Preparation method and application of modified polyvinyl alcohol quaternary ammonium salt material

Abstract

The invention discloses a preparation method and application of a modified polyvinyl alcohol quaternary ammonium salt material, and relates to the technical field of high polymer materials. The modified polyvinyl alcohol quaternary ammonium salt material is obtained by performing chlorination treatment on modified polyvinyl alcohol quaternary ammonium salt. Functional molecules 6-TCPM-DOPO are adopted for modifying polyvinyl alcohol, a one-pot synthesis mode is adopted, Cl at the tail end of the functional molecules and N on pyridine-4-formaldehyde acetalated polyvinyl alcohol are combined through ionic bonds to form modified polyvinyl alcohol quaternary ammonium salt, and the modified polyvinyl alcohol quaternary ammonium salt is endowed with an efficient composite antibacterial function through chlorination treatment. The modified polyvinyl alcohol quaternary ammonium salt material prepared by the preparation method disclosed by the invention can adsorb bacteria to antibacterial sites through a charge adsorption effect of quaternary ammonium salt besides a single halamine group antibacterial function, and further strengthens the antibacterial effect through a synergistic effect with the halamine group, and in addition, the introduction of DOPO also endows the material with excellent flame retardant property.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly to a preparation method and application of a modified polyvinyl alcohol quaternary ammonium salt material. Background Art

[0002] In the broad field of modern materials, polymer materials are widely used in modern society due to their light weight, versatility, easy processing, low cost, etc. However, with the increasing environmental pollution and the gradual depletion of petroleum resources, people's attention has shifted to the development of alternative bio-based and renewable polymers. In recent years, multifunctional polyvinyl alcohol (PVA) synthesized by non-petroleum routes has been widely used in industrial and civilian fields due to its biodegradable and non-toxic properties, as well as excellent properties such as mechanical properties, film-forming properties, and transparency. Unfortunately, the limiting oxygen index of PVA is only about 19%-20%, which means it is prone to combustion in air and poses a great safety hazard. And PVA contains a large number of hydroxyl groups, which are hydrophilic, making PVA-related products prone to moisture absorption, leading to the growth of bacteria and endangering human health. To address the above problems, it is meaningful to develop multifunctional PVA with antibacterial and flame retardant effects, which can greatly expand the application range of PVA.

[0003] Previous modifications of PVA were relatively single and could not meet its multifunctional requirements. Moreover, a single antibacterial mechanism sometimes could not meet the antibacterial effect requirements. Therefore, it is of particular significance to develop a multifunctional PVA material with a synergistic antibacterial effect and a flame retardant effect. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method and application of a modified polyvinyl alcohol quaternary ammonium salt material to solve the problems existing in the above-mentioned prior art. The modified polyvinyl alcohol quaternary ammonium salt material has a synergistic antibacterial effect and excellent flame retardant properties.

[0005] To achieve the above purpose, the present invention provides the following solutions:

[0006] The present invention provides a functional molecule for improving the antibacterial and flame retardant properties of polyvinyl alcohol. The structural formula of the functional molecule is as follows:

[0007]

[0008] The present invention also provides a modified polyvinyl alcohol quaternary ammonium salt. The structural formula of the modified polyvinyl alcohol quaternary ammonium salt is as follows:

[0009]

[0010] The present invention also provides the application of the above functional molecule in the preparation of a modified polyvinyl alcohol quaternary ammonium salt material with antibacterial and flame retardant properties.

[0011] The present invention also provides a modified polyvinyl alcohol quaternary ammonium salt material with antibacterial and flame retardant properties, and the modified polyvinyl alcohol quaternary ammonium salt material is obtained by chlorinating the above-mentioned modified polyvinyl alcohol quaternary ammonium salt.

[0012] The present invention also provides a preparation method of the above-mentioned functional molecule, including the following steps:

[0013] Carry out a first reflux reaction on p-hydroxybenzaldehyde, bromochloroalkane and an acid-binding agent in a solvent to obtain a mixture;

[0014] Add an acidic catalyst and 1,2,4-triazole to the mixture, carry out a second reflux reaction, and then add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to carry out a third reflux reaction to obtain the functional molecule.

