Antifouling antibacterial thermoplastic polyurethane elastomer and method for preparing the same

Abstract

The application discloses an antifouling and antibacterial thermoplastic polyurethane elastomer and a preparation method thereof, and belongs to the technical field of polyurethane elastomers. The elastomer is composed of polyols, diisocyanate, a composite antibacterial agent and polyethylene glycol. The bio-based polyol in the polyols is prepared from castor oil through fluorination modification, acid anhydride reaction and mercapto esterification. The fluoralkyl side chain and the amphiphilic group introduced in the molecular structure endow the material body with antifouling properties. The elastomer can inhibit the adhesion and penetration of stains without relying on post-treatment coating. The composite antibacterial agent is composed of a zwitterionic quaternary ammonium salt, silver nitrate and tannic acid, and has a multiple antibacterial mechanism of electrostatic adsorption, metal ion release and biological membrane inhibition. The elastomer realizes excellent antifouling and antibacterial properties through the antifouling design of the bio-based polyol and the synergistic effect of the composite antibacterial agent. Meanwhile, the elastomer has the environmental protection advantages of bio-based components, and is suitable for industrial production in easy-pollution scenes such as medical treatment and sports equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane elastomers, more particularly, it relates to an antifouling and antibacterial thermoplastic polyurethane elastomer and a preparation method thereof. BACKGROUND

[0002] Thermoplastic polyurethane elastomer (TPU) is a kind of polymer material with rubber elasticity and plastic processing performance. Due to its excellent wear resistance, oil resistance, low temperature resistance and mechanical properties, it has been widely used in medical, sports equipment, automobile, electronic equipment and other fields. However, with the continuous expansion of application scenarios, higher requirements are put forward for the antibacterial and antifouling performance of TPU. Especially in the fields of medical and sports equipment, bacteria are easy to breed on the surface of the material, and dirt is easy to adhere, which not only affects the service life, but also may cause cross infection and other problems. Therefore, it is of great practical significance to develop TPU with intrinsic antifouling and antibacterial properties.

[0003] At present, the common antibacterial and antifouling methods mostly rely on surface coating technology, which realizes antibacterial and antifouling by coating a coating with antibacterial and antifouling function on the surface of the material. However, such coating has the problems of poor durability, easy wear and tear, and easy peeling, which limits its long-term application effect. For example, patent CN117210795A discloses a method for low-temperature evaporation coating on the surface of TPU, which improves the stability of the interface between the TPU matrix and the coating by surface treatment of the matrix, low-temperature evaporation and optimization of the coating composition. However, its preparation process is complex, and the durability of the coating still needs to be improved. Patent CN115044088A proposes a method for preparing a flexible Cu-Ag conductive super-hydrophobic coating on the surface of TPU plastic, which realizes the preparation of super-hydrophobic coating by chemical copper plating and spraying silver-containing solution. However, its preparation process involves multiple chemical treatments, which is difficult to realize industrialized mass production. In the field of composite antibacterial agents, patent CN118435941A discloses a lignin-nano silver composite antibacterial agent, which realizes antibacterial effect through the synergistic effect of lignin and nano silver, but does not involve antifouling performance. Therefore, the present application proposes an antifouling and antibacterial thermoplastic polyurethane elastomer and a preparation method thereof to solve the above technical problems. SUMMARY

[0004] The purpose of the present application is to provide an antifouling and antibacterial thermoplastic polyurethane elastomer and a preparation method thereof. The elastomer realizes excellent antifouling and antibacterial performance through the antifouling design of bio-based polyol and the synergistic effect of composite antibacterial agent, and has the environmental protection advantage of bio-based components, which is suitable for industrialized production in easy pollution scenarios such as medical and sports equipment.

[0005] To achieve the above purpose, the present application provides the following technical scheme:

[0006] The application discloses an antifouling and antibacterial thermoplastic polyurethane elastomer which is prepared from the following raw materials in parts by weight: 35-40 parts of polyol, 15-20 parts of diphenyl methane diisocyanate, 3-8 parts of composite antibacterial agent and 5-10 parts of polyethylene glycol.

[0007] Preferably, the polyol is composed of bio-based polyol and petroleum-based polyol in a mass ratio of 1-3:4-6.

