Super-hydrophobic polyvinyl alcohol film and preparation method thereof
By preparing super-hydrophobic polyvinyl alcohol film, the problem of poor water resistance of polyvinyl alcohol film is solved, and high water resistance and degradability are achieved, which is suitable for fields such as nuclear power plant protective clothing.
Patent Information
- Application Number
- CN202510915742.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-03
- Publication Date
- 2025-09-19
AI Technical Summary
Polyvinyl alcohol film is prone to adhesion after absorbing moisture or water and has poor water resistance, which limits its application in fields such as protective clothing in nuclear power plants.
A super-hydrophobic polyvinyl alcohol film was prepared by preparing a polyvinyl alcohol solution in an oxygen-free environment, adding a surfactant, a plasticizer and a carboxylic acid cross-linking agent, standing for defoaming and then drying, preparing a silane coupling agent solution for immersion treatment, and combining with ultrasonic composite non-woven fabrics.
The water resistance and waterproof performance of the film are improved, making its contact angle greater than 150°, achieving a super-hydrophobic state, and it can be quickly degraded through processes such as dissolution, filtration, and catalytic oxidation, which is environmentally friendly and pollution-free.
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Figure CN120665337A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of nuclear power plant radiation protection technology, and in particular relates to a super-hydrophobic polyvinyl alcohol film and a preparation method thereof. Background Art
[0002] The creation of plastic products has brought great convenience to people's lives. They are often favored for their excellent properties, such as light weight, waterproofness, high strength, and corrosion resistance. However, despite these advantages, the production and disposal of plastics have an increasingly negative impact on the environment, polluting land and oceans and threatening the health of human society and the economy.
[0003] Traditional plastics are primarily made from polymers such as polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC). These polymers are stable and difficult to decompose in the natural environment after use and disposal, thus becoming permanent waste. Polyvinyl alcohol (PVA) film is soft, transparent, breathable, non-toxic, and biocompatible. It also possesses excellent mechanical properties and is fully biodegradable, meeting the needs of green and environmentally friendly development. Therefore, replacing non-degradable PE and PP materials with environmentally friendly PVA film is a major future trend.
[0004] In the field of nuclear power plant protective equipment, after the use of disposable protective equipment made of polyvinyl alcohol, the waste is dissolved into liquid through a special high-efficiency degradation system, and is finally completely oxidized to produce CO2 and H2O through the Fenton reaction. The radioactive nuclides remain in the reaction residue. After treatment and monitoring, if it is lower than the liquid effluent emission standard, it can be directly discharged into the environment. If it does not meet the emission standard, it can be sent to the waste liquid treatment system for evaporation treatment, and the evaporated residual liquid is subjected to cement solidification and other treatments.
[0005] Polyvinyl alcohol contains many hydroxyl groups on its molecular chain, which can form hydrogen bonds with water. It is easily soluble in water but has poor water resistance. After absorbing moisture or water, its film is prone to adhesion due to its water absorption and swelling effect, which limits its application. Summary of the Invention
[0006] The purpose of this application is to provide a super-hydrophobic polyvinyl alcohol film and a preparation method thereof, so as to solve the problems of non-degradable protective clothing and poor water resistance of degradable protective clothing, and is suitable for protective products such as disposable protective clothing for nuclear power plants.
[0007] In order to achieve the above objectives, this application provides the following technical solutions:
[0008] In a first aspect, the present application provides a method for preparing a super-hydrophobic polyvinyl alcohol film, comprising:
[0009] Step 1: In an oxygen-free environment, PVA resin, surfactant, plasticizer, and carboxylic acid crosslinking agent are added to deionized water, heated and stirred to prepare a polyvinyl alcohol solution;
[0010] Step 2: After the reaction is completed, the film is placed on standby for defoaming, and then cast and dried to obtain a preliminarily modified polyvinyl alcohol film;
[0011] Step 3: Prepare silane coupling agent ethanol solution;
[0012] Step 4: soaking the preliminarily cross-linked modified polyvinyl alcohol film in an ethanol solution of a silane coupling agent, cleaning the surface of the film with ethanol, and obtaining the polyvinyl alcohol film after drying.
[0013] As an practicable manner, the components of the polyvinyl alcohol solution by mass percentage are: polyvinyl alcohol resin 10% to 15%, plasticizer 1% to 1.5%, surfactant 0.3% to 0.5%, carboxylic acid crosslinking agent 5‰ to 1.5%, and the balance is deionized water.
[0014] As an practicable manner, the degree of polymerization of the polyvinyl alcohol resin is 500 to 2600, and the degree of alcoholysis is above 99%.