[0015] Furthermore, the structural formula of the bromochloroalkane is as follows:

[0016]

[0017] Furthermore, the bromochloroalkane is 1-bromo-3-chloropropane; and / or

[0018] The acid-binding agent is anhydrous potassium carbonate; and / or

[0019] The acidic catalyst is hydrochloric acid or acetic acid; and / or

[0020] The molar ratio of p-hydroxybenzaldehyde, bromochloroalkane, and acid-binding agent is 1:1:(1-2), preferably 1:1:1; and / or

[0021] The molar ratio of 1,2,4-triazole to p-hydroxybenzaldehyde is 1:(1-2), preferably 1:1; and / or

[0022] The molar ratio of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to 1,2,4-triazole is 1:1.

[0023] The present invention also provides a preparation method of the above-mentioned modified polyvinyl alcohol quaternary ammonium salt material, including the following steps:

[0024] Dissolve polyvinyl alcohol in water to prepare a polyvinyl alcohol solution, adjust the pH to 1-2, dropwise add a pyridine-4-carboxaldehyde solution and then carry out an acetalization reaction, after cooling, adjust the pH to 8-9, and after drying treatment, obtain acetalized polyvinyl alcohol;

[0025] After mixing and reacting the acetalized polyvinyl alcohol with the functional molecule described in Claim 1 in a solvent, a film is prepared using a mold to obtain a DOPO-PVA film;

[0026] The DOPO-PVA film is chlorinated to obtain the modified polyvinyl alcohol quaternary ammonium salt material.

[0027] Further, the molar ratio of pyridine-4-carboxaldehyde to polyvinyl alcohol is 1.2:9; and / or

[0028] The molar ratio of the functional molecule to pyridine-4-carboxaldehyde is 1:1.2.

[0029] Further, the chlorination treatment is to soak and react the DOPO-PVA film in a sodium hypochlorite solution.

[0030] The present invention discloses the following technical effects:

[0031] In the present invention, PVA is aldehydeized with pyridinecarboxaldehyde. Using pyridine as a bridge, an ionic bond is formed with the terminal chlorine group of the functional molecule 6-TCPM-DOPO to prepare a modified polyvinyl alcohol quaternary ammonium salt material with antibacterial and flame retardant properties. Specifically, the PVA is modified with a functional molecule, and a "one-pot" synthesis method is adopted. An ionic bond is formed between the terminal Cl of the functional molecule and the N on the acetalized PVA of pyridine-4-carboxaldehyde to form a modified polyvinyl alcohol quaternary ammonium salt, and then chlorination treatment is carried out to endow it with an efficient composite antibacterial effect. The modified polyvinyl alcohol quaternary ammonium salt material prepared by the present invention can not only antibacterial with a single haloamine group, but also adsorb bacteria to the antibacterial site through the charge adsorption effect of the quaternary ammonium salt, and further enhance the antibacterial effect through synergistic action with the haloamine group. In addition, the introduction of DOPO also endows it with excellent flame retardant properties.

[0032] After antibacterial and flame retardant tests, it shows that the modified polyvinyl alcohol quaternary ammonium salt material prepared by the present invention has excellent antibacterial and flame retardant properties, and after washing resistance tests, it still maintains good antibacterial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 is the structural formula of 6-TCPM-DOPO;

[0035] Figure 2Schematic diagram of the preparation route of DOPO-PVA;

[0036] Figure 3 Structural formula of DOPO-PVA;

[0037] Figure 4 For 6-TCPM-DOPO 1 1H NMR spectrum;

[0038] Figure 5 For DOPO-PVA 1 1H NMR spectrum;

[0039] Figure 6 X-ray photoelectron spectroscopy of DOPO-PVA;

[0040] Figure 7 Detection result graph of the antibacterial performance of DOPO-PVA;

[0041] Figure 8 Schematic diagram of the synergistic antibacterial mechanism of DOPO-PVA;

[0042] Figure 9 Detection result graph of the flame retardant performance of DOPO-PVA. Detailed implementation manners

[0043] Now, various exemplary implementation manners of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0044] It should be understood that the terms described in the present invention are only for describing specific implementation manners and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0045] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0046] Without departing from the scope or spirit of the present invention, various modifications and variations can be made to the specific embodiments of the present invention's specification, which will be apparent to those skilled in the art. Other embodiments obtained from the specification of the present invention will be apparent to those skilled in the art. The specification and examples of the present invention are merely exemplary.

