Moisture-resistant polyvinyl alcohol medical fabric packaging film and preparation method thereof

Abstract

The invention relates to a moisture-resistant polyvinyl alcohol medical fabric packaging film and a preparation method thereof, and the method comprises the following steps: selecting polyvinyl alcohol with the molecular weight of 110000-130000 and glycidyl methacrylate with the purity of greater than or equal to 99%; dissolving polyvinyl alcohol in a mixed solvent of ethanol and water to obtain a mixed solution; adding an initiator and glycidyl methacrylate into the mixed solution, and reacting under the protection of nitrogen to form a grafted modified polyvinyl alcohol solution; and pouring the grafted modified polyvinyl alcohol solution into a mold, and drying to obtain the film. According to the method, the polyvinyl alcohol and the glycidyl methacrylate are subjected to the grafting reaction through the initiator to form the grafted modified polyvinyl alcohol solution, the film is obtained after drying, hydrophobic groups are introduced into polyvinyl alcohol molecular chains of the film, the hydroxyl hydrogen-bond interaction between the polyvinyl alcohol molecular chains is reduced through the hydrophobic groups, and therefore the film has the advantages that the film is more stable; the adsorption capacity of a molecular chain on water molecules is reduced, and excellent moisture-proof and moisture-proof performance is achieved.

Description

Technical Field

[0001] This application relates to the technical field of polymer material modification, and particularly to a moisture-resistant polyvinyl alcohol medical fabric packaging film and a preparation method thereof. Background Art

[0002] Due to its excellent biocompatibility, degradability and mechanical properties, polyvinyl alcohol (PVA) has been widely used in the field of medical fabric packaging materials, especially suitable for medical scenarios with high requirements for material safety and environmental protection. However, the hydrophilic property of PVA molecular chains rich in hydroxyl groups makes its film materials extremely sensitive to environmental humidity, prone to swelling, softening or even dissolution in high-humidity environments, seriously affecting its barrier performance, mechanical strength and long-term stability. This limits the popularization and application of PVA-based medical packaging films in humid climate regions or high-humidity medical environments. The existing technology mainly alleviates the humidity impact by introducing traditional moisture-proof agents (such as silica gel, mineral fillers). However, traditional moisture-proof agents are prone to failure in high-humidity environments. Summary of the Invention

[0003] In view of the above, it is necessary to propose a moisture-resistant polyvinyl alcohol medical fabric packaging film and a preparation method thereof to enhance the moisture resistance of the polyvinyl alcohol medical fabric packaging film.

[0004] In a first aspect, an embodiment of the present application provides a preparation method of a moisture-resistant polyvinyl alcohol medical fabric packaging film, including the following steps:

[0005] Select polyvinyl alcohol with a molecular weight of 110,000 - 130,000 and glycidyl methacrylate, wherein the purity of the glycidyl methacrylate is ≥99%;

[0006] Dissolve the polyvinyl alcohol in a mixed solvent of ethanol and water to obtain a mixed solution;

[0007] Add an initiator and glycidyl methacrylate to the mixed solution, and react under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0008] Pour the graft-modified polyvinyl alcohol solution into a mold, and obtain a film after drying.

[0009] In the preparation method of the polyvinyl alcohol medical fabric packaging film according to the embodiments of the present application, polyvinyl alcohol and glycidyl methacrylate undergo a graft reaction through an initiator to form a graft-modified polyvinyl alcohol solution. After drying, a film is obtained. Since hydrophobic groups are introduced into the polyvinyl alcohol molecular chain, the hydrophobic groups reduce the hydrogen bonding between the hydroxyl groups of the polyvinyl alcohol molecular chains through physical entanglement or chemical bonding, reducing the adsorption ability of the molecular chains to water molecules, and having excellent moisture-proof and moisture-resistant properties. And by selecting polyvinyl alcohol with a molecular weight of 110,000 - 130,000, the grafted film can still maintain high mechanical strength in a high-humidity environment, and the oxygen barrier performance is also excellent.

