Polyvinyl alcohol composite material based on ellagic acid polymer modified MXene crosslinking and preparation

Abstract

The invention discloses a polyvinyl alcohol composite material based on ellagic acid polymer modified MXene crosslinking and a preparation method thereof, and relates to the technical field of food packaging materials and drug sustained-release carrier materials. The ellagic acid polymer modified MXene is used as a constituent part of a three-dimensional cross-linked network of the polyvinyl alcohol composite material, so that external force and heat in the composite material can be smoothly transferred to the ellagic acid polymer modified MXene with good oxidation resistance and high strength from a polyvinyl alcohol molecular chain, and the oxidation resistance and the strength of the composite film are remarkably improved; the preparation process is simple, the reaction conditions are mild, and the obtained material has obvious comprehensive performance advantages and high cost performance.

Description

Technical Field

[0001] This invention relates to the technical field of food packaging materials and drug sustained-release carrier materials, specifically to a polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking and its preparation method. Background Technology

[0002] Petroleum-based polymers have been widely used in packaging materials and other fields due to their excellent overall properties and low cost. However, these polymers are non-biodegradable, and their large-scale use poses a significant threat to environmental protection and human health. In recent years, replacing traditional non-biodegradable petroleum-based polymers with biodegradable polymers has gained increasing attention. Polyvinyl alcohol (PVA) exhibits good biodegradability due to the large number of hydroxyl groups in its molecular chain. However, PVA's biodegradation rate is relatively slow, often requiring the addition of fast-degrading components such as starch to improve its degradation rate. Adding starch, however, results in poor overall properties of PVA materials, such as strength and antioxidant capacity, severely limiting the practical application prospects of PVA materials.

[0003] Adding nanoparticles is one of the most effective methods to improve the overall performance of PVA. MXene is a class of two-dimensional inorganic compounds composed of transition metal carbides, nitrides, or carbonitrides with a thickness of several atomic layers. As a high-strength material, it occupies a special position in hybrid mesoscopic materials, possessing advantages such as good biocompatibility, low cost, and easy reactivity. Due to its excellent comprehensive properties, MXene has been used as a nanofiller in polymer nanocomposites to improve the mechanical strength and other properties of the materials.

[0004] The dispersion state of MXene polymers in the polymer matrix and the interfacial interactions between the polymer matrix and the matrix are two key factors determining the final properties of polymer / MXene composites. Good dispersion and strong interfacial bonding can fully realize the improving effect of MXene on the overall polymer properties. Conversely, poor dispersion and interfacial bonding can prevent MXene from fully exerting its reinforcing effects on the polymer matrix. Due to the special structure and surface effects of nanoparticles, MXene is prone to agglomeration in polymers, resulting in poor dispersion and weak interfacial bonding. Therefore, the improving effect of MXene on the overall polymer properties cannot be fully realized, and the final performance improvement of the resulting composite material is extremely limited. To improve the dispersion state of MXene in polymers and enhance the interfacial bonding, surface modification of MXene is currently the main method. Common surface modifiers are various coupling agents. However, existing MXene modifiers generally suffer from single-function defects, making it difficult to impart the necessary key properties such as antioxidant properties to polymer materials, severely limiting the service life of polymer products.

[0005] Therefore, a new solution is needed to address the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking and its preparation method, so as to solve the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking, comprising ellagic acid polymer-modified MXene and polyvinyl alcohol;

[0008] Ellagic acid polymer-modified MXene was introduced into the three-dimensional crosslinking network of polyvinyl alcohol as a crosslinking agent;

[0009] The ellagic acid polymer-modified MXene includes ellagic acid and MXene.

[0010] Furthermore, the amount of MXene modified with ellagic acid polymer added is 1% to 7% of the mass of polyvinyl alcohol.

[0011] A method for preparing polyvinyl alcohol based on ellagic acid polymer-modified MXene crosslinking includes at least the following steps:

[0012] MXene and ellagic acid were dispersed in water to obtain a suspension. The suspension was stirred at 60-90°C for 12-24 hours. The ellagic acid polymer was loaded onto the MXene surface by the self-polymerization reaction of ellagic acid on the MXene surface. After washing and drying, the MXene modified with the ellagic acid polymer was obtained.