[0047] Regarding the terms "comprising", "including", "having", "containing", etc. used herein, they are all open-ended terms, meaning including but not limited to.

[0048] The present invention has developed a terminal chlorine-based triazole-haloamine-DOPO functional molecule, 6-(((1H-1,2,4-triazol-3-yl)amino)(4-(3-chloropropoxy)phenyl)methyl)dibenzo[c,e][1,2]oxaphosphinine 6-oxide, abbreviated as 6-TCPM-DOPO. It is prepared from 1-bromo-3-chloropropane, p-hydroxybenzaldehyde, 1,2,4-triazole and DOPO as raw materials; wherein, the chemical structural formula of 6-TCPM-DOPO is as Figure 1 shown.

[0049] The present invention adopts a "one-pot" synthesis method to form a quaternary ammonium salt by ionic bonding of the terminal Cl of the functional molecule with the N on pyridine-4-carboxaldehyde acetalized PVA (see the schematic diagram of the preparation route in Figure 2 ), and then through chlorination treatment to endow it with an efficient composite antibacterial effect (see the schematic diagram of the synergistic antibacterial mechanism in Figure 8 ), to obtain an efficient antibacterial and flame-retardant material DOPO-PVA (the structural formula is shown in Figure 3 ). This method can effectively improve the washability of the finishing PVA. After antibacterial and flame-retardant tests, it shows that the obtained DOPO-PVA has excellent antibacterial and flame-retardant properties.

[0050] Example 1

[0051] This example provides a preparation method of the functional molecule 6-TCPM-DOPO, which specifically includes:

[0052] (1) First, dissolve 0.2 mol of p-hydroxybenzaldehyde, 0.2 mol of 1-bromo-3-chloropropane and 0.2 mol of anhydrous potassium carbonate (acid-binding agent) in acetonitrile, and react under reflux condensation at 70 °C for 24 hours. After the reaction, filter to obtain a mixture (reddish-brown liquid).

[0053] (2) Add 8 mL of glacial acetic acid solution with a concentration of 15% (v / v) (as a catalyst) and 0.2 mol of 1,2,4-triazole to the mixture obtained in step (1), and carry out condensation reflux at 70 °C for 24 hours. Then add 0.2 mol of DOPO to a round-bottom flask and continue the reaction at 70 °C under reflux conditions for 24 hours.

[0054] (3) After the reaction in step (2) is completed, filter the unreacted raw materials while it is hot, collect the solid, wash it several times with hot acetonitrile, and then dry it at 70 °C to obtain the white solid product 6-TCPM-DOPO.

[0055] From the perspectives of operation and practicality, the synthesized 6-TCPM-DOPO with a terminal chloro group structure has better superiority, is easy to form stable ionic bonds, and then generates quaternary ammonium salts. Compared with traditional antibacterial agents, 6-TCPM-DOPO will have better antibacterial effects.

[0056] Perform nuclear magnetic resonance analysis (NMR, AVANCE III, Switzerland) on the prepared 6-TCPM-DOPO, and the results are as Figure 4 shown. Among them, it can be seen from the signals in the nuclear magnetic resonance spectrum that the structure of the target synthesized compound corresponds one by one to the peaks in the 1 HNMR spectrum, so it can be determined that the synthesized product is the target synthesized compound 6-TCPM-DOPO.

