the five gases are all less than 300 cm 3 ·m -2 ·day -1 ·0.1 MPa -1 ; By performing the H2 permeation stability test on the gas barrier film and plotting the permeation stability performance graph of the gas barrier film, as Figure 4 shown, it is analyzed that the H2 permeation rate does not show a significant increase during the test process, thus verifying that the gas barrier film prepared by the method of the present invention has excellent stability and can be used for long-term gas isolation.

[0074] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the essence of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for preparing a gas barrier film based on microwave heating method, characterized in that, The prepared gas barrier film is used to isolate H2, N2, CO2 and CH4, and the gas permeation rate is lower than 300 cm 3 ·m -2 ·day -1 ·0.1MPa -1 , and specifically includes the following steps: Step 1: Mix the polymerization monomer and the initiator. The mass ratio of the initiator to the polymerization monomer is 0.8% - 15%. Then, use stirring and ultrasonic treatment to mix the two evenly to prepare a casting solution, and perform degassing treatment. Step 2: Pre-polymerize the degassed casting solution at a preset temperature, and detect the viscosity of the casting solution. When the viscosity of the casting solution is not less than 2000 mPa·s and not more than 10000 mPa·s, stop the pre-polymerization and use a doctor blade to evenly coat the casting solution on the substrate. Step 3: Perform microwave curing treatment on the casting solution coated on the substrate so that the casting solution is cured on the substrate without coking, to obtain a gas barrier film for gas isolation. The polymerization monomer is self-polymerization of the same monomer or copolymerization of different monomers. The polymerization monomer has active groups and can undergo cross-linking reactions. The cross-linking reactions are at least one of self-polymerization reaction of epoxy groups, reaction of epoxy groups with amino groups, reaction of epoxy groups with carboxyl groups, reaction of epoxy groups with acid anhydrides, and reaction of epoxy groups with hydroxyl groups. In Step 1, both the polymerization monomer and the initiator are liquid. The polymerization monomer is glycerol triglycidyl ether, a mixture of glycerol triglycidyl ether and polyethyleneimine, or a mixture of glycerol triglycidyl ether and ethylenediamine. The initiator is 2, 4, 6-tris(dimethylaminomethyl)phenol. In Step 2, the preset temperature is 0 - 30 °C, and the pre-polymerization duration is 1 - 12 h; the height of the doctor blade is set to 50 - 400 μm. In Step 3, during the microwave curing treatment, the power of the microwave is set to 400 - 800 W, and the microwave curing treatment duration does not exceed 5 min.

2. The method for preparing a gas barrier film based on microwave heating according to claim 1, wherein The degassing treatment is at least one of vacuum degassing, ultrasonic degassing, and centrifugal degassing.

3. The method for preparing a gas barrier film based on microwave heating according to claim 1, characterized in that, The degassed casting solution is pre-polymerized at room temperature or in an ice-water bath.

4. The method for preparing a gas barrier film based on microwave heating according to claim 1, characterized in that, The substrate is at least one of non-woven fabric, plastic sheet, and steel.

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