A citronellol-based antibacterial polymer, and a preparation method and application thereof

Abstract

The application discloses a citronellol-based antibacterial polymer and a preparation method and application thereof. First, a citronellol-based initiator is synthesized through esterification reaction of citronellol and an acyl halide, and then DMAEMA and HEMA are polymerized through ATRP to obtain the citronellol-based antibacterial polymer; and then the citronellol-based antibacterial polymer is connected to cotton through a covalent bond by using diisocyanate to obtain a washing-resistant antibacterial cotton fabric, which has greater application value in the field of medical cotton fabrics. The citronellol-based antibacterial polymer prepared by modifying citronellol and combining with the polymer has obviously enhanced antibacterial effect and is firmly grafted to the cotton, and is expected to be used in industrial production.

Description

Technical Field

[0001] This invention belongs to the field of polymer synthetic chemistry, specifically relating to a citronellol-based antibacterial polymer, its preparation method, and its application. Background Technology

[0002] Numerous studies have confirmed that microorganisms can adhere to and proliferate on artificial surfaces, such as clothing, medical devices, and food packaging. Despite significant progress in the development of antimicrobial and anticontamination surfaces, microbial adhesion and the resulting biofilm adhesion to synthetic surfaces remain a major challenge for humanity. Simultaneously, the widespread use of antibiotics has led to the emergence of antibiotic-resistant bacteria. Due to the slow development of new antibiotics to replace ineffective ones, drug-resistant bacteria pose a significant threat to public health. The impact of microbial resistance can be greatly reduced by decreasing antibiotic consumption. Therefore, there is a need to develop new, highly effective antimicrobial compounds that are less susceptible to bacterial resistance to reduce antibiotic use. Renewable resources, as precursors for developing custom bioactive polymers, have attracted considerable attention from researchers. Therefore, it is necessary to continue developing green, renewable, highly effective, and resistance-free antimicrobial polymers based on current research.

[0003] Poly(dimethylaminoethyl methacrylate) (PDMAEMA), due to its abundant tertiary amines, carries a positive charge when dissolved in acidic media. It can disrupt bacterial membrane stability by causing cell death through exchange with divalent cations. As a cationic bactericide, it has been proven to kill most Gram-negative and Gram-positive bacteria. PDMAEMA can adhere to various planar substrates, including glass, polystyrene, and polypropylene, thus endowing these materials with certain antibacterial properties. The antibacterial effect increases with increasing PDMAEMA grafting density, but the antibacterial properties of physically adhered planar substrates are not durable. Poly(hydroxyethyl methacrylate) (PHEMA), on the other hand, is a widely used and researched biocompatible polymer. Each repeating unit has a hydroxyl (OH) group, which allows the polymer to be chemically bonded to the substrate surface, resulting in a long-lasting antibacterial polymer. Citronellol is a natural monoterpene alcohol with a rose-like scent, widely found in the essential oils of various aromatic plants. Many studies have shown that citronellol possesses various pharmacological functions, including antibacterial, antifungal, antihypertensive, vasodilatory, antioxidant, and anti-inflammatory effects. However, its insolubility in water limits its application, and it is urgent to overcome this shortcoming in order to make it more widely used in medicine. Summary of the Invention

[0004] To address the shortcomings and deficiencies of existing technologies, the primary objective of this invention is to provide a citronellol-based antibacterial polymer.

[0005] Another objective of this invention is to provide a method for preparing the above-mentioned citronellol-based antibacterial polymer. This invention modifies citronellol, a natural plant essential oil component, to synthesize a citronellol-based initiator, which initiates the polymerization of methacrylate monomers dimethylaminoethyl methacrylate (DMAEMA) and hydroxyethyl methacrylate (HEMA) via ATRP, thereby combining the antibacterial properties of citronellol with the antibacterial properties of PDMAEMA and the biocompatibility with PHEMA to obtain a citronellol-based antibacterial polymer.

[0006] Another object of the present invention is to provide the application of the above-mentioned citronellol-based antibacterial polymer, by using diisocyanate to covalently link the citronellol-based antibacterial polymer to cotton fabric, thereby obtaining a wash-resistant antibacterial cotton fabric, which can play a greater application value in the field of medical cotton fabrics.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A citronellol-based antibacterial polymer, characterized in that: citronellol is modified by esterification of citronellol and acyl halide to synthesize a citronellol-based initiator, which then initiates the one-step polymerization of DMAEMA and HEMA via ATRP.

