Antibacterial nylon material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of antibacterial high polymer materials, in particular to an antibacterial nylon material as well as a preparation method and application thereof. The method comprises the following steps: carrying out anion ring-opening copolymerization on a seven-membered ring lysine monomer obtained by ring formation of lysine and a lactam monomer to obtain copolyamide, dissolving the copolyamide, and carrying out complete quaternization reaction by using halogenated hydrocarbon to obtain the antibacterial nylon material. The preparation method provided by the invention effectively avoids the problems of insufficient antibacterial property, obvious mechanical property reduction, poor thermal stability and the like of an antibacterial nylon material prepared by hydrochloric acid protonation in the prior art. Meanwhile, the seven-membered cyclic lysine monomer can be copolymerized without alkylation, the synthesis process is greatly simplified, the production efficiency is high, and the production cost is low. The prepared antibacterial nylon material has the characteristics of lasting and efficient antibacterial performance, high safety, environment friendliness, excellent mechanical property and thermal stability and the like, and can be widely applied to the fields of textiles, daily necessities, packaging materials, panels and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of antibacterial polymer materials, and particularly relates to an antibacterial nylon material, a preparation method thereof, and an application thereof. Background Art

[0002] Nylon materials have excellent comprehensive properties and are widely used in multiple industries and fields of national production and life, and have become an indispensable key material in modern society. However, water molecules are easily adsorbed on the surface of nylon to form a slightly wet environment, which is prone to contamination and growth of various bacteria and fungi, including pathogenic bacteria, resulting in aging, mildew, discoloration, odor, etc. of nylon materials, and may also lead to disease transmission, causing certain harm to people's property and life safety. Therefore, the development of new antibacterial nylon materials is of great significance for reducing property losses, improving environmental hygiene conditions, and reducing disease transmission.

[0003] Currently, commercially available antibacterial nylon materials are mainly prepared by melt blending small molecule antibacterial agents with nylon materials. For example, Chinese invention patent document 202310429959.6 provides a preparation method of an antibacterial nylon material. Although this method can make up for the lack of antibacterial performance of traditional nylon materials, during use, the small molecule antibacterial agents in such antibacterial nylon materials are prone to migration and loss, causing the material to lose its antibacterial performance, and the lost small molecule antibacterial agents may harm human health and pollute the environment, and there are many problems in terms of the durability, safety, and environmental friendliness of antibacterial performance.

[0004] In addition to the above methods, some researchers have prepared antibacterial nylon materials through chemical modification. The English literature Organocatalytic Copolymerization of Cyclic Lysine Derivative and ε-Caprolactam toward Antibacterial Nylon-6 Polymers (published in the English journal ACS Macro Letters on November 4, 2022, pages 46 - 52) prepared a seven-membered cyclic lysine monomer by cyclizing lysine. Utilizing its same seven-membered cyclic structure as ε-caprolactam, a copolyamide with dimethylamino groups on the side chains was prepared through ring-opening copolymerization. After being dissolved in trifluoroethanol, it was further reacted with a halogenated hydrocarbon to obtain an antibacterial nylon material. Chinese invention patent document 202110960422.3 provides a method for preparing an antibacterial nylon material by ring-opening copolymerization of a cyclic lysine monomer and ε-caprolactam, and then performing quaternization with a halogenated hydrocarbon or protonation with hydrochloric acid after dissolving the copolyamide. In the above methods, the antibacterial nylon material prepared by protonation with hydrochloric acid has insufficient antibacterial performance and significantly decreased mechanical properties. At the same time, the quaternary ammonium salt formed by acid protonation has poor thermal stability, is easily decomposed during the processing, and is sensitive to the pH value, and is prone to deprotonation under alkaline conditions, causing the material to lose its antibacterial performance. In comparison, the antibacterial nylon material prepared by quaternization with a halogenated hydrocarbon has persistent and high antibacterial performance, and its mechanical properties are comparable to those of conventional nylon. Moreover, the quaternary ammonium salt formed by quaternization with a halogenated hydrocarbon has good thermal stability, is not affected by changes in the pH value, requires lower equipment requirements, and is easy to prepare on a large scale. However, in the above methods, the exocyclic amino groups of the seven-membered cyclic lysine monomers used need to be doubly protected, which increases the monomer preparation process, reduces the production efficiency, and increases the production cost.