[0057] Example 2

[0058] This example provides a preparation method of the functional molecule 6-TCPM-DOPO, which specifically includes:

[0059] (1) First, dissolve 0.2 mol of p-hydroxybenzaldehyde, 0.2 mol of 1-bromo-3-chloropropane, and 0.3 mol of anhydrous potassium carbonate in acetonitrile, and react under condensation reflux conditions at 90 °C for 10 hours. After the reaction is completed, filter to obtain a mixture (reddish-brown liquid).

[0060] (2) Add 8 mL of dilute hydrochloric acid solution with a concentration of 15% (v / v) (as a catalyst) and 0.1 mol of 1,2,4-triazole to the mixture obtained in step (1), and carry out condensation reflux at 90 °C for 10 hours. Then add 0.2 mol of DOPO to a round-bottom flask and continue the reaction at 90 °C under reflux conditions for 10 hours.

[0061] (3) After the reaction in step (2) is completed, filter the unreacted raw materials while it is hot, collect the solid, wash it several times with hot acetonitrile, and then dry it at 70 °C to obtain the white solid product 6-TCPM-DOPO.

[0062] Example 3

[0063] This embodiment provides a preparation method of the functional molecule 6-TCPM-DOPO, which specifically includes:

[0064] (1) First, dissolve 0.2 mol of p-hydroxybenzaldehyde, 0.2 mol of 1-bromo-3-chloropropane, and 0.4 mol of anhydrous potassium carbonate in acetonitrile, and react under reflux condensation at 80 °C for 48 hours. After the reaction is completed, filter to obtain a mixture (reddish-brown liquid).

[0065] (2) Add 8 mL of a dilute hydrochloric acid solution with a concentration of 15% (v / v) (as a catalyst) and 0.2 mol of 1,2,4-triazole to the mixture obtained in step (1), and carry out reflux condensation at 80 °C for 48 hours. Then add 0.2 mol of DOPO to a round-bottom flask and continue the reaction under reflux conditions at 80 °C for 48 hours.

[0066] (3) When the reaction in step (2) is completed, filter the unreacted raw materials while it is hot, collect the solid, wash it several times with hot acetonitrile, and then dry it at 70 °C to obtain the white solid product 6-TCPM-DOPO.

[0067] Example 4

[0068] Use the 6-TCPM-DOPO prepared in Example 1 for antibacterial and flame-retardant modification of PVA, which specifically includes:

[0069] (1) Dissolve 10 g of PVA (2099 series) in water to prepare a PVA solution with a mass concentration of 10%.

[0070] (2) Heat the PVA solution to 80 °C, dropwise add a HCl solution with a concentration of 10% (v / v) under stirring to adjust the pH to 1, then dropwise add a 30% (v / v) pyridine-4-carboxaldehyde solution within 0.5 h, react for 1 h, cool to 60 °C, dropwise add ammonia water to adjust the pH to 8, and then dry it under vacuum at 70 °C to obtain an acetalized PVA solid. Among them, the molar ratio of pyridine-4-carboxaldehyde to PVA is 1.2:9.

[0071] (3) Add the acetalized PVA solid to 90 mL of dimethyl sulfoxide, dissolve it at 105 °C, and then add 6-TCPM-DOPO, and keep the temperature for reaction for 4 h. Among them, the molar ratio of 6-TCPM-DOPO to the pyridine-4-carboxaldehyde in step (2) is 1:1.2.

[0072] (4) After the reaction in step (3) is completed, pour the PVA solution onto a glass plate and dry it into a film at 70 °C to obtain DOPO-PVA.

[0073] (5) The DOPO-PVA obtained in step (4) was soaked in a 10 wt% sodium hypochlorite solution and reacted for 1 hour, then taken out, adjusted to neutral pH, washed thoroughly with a large amount of deionized water, and dried in an oven to obtain chlorinated DOPO-PVA.