[0008] Preferably, the preparation method of the bio-based polyol is as follows:

[0009] A1, castor oil, dodecafluoroheptyl acrylate and diisopropyl peroxybenzoate are mixed, stirring is carried out under nitrogen protection at 70-75 DEG C for 1-3 h, after the reaction is completed, centrifugal drying is carried out to obtain fluorinated castor oil, then the fluorinated castor oil is mixed with itaconic anhydride, stirring is carried out at 100-110 DEG C for 4-6 h to obtain modified castor oil;

[0010] A2, the modified castor oil is mixed with thiomalic acid, stirring is carried out under nitrogen protection at 80-85 DEG C for 2-4 h, then purification is carried out by using ether precipitation, and vacuum drying is carried out to obtain bio-based polyol.

[0011] Preferably, in step A1, the castor oil is 35-40 parts by weight, the dodecafluoroheptyl acrylate is 15-20 parts by weight, the diisopropyl peroxybenzoate is 1.0-1.5 parts by weight and the itaconic anhydride is 8-12 parts by weight.

[0012] Preferably, in step A2, the modified castor oil is 30-35 parts by weight and the thiomalic acid is 4-8 parts by weight.

[0013] Preferably, the preparation method of the composite antibacterial agent is as follows:

[0014] S1, N-methyldiethanolamine is mixed with 1,3-propane sulfonic acid lactone under nitrogen protection at 50-60 DEG C, stirring is carried out for 1-3 h, then dimethyl sulfate is added, reaction is carried out at room temperature for 2-4 h, precipitation is carried out by using ethanol, and vacuum drying is carried out to obtain a zwitterionic quaternary ammonium salt;

[0015] S2, silver nitrate, tannic acid and the zwitterionic quaternary ammonium salt are mixed in deionized water, stirring is carried out under light-shielding conditions at 60-70 DEG C for 1-3 h, centrifugal separation, water washing and drying are carried out to obtain the composite antibacterial agent.

[0016] Preferably, in step S1, the N-methyldiethanolamine is 10-15 parts by weight, the 1,3-propane sulfonic acid lactone is 8-12 parts by weight and the dimethyl sulfate is 5-10 parts by weight.

[0017] Preferably, in step S2, the silver nitrate is 5-10 parts by weight, the tannic acid is 3-6 parts by weight, the zwitterionic quaternary ammonium salt is 8-14 parts by weight and the deionized water is 80-90 parts by weight.

[0018] The application discloses a preparation method of an antifouling and antibacterial thermoplastic polyurethane elastomer, and comprises the following steps: mixing polyol, diphenyl methane diisocyanate and polyethylene glycol, stirring and reacting under the protection of nitrogen at 80-90 DEG C for 2-4 hours to form a prepolymer, then adding a composite antibacterial agent, continuously stirring and reacting at 70-80 DEG C for 1-2 hours to complete chain extension, finally injecting the reaction product into a mold, hot-pressing and forming at 100-120 DEG C for 10-20 minutes, and demolding after cooling to obtain the finished product.

[0019] In summary, the application has the following advantages:

[0020] 1. The application is based on the fluorinated modification and double-polar-group modification of castor oil, and the fluoralkyl side chain introduced in the bio-based polyol significantly reduces the surface energy of the material and inhibits the adhesion of stains; the carboxylic acid groups formed by the ring opening of anhydride and the double-polar structure introduced by thioesterification synergistically regulate the balance of surface polarity, forming a dynamic antifouling interface, which can effectively block the penetration and retention of organic stains such as oil and protein without relying on post-processing coatings, realizing the intrinsic antifouling function of the material. The bio-based castor oil derivative replaces part of the petroleum-based polyol, and the degradable ester bond introduced by thiomalic esterification reduces the dependence of the material on non-renewable resources.

[0021] 2. In the application, the composite antibacterial agent destroys the bacterial cell membrane through electrostatic adsorption of the quaternary ammonium salt, the silver ions released by silver nitrate interfere with microbial metabolism, and tannic acid inhibits the formation of biofilm, thereby constructing a multi-level antibacterial network of "contact killing-ion release-biofilm inhibition", which has high-efficiency and broad-spectrum antibacterial activity, and the silver ion release characteristic endows the material with long-acting antibacterial stability.

