Preparation and application of triazole-halamine-dopo multifunctional molecule with terminal chlorine group

Abstract

The present application relates to the synthesis of triazole-halamine-DOPO multifunctional molecule (TD@Cl) with terminal chloro group and its finishing process on textiles, belonging to the field of synthesis of antibacterial and flame-retardant compounds and textile finishing technology. This paper focuses on the design of an antibacterial and flame-retardant composite precursor containing terminal chlorine group. By using the "one-bath method", the hydroxyl groups on the cotton fabric are combined with the precursor through a simple substitution reaction to form a chemical bond, giving the cotton fabric persistent antibacterial and flame-retardant properties. The antibacterial and flame-retardant functional precursor designed by the method can prepare multifunctional textile materials with high efficiency of antibacterial and flame-retardant through simple operation. In addition, the textile prepared by the finishing process is firm and stable, and has good washing resistance.

Description

Technical Field

[0001] This invention relates to the synthesis of a terminal chlorine-terminated triazole-haloamine-DOPO multifunctional molecule (TD@Cl) and its finishing process for textiles, belonging to the fields of antibacterial and flame-retardant compound synthesis and textile finishing technology. Background Technology

[0002] Natural cellulose fibers play an indispensable role in the textile industry. Due to their excellent hygroscopicity, cellulose textiles are highly susceptible to bacterial growth during storage and use, causing a series of adverse effects on both the textiles and the users. In recent years, intensive development has been promoted in both the market and scientific research to reduce or solve the problem of bacterial growth in cellulose textiles. Furthermore, a single function (such as antibacterial properties) may not be sufficient to attract high-end consumers or meet special needs. By adding other functions on top of antibacterial properties, products with unique competitiveness can be created to meet the needs of different consumers in the market. Currently, finishing methods for functional textiles are divided into physical modification and chemical modification, usually classified according to whether chemical bonds are formed with the textile surface. Physical methods mainly adsorb functional additives onto the fabric through van der Waals forces, hydrogen bonds, and electrostatic interactions, thus presenting certain technical challenges, such as poor durability and fabric hardening. Chemical modification methods form stable covalent interactions with the hydroxyl groups on cellulose, making them often effective candidates for constructing long-lasting functional textiles. However, many chemical modification methods are not a one-step process. Common step-by-step processing methods include pretreatment, modification, and curing. Each step requires specialized equipment, time, and labor, leading to increased overall production costs. For example, cotton fabrics, due to their limited number of reactive groups, typically require pretreatment processes and technologies to improve the availability of reactive sites and fibers. Flame-retardant cotton fabrics often use urea and dicyandiamide as catalysts, but these chemicals may release formaldehyde or other harmful gases during processing, posing serious health risks and environmental hazards. The patent applications "Multifunctional antibacterial cotton fabrics based on a triazole-halamine-diethyl phosphite, Li Lifan, Southwest University" and "A triazole-based halamine antibacterial flame retardant and its preparation method and application in cotton fabrics, application (patent) number: CN202210965739.0" disclose the design and synthesis of antibacterial and flame-retardant halamine precursors with a "two birds with one stone" effect, which can endow cotton fabrics with excellent antibacterial properties and achieve flame retardant effects. Both experimental methods use silane crosslinking agents for stepwise treatment. Although the crosslinking agents are relatively safe and stable, the method usually does not have durability, and the functionality decreases or even loses its functionality with time and washing cycles. At the same time, the method will also bring other adverse effects, including affecting the hand feel of the fabric, increasing processing costs, and environmental issues. Compared with these two antibacterial and flame-retardant halamine precursors, the antibacterial and flame-retardant precursor of this invention mainly plays a major role in flame retardancy through the DOPO flame-retardant group, and can prepare antibacterial and flame-retardant textiles through a simpler, more effective, and lower-cost process. Summary of the Invention

[0003] One objective of this invention is to provide a novel method for preparing an antibacterial and flame-retardant agent. This method achieves highly efficient antibacterial effects by combining triazole with a haloamine, and further enhances flame retardancy by introducing a DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) structure. Furthermore, by introducing a halogenated group at the end, it forms an ether bond with a reactive group (e.g., a hydroxyl group), allowing it to be applied to materials.

[0004] Another objective of this invention is to provide a highly efficient and simple finishing process for multifunctional materials. Here, we provide a finishing method for durable, antibacterial, and flame-retardant cellulosic textiles, which uses hydroxyl groups on cellulose fibers as bridges to bond with terminal chloroalkyl groups of bifunctional compound precursors via strong covalent bonds.