[0009] The number of repeating units in DMAEMA is 5 to 13, and the number of repeating units in HEMA is 3 to 4. Preferably, the number of repeating units in DMAEMA is 11 and the number of repeating units in HEMA is 3.

[0010] The preparation method of the citronellol-based antibacterial polymer includes the following steps:

[0011] (1) Citronellol-based initiators were synthesized by esterification reaction using citronellol and acyl halide as raw materials under inert gas.

[0012] (2) The citronellol-based initiator, methacrylate monomer, ligand and catalyst obtained in step (1) are added and dispersed in the solvent system in proportion. After deoxygenation treatment by freeze degassing, the polymerization reaction is carried out under heating and stirring conditions to prepare citronellol-based antibacterial polymer.

[0013] The esterification reaction described in step (1) is as follows: under an inert gas atmosphere, citronellol and triethylamine are dissolved in an organic solvent, and then acyl halides are added dropwise under an ice-water bath and reflux. After the addition is completed, the ice-water bath is removed, and the mixture is refluxed at room temperature. After reacting for a period of time, the mixture is purified and rotary evaporated to obtain the citronellol-based initiator.

[0014] The molar ratio of citronellol, triethylamine, and acyl halide is 1:1.2-1.5:1.2-1.5.

[0015] The acyl halide is 2-bromoisobutyryl bromide.

[0016] The organic solvent is dichloromethane.

[0017] The reflux time in the ice-water bath is 1-2 hours; the reflux time at room temperature is 4-6 hours.

[0018] In step (2), the methacrylate monomers are DMAEMA and HEMA.

[0019] In step (2), the solvent is anhydrous toluene.

[0020] In step (2), the ligand is pentamethyldiethylenetriamine (PMDETA).

[0021] In step (2), the catalyst is cuprous bromide.

[0022] In step (2), the reaction molar ratio of the citronellol initiator, ligand, catalyst, DMAEMA and HEMA is 1:1.2:1.2:(5-15):(1-5).

[0023] In step (2), the polymerization reaction temperature is 60-65℃ and the polymerization reaction time is 12-24h.

[0024] The application of the above-mentioned citronellol-based antibacterial polymer in the preparation of antibacterial cotton fabric is obtained by covalently linking the citronellol-based antibacterial polymer with cotton fabric: the diisocyanate and the catalyst are uniformly dispersed in the solvent to form a mixed solution, and the cleaned cotton fabric is soaked in the above mixed solution, cured, washed and dried to obtain cotton fabric with antibacterial properties.

[0025] The molar ratio of citronellol-based antibacterial polymer, diisocyanate and catalyst is 1:1.2-2:0.12.

[0026] The diisocyanate mentioned isophorone diisocyanate (IPDI).

[0027] The catalyst is di-n-butyltin dilaurate.

[0028] The solvent is tetrahydrofuran.

[0029] The cleaning procedure for the cotton fabric is as follows: stir with ordinary household detergent solution for 30 minutes, rinse with tap water until no foam is present, soak in distilled water and sonicate for 20 minutes, repeat 3 times, soak in acetone and sonicate for 20 minutes, repeat 3 times, soak in ethanol and sonicate for 20 minutes, repeat 3 times, and then vacuum dry.

[0030] The soaking time is 30 minutes.

[0031] The curing temperature is 110-130℃.

[0032] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0033] (1) This invention is a method for synthesizing antibacterial polymers using natural products, providing a new approach for synthesizing broad-spectrum environmentally friendly bio-antibacterial materials.

[0034] (2) The antibacterial polymer of the present invention is covalently bonded to the surface of cotton fabric to obtain a washable antibacterial cotton fabric, which can achieve long-lasting antibacterial properties.

[0035] (3) In the experiment, cotton fabrics with good antibacterial properties can be obtained through a simple impregnation-curing-washing-drying process. The operation is simple and time-saving, and it is expected to be used for industrial production. Attached Figure Description

[0036] Figure 1 The NMR spectra are for citronellol and citronellol-based initiators.