[0005] Therefore, developing an antibacterial nylon material with persistent antibacterial performance, high safety, and a simple preparation process, as well as its preparation method, is beneficial to promoting the innovation and development of the antibacterial nylon material industry and expanding its application fields. Summary of the Invention

[0006] In order to solve the problems that the antibacterial nylon materials prepared by melt blending of small molecule antibacterial agents in the prior art have non-persistent antibacterial performance, low safety, and poor environmental friendliness, and the problems that the antibacterial nylon materials prepared by copolymerizing cyclic lysine and ε-caprolactam through protonation with hydrochloric acid have poor material properties and a long process route, the present invention proposes an antibacterial nylon material, its preparation method, and its application.

[0007] An antibacterial nylon material is prepared by the above preparation method. The molecular structure of the antibacterial nylon material contains two different repeating units shown in Formula I and Formula II:

[0008]

[0009] In Formulas I and II, R is a substituted or unsubstituted straight-chain or branched-chain C 1-20 aliphatic hydrocarbon group, a substituted or unsubstituted C 3-12 alicyclic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group; n is any natural number from 1 to 8; x and y are the molar ratios of the two repeating units respectively, the range of x is 0.01 to 0.50, the range of y is 0.50 to 0.99, and the relationship between x and y is x + y = 1.

[0010] A method for preparing the above antibacterial nylon material, comprising the following steps:

[0011] S1: Put the seven-membered cyclic lysine monomer and the lactam monomer into a polymerization kettle, add a catalyst and an activator for anionic ring-opening copolymerization to prepare a copolyamide;

[0012] S2: Dissolve the copolyamide, add a halogenated hydrocarbon to the solution for a complete quaternization reaction, and after the reaction is completed, sediment and dry to prepare the antibacterial nylon material;

[0013] The structural formula of the halogenated hydrocarbon is R-Hal; wherein, R is a substituted or unsubstituted straight-chain or branched-chain C 1-20 aliphatic hydrocarbon group, a substituted or unsubstituted C 3-12 alicyclic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group; Hal is a halogen, and the halogen is any one of chlorine, bromine, and iodine.

[0014] Further, the structural formula of the seven-membered cyclic lysine monomer in S1 is as shown in Formula III:

[0015]

[0016] The preparation method of the seven-membered cyclic lysine monomer is: mix lysine (or lysine salt or aqueous solution containing lysine) with a solvent, and carry out a dehydration cyclization reaction at 100 to 250 °C to obtain the seven-membered cyclic lysine monomer - aminocaprolactam; the solvent is one or at least two combinations of methanol, ethanol, propanol, n-butanol, isopropanol, toluene, xylene, mesitylene, tetrahydrofuran, dioxane, dichloromethane, chloroform, N,N-dimethylformamide, N,N-dimethylacetamide, or dimethyl sulfoxide.

[0017] The structural formula of the lactam monomer is as shown in Formula IV:

[0018]

[0019] The structural formula of the activator is as shown in Formula V:

[0020]

[0021] In the formula, R1 is a substituted or unsubstituted straight-chain or branched C 1-5 aliphatic hydrocarbon group, a substituted or unsubstituted aryl group; preferably any one of methyl, ethyl, phenyl, tert-butylphenyl, p-methoxyphenyl, pentafluorophenyl, trifluoromethylphenyl;

[0022] Further, the catalyst in S1 is one or at least two combinations of an alkali metal, an alkali metal oxide, an alkali metal hydroxide, an alkali metal hydride, an alkali metal alkoxide, an alkaline earth metal, an alkaline earth metal oxide, an alkaline earth metal hydroxide, an alkaline earth metal hydride, an alkaline earth metal alkoxide, a carbene reagent, a guanidine reagent, an amidine reagent, a phosphazene reagent;

[0023] Further, the catalyst in S1 is any one of sodium hydride, potassium hydride, sodium hydroxide, phosphazene base, potassium tert-butoxide, sodium methoxide, potassium methoxide, sodium, potassium, DUB, TBD;