[0005] To achieve the above technical objectives, the following technical solution is proposed:

[0006] The primary objective of this invention is to propose a multifunctional triazole-haloamine-DOPO molecule with a terminal chlorine group, prepared from 1-bromo-3-chloropropane, p-hydroxybenzaldehyde, 1,2,4-triazole, and DOPO, abbreviated as TD@Cl. The molecule is 6-(((1H-1,2,4-triazol-3-yl)amino)(4-(3-chloropropoxy)phenyl)methyl)dibenzo[c,e][1,2]oxaphosphinine6-oxide. The chemical structural formula of TD@Cl is as follows: Figure 1 :

[0007] Figure 1

[0008] The second objective of this invention is to provide a method for preparing a triazole-haloamine-DOPO functional molecule, comprising the following steps: First, weigh 24.4 g of p-hydroxybenzaldehyde and 31.5 g of 1-bromo-3-chloropropane and anhydrous potassium carbonate, dissolve them in acetonitrile, and reflux at 70°C for 24 h. At the end of the reaction, filter to obtain a reddish-brown liquid A.

[0009] Next, 8 mL of acidic solution and 16.8 g of 1,2,4-triazole were added to the reddish-brown liquid A, and the mixture was refluxed at 70 °C for 24 h to obtain a white solid powder B. Then, DOPO was added to the reaction flask, and the mixture was refluxed at 70 °C for another 24 h. After the reaction was complete, the mixture was filtered while hot (to remove unreacted reactants), and the solid was collected, washed repeatedly with acetonitrile, and finally dried at 70 °C to obtain a white solid product C (TD@Cl).

[0010] The further optimized scheme is as follows: (1) The molar ratio of p-hydroxybenzaldehyde to 1-bromo-3-chloropropane and anhydrous potassium carbonate is 1:1:1. (2) The molar ratio of p-hydroxybenzaldehyde to 1,2,4-triazole is 1:1. (3) The acidity of the acidic solution should not be too strong, because the Schiff base structure is easily decomposed in an overly acidic environment. Therefore, glacial acetic acid solution is preferred. (4) The molar ratio of DOPO to 1,2,4-triazole is 1:1. (5) The acetonitrile washing is performed using a 70°C acetonitrile solution to further remove unreacted raw materials.

[0011] This invention also proposes an application of the above-mentioned TD@Cl in antibacterial and flame-retardant textiles. First, TD@Cl is dissolved in an N,N-dimethylformamide solution, and a small amount of strong alkali is added to prepare a reaction solution. Then, the washed cotton fabric is co-bathed with the reaction solution at 80°C for 6 hours. Subsequently, the cotton fabric is removed and soaked in an N,N-dimethylformamide solution for several minutes to remove TD@Cl adhering to the fabric surface. The treated cotton is washed with deionized water and dried in a 50°C oven to constant weight to obtain cotton fabric COTD. Finally, the COTD is soaked in a 10 wt% sodium hypochlorite solution for 1 hour, then removed, washed with a large amount of light water, and dried in an oven to obtain COTD-Cl.

[0012] The further optimization scheme is as follows: (1) The concentration ratio of TD@Cl to N,N-dimethylformamide solution in the reaction solution is 0.5 g / mL. (2) The strong alkali substance used in this experiment is potassium hydroxide. (3) The bath ratio of the washed cotton fabric to the reaction solution is 1:20-30. (4) The reaction time of the cotton fabric and the reaction solution in the bath is 6-10 h. (5) The bath ratio of COTD of cotton fabric to sodium hypochlorite solution is 1:30, and the sodium hypochlorite solution is adjusted to neutral with glacial acetic acid.

[0013] Compared with the prior art, the present invention has the following advantages: (1) The halogen amine antibacterial agent of the present invention has the disadvantage of short antibacterial effect during application. By adding a triazole structure to the halogen amine antibacterial agent, its composite antibacterial effect can achieve efficient regeneration of the antibacterial agent. Furthermore, by introducing the DOPO structure, a functional molecule with a "two birds with one stone" effect was designed and synthesized. (2) The present invention grafts the functional molecule onto cotton fabric. By substituting the terminal chlorine group of the functional molecule with the hydroxyl group on the surface of the cotton fabric, it can be bonded to the surface of the cotton fabric. After chlorination treatment, it is given a highly efficient composite antibacterial effect. This method effectively improves the wash resistance of the finished cotton fabric. (3) In addition, the method of grafting the functional molecule onto cotton fabric in the present invention is simple and can save time and labor costs. (4) The functional molecule of the present invention is applied to the preparation of antibacterial materials. After antibacterial testing, the results show that the obtained textiles have excellent antibacterial properties and high antibacterial efficiency. The cotton fabric prepared by this method also has good flame retardant effect.

[0014] At the same time, this method can also have other adverse effects, including the breathability and tensile strength of the fabric. Attached Figure Description

[0015] Figure 1 The chemical structural formula of TD@Cl.

[0016] Figure 2 For example TD@Cl in Example 1 of this invention １ H NMR spectrum.

[0017] Figure 3 This is the preparation route for the multifunctional cotton fabric COTD-Cl in Example 2 of the present invention.

[0018] Figure 4 The images shown are SEM, EDX, and FT-IR images of the cotton fabric treated in Example 2 of this invention.

[0019] Figure 5 This is a schematic diagram of the antibacterial properties of the cotton fabric treated in Example 2 of the present invention.