[0015] As an practicable manner, the surfactant is one or more of sodium lauryl sulfate, Tween-80, OP-10, fatty alcohol, and fatty acid.
[0016] As an practicable embodiment, the plasticizer is glycerol.
[0017] As an practicable manner, the carboxylic acid cross-linking agent is one or more of boric acid, citric acid, oxalic acid, malic acid, and maleic acid.
[0018] As an practicable method, the standing time is 12 hours to 24 hours, and the drying condition is drying at 80° C. for 10 minutes.
[0019] As an practicable manner, the silane coupling agent is one or more of octafluorodecyltrimethoxysilane, octadecyltrimethoxysilane, and hexadecyltrimethoxysilane, and the concentration of the ethanol solution is 5%.
[0020] As an practicable manner, the soaking condition is soaking at 60° C. for 2 hours or soaking at 25° C. for 2 hours.
[0021] As an practicable manner, the method further includes step 5: compounding the super-hydrophobic film with the polyvinyl alcohol non-woven fabric by ultrasonic treatment to obtain a degradable industrial protective clothing product with stable water and oil repellency.
[0022] In a second aspect, the present application provides a super-hydrophobic polyvinyl alcohol film prepared using the above method.
[0023] Compared with the prior art, the super-hydrophobic polyvinyl alcohol film and the preparation method thereof provided by the present application have the following beneficial effects:
[0024] The present application shields the hydrophilic hydroxyl groups on the molecular chain by esterification reaction, increases the cross-linking degree and compactness of the film, improves the water resistance of the film, and on this basis, utilizes fluoride or long carbon chain alkane reagent to carry out surface modification to the film, because the hydroxyl groups rich in the side chain of PVA can easily react with the silicon oxygen bond, and even can trigger olefin double bonds to polymerize in the side chain by generating free radical monomers, thereby introducing functional groups or compounds into the polymer structure, significantly improving the water resistance of PVA film, and tests show that its contact angle is greater than 150 °, reaching super hydrophobic state. Functional structure is covalently bonded to polyvinyl alcohol, and modified film has excellent stability, and there is no problem of migration and leakage of auxiliary agents over time causing performance degradation. After the composite material is abandoned, rapid degradation can be achieved by processes such as dissolution, filtration, catalytic oxidation, and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In order to more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings required for the technical description.
[0026] Figure 1 A flow chart of the super-hydrophobic polyvinyl alcohol film and its preparation method provided in this application;
[0027] Figure 2 This is a comparison chart of the contact angle tests of the PE film and modified super-hydrophobic PVA film provided in this application. DETAILED DESCRIPTION
[0028] The following is further explained in detail through specific implementation methods.
[0029] like Figure 1 As shown, the present application provides a method for preparing a super-hydrophobic polyvinyl alcohol film, comprising:
[0030] Step 1: In an oxygen-free environment, PVA resin, surfactant, plasticizer, and carboxylic acid crosslinking agent are added to deionized water, heated and stirred at 90°C for more than 2 hours until all are completely dissolved to prepare a polyvinyl alcohol solution;
[0031] Step 2: After the reaction is completed, the film is placed on standby for defoaming, and then cast and dried to obtain a preliminarily modified polyvinyl alcohol film;
[0032] Step 3: Prepare a 5% silane coupling agent ethanol solution;
[0033] Step 4: soaking the preliminarily cross-linked modified polyvinyl alcohol film in a silane coupling agent ethanol solution for 2 hours, washing the film surface with ethanol several times, and drying the film to obtain a polyvinyl alcohol film;
[0034] Step 5: The super-hydrophobic film and the polyvinyl alcohol non-woven fabric are ultrasonically compounded to finally obtain a biodegradable industrial protective clothing product with stable water and oil repellency.
[0035] In step 1, the polyvinyl alcohol solution includes the following components in percentage by mass: 10% to 15% of polyvinyl alcohol resin, 1% to 1.5% of plasticizer, 0.3% to 0.5% of surfactant, 5‰ to 1.5% of carboxylic acid crosslinking agent, and the balance is deionized water.
[0036] In step 1, the degree of polymerization of the polyvinyl alcohol resin is 500 to 2600, and the degree of alcoholysis is above 99%.
[0037] In step 1, the surfactant is one or more of sodium lauryl sulfate, Tween-80, OP-10, fatty alcohol, and fatty acid.
[0038] In step 1, the plasticizer is glycerol.
[0039] In step 1, the carboxylic acid cross-linking agent is one or more of boric acid, citric acid, oxalic acid, malic acid, and maleic acid.
[0040] In step 2, the standing time is 12 h to 24 h, and the drying condition is drying at 80° C. for 10 min.