[0010] Polyvinyl alcohol is biodegradable and has good biocompatibility, so it is mostly used in the fields of food packaging or medical packaging materials. However, since it contains multiple hydroxyl groups on its molecular chain and can form hydrogen bonds with water molecules, its water resistance is poor and its strength cannot meet the actual requirements. Therefore, to improve the comprehensive performance of the polyvinyl alcohol film, glycidyl methacrylate is introduced. On the one hand, the epoxy group in the glycidyl methacrylate molecule can react with the hydroxyl group in the polyvinyl alcohol molecule to form a cross-linked structure, which can effectively block the penetration of water molecules. On the other hand, the graft modification process can enhance the interaction between the polyvinyl alcohol molecular chains, improving the mechanical properties of the product and the tensile strength.

[0011] Furthermore, by selecting glycidyl methacrylate with a purity greater than or equal to 99%, the modified film can retain the natural biocompatibility of polyvinyl alcohol while improving its moisture resistance, meeting the safety standards of medical packaging materials.

[0012] In some embodiments, the step of dissolving polyvinyl alcohol in a mixed solvent of ethanol and water to obtain a mixed solution specifically includes:

[0013] Dissolve polyvinyl alcohol in a mixed solvent of ethanol and water with a volume ratio of ethanol to water of 1:1 to obtain a mixed solution.

[0014] In some embodiments, the step of adding an initiator and glycidyl methacrylate to the mixed solution and reacting under nitrogen protection to form a graft-modified polyvinyl alcohol solution specifically includes:

[0015] Add an initiator and glycidyl methacrylate to the mixed solution and react at 72°C - 78°C for 3.2 h - 3.8 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution, where the amount of the initiator is 0.6% - 0.8% of the mass of the polyvinyl alcohol.

[0016] In some embodiments, the initiator is one of ammonium persulfate, potassium persulfate, sodium persulfate, and 2,2'-azobis(2-methylpropionamidine) dihydrochloride.

[0017] In some embodiments, the step of pouring the graft-modified polyvinyl alcohol solution into a mold and drying to obtain a film specifically includes:

[0018] Adding a microsphere template agent to the graft-modified polyvinyl alcohol solution to obtain a reaction solution, wherein the dosage of the microsphere template agent is 6%-9% of the mass of the reaction solution, and the diameter of the microsphere template agent is 60 nm - 90 nm;

[0019] Pouring the reaction solution into a mold and drying to obtain a film with multiple pores.

[0020] In some embodiments, the microsphere template agent is one of a polystyrene microsphere template agent, a polymethyl methacrylate microsphere template agent, and a chitosan microsphere template agent.

[0021] In some embodiments, the step of pouring the reaction solution into a mold and drying to obtain a film with multiple pores specifically includes:

[0022] Pouring the reaction solution into a mold, drying at room temperature for 25 h - 35 h, and then drying in an oven at 62°C - 68°C for 8.5 h - 9.5 h to obtain a film with multiple pores.

[0023] In some embodiments, the steps after pouring the graft-modified polyvinyl alcohol solution into a mold and drying to obtain a film specifically include:

[0024] Treating the surface of the film with a coupling agent having a concentration of 1.2% - 1.8% for 1.2 h - 1.8 h to obtain a hydrophobic film.

[0025] In some embodiments, the coupling agent is one of a fluorosilane coupling agent, a fluorocarbon coupling agent, a silane coupling agent, a titanate coupling agent, and a zirconate coupling agent.

[0026] In a second aspect, an embodiment of the present application provides a polyvinyl alcohol medical fabric packaging film prepared from the film obtained by the method described in any one of the above.

[0027] Due to the introduction of hydrophobic groups into the polyvinyl alcohol molecular chain, the hydrophobic groups reduce the hydrogen bonding of hydroxyl groups between polyvinyl alcohol molecular chains through physical entanglement or chemical bonding, reducing the water molecule adsorption ability of the molecular chain. The polyvinyl alcohol medical fabric packaging film of the embodiment of the present application has excellent moisture-proof and water-resistant properties. By selecting polyvinyl alcohol with a molecular weight of 110,000 - 130,000, the grafted film can maintain high mechanical strength in a high-humidity environment, and its oxygen barrier performance is also excellent. To improve the comprehensive performance of the polyvinyl alcohol film, glycidyl methacrylate is introduced. On the one hand, the epoxy group in the glycidyl methacrylate molecule can react with the hydroxyl group in the polyvinyl alcohol molecule to form a cross-linked structure, which can effectively hinder the penetration of water molecules. On the other hand, the graft modification process enhances the interaction between polyvinyl alcohol molecular chains, improving the mechanical properties of the product and the tensile strength. Further, by selecting glycidyl methacrylate with a purity of greater than or equal to 99%, the modified film can retain the natural biocompatibility of polyvinyl alcohol while improving its moisture resistance, meeting the safety standards of medical packaging materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 FIG. is a flowchart of a method for preparing a moisture-resistant polyvinyl alcohol medical fabric packaging film provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following details the embodiments of the present application. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for explaining the present application and should not be construed as limiting the present application.