[0022] 3. The application adopts a pre-polymerization-chain extension-hot-pressing integrated process, and the composite antibacterial agent is uniformly embedded in the polyurethane matrix through chemical bonding, avoiding the interface peeling risk of the traditional coating method; the stable combination of the fluoralkyl segment and the microphase separation structure of the polyurethane hard segment ensures that the material still maintains stable antifouling and antibacterial properties after repeated deformation or mechanical wear. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0024] The experimental methods in the following examples are all conventional methods, and the experimental materials used are all purchased from conventional biochemical reagent stores, unless otherwise specified. The quantitative tests in the following examples are all set up with three repeated experiments, and the data are the average values of the three repeated experiments or the average values ± standard deviations.

[0025] Example 1

[0026] Preparation of bio-based polyol: A1. 35 parts of castor oil, 15 parts of dodecafluoroheptyl acrylate, and 1.0 part of diisopropylbenzene peroxide were mixed, the stirring rate was controlled at 300 rpm, and the mixture was stirred at 70°C for 3 h under nitrogen protection, and then centrifuged and dried to obtain fluorinated castor oil; 8 parts of itaconic anhydride was further added, and the mixture was stirred at 100°C for 6 h to obtain modified castor oil; A2. 30 parts of the modified castor oil and 4 parts of thiomalic acid were reacted at 80°C for 4 h under nitrogen protection, and then precipitated and purified with diethyl ether, and vacuum dried to obtain bio-based polyol.

[0027] Preparation of composite antibacterial agent: S1. 10 parts of N-methyldiethanolamine, 8 parts of 1,3-propane sulfonic acid lactone were reacted at 50°C for 3 h under nitrogen protection, and then 5 parts of dimethyl sulfate was added and reacted at room temperature for 4 h, and then precipitated with ethanol to obtain a zwitterionic quaternary ammonium salt; S2. 5 parts of silver nitrate, 3 parts of tannic acid, and 8 parts of the zwitterionic quaternary ammonium salt were dissolved in 80 parts of deionized water, and the mixture was reacted at 60°C for 3 h in the dark, and then centrifuged, washed with water, and dried to obtain a composite antibacterial agent.

[0028] Preparation of antifouling and antibacterial thermoplastic polyurethane elastomer: bio-based polyol and polytetrahydrofuran ether diol were mixed at a mass ratio of 1:4 (total polyol 35 parts), 15 parts of diphenylmethane diisocyanate and 5 parts of polyethylene glycol were added, the stirring rate was controlled at 320 rpm, and the mixture was stirred at 80°C for 4 h to form a prepolymer; 3 parts of the composite antibacterial agent was further added, and the mixture was continuously stirred at 70°C for 2 h to complete the chain extension, and finally the reaction product was injected into a mold, and hot-pressed at 100°C for 20 min to obtain the finished product.

[0029] Example 2

[0030] Preparation of bio-based polyol: A1. 38 parts of castor oil, 18 parts of dodecafluoroheptyl acrylate, and 1.3 parts of diisopropylbenzene peroxide were mixed, the stirring rate was controlled at 320 rpm, and the mixture was stirred at 72°C for 2.8 h under nitrogen protection, and then centrifuged and dried to obtain fluorinated castor oil; 10 parts of itaconic anhydride was further added, and the mixture was stirred at 105°C for 5.8 h to obtain modified castor oil; A2. 33 parts of the modified castor oil and 6 parts of thiomalic acid were reacted at 83°C for 3.8 h under nitrogen protection, and then precipitated and purified with diethyl ether, and vacuum dried to obtain bio-based polyol.

[0031] Antibacterial agent preparation: S1. Control the stirring rate at 320 rpm, under nitrogen protection, 12 parts of N-methyldiethanolamine, 10 parts of 1,3-propane sulfonic acid lactone were reacted at 55°C for 2.5h, then 7 parts of dimethyl sulfate was added and reacted at room temperature for 3.5h, and then precipitated with ethanol to obtain a zwitterionic quaternary ammonium salt; S2. 7 parts of silver nitrate, 4 parts of tannic acid, 11 parts of zwitterionic quaternary ammonium salt were dissolved in 85 parts of deionized water, and reacted at 65°C for 2.7h in the dark, centrifuged, washed with water and dried to obtain the composite antibacterial agent.