[0074] Nuclear magnetic resonance analysis was performed on the prepared DOPO-PVA, and the results are as Figure 5 shown. It can be seen from the signals in the nuclear magnetic resonance spectrum that the structure of the target synthetic compound corresponds one by one to the peaks in the 1 HNMR spectrum, so it can be determined that the synthesized product is the target synthetic compound DOPO-PVA. X-ray photoelectron spectroscopy ((XPS, Thermo Scientific K-Alpha, USA) was used to characterize the structures of PVA and DOPO-PVA, as Figure 6 shown. The characterization results show that 6-TCPM-DOPO was successfully incorporated onto PVA.

[0075] Example 5

[0076] The 6-TCPM-DOPO prepared in Example 1 was used for antibacterial and flame-retardant modification of PVA, specifically including:

[0077] (1) 10 g of PVA (series 1799) was dissolved in water to prepare a PVA solution with a mass concentration of 10%.

[0078] (2) The PVA solution was heated to 80 °C, and the pH was adjusted to 1.5 by dropwise addition of a 10% (v / v) HCl solution under stirring. Then, a 30% (v / v) pyridine-4-carboxaldehyde solution was added dropwise within 0.5 h, and the reaction was carried out for 1 h. After cooling to 60 °C, ammonia water was added dropwise to adjust the pH to 8.5, and then it was dried under vacuum at 70 °C to obtain acetalized PVA solid. Among them, the molar ratio of pyridine-4-carboxaldehyde to PVA was 1.2:9.

[0079] (3) The acetalized PVA solid was added to 90 mL of dimethyl sulfoxide and dissolved at 90 °C, and then 6-TCPM-DOPO was added, and the reaction was carried out at a constant temperature for 2 h. Among them, the molar ratio of 6-TCPM-DOPO to pyridine-4-carboxaldehyde in step (2) was 1:1.2.

[0080] (4) After the reaction in step (3) was completed, the PVA solution was poured onto a glass plate and dried into a film at 70 °C to obtain DOPO-PVA.

[0081] (5) The DOPO-PVA obtained in step (4) was soaked in a 10 wt% sodium hypochlorite solution and reacted for 1 hour, then taken out, adjusted to neutral pH, washed thoroughly with a large amount of deionized water, and dried in an oven to obtain chlorinated DOPO-PVA.

[0082] Example 6

[0083] The 6-TCPM-DOPO prepared in Example 1 was used for antibacterial and flame-retardant modification of PVA, specifically including:

[0084] (1) Dissolve 10 g of PVA (2099 series) in water to prepare a PVA solution with a mass concentration of 10%.

[0085] (2) Heat the PVA solution to 80 °C, adjust the pH to 2 by dropwise adding a 10% (v / v) HCl solution under stirring, then dropwise add a 30% (v / v) pyridine-4-carboxaldehyde solution within 0.5 h, react for 1 h, cool to 60 °C, dropwise add ammonia water to adjust the pH to 9, and then vacuum dry at 70 °C to obtain acetalized PVA solid. Among them, the molar ratio of pyridine-4-carboxaldehyde to PVA is 1.2:9.

[0086] (3) Add the acetalized PVA solid to 90 mL of dimethyl sulfoxide, dissolve it at 120 °C, and then add 6-TCPM-DOPO, and keep the temperature for reaction for 5 h. Among them, the molar ratio of 6-TCPM-DOPO to the pyridine-4-carboxaldehyde in step (2) is 1:1.2.

[0087] (4) After the reaction in step (3) is completed, pour the PVA solution onto a glass plate and dry it into a film at 70 °C to obtain DOPO-PVA.

[0088] (5) Immerse the DOPO-PVA obtained in step (4) in a 10 wt% sodium hypochlorite solution and react for 1 hour, then take it out, adjust the pH to neutral, wash it with a large amount of deionized water, and place it in an oven to dry to obtain chlorinated DOPO-PVA.

[0089] Effect verification example

[0090] The antibacterial performance of the chlorinated DOPO-PVA prepared in Example 4 was detected, and the results are as Figure 7 shown. It can be seen from Figure 7 that a large number of colonies grew on the culture dishes of Escherichia coli and Staphylococcus aureus in contact with PVA, while no colonies were formed on the modified PVA, indicating that the bacteriostatic rate of DOPO-PVA reached 99.99%.