[0030] In a first aspect, please refer to Figure 1 , an embodiment of the present application provides a method for preparing a moisture-resistant polyvinyl alcohol medical fabric packaging film, including the following steps:

[0031] S10. Select polyvinyl alcohol with a molecular weight of 110,000 - 130,000 and glycidyl methacrylate, where the purity of glycidyl methacrylate is ≥99%. Preferably, the molecular weight of polyvinyl alcohol is 120,000.

[0032] S20. Dissolve the polyvinyl alcohol in a mixed solvent of ethanol and water to obtain a mixed solution.

[0033] S30. Add an initiator and glycidyl methacrylate to the mixed solution and react under nitrogen protection to form a graft-modified polyvinyl alcohol solution.

[0034] S40. Pour the graft-modified polyvinyl alcohol solution into a mold, and obtain a film after drying.

[0035] In the polyvinyl alcohol medical fabric packaging film and its preparation method according to the embodiments of the present application, polyvinyl alcohol and glycidyl methacrylate undergo a graft reaction through an initiator to form a graft-modified polyvinyl alcohol solution, and a film is obtained after drying. Since a hydrophobic group is introduced into the polyvinyl alcohol molecular chain, the hydrophobic group reduces the hydrogen bond interaction between the polyvinyl alcohol molecular chains through physical entanglement or chemical bonding, reduces the adsorption ability of the molecular chain to water molecules, and has excellent moisture-proof and water-resistant properties. And by selecting polyvinyl alcohol with a molecular weight of 110,000 - 130,000, the grafted film can still maintain a relatively high mechanical strength in a high-humidity environment, and the oxygen barrier performance is also very excellent.

[0036] Polyvinyl alcohol has biodegradability and good biocompatibility, so it is mostly used in the fields of food packaging or medical packaging materials. However, since there are multiple hydroxyl groups on its molecular chain, which can form hydrogen bonds with water molecules, its water-resistant performance is poor and its strength cannot meet the actual requirements. Therefore, to improve the comprehensive performance of the polyvinyl alcohol film, glycidyl methacrylate is introduced. On the one hand, the epoxy group in the glycidyl methacrylate molecule can react with the hydroxyl group in the polyvinyl alcohol molecule to form a cross-linked structure, which can effectively hinder the penetration of water molecules. On the other hand, the graft modification process can enhance the interaction between the polyvinyl alcohol molecular chains, enhance the mechanical properties of the product, and improve the tensile strength.

[0037] Furthermore, by selecting glycidyl methacrylate with a purity greater than or equal to 99%, the modified film can retain the natural biocompatibility of polyvinyl alcohol while improving its moisture resistance, meeting the safety standards of medical packaging materials.

[0038] In some embodiments, the step of dissolving polyvinyl alcohol in a mixed solvent of ethanol and water to obtain a mixed solution specifically includes:

[0039] Dissolve polyvinyl alcohol in a mixed solvent of ethanol and water with a volume ratio of ethanol to water of 1:1 to obtain a mixed solution.

[0040] Among them, a mixed solvent with a volume ratio of ethanol to water of 1:1 is used to dissolve polyvinyl alcohol. On the one hand, the synergistic effect of ethanol and water at this ratio can effectively reduce the hydrogen bond interaction between polyvinyl alcohol molecules, enabling polyvinyl alcohol to dissolve more quickly and fully, improving the dissolution efficiency and the uniformity of the mixed solution, and providing a stable and homogeneous system for the subsequent grafting reaction. On the other hand, this solvent ratio can adjust the polarity and surface tension of the solution, which helps glycidyl methacrylate to be evenly dispersed in the solution, promotes its effective contact and reaction with the polyvinyl alcohol molecular chain, enhances the grafting efficiency, and further improves the humidity tolerance of the modified polyvinyl alcohol. At the same time, in the process of drying and film formation of this mixed solvent system, it is beneficial for the solvent to volatilize quickly and not easily remain, avoiding affecting the film properties, ensuring the integrity of the formed film structure and stable performance, better achieving the balance between breathability and moisture resistance, and further guaranteeing the use effect of the polyvinyl alcohol medical fabric packaging film in a high-humidity environment.