[0024] Further, the molar feed ratio of the seven-membered cyclic lysine monomer to the lactam monomer in S1 is 0.01 - 1:1; the ratio of the total molar amount of the seven-membered cyclic lysine monomer and the lactam monomer to the molar amount of the catalyst and the molar amount of the activator is 100:0.1 - 5:0.1 - 5; the temperature of the copolymerization is 140 - 230 °C, and the time of the copolymerization is 1 - 6 h;

[0025] Further, the solvent used for dissolution in S2 is one or at least two combinations of methanol, ethanol, trifluoroethanol, hexafluoroisopropanol, N-methylpyrrolidone, benzyl alcohol, ethylene glycol, cyclohexanol, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), triethylene glycol, dimethyl sulfoxide (DMSO), hexamethylphosphoric triamide (HMPA), 1,3-dimethylpropyleneurea (DMPU); the temperature of the reaction is 40 - 100 °C, and the time of the reaction is 6 - 24 h;

[0026] Further, the solvent used for sedimentation in S2 is one or at least two combinations of water, methanol, ethanol, ether, ethyl acetate, acetone, n-hexane, petroleum ether.

[0027] An application of an antibacterial nylon material in the preparation of textiles, daily necessities, packaging materials or panels.

[0028] Compared with the prior art, the present invention solves the problems in the prior art that the antibacterial nylon materials prepared by melt blending of small molecule antibacterial agents have the problems of non - persistent antibacterial performance, low safety, and poor environmental friendliness, and the problems that the antibacterial nylon materials prepared by copolymerizing cyclic lysine and caprolactam through hydrochloric acid protonation have poor material properties and a long process route. The specific beneficial effects are as follows:

[0029] 1. Persistent, efficient antibacterial performance, high safety, and environmental friendliness: The present invention prepares an antibacterial nylon material by ring - opening copolymerization of a heptacyclic lysine monomer and a lactam monomer, and then performing a quaternization reaction with a halogenated hydrocarbon. The quaternary ammonium salt group, as the antibacterial component, is covalently connected to the nylon molecular chain and is not easily migrated to the external environment, effectively avoiding the defect of the migration and loss of small molecule antibacterial agents in traditional antibacterial nylon materials, ensuring the persistent and efficient antibacterial performance of the antibacterial nylon material, greatly reducing the antibacterial components released into the environment, and reducing the potential risks to the human body and the environment, thereby improving the safety and environmental friendliness of the antibacterial material.

[0030] 2. Excellent mechanical properties and thermal stability: In the present invention, the copolyamide is dissolved and then completely quaternized with a halogenated hydrocarbon to ensure that the material has excellent mechanical properties and thermal stability, effectively improving the defects of obvious decline in mechanical properties and poor thermal stability of the antibacterial nylon materials prepared by the hydrochloric acid protonation method in the prior art.

[0031] 3. Simple preparation process, suitable for large - scale application: The present invention uses a heptacyclic lysine monomer with unprotected amino groups to replace the monomer with double - protected amino groups in the prior art to prepare a copolyamide. The quaternary ammonium salt formed by the complete quaternization of the copolyamide with a halogenated hydrocarbon has excellent thermal stability and is not affected by pH value changes. The prepared antibacterial nylon material has low requirements for equipment, simplifies the preparation process of the antibacterial nylon material, improves production efficiency, and reduces production costs. The antibacterial nylon material can be processed and formed in various ways and has broad application potential in the fields of textiles, daily necessities, packaging materials, and panels. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of the synthesis route of the antibacterial nylon material;

[0033] Figure 2 is a comparison chart of the antibacterial effects of the conventional nylon material prepared in Comparative Example 1 and the antibacterial nylon material prepared in Example 4 against Staphylococcus aureus;

[0034] Figure 3 is a comparison chart of the antibacterial effects of the conventional nylon material prepared in Comparative Example 1 and the antibacterial nylon material prepared in Example 4 against Escherichia coli. DETAILED DESCRIPTION OF THE INVENTION

[0035] To make the technical solution of the present invention clearer, the following will clearly and completely describe the technical solution in the embodiments of the present invention in conjunction with the accompanying drawings of the present invention. It should be noted that the following embodiments are only used to better understand the technical solution of the present invention and should not be construed as a limitation to the present invention.