[0041] In step 3, the silane coupling agent is one or more of octafluorodecyltrimethoxysilane, octadecyltrimethoxysilane, and hexadecyltrimethoxysilane, and the concentration of the ethanol solution is 5%.
[0042] In step 4, the soaking condition is soaking at 60° C. for 2 h or soaking at room temperature (25° C.) for 2 h.
[0043] Example 1
[0044] Under nitrogen, 20g of PVA1799 was placed in a beaker, followed by the addition of 0.6g of sodium lauryl sulfate, 2.0g of glycerol, 2.0g of boric acid, and 180g of deionized water. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved and fully reacted with the crosslinker. The mixture was allowed to stand for defoaming, then cast and dried at 80°C for 10 minutes. The resulting cross-linked polyvinyl alcohol film was then peeled off. A 5% octafluorodecyltrimethoxysilane solution in ethanol was prepared, and the cross-linked film was placed in the solution. After soaking at 60°C for 2 hours, the surface was rinsed several times with ethanol, and dried at 80°C for 10 minutes to produce a superhydrophobic polyvinyl alcohol film. The film was then ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to obtain the product.
[0045] Example 2
[0046] Under nitrogen, 20g of PVA1799 was placed in a beaker, followed by the addition of 0.6g of sodium lauryl sulfate, 2.0g of glycerol, 2.0g of citric acid, and 180g of deionized water. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved and fully reacted with the crosslinker. The mixture was allowed to stand for defoaming, then cast and dried at 80°C for 10 minutes. The resulting cross-linked polyvinyl alcohol film was then peeled off. A 5% octafluorodecyltrimethoxysilane solution in ethanol was prepared, and the cross-linked film was placed in the solution. After soaking at 60°C for 2 hours, the surface was rinsed several times with ethanol and dried at 80°C for 10 minutes to produce a superhydrophobic polyvinyl alcohol film. The film was then ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to obtain the product.
[0047] Example 3
[0048] Under nitrogen, 20g of PVA1799 was placed in a beaker, followed by the addition of 0.6g of sodium lauryl sulfate, 2.0g of glycerol, 2.0g of oxalic acid, and 180g of deionized water. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved and fully reacted with the crosslinker. The mixture was allowed to stand for defoaming, then cast and dried at 80°C for 10 minutes. The resulting cross-linked polyvinyl alcohol film was then peeled off. A 5% octafluorodecyltrimethoxysilane solution in ethanol was prepared, and the cross-linked film was placed in the solution. After soaking at 60°C for 2 hours, the surface was rinsed several times with ethanol and dried at 80°C for 10 minutes to produce a superhydrophobic polyvinyl alcohol film. The film was then ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to obtain the product.
[0049] Example 4
[0050] Under nitrogen, 20g of PVA1799 was placed in a beaker, followed by the addition of 0.6g of sodium lauryl sulfate, 2.0g of glycerol, 2.0g of malic acid, and 180g of deionized water. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved and fully reacted with the crosslinker. The mixture was allowed to stand for defoaming, then cast and dried at 80°C for 10 minutes. The resulting cross-linked polyvinyl alcohol film was then peeled off. A 5% octafluorodecyltrimethoxysilane solution in ethanol was prepared, and the cross-linked film was placed in the solution. After soaking at 60°C for 2 hours, the surface was rinsed several times with ethanol, and dried at 80°C for 10 minutes to produce a superhydrophobic polyvinyl alcohol film. The film was then ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to obtain the product.
[0051] Example 5
[0052] Under nitrogen, 20g of PVA1799 was placed in a beaker, followed by the addition of 0.6g of sodium lauryl sulfate, 2.0g of glycerol, 2.0g of maleic acid, and 180g of deionized water. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved and fully reacted with the crosslinker. The mixture was allowed to stand for defoaming, then cast and dried at 80°C for 10 minutes. The resulting cross-linked polyvinyl alcohol film was then peeled off. A 5% octafluorodecyltrimethoxysilane solution in ethanol was prepared, and the cross-linked film was placed in the solution. The film was then soaked at 60°C for 2 hours, rinsed several times with ethanol, and dried at 80°C for 10 minutes to produce a superhydrophobic polyvinyl alcohol film. The film was then ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to yield the product.