[0041] In some embodiments, adding an initiator and glycidyl methacrylate to the mixed solution and reacting under nitrogen protection to form a graft-modified polyvinyl alcohol solution specifically includes:

[0042] Adding an initiator and glycidyl methacrylate to the mixed solution and reacting at 72°C - 78°C for 3.2 h - 3.8 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution, where the dosage of the initiator is 0.6% - 0.8% of the mass of polyvinyl alcohol.

[0043] Among them, the reaction temperature of 72°C - 78°C is within the optimal activity range for the grafting reaction of polyvinyl alcohol and glycidyl methacrylate. It can not only accelerate the molecular chain movement and reaction rate but also avoid the degradation of polyvinyl alcohol or the occurrence of side reactions due to too high temperature. The reaction duration of 3.2 h - 3.8 h ensures the full progress of the grafting reaction, enables an ideal grafting rate of glycidyl methacrylate on the polyvinyl alcohol molecular chain, and effectively constructs a moisture-resistant cross-linked structure. Controlling the initiator dosage at 0.6% - 0.8% of the mass of polyvinyl alcohol can, while ensuring the initiation efficiency, avoid the occurrence of free radical polymerization side reactions or residual safety hazards due to excessive initiator. The nitrogen protection excludes the interference of oxygen, prevents the oxidation and degradation of polyvinyl alcohol and inhibits the premature decomposition of the initiator, maintains the stability of the reaction system, ensures the uniform quality of the graft-modified polyvinyl alcohol solution, lays a foundation for the subsequent film-forming step, and ultimately further optimizes the moisture resistance and stability of the prepared medical fabric packaging film.

[0044] In some embodiments, the initiator is one of ammonium persulfate, potassium persulfate, sodium persulfate, and 2,2'-azobis(2-methylpropionamidine) dihydrochloride.

[0045] Among them, ammonium persulfate, potassium persulfate, and sodium persulfate are used as inorganic peroxide initiators. The sulfate radicals decomposed from them have moderate activity, can stably initiate the grafting reaction of polyvinyl alcohol and glycidyl methacrylate at a reaction temperature of 72°C - 78°C, and the decomposition products have good water solubility and are easily volatilized with the solvent during the subsequent drying and film-forming process, reducing the residual risk. 2,2'-Azobis(2-methylpropionamidine) dihydrochloride is used as an azo initiator. No oxygen is generated during the decomposition process. In a reaction environment protected by nitrogen, the oxidation risk of the system can be further reduced. At the same time, its decomposition temperature is well adapted to the reaction temperature, can accurately control the free radical generation rate, and ensure the smooth progress of the grafting reaction.

[0046] In some embodiments, the steps of pouring the graft-modified polyvinyl alcohol solution into a mold and drying to obtain a film specifically include:

[0047] Adding a microsphere template agent to the graft-modified polyvinyl alcohol solution to obtain a reaction solution. Among them, the dosage of the microsphere template agent is 6% - 9% of the mass of the reaction solution, and the diameter of the microsphere template agent is 60 nm - 90 nm;

[0048] Pouring the reaction solution into a mold and drying to obtain a film with multiple pores.

[0049] Among them, the dosage of the microsphere template agent accounts for 6% - 9% of the mass of the reaction solution. This ratio can not only ensure the formation of a sufficient number of pores in the film, achieve moderate moisture exchange inside and outside the package, maintain the balance between air permeability and moisture barrier property, but also avoid the loosening of the film structure and the decrease of mechanical strength caused by excessive dosage. The microsphere diameter of 60 nm - 90 nm forms pores with appropriate sizes, which can effectively prevent the rapid penetration of large molecule water vapor, maintain a certain moisture barrier effect, and enable small molecule water vapor to pass through smoothly, preventing the humidity inside the package from being too high. At the same time, the microspheres of this size have good dispersibility in the solution, can be evenly distributed, ensure the uniformity of the pore structure after film formation, make the performance of the packaging film stable in different regions, further improve its applicability and reliability in a high-humidity medical environment, and ensure the packaging effect of medical textiles.