[0036] Any specific numerical value (including the endpoints of a numerical range) disclosed herein is not limited to the exact value of that numerical value, but should be understood to also cover values close to that exact value, for example, all possible numerical values within ±5% of that exact value. And, for the disclosed numerical range, between the endpoint values of the range, between the endpoint value and the specific point value within the range, and between each specific point value, any combination can be obtained to form one or more new numerical ranges, and these new numerical ranges should also be regarded as specifically disclosed herein.

[0037] Unless otherwise specified, the terms used herein have the same meaning as commonly understood by those skilled in the art. If a term is defined in this document and its definition is different from the common understanding in the art, the definition in this document shall prevail.

[0038] In this document, except for the clearly stated content, any matter or thing not mentioned directly applies to those known in the art without any change. Moreover, any embodiment described in this document can be freely combined with one or more other embodiments described in this document, and the technical solutions or technical ideas formed thereby shall be regarded as part of the original disclosure or original record of the present invention, and should not be regarded as new content not disclosed or anticipated in this document, unless those skilled in the art consider that the combination is obviously unreasonable.

[0039] All patents and non-patent documents mentioned in this document, including but not limited to textbooks and journal articles, etc., are incorporated herein by reference in their entirety.

[0040] Example 1.

[0041] S1: Add 6 kg of lysine fermentation broth (lysine mass concentration is 60%) and 50 L of methanol into a 100 L reaction kettle. Under a nitrogen atmosphere, stir and react at 220 °C for 2 h. After the reaction is completed, cool to room temperature, distill out and recover n-butanol, and recrystallize with ethyl acetate to obtain the heptacyclic lysine monomer - aminocaprolactam, with a yield of 95%. According to 1H NMR analysis, its purity is 99%. 1 1H NMR (300 MHz, D2O) δ 3.69 - 3.72 (dd, 1H), 3.22 - 3.26 (m, 2H), 1.26 - 1.99 (m, 6H).

[0042] S2: Weigh 55 mmol of the seven-membered cyclic lysine monomer-caprolactam prepared in S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 21 mmol of sodium hydride and 21 mmol of N-benzoylcaprolactam activator. After evacuation and replacement of gas, maintain a nitrogen atmosphere and react at 180 °C for 6 h. After the reaction is completed, cool to room temperature, add trifluoroethanol to dissolve the product, and take a part of the solution for NMR characterization. 1 1H NMR (300 MHz, DMSO-d6 / TFA, v:v = 5:1) δ 4.56 - 4.80, 3.45 - 3.56, 2.55 - 2.82, 0.52 - 0.75, 0.34 - 0.50. Add 220 mmol of bromoethane and 165 mmol of potassium carbonate to the remaining solution, stir and react at 40 °C for 12 h. After cooling, precipitate in a mixed solvent of water and methanol (volume ratio of water to methanol is 1:1), and obtain the antibacterial nylon material after centrifugal drying with a yield of 95%. The molar percentage content of quaternized seven-membered cyclic lysine in this antibacterial nylon material is about 5%. As Figure 1 is the schematic diagram of the synthesis route of the antibacterial nylon material.

[0043] Example 2.

[0044] Weigh 140 mmol of the seven-membered cyclic lysine monomer-caprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 57 mmol of sodium hydride and 57 mmol of N-benzoylcaprolactam activator. After evacuation and replacement of gas, maintain a nitrogen atmosphere and react at 180 °C for 6 h. After the reaction is completed, cool to room temperature, add trifluoroethanol to dissolve the product, then add 700 mmol of bromoethane and 420 mmol of potassium carbonate, stir and react at 40 °C for 12 h. After cooling, precipitate in a mixed solvent of water and methanol (volume ratio of water to methanol is 1:1), and obtain the antibacterial nylon material after centrifugal drying with a yield of 98%. The molar percentage content of quaternized seven-membered cyclic lysine in this antibacterial nylon material is about 10%.

[0045] Example 3.