[0053] Example 6
[0054] Under nitrogen, 20g of PVA1799 was placed in a beaker, followed by the addition of 0.6g of sodium lauryl sulfate, 2.0g of glycerol, 2.0g of boric acid, and 180g of deionized water. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved and fully reacted with the crosslinker. The mixture was allowed to stand for defoaming, then cast and dried at 80°C for 10 minutes. The resulting cross-linked polyvinyl alcohol film was then peeled off. A 5% octadecyltrimethoxysilane ethanol solution was prepared, and the cross-linked film was placed in the solution. After soaking at 60°C for 2 hours, the surface was rinsed several times with ethanol and dried at 80°C for 10 minutes to produce a superhydrophobic polyvinyl alcohol film. The film was then ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to obtain the product.
[0055] Example 7
[0056] Under nitrogen, 20g of PVA1799 was placed in a beaker, followed by the addition of 0.6g of sodium lauryl sulfate, 2.0g of glycerol, 2.0g of boric acid, and 180g of deionized water. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved and fully reacted with the crosslinker. The mixture was allowed to stand for defoaming, then cast and dried at 80°C for 10 minutes. The resulting cross-linked polyvinyl alcohol film was then peeled off. A 5% hexadecyltrimethoxysilane ethanol solution was prepared, and the cross-linked film was placed in the solution. After soaking at 60°C for 2 hours, the surface was rinsed several times with ethanol, and dried at 80°C for 10 minutes to produce a superhydrophobic polyvinyl alcohol film. The film was then ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to obtain the final product.
[0057] Comparative Example 1
[0058] Under nitrogen, 20g of PVA1799 was placed in a beaker. 0.6g of sodium lauryl sulfate, 2.0g of glycerol, and 180g of deionized water were added sequentially. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved. The mixture was allowed to stand for defoaming, and then cast and dried at 80°C for 10 minutes. The resulting polyvinyl alcohol film was then peeled off and ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to obtain the final product.
[0059] Comparative Example 2
[0060] Under nitrogen, 20g of PVA1799 was placed in a beaker. 0.6g of sodium lauryl sulfate, 2.0g of glycerol, 2.0g of boric acid, and 180g of deionized water were added in that order. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved and fully reacted with the crosslinker. The mixture was allowed to stand for defoaming, and then cast and dried at 80°C for 10 minutes. The resulting crosslinked polyvinyl alcohol film was then exfoliated and ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to obtain the final product.
[0061] Comparative Example 3
[0062] Under nitrogen, 20g of PVA1799 was placed in a beaker, followed by the addition of 0.6g of sodium lauryl sulfate, 2.0g of glycerol, and 180g of deionized water. The mixture was heated and stirred at 90°C for at least 2 hours until the PVA was completely dissolved. The mixture was allowed to stand for defoaming, and then cast and dried at 80°C for 10 minutes. The resulting polyvinyl alcohol film was then peeled off. A 5% octadecyltrimethoxysilane ethanol solution was prepared, and the polyvinyl alcohol film was placed in the solution. The film was then soaked at 60°C for 2 hours, rinsed several times with ethanol, and dried at 80°C for 10 minutes to produce the modified polyvinyl alcohol film. The film was then ultrasonically laminated with a 65gsm polyvinyl alcohol nonwoven fabric to obtain the final product.
[0063] The mechanical properties and contact angles of Examples 1 to 7, Comparative Examples 1 to 3, and common PE and PP films on the market were tested, and the test results are shown in Table 1.
[0064] Table 1 Performance comparison results of the embodiment and market products
[0065] / Tensile strength / MPa Elongation at break / % Contact angle / ° Example 1 75 156 158 Example 2 72 160 144 Example 3 66 175 136 Example 4 73 160 155 Example 5 48 178 138 Example 6 75 158 152 Example 7 76 155 150 Comparative Example 1 35 360 32 Comparative Example 2 74 152 66 Comparative Example 3 38 362 54 PE 40 350 105 PP 36 300 100
[0066] As shown in Table 1, the introduction of carboxylic acid cross-linking agents increases the cross-linking density of PVA films. The molecular chains are entangled with each other, and a greater force is required to deform the material. Therefore, the tensile strength increases and the elongation at break decreases. At the same time, it is found that the silane coupling agent has no obvious effect on the mechanical properties of the film.
[0067] It can be seen from the table that super-hydrophobic films cannot be prepared by cross-linking agent modification or silane coupling agent treatment alone. The two have a synergistic effect. First, a carboxylic acid cross-linking agent is used to undergo an esterification reaction with polyvinyl alcohol to reduce the sensitivity of the polyvinyl alcohol film to water molecules by shielding the side chain hydroxyl groups. On this basis, the modified polyvinyl alcohol film is immersed in a silane coupling agent for surface modification, and low surface energy substances are enriched on the film surface, thereby achieving the purpose of super-hydrophobic modification.