[0050] In some embodiments, the microsphere template agent is one of a polystyrene microsphere template agent, a polymethyl methacrylate microsphere template agent, and a chitosan microsphere template agent.

[0051] Among them, the polystyrene microsphere template has high hardness and regular shape, and has good dispersibility in the reaction solution. After removal, it can form pores with uniform size and stable structure, which helps to ensure the mechanical strength and stable air permeability and moisture barrier properties of the packaging film. The surface polarity of the polymethyl methacrylate microsphere template is moderate, and it has good compatibility with the grafted modified polyvinyl alcohol solution. It is not easy to agglomerate during the film formation process, and can form a uniform porous structure, so that the packaging film has good water exchange efficiency and barrier capacity. As a natural polymer material, the chitosan microsphere template has good biocompatibility and degradability. It can not only construct functional pores in the packaging film, but also improve the overall biosafety and environmental protection of the packaging film, which meets the strict requirements of the medical field for materials.

[0052] In some embodiments, the step of pouring the reaction solution into a mold and drying to obtain a film having a plurality of pores specifically comprises:

[0053] The reaction solution is poured into a mold, dried at room temperature for 25 h to 35 h, and then dried in an oven at 62° C. to 68° C. for 8.5 h to 9.5 h, thereby obtaining a film with multiple pores.

[0054] Among them, drying at room temperature for 25h-35h can slowly remove most of the solvent in the reaction solution, avoiding cracking of the film surface and collapse of the internal structure due to rapid evaporation, while providing sufficient time for the microsphere template agent and polyvinyl alcohol to fully react and ensure the uniformity of the porous structure. Subsequently, drying in an oven at 62℃-68℃ for 8.5h-9.5h can further remove the residual solvent at a lower temperature and promote the stable formation of the cross-linked structure between the polyvinyl alcohol molecular chains, which can prevent high temperature from destroying the moisture-resistant structure formed by grafting modification.

[0055] In some embodiments, the steps after pouring the grafted modified polyvinyl alcohol solution into a mold and drying to obtain a film specifically include:

[0056] The surface of the film is treated with a coupling agent having a concentration of 1.2% to 1.8% for 1.2h to 1.8h to obtain a hydrophobic film.

[0057] Among them, the coupling agent concentration of 1.2%-1.8% can ensure the formation of a complete hydrophobic layer on the film surface, reduce surface energy, and improve moisture resistance, while avoiding excessive concentration causing coupling agent aggregation to affect film performance. The treatment time of 1.2h-1.8h allows the coupling agent molecules to fully react and combine with the film surface, enhancing the surface modification effect.

[0058] Among them, toluene solvent immersion can be used to remove the microsphere template agent to obtain a hydrophobic film. Specifically, by virtue of the good solubility of toluene in common microsphere template agents such as polystyrene and polymethyl methacrylate, the template agent can be removed efficiently and thoroughly, leaving a uniform and stable porous structure to ensure the gas permeability and moisture barrier function of the film. At the same time, toluene has strong volatility and less residue, which will not have a negative impact on the biological safety and medical applicability of the packaging film.

[0059] In some embodiments, the coupling agent is one of a fluorosilane coupling agent, a fluorocarbon coupling agent, a silane coupling agent, a titanate coupling agent, and a zirconate coupling agent.

[0060] Among them, fluorosilane coupling agents and fluorocarbon coupling agents can construct a highly hydrophobic layer on the film surface with their extremely low surface energy, significantly improving the moisture-proof performance of the packaging film in a high-humidity environment and endowing it with certain anti-fouling ability. Silane coupling agents can form a stable silicone network structure on the film surface, enhancing the wear resistance and chemical stability of the film surface. Moreover, its hydrolysis products are environmentally friendly and harmless, meeting the safety requirements of the medical field. Titanate coupling agents and zirconate coupling agents can form strong chemical bonds on the film surface by reacting with the groups on the molecular chain of polyvinyl alcohol, not only improving the hydrophobic performance of the film surface but also enhancing the cross-linking degree inside the film, improving the overall mechanical strength and weather resistance of the packaging film.