[0046] Weigh 200 mmol of the heptacyclic lysine monomer-caprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 60 mmol of sodium hydride and 60 mmol of N-benzoylcaprolactam activator. After evacuation and replacement of the gas, maintain a nitrogen atmosphere and react at 180 °C for 6 h. After the reaction is completed, cool to room temperature, add N,N-dimethylformamide to dissolve the product, then add 800 mmol of bromoethane and 600 mmol of potassium carbonate, and stir and react at 40 °C for 12 h. After cooling, sediment in a mixed solvent of water and methanol (the volume ratio of water to methanol is 1:1), and obtain an antibacterial nylon material after centrifugal drying. The yield is 98%, and the molar percentage content of quaternized heptacyclic lysine in the antibacterial nylon material is about 15%.

[0047] Example 4.

[0048] Weigh 250 mmol of the heptacyclic lysine monomer-caprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 50 mmol of sodium hydride and 50 mmol of N-benzoylcaprolactam activator. After evacuation and replacement of the gas, maintain a nitrogen atmosphere and react at 180 °C for 6 h. After the reaction is completed, cool to room temperature, add N,N-dimethylacetamide to dissolve the product, then add 1250 mmol of bromoethane and 750 mmol of potassium carbonate, and stir and react at 40 °C for 12 h. After cooling, sediment in a mixed solvent of water and methanol (the volume ratio of water to methanol is 1:1), and obtain an antibacterial nylon material after centrifugal drying. The yield is 96%, and the molar percentage content of quaternized heptacyclic lysine in the antibacterial nylon material is about 19%.

[0049] Example 5.

[0050] Weigh 150 mmol of the heptacyclic lysine monomer-caprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 57 mmol of sodium hydride and 57 mmol of N-benzoylcaprolactam activator. After evacuation and replacement of the gas, maintain a nitrogen atmosphere and react at 180 °C for 6 h.

[0051] Cool to room temperature, add hexafluoroisopropanol to dissolve, then add 750 mmol of iodomethane and 450 mmol of potassium carbonate, and stir and react at room temperature for 12 h. After cooling, sediment in a mixed solvent of water and methanol (the volume ratio of water to methanol is 1:1), and obtain an antibacterial nylon material after centrifugal drying. The yield is 97%, and the molar percentage content of quaternized heptacyclic lysine in the antibacterial nylon material is about 13%.

[0052] Example 6.

[0053] Weigh 150 mmol of the heptacyclic lysine monomer - aminocaprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 57 mmol of sodium and 57 mmol of N - benzoylcaprolactam activator. After evacuation and replacement of gas, maintain a nitrogen atmosphere and react at 200 °C for 4 h. After the reaction is completed, cool to room temperature, add DMPU to dissolve the product, then add 900 mmol of n - butyl bromide and 450 mmol of potassium carbonate, and stir and react at 80 °C for 12 h. After cooling, sediment in a mixed solvent of water and methanol (the volume ratio of water to methanol is 1:1), and obtain an antibacterial nylon material after centrifugal drying. The yield is 97%, and the molar percentage content of quaternized heptacyclic lysine in this antibacterial nylon material is about 10%.

[0054] Example 7.

[0055] Weigh 150 mmol of the heptacyclic lysine monomer - aminocaprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 55 mmol of sodium and 55 mmol of N - benzoylcaprolactam activator. After evacuation and replacement of gas, maintain a nitrogen atmosphere and react at 200 °C for 4 h. After the reaction is completed, cool to room temperature, add HMPA to dissolve the product, then add 900 mmol of 1 - bromooctane and 450 mmol of potassium carbonate, and stir and react at 80 °C for 12 h. After cooling, sediment in a mixed solvent of water and methanol (the volume ratio of water to methanol is 1:1), and obtain an antibacterial nylon material after centrifugal drying. The yield is 95%, and the molar percentage content of quaternized heptacyclic lysine in this antibacterial nylon material is about 8%.

[0056] Example 8.

[0057] Weigh 150 mmol of the heptacyclic lysine monomer - aminocaprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 57 mmol of sodium methoxide and 57 mmol of N - benzoylcaprolactam activator. After evacuation and replacement of gas, maintain a nitrogen atmosphere and react at 180 °C for 5 h. After the reaction is completed, cool to room temperature, add N - methylpyrrolidone to dissolve the product, then add 900 mmol of cetyl bromide and 450 mmol of potassium carbonate, and stir and react at 90 °C for 12 h. After cooling, sediment in a mixed solvent of water and acetone (the volume ratio of water to acetone is 1:1), and obtain an antibacterial nylon material after centrifugal drying. The yield is 96%, and the molar percentage content of quaternized heptacyclic lysine in this antibacterial nylon material is about 5%.