[0032] Antibacterial and antifouling thermoplastic polyurethane elastomer preparation: Mix the bio-based polyol with polyethylene glycol adipate diol at a mass ratio of 2:5 (total polyol 38 parts), add 18 parts of diphenyl methane diisocyanate and 7 parts of polyethylene glycol, control the stirring rate at 340 rpm, and stir at 85°C for 3.5h to form a prepolymer; then add 5 parts of the composite antibacterial agent, continue to stir at 75°C for 1.7h to complete the chain extension, finally pour the reaction product into a mold, heat press at 105°C for 18min, and then demold after cooling to obtain the finished product.

[0033] Example 3

[0034] Bio-based polyol preparation: A1. Mix 40 parts of castor oil, 20 parts of dodecafluoroheptyl acrylate, and 1.5 parts of diisopropylbenzene peroxide, control the stirring rate at 350 rpm, and stir at 75°C for 1h under nitrogen protection, then centrifuge and dry to obtain fluorinated castor oil; then add 12 parts of itaconic anhydride, stir at 110°C for 4h to obtain modified castor oil; A2. Take 35 parts of modified castor oil and 8 parts of thiomalic acid, react at 85°C for 2h under nitrogen protection, then precipitate and purify with diethyl ether, and vacuum dry to obtain bio-based polyol.

[0035] Antibacterial agent preparation: S1. Control the stirring rate at 350 rpm, under nitrogen protection, 15 parts of N-methyldiethanolamine, 12 parts of 1,3-propane sulfonic acid lactone were reacted at 60°C for 1h, then 10 parts of dimethyl sulfate was added and reacted at room temperature for 2h, and then precipitated with ethanol to obtain a zwitterionic quaternary ammonium salt; S2. 10 parts of silver nitrate, 6 parts of tannic acid, 14 parts of zwitterionic quaternary ammonium salt were dissolved in 90 parts of deionized water, and reacted at 70°C for 1h in the dark, centrifuged, washed with water and dried to obtain the composite antibacterial agent.

[0036] Antibacterial and antifouling thermoplastic polyurethane elastomer preparation: Mix the bio-based polyol with polyethylene glycol adipate diol at a mass ratio of 3:6 (total polyol 40 parts), add 20 parts of diphenyl methane diisocyanate and 8 parts of polyethylene glycol, control the stirring rate at 350 rpm, and stir at 90°C for 2h to form a prepolymer; then add 8 parts of the composite antibacterial agent, continue to stir at 80°C for 1h to complete the chain extension, finally pour the reaction product into a mold, heat press at 120°C for 10min, and then demold after cooling to obtain the finished product.

[0037] Example 4

[0038] Bio-based polyol preparation: A1. Mix 38 parts of castor oil, 18 parts of dodecafluoroheptyl acrylate, 1.3 parts of diisopropylbenzene peroxide, control the stirring rate at 330 rpm, and stir at 73°C for 2.5 h under nitrogen protection. Centrifugal drying to obtain fluorinated castor oil; then add 10 parts of itaconic anhydride, and stir at 108°C for 5 h to obtain modified castor oil; A2. Take 33 parts of modified castor oil and 6 parts of thiomalic acid, react at 82°C for 3.5 h under nitrogen protection, then precipitate and purify with diethyl ether, and vacuum drying to obtain bio-based polyol.

[0039] Composite antimicrobial agent preparation: S1. Control the stirring rate at 330 rpm, and react 15 parts of N-methyldiethanolamine, 10 parts of 1,3-propane sulfonic acid lactone at 58°C for 2.5 h under nitrogen protection, then add 8 parts of dimethyl sulfate and react at room temperature for 3.5 h, and precipitate to obtain a zwitterionic quaternary ammonium salt; S2. Dissolve 8 parts of silver nitrate, 5 parts of tannic acid, and 12 parts of the zwitterionic quaternary ammonium salt in 90 parts of deionized water, react at 68°C for 2.5 h in the dark, centrifugal washing, and drying to obtain a composite antimicrobial agent.

[0040] Antifouling and antibacterial thermoplastic polyurethane elastomer preparation: Mix bio-based polyol and polytetrahydrofuran ether diol at a mass ratio of 2.5:5.5 (total polyol 38 parts), add 19 parts of diphenylmethane diisocyanate and 8 parts of polyethylene glycol, control the stirring rate at 350 rpm, and stir at 88°C for 3.5 h to form a prepolymer; then add 6 parts of the composite antimicrobial agent, continue to stir at 78°C for 1.8 h to complete chain extension, finally inject the reaction product into a mold, and hot-press at 115°C for 15 min to obtain the finished product.