[0037] Figure 2 NMR spectra of citronellol-based antibacterial polymers and DMAEMA and HEMA polymers MPH without citronellol.

[0038] Figure 3 The graph shows the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of citronellol-based antibacterial polymers against Escherichia coli and Staphylococcus aureus.

[0039] Figure 4 Different concentrations of citronellol-based antibacterial polymer CD 11 Infrared images of H3-grafted cotton fabric, where a represents untreated cotton fabric and b represents cotton fabric treated with 40 mg / mL CD3. 11 H3-grafted cotton cloth, c with 20 mg / mL CD 11 H3-grafted cotton cloth, d is the amount of CD10mg / mL 11 H3 grafted cotton fabric.

[0040] Figure 5 To use different concentrations of CD 11 The bactericidal effect of H3-treated cotton fabric on Escherichia coli and Staphylococcus aureus.

[0041] Figure 6 For use of CD 11 The bactericidal effect of H3-treated cotton fabric on Escherichia coli and Staphylococcus aureus after washing different numbers of times.

[0042] Figure 7 CD is a citronellol-based antibacterial polymer 11 Preparation route diagram of H3 grafted cotton fabric. Detailed Implementation

[0043] The present invention will be further described in detail below with reference to embodiments, but the embodiments of the present invention are not limited thereto. All raw materials involved in the present invention can be purchased directly from the market. For process parameters not specifically specified, conventional techniques can be referred to.

[0044] Example 1: Preparation of Citronellol-based Initiator

[0045] In a 500 mL three-necked round-bottom flask, add 12 mL (66.04 mmol) of citronellol and 18 mL (0.1295 mol) of triethylamine, then add approximately 200 mL of dichloromethane to dissolve. Place a magnetic stir bar in the flask, connect it to a cooling system, purge with nitrogen, and close the stopcock of the constant-pressure funnel. Add 16 mL (0.1294 mol) of 2-bromoisobutyryl bromide, then rinse the funnel with 30 mL of dichloromethane and seal the system. Add the diluted 2-bromoisobutyryl bromide mixture dropwise at a constant rate under magnetic stirring in an ice-water bath for approximately 1 hour. After the addition is complete, remove the ice-water bath and allow the reaction to proceed at room temperature for 4 hours, during which the system changes from white to pale yellow. After the reaction is complete, remove the insoluble salts by vacuum filtration, remove the dichloromethane by rotary evaporation, and dissolve the remaining substances in an appropriate amount of deionized water. Extract the residue using diethyl ether (25 mL × 3), 0.1 mol / L dilute hydrochloric acid, and saturated sodium bicarbonate solution, respectively. Sufficient anhydrous magnesium sulfate was added to the obtained extract and stirred overnight to remove residual water. The filtered product was rotary evaporated to remove the solvent, and then passed through a silica gel column (using n-hexane:ethyl acetate = 9:1 as eluent). After rotary evaporation, 12.25 g of product was obtained, with a yield of 61.2%. The NMR spectrum of the citronellol initiator is shown in [reference needed]. Figure 1 .

[0046] Example 2: Preparation of Citronellol-based Antibacterial Polymer (CD9H3)

[0047] In a 100 mL Srank flask, citronellol initiator (1.03 g, 3.38 mmol), PMDETA (0.85 mL, 4.05 mmol), DMAEMA (5 mL, 29.67 mmol), and HEMA (0.8 mL, 6.60 mmol) were added sequentially and dissolved in 10 mL of anhydrous toluene. Under nitrogen atmosphere, the Srank flask was closed and placed in liquid nitrogen for freezing. After freezing, the stopcock was opened and a vacuum was applied for 7 min, followed by nitrogen purging. Once the system returned to atmospheric pressure, the Srank flask was placed in water to thaw. This constituted one freeze-degassing step, which was repeated three times. After the third nitrogen purging, cuprous bromide powder (0.527 g, 3.63 mmol) was quickly added, followed by thawing in water. After two more freeze-degassing cycles, the Srank flask was placed in a 60 °C oil bath and heated with stirring for 12 h. After the reaction was complete, the Srank flask was placed in an ice-water bath and quenched under atmospheric pressure. After removing the solvent by rotary evaporation, the catalyst cuprous bromide was removed using a neutral alumina column. The filtrate was concentrated by rotary evaporation, then precipitated in ice-cold n-hexane. The precipitate was collected and dried under vacuum at room temperature to obtain 3.36 g of citronellol-based antibacterial polymer (CD9H3), with a calculated yield of 50.22%. In this example, the polymer prepared had 9 repeating units of DMAEMA and 3 repeating units of HEMA.