[0013] Furthermore, the mass ratio of the amount of ellagic acid to the amount of MXene is 0.5-3.

[0014] A method for preparing a polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking, comprising at least the following steps:

[0015] Corn starch and polyvinyl alcohol were dissolved in hot water to obtain a mixture, and then MXene modified with ellagic acid polymer was added to form a complex.

[0016] The complex was stirred and reacted at a certain temperature, and then poured into a mold;

[0017] The polyvinyl alcohol composite film based on ellagic acid polymer and MXene crosslinking is obtained after natural air drying.

[0018] Furthermore, the mass ratio of starch to polyvinyl alcohol is 1:4, and the stirring reaction temperature of the composite is 70-90℃, and the time is 2-6h.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention innovatively uses ellagic acid polymer-modified MXene as a crosslinking agent. It cleverly constructs a three-dimensional crosslinked structure of PVA molecular chains through high-density hydrogen bonds formed between the phenolic hydroxyl groups of the ellagic acid polymer and the alcoholic hydroxyl groups of the PVA molecular chains. Simultaneously, MXene is introduced into the crosslinked network of PVA, effectively solving the dispersion problem of MXene in the PVA matrix and enhancing the interfacial bonding between MXene and PVA. This method successfully overcomes the defects commonly found in existing PVA / MXene composites, such as poor MXene dispersion, weak interfacial bonding, and stress concentration effects, providing a new approach for the preparation of high-performance PVA / MXene composites based on molecular structure design.

[0021] 2. This invention uses ellagic acid polymer as a novel surface modifier for MXene, which not only significantly improves the stress transmission path at the interface in the PVA / MXene composite film, that is, external force can be efficiently transmitted through the PVA molecular chain to the ellagic acid polymer and MXene interface with high oxidation stability and strength, significantly improving the mechanical strength of the material, but also utilizes the high density of phenolic hydroxyl structures in the ellagic acid polymer to endow the PVA composite film with excellent free radical scavenging ability, achieving a substantial breakthrough in antioxidant performance;

[0022] 3. The preparation process involved in this invention is simple and the reaction conditions are mild. Compared with existing methods for preparing PVA / MXene composite materials, the resulting materials have significant advantages in mechanical and oxidation resistance properties and are cost-effective. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 The infrared spectrum of MXene modified with ellagic acid polymer according to the present invention;

[0025] Figure 2 Infrared spectrum of a polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking according to the present invention;

[0026] Figure 3This is an oxidation resistance diagram of a polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking according to the present invention;

[0027] Figure 4 The mechanical properties of a polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking according to the present invention are described. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0029] Example 1

[0030] This embodiment describes a method for preparing polyvinyl alcohol composite films using MXene crosslinked polyvinyl alcohol modified with ellagic acid polymers. The specific steps are as follows:

[0031] (1) 1g of MXene was ultrasonically dispersed in 100mL of distilled water, and then 1g of ellagic acid was added. The mixture was magnetically stirred and reacted at 80℃ for 24 hours. The product was washed and dried to obtain ellagic acid polymer-modified MXene. The infrared spectra of MXene and ellagic acid polymer-modified MXene (MX-PEa) are shown below. Figure 1 As shown in the figure, compared with the infrared spectrum of unmodified MXene, the infrared spectrum of MX-Pea is at 3516 cm⁻¹. -1 3231cm -1 and 1000-1600cm -1 The appearance of new absorption peaks in the range confirms the successful preparation of MXene modified with ellagic acid polymer;

[0032] (2) Dissolve 1g of corn starch and 4g of PVA in 25mL of distilled water and react at 90℃ for 2 hours with magnetic stirring.

[0033] (3) MXene modified with 5% of PVA by mass of ellagic acid polymer was ultrasonically dispersed in 10 mL of distilled water, and then added to a mixture of corn starch and PVA. The mixture was stirred at 90 °C for 3 hours.

[0034] (4) Pour the product from step (3) into a polytetrafluoroethylene mold and air dry it naturally to obtain a polyvinyl alcohol composite film.