[0041] Comparative Example 1

[0042] An antifouling and antibacterial thermoplastic polyurethane elastomer, which is different from Example 4 in that bio-based polyol is not used, and the polyol is composed of petroleum-based polyol, i.e., the polyol is all polytetrahydrofuran ether diol, and the rest of the raw material composition and preparation method are the same as those of Example 4.

[0043] Comparative Example 2

[0044] An antifouling and antibacterial thermoplastic polyurethane elastomer, which is different from Example 4 in that the bio-based polyol is not modified by fluorination, specifically, the reaction process of dodecafluoroheptyl acrylate and diisopropylbenzene peroxide in step A1 is omitted, and castor oil is directly reacted with itaconic anhydride, and the rest of the raw material composition and preparation method are the same as those of Example 4.

[0045] Comparative Example 3

[0046] A kind of antifouling antibacterial thermoplastic polyurethane elastomer, the difference with example 4 is that the bio-based polyol does not carry out mercapto esterification reaction, specifically, the thiomalic acid reaction step in step A2 is omitted, directly with the modified castor oil obtained in step A1 as bio-based polyol, the rest of raw material composition and preparation method are same with example 4.

[0047] Comparative example 4

[0048] A kind of antifouling antibacterial thermoplastic polyurethane elastomer, the difference with example 4 is that the composite antibacterial agent is not added, the composite antibacterial agent adding step is omitted in preparation process, the rest of raw material composition and preparation method are same with example 4.

[0049] Comparative example 5

[0050] A kind of antifouling antibacterial thermoplastic polyurethane elastomer, the difference with example 4 is that the composite antibacterial agent only contains zwitterionic quaternary ammonium salt, specifically, the silver nitrate and tannic acid in step S2 are omitted, only with the zwitterionic quaternary ammonium salt obtained in step S1 as antibacterial agent, the rest of raw material composition and preparation method are same with example 4.

[0051] Comparative example 6

[0052] A kind of antifouling antibacterial thermoplastic polyurethane elastomer, the difference with example 4 is that: the zwitterionic quaternary ammonium salt is not used in the composite antibacterial agent, specifically, the zwitterionic quaternary ammonium salt prepared in step S1 is omitted in step S2, only with silver nitrate and tannic acid as antibacterial agent, the rest of raw material composition and preparation method are same with example 4.

[0053] Performance test

[0054] Antifouling performance: according to GB / T 30693-2014 standard, the contact angle of the antifouling antibacterial thermoplastic polyurethane elastomer prepared in examples 1-4 and comparative examples 1-6 is tested, using contact angle measuring instrument, the static contact angle of soybean oil and deionized water on the surface of the material is measured respectively, and the average value of three measurements is taken, and the test results are shown in table 1.

[0055] Antibacterial performance: according to ISO 22196-2011 standard, the antibacterial rate of escherichia coli of the antifouling antibacterial thermoplastic polyurethane elastomer prepared in examples 1-4 and comparative examples 1-6 is tested, and the test results are shown in table 1.

[0056] Mechanical property: according to ASTM D412 standard, the tensile strength and elongation at break of the antifouling antibacterial thermoplastic polyurethane elastomer prepared in examples 1-4 and comparative examples 1-6 are tested, and the test results are shown in table 1.

[0057] Table 1

[0058] Test item Contact angle / ° (oil / water) Bacteriostatic rate / % Tensile strength / MPa Elongation at break / % Example 1 128 / 115 95.1 52.5 680 Example 2 132 / 122 96.7 54.2 710 Example 3 135 / 130 98.3 56.8 730 Example 4 138 / 135 82 58.7 750 Comparative Example 1 101 / 93 94.7 53.6 560 Comparative Example 2 106 / 99 96.2 50.5 600 Comparative Example 3 115 / 103 91 51.2 655 Comparative Example 4 120 / 107 75 50.1 580 Comparative Example 5 125 / 110 91 50.4 660 Comparative Example 6 122 / 108 89 52 665