[0048] Example 3: Preparation of Citronellol-based Antibacterial Polymer (CD5H3)

[0049] In a 100 mL Srank flask, citronellol initiator (1.39 g, 4.95 mmol), PMDETA (1.14 mL, 4.05 mmol), DMAEMA (5 mL, 29.67 mmol), and HEMA (1.8 mL, 14.84 mmol) were added sequentially and dissolved in 10 mL of anhydrous toluene. Under nitrogen atmosphere, the Srank flask was closed and placed in liquid nitrogen for freezing. After freezing, the stopcock was opened and a vacuum was applied for 7 min, followed by nitrogen purging. Once the system returned to atmospheric pressure, the Srank flask was placed in water to thaw. This constituted one freeze-degassing step, which was repeated three times. After the third nitrogen purging, cuprous bromide powder (0.78 g, 5.44 mmol) was quickly added, followed by thawing in water. After two more freeze-degassing cycles, the Srank flask was placed in a 60 °C oil bath and heated with stirring for 12 h. After the reaction was complete, the Srank flask was placed in an ice-water bath and quenched under atmospheric pressure. After removing the solvent by rotary evaporation, the catalyst cuprous bromide was removed using a neutral alumina column. The filtrate was concentrated by rotary evaporation, then precipitated in ice-cold n-hexane. The precipitate was collected and dried under vacuum at room temperature to obtain 1.70 g of citronellol-based antibacterial polymer (CD5H3), with a calculated yield of 21.00%. In this example, the polymer prepared had 5 repeating units of DMAEMA and 3 repeating units of HEMA.

[0050] Example 4 Citronellol-based antibacterial polymer (CD) 11 Preparation of H3)

[0051] In a 100 mL Srank flask, citronellol initiator (2.08 g, 6.82 mmol), PMDETA (1.50 mL, 7.18 mmol), DMAEMA (10 mL, 59.34 mmol), and HEMA (1.6 mL, 13.20 mmol) were added sequentially and dissolved in 15 mL of anhydrous toluene. Under nitrogen atmosphere, the Srank flask was closed and placed in liquid nitrogen for freezing. After freezing, the stopcock was opened and a vacuum was created for 7 min, followed by nitrogen purging. Once the system returned to atmospheric pressure, the Srank flask was placed in water to thaw. This constituted one freeze-degassing step, which was repeated three times. After the third nitrogen purging, cuprous bromide powder (1.05 g, 7.26 mmol) was quickly added, followed by thawing in water. After two more freeze-degassing cycles, the Srank flask was placed in a 60 °C oil bath and heated with stirring for 12 h. After the reaction was complete, the Srank flask was placed in an ice-water bath and quenched under atmospheric pressure. After removing the solvent by rotary evaporation, the catalyst cuprous bromide was removed using a neutral alumina column. The filtrate was concentrated by rotary evaporation, then precipitated in ice-cold n-hexane. The precipitate was collected and dried under vacuum at room temperature to obtain the citronellol-based antibacterial polymer (CD). 11 6.56 g of H3 was used, and the calculated reaction yield was 48.63%. In this example, the polymer prepared had 11 repeating units of DMAEMA and 3 repeating units of HEMA. The NMR spectra are shown below. Figure 2 As shown in b.

[0052] Example 5: Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC)