[0035] The infrared spectra of the polyvinyl alcohol composite film (PVA / ST / MX-PEa) and the PVA / ST film obtained in Example 1 are as follows: Figure 2 As shown. There are Figure 1-4It can be seen that, compared with PVA / ST film, the position of the hydroxyl absorption peak of PVA / ST / MX-PEa composite film is higher than that of PVA / ST / MX-PEa composite film. -1 The redshift reached 3267cm. -1 This indicates that hydrogen bonds are formed between MX-PEa and the PVA molecular chains, meaning that the ellagic acid polymer-modified MXene crosslinks the PVA molecular chains through hydrogen bond interactions, thereby forming a three-dimensional crosslinked network structure. The oxidation resistance of the PVA / ST / MX-PEa composite film is as follows: Figure 3 As shown in the figure, it can be observed that the composite film with only unmodified MXene showed a significant color change after 10 minutes of H2O2 oxidation, indicating that the composite film was severely oxidized. In contrast, the PVA / ST / MX-PEa composite film maintained essentially the same color after 10 minutes of H2O2 oxidation, fully demonstrating its excellent antioxidant properties; the mechanical properties of the composite film are as follows... Figure 4 As shown, the tensile strength and elongation at break of the PVA / ST / MX-PEa composite film are significantly better than those of the composite film with added unmodified MXene, indicating that the MXene modified by ellagic acid polymer has a significant reinforcing and toughening effect on PVA.

[0036] Example 2

[0037] This embodiment describes a method for preparing polyvinyl alcohol composite films using MXene crosslinked polyvinyl alcohol modified with ellagic acid polymers. The specific steps are as follows:

[0038] (1) 1g of MXene was ultrasonically dispersed in 100mL of distilled water, and then 0.5g of ellagic acid was added. The mixture was magnetically stirred and reacted at 90℃ for 12 hours. The product was washed and dried to obtain MXene modified with ellagic acid polymer, namely MX-PEa.

[0039] (2) Dissolve 1g of corn starch and 4g of PVA in 25mL of distilled water and react at 70℃ for 6 hours with magnetic stirring.

[0040] (3) 1% of the mass of PVA was ultrasonically dispersed in 10 mL of distilled water, and then added to a mixture of corn starch and PVA. The mixture was stirred at 90 °C for 2 hours.

[0041] (4) Pour the product from step (3) into a polytetrafluoroethylene mold and air dry it naturally to obtain a polyvinyl alcohol composite film.

[0042] Example 3

[0043] This embodiment describes a method for preparing polyvinyl alcohol composite films using MXene crosslinked polyvinyl alcohol modified with ellagic acid polymers. The specific steps are as follows:

[0044] (1) 1g of MXene was dispersed in 100mL of distilled water by ultrasonication, and then 3g of ellagic acid was added. The mixture was stirred magnetically and reacted at 60℃ for 24 hours. The product was washed and dried to obtain MXene modified with ellagic acid polymer, namely MX-PEa.

[0045] (2) Dissolve 1g of corn starch and 4g of PVA in 25mL of distilled water and react at 80℃ for 3 hours with magnetic stirring.

[0046] (3) 7% of the mass of PVA was ultrasonically dispersed in 10 mL of distilled water, and then added to a mixture of corn starch and PVA. The mixture was stirred at 70 °C for 6 hours.

[0047] (4) Pour the product from step (3) into a polytetrafluoroethylene mold and air dry it naturally to obtain a polyvinyl alcohol composite film.

[0048] Example 4

[0049] This embodiment describes a method for preparing polyvinyl alcohol composite films using MXene crosslinked polyvinyl alcohol modified with ellagic acid polymers. The specific steps are as follows:

[0050] (1) 0.5g of MXene was ultrasonically dispersed in 50mL of distilled water, and then 1g of ellagic acid was added. The mixture was magnetically stirred and reacted at 70℃ for 12 hours. The product was washed and dried to obtain MXene modified with ellagic acid polymer, namely MX-PEa.