[0091] The DOPO-PVA was washed 20 and 40 times respectively, and the antibacterial effect of PVA was detected. The results are as Figure 7As shown. It can be seen from the results that the antibacterial rates of the cotton fabric against Escherichia coli and Staphylococcus aureus can still reach 99.99% after 20 times of laundering. As the number of laundering times increases to 40 times, the antibacterial rate against Staphylococcus aureus is still 99.99%. Although the antibacterial rate against Escherichia coli decreases slightly, it is still 99.75%. This shows that the antibacterial molecules are firmly combined with PVA by chemical bonds, and DOPO-PVA has good washability.

[0092] The vertical burning test method was used to explore whether DOPO-PVA has flame retardant effect. The test related data of the chlorinated DOPO-PVA in Example 4 are as Figure 9 shown in Table 1. The results prove that the 6-TCPM-DOPO modified PVA has good flame retardant effect.

[0093] Table 1 Detection results of flame retardant properties

[0094]

[0095] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A functional molecule for improving the antibacterial and flame retardant properties of polyvinyl alcohol, characterized in that: The structural formula of the functional molecule is as follows:

2. A modified polyvinyl alcohol quaternary ammonium salt, characterized in that: The structural formula of the modified polyvinyl alcohol quaternary ammonium salt is as follows:

3. Use of the functional molecule as claimed in claim 1 in the preparation of a modified polyvinyl alcohol quaternary ammonium salt material with antibacterial and flame retardant properties.

4. A modified polyvinyl alcohol quaternary ammonium salt material with antibacterial and flame retardant properties, characterized in that: The modified polyvinyl alcohol quaternary ammonium salt material is obtained by chlorinating the modified polyvinyl alcohol quaternary ammonium salt described in claim 2.

5. A method for preparing a functional molecule according to claim 1, characterized in that: The following steps are involved: Carrying out a first reflux reaction of p-hydroxybenzaldehyde, bromochloroethane and an acid-binding agent in a solvent to obtain a mixture; An acidic catalyst and 1,2,4-triazole are added to the mixture to carry out a second reflux reaction, and then 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is added to carry out a third reflux reaction to obtain the functional molecule.

6. The preparation method according to claim 5, characterized in that: The structural formula of the bromochloroalkane is as follows:

7. The preparation method according to claim 6, characterized in that: The bromochloroalkane is 1-bromo-3-chloropropane; and / or The acid binding agent is anhydrous potassium carbonate; and / or The acidic catalyst is hydrochloric acid or acetic acid; and / or The molar ratio of the p-hydroxybenzaldehyde, the bromochloroethane and the acid binding agent is 1:1:(1-2); and / or The molar ratio of the 1,2,4-triazole to the p-hydroxybenzaldehyde is 1:(1-2); and / or The molar ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the 1,2,4-triazole is 1:

1.

8. A method for preparing the modified polyvinyl alcohol quaternary ammonium salt material as claimed in claim 4, characterized in that: The following steps are involved: Dissolving polyvinyl alcohol in water to prepare a polyvinyl alcohol solution, adjusting the pH to 1-2, adding a pyridine-4-carboxaldehyde solution dropwise to carry out an acetalization reaction, adjusting the pH to 8-9 after cooling, and drying to obtain acetalized polyvinyl alcohol; The acetalized polyvinyl alcohol and the functional molecule according to claim 1 are mixed and reacted in a solvent, and then formed into a film using a mold to obtain a DOPO-PVA film; The DOPO-PVA film is subjected to chlorination treatment to obtain the modified polyvinyl alcohol quaternary ammonium salt material.

9. The preparation method according to claim 8, characterized in that: The molar ratio of the pyridine-4-carboxaldehyde to the polyvinyl alcohol is 1.2:9; and / or The molar ratio of the functional molecule to the pyridine-4-carboxaldehyde is 1:1.

2.

10. The preparation method according to claim 8, characterized in that: The chlorination treatment is to immerse the DOPO-PVA film in a sodium hypochlorite solution for reaction.

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