[0061] In a second aspect, an embodiment of the present application provides a polyvinyl alcohol medical fabric packaging film prepared from the film obtained by the above method.

[0062] The polyvinyl alcohol medical fabric packaging film of the embodiment of the present application has excellent moisture-proof and water-resistant performance because hydrophobic groups are introduced into the polyvinyl alcohol molecular chain, and the hydrophobic groups reduce the hydrogen bond interaction between the polyvinyl alcohol molecular chains through physical entanglement or chemical bonding, reducing the water molecule adsorption ability of the molecular chain. By selecting polyvinyl alcohol with a molecular weight of 110,000 - 130,000, the grafted film can still maintain high mechanical strength in a high-humidity environment, and its oxygen barrier performance is also excellent. To improve the comprehensive performance of the polyvinyl alcohol film, glycidyl methacrylate is introduced. On the one hand, the epoxy group in the glycidyl methacrylate molecule can react with the hydroxyl group in the polyvinyl alcohol molecule to form a cross-linked structure, which can effectively block the penetration of water molecules. On the other hand, the graft modification process will enhance the interaction between the polyvinyl alcohol molecular chains, enhancing the mechanical properties of the product and improving the tensile strength. Further, by selecting glycidyl methacrylate with a purity greater than or equal to 99%, the modified film can retain the natural biocompatibility of polyvinyl alcohol while improving its moisture resistance, meeting the safety standards of medical packaging materials.

[0063] The technical solution of this application is not limited to the specific embodiments exemplified below, and also includes any combination between the specific embodiments.

[0064] Example 1

[0065] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0066] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0067] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0068] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, place the mold in an oven, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0069] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0070] Example 2

[0071] Select 50 g of polyvinyl alcohol with a molecular weight of 110,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0072] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0073] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0074] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0075] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0076] Example 3

[0077] Select 50 g of polyvinyl alcohol with a molecular weight of 130,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0078] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0079] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0080] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0081] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0082] Example 4

[0083] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0084] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0085] Add 0.3 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0086] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0087] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0088] Example 5

[0089] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0090] Dissolve polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a homogeneous mixed solution.

[0091] Add 0.4 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0092] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0093] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0094] Example 6

[0095] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0096] Dissolve polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a homogeneous mixed solution.

[0097] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 72 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0098] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0099] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0100] Example 7

[0101] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0102] Dissolve polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a homogeneous mixed solution.

[0103] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 78 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0104] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0105] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemicals.

[0106] Example 8

[0107] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0108] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0109] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.2 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0110] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0111] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemicals.

[0112] Example 9

[0113] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0114] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0115] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.8 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0116] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry it at room temperature for 30 h, and then dry it in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0117] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0118] Example 10

[0119] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0120] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0121] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0122] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry it at room temperature for 25 h, and then dry it in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0123] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0124] Example 11

[0125] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0126] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0127] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0128] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry it at room temperature for 35 h, and then dry it in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0129] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0130] Example 12

[0131] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0132] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0133] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0134] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry it at room temperature for 30 h, and then dry it in an oven at 62 °C for 9 h to obtain a film with multiple pores;

[0135] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0136] Example 13

[0137] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0138] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0139] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0140] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry it at room temperature for 30 h, and then dry it in an oven at 68 °C for 9 h to obtain a film with multiple pores;

[0141] Take out the dried film, soak it in deionized water for 24 hours to remove unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemicals.

[0142] Example 14

[0143] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0144] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0145] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0146] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry it at room temperature for 30 h, and then dry it in an oven at 65 °C for 8.5 h to obtain a film with multiple pores;

[0147] Take out the dried film, soak it in deionized water for 24 hours to remove unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemicals.

[0148] Example 15

[0149] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0150] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0151] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0152] Pour the graft-modified polyvinyl alcohol solution into a mold, control the thickness of the graft-modified polyvinyl alcohol solution to be 0.1 mm, dry it at room temperature for 30 h, and then dry it in an oven at 65 °C for 9.5 h to obtain a film with multiple pores;

[0153] Take out the dried film, soak it in deionized water for 24 hours to remove unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemicals.