[0059] Through the test analysis of contact angle, bacteriostatic rate, tensile strength and elongation at break, the surface antifouling performance, broad-spectrum antibacterial activity and mechanical stability of the material are significantly improved by the fluorination modification and thiol esterification design of the bio-based polyol, combined with the synergistic effect of the composite antibacterial agent. Compared with the comparative examples which lack the key modification steps or components, the examples of the present application show obvious advantages in contact angle, bacteriostatic rate and mechanical properties, confirming the key influence of the synergistic effect of each technical feature on the antifouling and antibacterial properties and the comprehensive performance of the material. Among them, the optimal example realizes a good balance between antifouling and antibacterial ability and tensile and breaking performance through parameter optimization. As shown by the results in Table 1 above, the antifouling and antibacterial thermoplastic polyurethane elastomers prepared in Examples 1-4 all show excellent comprehensive performance in antifouling performance, bacteriostatic performance and mechanical properties, while the performance of Comparative Examples 1-6 decreases significantly.

[0060] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific embodiments, as long as they do not deviate from the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A stain-resistant and antibacterial thermoplastic polyurethane elastomer, characterized in that, It is composed of the following raw materials in parts by weight: 35-40 parts polyol, 15-20 parts diphenylmethane diisocyanate, 3-8 parts composite antibacterial agent and 5-10 parts polyethylene glycol; The polyol is composed of bio-based polyol and petroleum-based polyol in a mass ratio of 1-3:4-6, wherein the petroleum-based polyol is polytetrahydrofuran ether diol or polyethylene adipate diol. The preparation method of the bio-based polyol is as follows: A1. Castor oil, dodecafluoroheptyl acrylate and diisobenzoyl peroxide are mixed and stirred at 70-75℃ for 1-3 hours under nitrogen protection. After the reaction is completed, the mixture is centrifuged and dried to obtain fluorinated castor oil. It is then mixed with itaconic anhydride and stirred at 100-110℃ for 4-6 hours to obtain modified castor oil. A2. Modified castor oil and thiomalic acid were mixed and reacted under nitrogen protection at 80-85℃ for 2-4 hours with stirring. The mixture was then purified by precipitation with diethyl ether and vacuum dried to obtain bio-based polyol. The preparation method of the composite antibacterial agent is as follows: S1. N-methyldiethanolamine and 1,3-propanesulfonate lactone were mixed and stirred at 50-60°C under nitrogen protection for 1-3 hours. Then dimethyl sulfate was added and reacted at room temperature for 2-4 hours. The zwitterionic quaternary ammonium salt was obtained by ethanol precipitation and vacuum drying. S2. Silver nitrate, tannic acid and zwitterionic quaternary ammonium salt are mixed in deionized water and stirred at 60-70℃ in the dark for 1-3 hours. After centrifugation, washing with water and drying, the composite antibacterial agent is obtained.

2. The antifouling and antibacterial thermoplastic polyurethane elastomer according to claim 1, characterized in that, In step A1, the ingredients are 35-40 parts by weight of castor oil, 15-20 parts of dodecafluoroheptyl acrylate, 1.0-1.5 parts of diisobenzoyl peroxide, and 8-12 parts of itaconic anhydride.

3. The antifouling and antibacterial thermoplastic polyurethane elastomer according to claim 1, characterized in that, In step A2, the amount of modified castor oil and thiomalic acid is 30-35 parts by weight.

4. The antifouling and antibacterial thermoplastic polyurethane elastomer according to claim 1, characterized in that, In step S1, the ingredients are 10-15 parts by weight of N-methyldiethanolamine, 8-12 parts by weight of 1,3-propanesulfonate lactone, and 5-10 parts by weight of dimethyl sulfate.

5. The antifouling and antibacterial thermoplastic polyurethane elastomer according to claim 1, characterized in that, In step S2, the ingredients are 5-10 parts by weight of silver nitrate, 3-6 parts of tannic acid, 8-14 parts of zwitterionic quaternary ammonium salt, and 80-90 parts of deionized water.

6. A method for preparing an antifouling and antibacterial thermoplastic polyurethane elastomer according to any one of claims 1-5, characterized in that, Includes the following steps: Polyol, diphenylmethane diisocyanate and polyethylene glycol are mixed and stirred at 80-90℃ under nitrogen protection for 2-4 hours to form a prepolymer. Then, a composite antibacterial agent is added and stirred at 70-80℃ for 1-2 hours to complete chain extension. Finally, the reaction product is injected into a mold and hot-pressed at 100-120℃ for 10-20 minutes. After cooling, the product is demolded to obtain the finished product.