[0068] After the esterification reaction between boric acid / malic acid and polyvinyl alcohol, whether the coupling agent is the fluoride octafluorodecyltrimethoxysilane or the long-chain alkane compounds octadecyltrimethoxysilane and hexadecyltrimethoxysilane, a super-hydrophobic polyvinyl alcohol modified film with a contact angle greater than 150° can be prepared, which makes up for the inherent defects of polyvinyl alcohol material and its waterproof performance has surpassed that of traditional PE and PP materials. Figure 2 The modified film not only has excellent properties and can replace PP / PE film, but also can achieve rapid industrial degradation and has broad application prospects.
[0069] In addition, the present application also provides a super-hydrophobic polyvinyl alcohol film prepared using the above method.
[0070] In addition, the present application also provides a degradable composite fabric. The degradable composite fabric is formed by ultrasonically compounding a super-hydrophobic polyvinyl alcohol film and a polyvinyl alcohol non-woven fabric. The degradable composite fabric includes a polyvinyl alcohol non-woven fabric and a polyvinyl alcohol film ultrasonically compounded. The polyvinyl alcohol film is surface modified by esterification cross-linking and low surface energy reagents to shield the hydrophilic hydroxyl groups on the molecular chain, reconstruct the microstructure of the natural polyvinyl alcohol-based film, and give the film and composite product a stable super-hydrophobic function, thereby expanding its application.
[0071] This application first utilizes a carboxylic acid crosslinker to esterify polyvinyl alcohol (PVA), thereby shielding the side chain hydroxyl groups and reducing the PVA film's sensitivity to water molecules. Furthermore, the modified PVA film is then immersed in a silane coupling agent for surface modification, resulting in a super-hydrophobic PVA film. Finally, the film is composited with a PVA nonwoven to create a protective clothing material with excellent waterproof properties.
[0072] The above description is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.
Claims
1. A method for preparing a super-hydrophobic polyvinyl alcohol film, characterized in that: include: Step 1: In an oxygen-free environment, PVA resin, surfactant, plasticizer, and carboxylic acid crosslinking agent are added to deionized water, heated and stirred to prepare a polyvinyl alcohol solution; Step 2: After the reaction is completed, the film is placed on standby for defoaming, and then cast and dried to obtain a preliminarily modified polyvinyl alcohol film; Step 3: Prepare silane coupling agent ethanol solution; Step 4: soaking the preliminarily cross-linked modified polyvinyl alcohol film in an ethanol solution of a silane coupling agent, cleaning the surface of the film with ethanol, and obtaining the polyvinyl alcohol film after drying.
2. The method for preparing a super-hydrophobic polyvinyl alcohol film according to claim 1, wherein In step 1, the components of the polyvinyl alcohol solution in mass percentage are: polyvinyl alcohol resin 10% to 15%, plasticizer 1% to 1.5%, surfactant 0.3% to 0.5%, carboxylic acid crosslinking agent 5‰ to 1.5%, and the balance is deionized water.
3. The method for preparing a super-hydrophobic polyvinyl alcohol film according to claim 1, wherein In step 1, the degree of polymerization of the polyvinyl alcohol resin is 500 to 2600, and the degree of alcoholysis is above 99%.
4. The method for preparing a super-hydrophobic polyvinyl alcohol film according to claim 1, wherein In step 1, the surfactant is one or more of sodium lauryl sulfate, Tween-80, OP-10, fatty alcohol, and fatty acid.
5. The method for preparing a super-hydrophobic polyvinyl alcohol film according to claim 1, wherein In step 1, the plasticizer is glycerol.
6. The method for preparing a super-hydrophobic polyvinyl alcohol film according to claim 1, wherein In step 1, the carboxylic acid cross-linking agent is one or more of boric acid, citric acid, oxalic acid, malic acid, and maleic acid.
7. The method for preparing a super-hydrophobic polyvinyl alcohol film according to claim 1, wherein In step 2, the standing time is 12 h to 24 h, and the drying condition is drying at 80° C. for 10 min.
8. The method for preparing a super-hydrophobic polyvinyl alcohol film according to claim 1, wherein In step 3, the silane coupling agent is one or more of octafluorodecyltrimethoxysilane, octadecyltrimethoxysilane, and hexadecyltrimethoxysilane, and the concentration of the ethanol solution is 5%.
9. The method for preparing a super-hydrophobic polyvinyl alcohol film according to claim 1, wherein The method also includes step 5: compounding the super-hydrophobic film and the polyvinyl alcohol non-woven fabric by ultrasonic treatment to obtain a degradable industrial protective clothing product with stable water- and oil-repellent functions.
10. A super-hydrophobic polyvinyl alcohol film, characterized in that: The method is as described in any one of claims 1 to 9.