[0058] Example 9.

[0059] Weigh 150 mmol of the heptacyclic lysine monomer-caprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 57 mmol of potassium tert-butoxide and 57 mmol of N-benzoylcaprolactam activator. After evacuation and replacement of the gas, maintain a nitrogen atmosphere and react at 200 °C for 4 h. After the reaction is completed, cool to room temperature, add dimethyl sulfoxide to dissolve the product, then add 900 mmol of bromocyclohexane and 450 mmol of potassium carbonate, and stir and react at 90 °C for 12 h. After cooling, sediment in a mixed solvent of water and acetone (the volume ratio of water to acetone is 1:1), and obtain an antibacterial nylon material after centrifugal drying. The yield is 95%, and the molar percentage content of quaternized heptacyclic lysine in this antibacterial nylon material is about 12%.

[0060] Example 10.

[0061] Weigh 150 mmol of the heptacyclic lysine monomer-caprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 57 mmol of potassium hydride and 57 mmol of N-benzoylcaprolactam activator. After evacuation and replacement of the gas, maintain a nitrogen atmosphere and react at 180 °C for 4 h. After the reaction is completed, cool to room temperature, add triethylene glycol to dissolve the product, then add 900 mmol of benzyl bromide and 450 mmol of potassium carbonate, and stir and react at 90 °C for 12 h. After cooling, sediment in a mixed solvent of water and acetone (the volume ratio of water to acetone is 1:1), and obtain an antibacterial nylon material after centrifugal drying. The yield is 95%, and the molar percentage content of quaternized heptacyclic lysine in this antibacterial nylon material is about 10%.

[0062] Comparative Example 1.

[0063] Weigh 1000 mmol of caprolactam into a polymerization reactor. Add 50 mmol of sodium hydride and 50 mmol of N-benzoylcaprolactam activator. After evacuation and replacement of the gas, maintain a nitrogen atmosphere and react at 180 °C for 6 h. After the reaction is completed, cool to room temperature, add trifluoroethanol to dissolve the product, sediment in a mixed solvent of water and methanol (the volume ratio of water to methanol is 1:1), and obtain an antibacterial nylon material after centrifugal drying. The yield is 98%.

[0064] Comparative Example 2.

[0065] Weigh 10 mmol of the heptacyclic lysine monomer - aminocaprolactam prepared in Example 1 S1 and 1000 mmol of caprolactam into a polymerization reactor. Add 50 mmol of sodium hydride and 50 mmol of N - benzoylcaprolactam activator. After evacuation and replacement of gas, maintain a nitrogen atmosphere and react at 180 °C for 6 h. After the reaction is completed, cool to room temperature, add trifluoroethanol to dissolve the product, then add 50 mmol of bromoethane and 30 mmol of potassium carbonate, and stir and react at 40 °C for 12 h. After cooling, sediment in a mixed solvent of water and methanol (volume ratio of water to methanol is 1:1), and obtain an antibacterial nylon material after centrifugation and drying. The yield is 98%, and the molar percentage content of quaternized heptacyclic lysine in the antibacterial nylon material is about 0.8%.

[0066] Comparative Example 3.

[0067] Weigh 500 mmol of the heptacyclic lysine monomer - aminocaprolactam prepared in Example 1 S1 and 200 mmol of caprolactam into a polymerization reactor. Add 35 mmol of sodium hydride and 35 mmol of N - benzoylcaprolactam activator. After evacuation and replacement of gas, maintain a nitrogen atmosphere and react at 180 °C for 6 h. After the reaction is completed, cool to room temperature, add trifluoroethanol to dissolve the product, then add 2000 mmol of bromoethane and 1500 mmol of potassium carbonate, and stir and react at 40 °C for 12 h. After cooling, sediment in a mixed solvent of water and methanol (volume ratio of water to methanol is 1:1), and obtain an antibacterial nylon material after centrifugation and drying. The yield is 98%, and the molar percentage content of quaternized heptacyclic lysine in the antibacterial nylon material is about 68%.