[0154] Comparative Example 1

[0155] Select 50 g of polyvinyl alcohol with a molecular weight of 100,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0156] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0157] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0158] Pour the graft-modified polyvinyl alcohol solution into a mold, control the solution thickness to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0159] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0160] Comparative Example 2

[0161] Select 50 g of polyvinyl alcohol with a molecular weight of 140,000 and 5 g of glycidyl methacrylate with a purity of 99.5%;

[0162] Dissolve the polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0163] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0164] Pour the graft-modified polyvinyl alcohol solution into a mold, control the solution thickness to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0165] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0166] Comparative Example 3

[0167] Select 50 g of polyvinyl alcohol with a molecular weight of 120,000 and 5 g of glycidyl methacrylate with a purity of 95%;

[0168] Dissolve polyvinyl alcohol in a mixed solvent of 500 ml of ethanol and water with a ratio of ethanol to water of 1:1 to obtain a uniform mixed solution.

[0169] Add 0.35 g of potassium persulfate initiator and glycidyl methacrylate to the mixed solution, and react at 75 °C for 3.5 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution;

[0170] Pour the graft-modified polyvinyl alcohol solution into a mold, control the solution thickness to be 0.1 mm, dry at room temperature for 30 h, and then dry in an oven at 65 °C for 9 h to obtain a film with multiple pores;

[0171] Take out the dried film, soak it in deionized water for 24 hours to remove the unreacted initiator and glycidyl methacrylate, then take out the film and rinse it 3 times with deionized water to ensure the removal of residual chemical substances.

[0172] Comparative Example 4

[0173] In Comparative Example 4, a polyvinyl alcohol medical fabric packaging film (polyvinyl alcohol film) with a molecular weight of 120,000 was selected, and the polyvinyl alcohol medical fabric packaging film was not modified.

[0174] Detection experiment:

[0175] Take the films prepared in Examples 1 to 15 and Comparative Examples 1 to 4, cut the films into dumbbell-shaped samples according to the method disclosed in ASTM882-95, and test their tensile strength with a tensile speed of 50 mm / min.

[0176] According to the method disclosed in GB / T1034-2008, weigh the film after drying, then place it in an environment of 25 °C and 50% relative humidity, take it out and weigh it after 24 h, and test and calculate the water absorption rate.

[0177] Take a film with a diameter of 12 cm and test the oxygen transmission coefficient of the film. The instrument is evacuated before the experiment, and the test conditions are: 23 °C and 50% relative humidity.

[0178]

[0179] As can be seen from the above table: For the tensile strength, in Examples 1 to 15 and Comparative Examples 1 to 3, due to graft modification to form a cross-linked structure, the tensile strength is significantly higher than that of Comparative Example 4 without modification. Moreover, the molecular weight of polyvinyl alcohol in Examples 1 to 15 is in the range of 110,000 - 130,000, and the performance is stable; in Comparative Examples 1 and 2, due to the molecular weight deviating from the range of 110,000 - 130,000, the regularity of the molecular chain decreases and the tensile strength decreases; in Comparative Example 3, due to the insufficient purity of glycidyl methacrylate, the cross-linking efficiency decreases and the tensile strength decreases partially.

[0180] For the water absorption rate, the cross-linked structure in Examples 1 to 15 hinders the penetration of water molecules, and the water absorption rate is significantly lower than that of Comparative Example 4; in Comparative Examples 1 to 3, due to the molecular weight deviating from the range of 110,000 - 130,000 or the insufficient purity of glycidyl methacrylate, the modification effect weakens and the water absorption rate increases to varying degrees.

[0181] For the oxygen transmission coefficient, the lower the value, the better the moisture resistance (barrier property). In Examples 1 to 15, a dense structure is formed through modification, and the barrier property is significantly better than that of Comparative Example 4 without modification. In Comparative Examples 1 to 3, due to the molecular weight deviating from the range of 110,000 - 130,000 or the insufficient purity of glycidyl methacrylate, the key parameters deviate and the barrier property deteriorates to varying degrees.