[0053] MIC refers to the lowest drug concentration that completely inhibits bacterial growth in a test tube or well in the dilution method for microbial identification. The most common and representative Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) are selected for testing. The lyophilized strains are revived and passaged 1-2 times before use. The second-generation bacterial culture is mixed with a 30% glycerol aqueous solution at a volume ratio of 1:1 in cryovials and stored in the freezer. The strain is inoculated into selective solid medium and cultured at 37°C for 24 hours. One strain is then inoculated into 2 mL of LB medium and cultured overnight for 12 hours. 30 μL of this culture is then transferred to 3 mL of LB medium for further expansion and culture for 6 hours before use. 100 μL of each of the various citronellol-based antibacterial polymers prepared in Examples 2-4 at a concentration of 2 mg / mL was added as the test sample to a 96-well plate containing 80 μL LB and serially diluted twofold. Simultaneously, 100 μL of MPH containing only DMAEMA and HEMA at a concentration of 2 mg / mL was used as a control, with 8 replicates for DMAEMA and 2 replicates for HEMA. The expanded bacterial culture was diluted to OD... 600 =0.1, then add 20uL of the diluted bacterial solution to a 96-well plate. After adding, seal the 96-well plate with breathable sealing film and incubate in a constant temperature incubator for 24 hours. Observe for bacterial growth. All tests are performed in triplicate, with a positive control (LB culture medium with only bacterial solution) and a negative control (pure LB culture medium without bacterial solution). MBC is the minimum drug concentration required to kill 99.9% (reducing by 3 orders of magnitude) of the test microorganisms. The test method is to drop 10uL of MIC and a culture medium with a concentration greater than MIC onto a solid culture medium, incubate in a constant temperature incubator for 24 hours, and observe for bacterial growth. The concentration at which no bacterial growth occurs is the MBC. Each sample is performed in triplicate. For specific values, see [link to sample details]. Figure 3 As shown.

[0054] Example 6: Preparation of Antibacterial Cotton Fabric

[0055] The citronellol-based antibacterial polymer CD from Example 4 was selected. 11 H3 was dissolved in 50 mL of tetrahydrofuran to prepare solutions of 40, 20, and 10 mg / mL. Isophorone diisocyanate and the catalyst dibutyltin dilaurate were then added, resulting in a molar ratio of -NCO, -OH to catalyst of 1.2:1:0.06. The solution was stirred at 60 °C for 30 min to ensure uniform dispersion. Cotton cloth was then soaked and stirred for 30 min, followed by curing at 120 °C for 5 min. The cloth was then washed with a clean tetrahydrofuran solution for 30 min, repeated three times. Finally, the washed cotton cloth was dried in a vacuum drying oven to obtain antibacterial cotton cloth. The infrared spectrum of the antibacterial cotton cloth is shown below. Figure 4As shown, a is untreated cotton cloth, and b is treated with 40 mg / mL CD 11 H3-grafted cotton cloth, c with 20 mg / mL CD 11 H3-grafted cotton cloth, d is the amount of CD10mg / mL 11 H3-grafted cotton fabric. Compared to unmodified cotton fabric, the modified cotton fabric has a length of 1724cm. -1 The absorption peak at that point is due to the stretching vibration of C=O, which originates from the DMAEMA of the citronellol-based antibacterial polymer. Therefore, it can be concluded that the cotton fabric has been successfully modified.

[0056] Example 7: Sterilization effect of antibacterial cotton cloth

[0057] Take 10 colony counts respectively 5 0.65 mL each of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacterial cultures were prepared in 9.35 mL of PBS buffer. Then, a 40 mg / mL CD45 solution was added to the culture. 11 H3-grafted antibacterial cotton cloth, treated with 20 mg / mL CD 11 H3-grafted antibacterial cotton cloth, treated with 10 mg / mL CD 11 0.1g of H3-grafted antibacterial cotton cloth was added to each culture medium. The bacterial culture medium without cotton cloth served as a blank control group. The prepared culture medium was incubated in a shaker at 200 rpm and 37°C for 24 hours. A 20 μL sample was then taken and diluted 10-fold. 100 μL of the diluted bacterial solution was evenly spread onto agar solid medium and incubated at 37°C for 24 hours. The number of bacteria was counted to calculate the sterilization rate. Different concentrations of CD... 11 The bactericidal effect of H3-treated antibacterial cotton cloth is as follows: Figure 5 As shown.