[0068] Antibacterial effect test:

[0069] Refer to the method of Chinese national standard GB / T 31402 - 2023 for the antibacterial effect test. The specific operation is as follows: Press the antibacterial nylon materials prepared in Examples 1 - 10 and the nylon materials prepared in Comparative Examples 1 - 3 into square sheets with a size of 5 cm × 5 cm respectively. Spray 75% alcohol and then dry in the air. Irradiate under an ultraviolet lamp for 30 min for sterilization treatment, and then drop a solution with a concentration of 6×10 50.4 mL of the bacterial suspension at CFU / mL was covered with a PET membrane and cultured at 37 °C for 24 h. The bacterial suspension was rinsed and diluted with 10 mL of SCDLP liquid medium, and after gradient dilution, it was mixed with PCA medium and cultured at 37 °C for 48 h. A fully automatic colony counter was used to count the colonies in the medium, and the bacterial concentration in the bacterial suspension after culture was estimated. The conventional nylon material obtained in Comparative Example 1 was used as the control group. The test bacteria used were Staphylococcus aureus (S. aureus) ATCC6538 and Escherichia coli (E. coli) ATCC25922. As Figure 2 , Figure 3 Figures 1 and 2 are respectively the comparison charts of the antibacterial effects of the conventional nylon material prepared in Comparative Example 1 and the antibacterial nylon material prepared in Example 4 against Staphylococcus aureus and Escherichia coli. It can be seen from the figures that compared with the conventional nylon material prepared in Comparative Example 1, the antibacterial nylon material prepared in Example 4 has a significant inhibitory effect on both Staphylococcus aureus and Escherichia coli. The detailed test results are shown in Table 1.

[0070] The antibacterial rate calculation formula is as follows:

[0071]

[0072] Mechanical property test:

[0073] The antibacterial nylon materials prepared in the above Examples 1-10 and the nylon materials prepared in Comparative Examples 1-3 were respectively injection molded into 5A type specimens (the dimensions refer to Chinese national standard GB / T 1040.2-2022), and tensile property tests were carried out. The results are shown in Table 1.

[0074] As shown in the data in Table 1, compared with the conventional nylon material prepared in Comparative Example 1, the antibacterial nylon material prepared in the present invention has a significant inhibitory effect on both Staphylococcus aureus and Escherichia coli, and the antibacterial rate can reach more than 90%. At the same time, the antibacterial nylon material retains the excellent mechanical properties of the conventional nylon material; the antibacterial properties of the antibacterial nylon materials prepared in Examples 1-10 are better than those of the nylon material prepared in Comparative Example 2. At the same time, the mechanical properties of the antibacterial nylon materials prepared in Examples 1-10 are better than those of the nylon material prepared in Comparative Example 3. It can be seen from this that the antibacterial nylon material prepared by the quaternization reaction of aminocaprolactam and halogenated hydrocarbon in the present invention can effectively avoid the migration and loss of small molecule antibacterial agents and endow the nylon material with excellent antibacterial properties and mechanical properties.

[0075] Table 1

[0076]

[0077]

[0078] The antibacterial nylon material is prepared by ring-opening copolymerization of a seven-membered cyclic lysine monomer and a lactam monomer, followed by complete quaternization reaction with a halogenated hydrocarbon. The antibacterial nylon material has persistent and efficient antibacterial properties, greatly reducing the antibacterial components released into the environment and lowering the potential risks to humans and the environment, thereby enhancing the safety and environmental friendliness of the antibacterial material. At the same time, the antibacterial nylon material has excellent mechanical properties and thermal stability, effectively improving the defects of the antibacterial nylon material prepared by the hydrochloric acid protonation method in the prior art, such as obvious decline in mechanical properties and poor thermal stability. The preparation process is simple and suitable for large-scale applications, and has broad application potential in the fields of textiles, daily necessities, packaging materials, and panels, etc.

[0079] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0080] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any suitable manner. To avoid unnecessary repetition, the present invention will not separately describe various possible combination manners.

[0081] In addition, any combination can be made between different embodiments of the present invention, as long as it does not violate the idea of the present invention, it should also be regarded as the content invented by the present invention.