[0182] Therefore, in the present solution, a polyvinyl alcohol medical fabric packaging film and its preparation method are disclosed. Polyvinyl alcohol and glycidyl methacrylate undergo a graft reaction through an initiator to form a graft-modified polyvinyl alcohol solution, and a film is obtained after drying. This film not only has excellent moisture-proof and water-resistant properties, but also due to the introduction of glycidyl methacrylate, the mechanical strength of the film is improved, and the oxygen barrier property is also very excellent, with high practicality and can be widely applied to fields such as drug packaging.

[0183] For those skilled in the art, it is obvious that this application is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of this application, this application can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of this application is defined by the appended claims rather than the above description. Therefore, it is intended to cover all changes falling within the meaning and scope of the equivalent elements of the claims in this application.

[0184] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and not to limit them. Although this application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of this application can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of this application.

Claims

1. A preparation method of a moisture-resistant medical fabric packaging film made of polyvinyl alcohol, characterized in that, It includes the following steps: Select polyvinyl alcohol with a molecular weight of 110,000 - 130,000 and glycidyl methacrylate, wherein the purity of the glycidyl methacrylate is ≥99%; Dissolve the polyvinyl alcohol in a mixed solvent of ethanol and water to obtain a mixed solution; Add an initiator and glycidyl methacrylate to the mixed solution, and react under nitrogen protection to form a graft-modified polyvinyl alcohol solution; Pour the graft-modified polyvinyl alcohol solution into a mold, and obtain a film after drying.

2. The preparation method according to claim 1, characterized in that, The step of dissolving the polyvinyl alcohol in a mixed solvent of ethanol and water to obtain a mixed solution specifically includes: Dissolve the polyvinyl alcohol in a mixed solvent of ethanol and water with a volume ratio of ethanol to water of 1:1 to obtain a mixed solution.

3. The preparation method according to claim 1, characterized in that, The step of adding an initiator and glycidyl methacrylate to the mixed solution and reacting under nitrogen protection to form a graft-modified polyvinyl alcohol solution specifically includes: Add an initiator and glycidyl methacrylate to the mixed solution, and react at 72°C - 78°C for 3.2 h - 3.8 h under nitrogen protection to form a graft-modified polyvinyl alcohol solution, wherein the dosage of the initiator is 0.6% - 0.8% of the mass of the polyvinyl alcohol.

4. The preparation method according to claim 1, characterized in that, The initiator is one of ammonium persulfate, potassium persulfate, sodium persulfate, and 2,2'-azobis(2-methylpropionamidine) dihydrochloride.

5. The preparation method according to claim 1, characterized in that, The step of pouring the graft-modified polyvinyl alcohol solution into a mold and obtaining a film after drying specifically includes: Add a microsphere template agent to the graft-modified polyvinyl alcohol solution to obtain a reaction solution, wherein the dosage of the microsphere template agent is 6% - 9% of the mass of the reaction solution, and the diameter of the microsphere template agent is 60 nm - 90 nm; Pour the reaction solution into a mold, and obtain a film with multiple pores after drying.

6. The preparation method according to claim 5, characterized in that, The microsphere template agent is one of a polystyrene microsphere template agent, a polymethyl methacrylate microsphere template agent, and a chitosan microsphere template agent.

7. The preparation method according to claim 5 or 6, characterized in that, The step of pouring the reaction solution into a mold and obtaining a film with multiple pores after drying specifically includes: Pour the reaction solution into a mold, dry it at room temperature for 25 h - 35 h, and then dry it in an oven at 62°C - 68°C for 8.5 h - 9.5 h to obtain a film with multiple pores.

8. The preparation method according to claim 7, characterized in that, The steps after pouring the graft-modified polyvinyl alcohol solution into a mold and obtaining a film specifically include: Treat the surface of the film with a coupling agent with a concentration of 1.2% - 1.8% for 1.2 h - 1.8 h to obtain a hydrophobic film.

9. The preparation method according to claim 8, characterized in that, The coupling agent is one of a fluorosilane coupling agent, a fluorocarbon coupling agent, a silane coupling agent, a titanate coupling agent, and a zirconate coupling agent.

10. A polyvinyl alcohol medical fabric packaging film, characterized in that, Prepared by using the film obtained by the method according to any one of claims 1 - 9.

Images