[0051] (2) Dissolve 0.5g corn starch and 2g PVA in 12.5mL of distilled water and react at 70℃ for 6 hours with magnetic stirring.

[0052] (3) 1% of the mass of PVA was ultrasonically dispersed in 10 mL of distilled water, and then added to a mixture of corn starch and PVA. The mixture was stirred at 90 °C for 2 hours.

[0053] (4) Pour the product from step (3) into a polytetrafluoroethylene mold and air dry it naturally to obtain a polyvinyl alcohol composite film.

[0054] Example 5

[0055] This embodiment describes a method for preparing polyvinyl alcohol composite films using MXene crosslinked polyvinyl alcohol modified with ellagic acid polymers. The specific steps are as follows:

[0056] (1) 2g of MXene was dispersed in 100mL of distilled water by ultrasonication, and then 2g of ellagic acid was added. The mixture was stirred magnetically and reacted at 90℃ for 12 hours. The product was washed and dried to obtain MXene modified with ellagic acid polymer, namely MX-PEa.

[0057] (2) Dissolve 2g of corn starch and 8g of PVA in 50mL of distilled water and react at 70℃ for 6 hours with magnetic stirring.

[0058] (3) MXene modified with 5% of PVA by mass of ellagic acid polymer was ultrasonically dispersed in 10 mL of distilled water, and then added to a mixture of corn starch and PVA. The mixture was stirred at 90 °C for 2 hours.

[0059] (4) Pour the product from step (3) into a polytetrafluoroethylene mold and air dry it naturally to obtain a polyvinyl alcohol composite film.

[0060] For overall technical effects, please refer to Figure 1-4 Examples 2, 3, 4 and 5 above all achieved experimental results with the same trend as Example 1.

[0061] In summary:

[0062] This invention uses MXene modified with ellagic acid polymer as a component of the three-dimensional crosslinking network of polyvinyl alcohol composite material. This facilitates the smooth transfer of external forces and heat from the polyvinyl alcohol molecular chain to the MXene modified with ellagic acid polymer, which has good oxidation resistance and high strength. This significantly improves the oxidation resistance and strength of the composite film. The preparation process is simple, the reaction conditions are mild, and the resulting material has obvious comprehensive performance advantages and high cost performance.

[0063] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking, characterized in that: Including MXene and polyvinyl alcohol modified with ellagic acid polymers; Ellagic acid polymer-modified MXene was introduced into the three-dimensional crosslinking network of polyvinyl alcohol as a crosslinking agent; The ellagic acid polymer-modified MXene includes ellagic acid and MXene.

2. The polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking according to claim 1, characterized in that: The amount of MXene modified with ellagic acid polymer added is 1% to 7% of the mass of polyvinyl alcohol.

3. A method for preparing polyvinyl alcohol based on ellagic acid polymer-modified MXene crosslinking, used in the polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking as described in any one of claims 1-2, characterized in that: At least the following steps are included: MXene and ellagic acid were dispersed in water to obtain a suspension. The suspension was stirred at 60-90°C for 12-24 hours. The ellagic acid polymer was loaded onto the MXene surface by the self-polymerization reaction of ellagic acid on the MXene surface. After washing and drying, the MXene modified with the ellagic acid polymer was obtained.

4. The method for preparing polyvinyl alcohol based on ellagic acid polymer-modified MXene crosslinking according to claim 3, characterized in that: The mass ratio of ellagic acid to MXene is 0.5-3.

5. A method for preparing a polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking, used in any one of claims 1-2, characterized in that: At least the following steps are included: Corn starch and polyvinyl alcohol were dissolved in hot water to obtain a mixture, and then MXene modified with ellagic acid polymer was added to form a complex. The complex was stirred and reacted at a certain temperature, and then poured into a mold; The polyvinyl alcohol composite film based on ellagic acid polymer and MXene crosslinking is obtained after natural air drying.

6. The method for preparing a polyvinyl alcohol composite material based on ellagic acid polymer-modified MXene crosslinking according to claim 5, characterized in that: The mass ratio of starch to polyvinyl alcohol is 1:4, and the stirring reaction temperature of the composite is 70-90℃, and the time is 2-6h.

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