Claims

1. An antibacterial nylon material, characterized in that, The molecular structure of the antibacterial nylon material contains two different repeating units shown in Formula I and Formula II: In Formula I and Formula II, R is any one of a substituted or unsubstituted straight-chain or branched-chain C 1-20 aliphatic hydrocarbon group, a substituted or unsubstituted C 3-12 alicyclic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group; n is any natural number from 1 to 8; x and y are respectively the molar ratios of the two repeating units, the range of x is from 0.01 to 0.50, the range of y is from 0.50 to 0.99, and the relationship between x and y is x + y = 1.

2. A preparation method of the antibacterial nylon material as described in claim 1, characterized in that, It includes the following steps: S1: Put the seven-membered cyclic lysine monomer and the lactam monomer into a polymerization kettle, add a catalyst and an activator for anionic ring-opening copolymerization to prepare a copolyamide; S2: Dissolve the copolyamide, add a halogenated hydrocarbon to the solution for a complete quaternization reaction, and after the reaction is completed, sediment and dry to prepare the antibacterial nylon material; The structural formula of the halogenated hydrocarbon is R-Hal; wherein, R is a substituted or unsubstituted straight-chain or branched-chain C 1-20 aliphatic hydrocarbon group, a substituted or unsubstituted C 3-12 alicyclic hydrocarbon group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group; Hal is a halogen, and the halogen is any one of chlorine, bromine, and iodine.

3. The preparation method of the antibacterial nylon material according to claim 2, wherein, The structural formula of the seven-membered cyclic lysine monomer described in S1 is shown in Formula III: The structural formula of the lactam monomer is shown in Formula IV: The structural formula of the activator is shown in Formula V: In the formula, R1 is a substituted or unsubstituted straight-chain or branched C 1-5 aliphatic hydrocarbon group, a substituted or unsubstituted aryl group.

4. The preparation method of the antibacterial nylon material according to claim 2, characterized in that, The catalyst described in S1 is one or at least two combinations of alkali metals, alkali metal oxides, alkali metal hydroxides, alkali metal hydrides, alkali metal alkoxides, alkaline earth metals, alkaline earth metal oxides, alkaline earth metal hydroxides, alkaline earth metal hydrides, alkaline earth metal alkoxides, carbene reagents, guanidine reagents, amidine reagents, phosphazene reagents.

5. The preparation method of the antibacterial nylon material according to claim 4, characterized in that, The catalyst described in S1 is any one of sodium hydride, potassium hydride, sodium hydroxide, phosphazene base, potassium tert-butoxide, sodium methoxide, potassium methoxide, sodium, potassium, DUB, TBD.

6. The preparation method of the antibacterial nylon material according to claim 2, wherein, The molar feeding ratio of the seven-membered cyclic lysine monomer to the lactam monomer in S1 is 0.01 - 1:1; the ratio of the total molar amount of the seven-membered cyclic lysine monomer and the lactam monomer to the molar amount of the catalyst and the molar amount of the activator is 100:0.1 - 5:0.1 - 5.

7. The preparation method of the antibacterial nylon material according to claim 2, characterized in that, The temperature of the copolymerization in S1 is 140 - 230 °C, and the time of the copolymerization is 1 - 6 h.

8. The preparation method of the antibacterial nylon material according to claim 2, characterized in that, The solvent used for dissolution in S2 is one or at least two combinations of methanol, ethanol, trifluoroethanol, hexafluoroisopropanol, N-methylpyrrolidone, benzyl alcohol, ethylene glycol, cyclohexanol, N,N-dimethylformamide, N,N-dimethylacetamide, triethylene glycol, dimethyl sulfoxide, hexamethylphosphoric triamide, 1,3-dimethylpropyleneurea; the temperature of the reaction is 40 - 100 °C, and the time of the reaction is 6 - 24 h.

9. The preparation method of the antibacterial nylon material according to claim 2, characterized in that, The solvent used for sedimentation in S2 is one or at least two combinations of water, methanol, ethanol, ether, ethyl acetate, acetone, n-hexane, petroleum ether.

10. Use of the antibacterial nylon material as described in claim 1 or the antibacterial nylon material prepared by the preparation method as described in any one of claims 1-9, characterized in that, It is applied to the preparation of textiles, daily necessities, packaging materials or panels.

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