[0058] Example 8: Washability of antibacterial cotton fabric

[0059] To examine the wash durability of antibacterial activity, the antibacterial effect of antibacterial cotton fabric CDH@CF was evaluated after different number of washes. Figure 6 The washing procedure was based on the washing procedure for antibacterial fabrics (FZ / T73023–2006) with slight modifications. An appropriate amount of tap water was added to a beaker containing antibacterial cotton fabric and ordinary household detergent. The mixture was magnetically stirred for 30 minutes to simulate a household drum washing machine. Then, the detergent was rinsed off with plenty of water. This completed one cycle, counting as 5 washes. These steps were repeated until the planned number of washes was reached. After washing, the cotton fabric was simply rinsed with deionized water and then dried in a vacuum drying oven for later use. The experiment used a shaking method to culture bacteria. Specifically, the bacterial solution, after 12 hours of overnight culture and 6 hours of expansion culture, was diluted to a concentration of 10. -4Add a piece of cotton cloth to each 50mL centrifuge tube and incubate in a constant temperature shaker at 37℃ for 24h at a speed of 190rpm. At the same time, set up an untreated cotton cloth as a blank control group. After the bacteria are in contact with the cotton cloth for 24h, take 100mL of co-culture medium and add it to the prepared solid agar medium. Spread it evenly with a spreader until dry. Invert the medium, seal it, and place it in a constant temperature incubator at 37℃ for 24h.

[0060] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A citronellol-based antibacterial polymer, characterized in that: Citronellol-based initiators are synthesized by esterification of citronellol and acyl halides, which then initiate the one-step polymerization of DMAEMA and HEMA via ATRP. The citronellol-based antibacterial polymer is prepared by the following method: (1) Citronellol-based initiators are synthesized by esterification reaction using citronellol and acyl halides as raw materials under inert gas conditions; (2) Citronellol-based initiator, methacrylate monomers, ligands and catalysts are added and dispersed in a solvent system in proportion. After deoxygenation treatment by freeze degassing, polymerization reaction is carried out under heating and stirring conditions to obtain citronellol-based antibacterial polymer; the methacrylate monomers are DMAEMA and HEMA. In step (1), the molar ratio of citronellol, triethylamine, and acyl halide is 1:1.2-1.5:1.2-1.5; In step (2), the reaction molar ratio of citronellol initiator, ligand, catalyst, DMAEMA and HEMA is 1:1.2:1.2:(5-15):(1-5).

2. The citronellol-based antibacterial polymer according to claim 1, characterized in that: The number of repeating units in DMAEMA is 5 to 13, and the number of repeating units in HEMA is 3 to 4.

3. The citronellol-based antibacterial polymer according to claim 2, characterized in that: The esterification reaction process described in step (1) is as follows: under an inert gas atmosphere, citronellol and triethylamine are dissolved in an organic solvent, and then acyl halides are added dropwise under an ice-water bath and reflux. After the dropwise addition is completed, the ice-water bath is removed, and the mixture is refluxed at room temperature. After reacting for a period of time, the mixture is purified and rotary evaporated to obtain the citronellol-based initiator. The acyl halide is 2-bromoisobutyryl bromide; The organic solvent is dichloromethane; The time for ice-water bath and reflux condensation is 1-2 h; the time for reflux condensation at room temperature is 4-6 h.

4. The citronellol-based antibacterial polymer according to claim 3, characterized in that: In step (2), the solvent is anhydrous toluene; the ligand is pentamethyldiethylenetriamine; and the catalyst is cuprous bromide. The polymerization reaction is carried out at a temperature of 60°C for 6-12 hours.

5. The application of the citronellol-based antibacterial polymer according to any one of claims 1 to 4 in the preparation of antibacterial cotton fabrics, characterized in that: After the citronellol-based antibacterial polymer is dissolved in a solvent, diisocyanate and a catalyst are added to form a mixed solution. The cleaned cotton cloth is then soaked, cured, washed, and dried in the mixed solution.

6. The application according to claim 5, characterized in that: The molar ratio of the citronellol-based antibacterial polymer, diisocyanate, and catalyst is 1:1.2-2:0.

12. The catalyst is di-n-butyltin dilaurate; The solvent is tetrahydrofuran; The diisocyanate mentioned is isophorone diisocyanate.

7. The application according to claim 6, characterized in that: The cotton cloth cleaning procedure is as follows: stir the detergent solution for 30 minutes, rinse with tap water until there is no foam, soak in distilled water and sonicate for 20 minutes, repeat 3 times, soak in acetone and sonicate for 20 minutes, repeat 3 times, soak in ethanol and sonicate for 20 minutes, repeat 3 times, and then vacuum dry. The cotton fabric is soaked in the mixed solution for 30 minutes. The curing temperature is 110-130℃.

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