[0020] Figure 6 This is a schematic diagram of the flame retardant properties of the cotton fabric treated in Example 2 of the present invention.

[0021] Figure 7 This is a schematic diagram illustrating the antibacterial properties of the ramie fabric after finishing in Example 2 of the present invention. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1

[0024] This embodiment provides a method for preparing a functional molecule (TD@Cl), specifically including: (1) First, 0.2 mol of p-hydroxybenzaldehyde, 0.2 mol of 1-bromo-3-chloropropane and a small amount of anhydrous potassium carbonate are dissolved in acetonitrile and reacted at 70°C under reflux for 24 hours. After the reaction is completed, a reddish-brown liquid is obtained by filtration. (2) A small amount of dilute hydrochloric acid as a catalyst and 0.2 mol of 1,2,4-triazole are added to the liquid obtained in (1) and refluxed at 70°C for 24 hours. Then, 0.2 mol of DOPO is added to a round-bottom flask and the reaction is continued at 70°C under reflux for 24 hours. (3) After the reaction in (2) is completed, the unreacted raw material is filtered while hot, the solid is collected, washed several times with hot acetonitrile, and then dried at 70°C to obtain a white solid product TD@Cl.

[0025] From the perspectives of operation and practicality, the synthesized TD@Cl with terminal chlorine group structure is more practical in industrial production and more convenient for antibacterial finishing of textiles.

[0026] Furthermore, the nuclear magnetic resonance analysis (NMR, AVANCE III, Switzerland) of the obtained TD@Cl yielded the following results: Figure 2-3 As shown, the signals in the nuclear magnetic resonance (NMR) image show that the structure of the target compound corresponds one-to-one with the peaks in the 1H NMR spectrum, thus confirming that the synthesized product is the target compound TD@Cl.

[0027] Application Example 1

[0028] This embodiment proposes to use the TD@Cl obtained in Example 1 for antibacterial and flame-retardant finishing of cotton fabrics, specifically including: (1) adding 25 g of TD@Cl to 50 ml of N,N-dimethylformamide solution, pyrolyzing at 120°C, and adding 0.480 g of potassium hydroxide to prepare a reaction solution. (2) reacting 2.9 g of washed dry cotton fabric with the reaction solution prepared in (1) at 80°C for 6 hours. (3) after the reaction, taking out the cotton fabric and soaking it in N,N-dimethylformamide solution for several minutes to remove the TD@Cl adhering to the surface of the fabric. (4) washing the treated cotton with deionized water and drying it in a 50°C oven to constant weight to obtain cotton fabric COTD. (5) soaking COTD in 10 wt% sodium hypochlorite solution (pH=7) for 1 hour, taking it out and washing it with a large amount of light water, and drying it in an oven to obtain COTD-Cl.

[0029] The process of TD@Cl for antibacterial finishing of cotton fabrics is as follows: Figure 3 As shown. Electron scanning spectroscopy (SEM, Phenom Pro, Netherlands), X-ray energy dispersive spectroscopy (XPS, Thermo Scientific K-Alpha, USA), and Fourier transform infrared spectroscopy (FTIR, Bruker-ALPHA FTIR, USA) were used to characterize the structure of the cotton fabrics before and after treatment, such as... Figure 4 As shown, the characterization results indicate that TD@Cl was successfully grafted onto cotton fabric.

[0030] The antibacterial properties of the obtained antibacterial cotton fabric were tested, and the results are as follows: Figure 5 As shown in the figure, the culture dishes containing *E. coli* and *Staphylococcus aureus* in contact with the original cotton fabric were covered with a large number of colonies, while no colonies were formed on the treated cotton fabric, indicating that the antibacterial rate of COTD and COTD-Cl reached 99.99%. The antibacterial effect of COTD on the fabric was tested after 20 and 40 washing cycles, and the results are shown in the figure. The results show that after 20 washes, the cotton fabric still maintained a 99.99% antibacterial rate against *E. coli* and *Staphylococcus aureus*. With the increase in the number of washes to 40, the antibacterial rate against *Staphylococcus aureus* remained at 99.99%. Although the antibacterial rate against *E. coli* decreased slightly, it still remained at 99.75%. This indicates that the antibacterial molecules formed strong chemical bonds with the cotton fabric, giving the treated cotton fabric good wash resistance.

[0031] The vertical burning test method was used to investigate whether COTD has a flame-retardant effect. The relevant test data are as follows: Figure 6 As shown in the figure. The results demonstrate that TD@Cl treatment of cotton fabrics has a good flame retardant effect.

[0032] Application Example 2

[0033] This embodiment proposes using the TD@Cl obtained in Example 1 for antibacterial and flame-retardant finishing of twill ramie fabric, specifically including: (1) adding 30 g of TD@Cl to 50 ml of N,N-dimethylformamide solution, pyrolyzing at 120°C, and adding 0.540 g of potassium hydroxide to prepare a reaction solution. (2) reacting 3 g of washed dry twill ramie fabric with the reaction solution prepared in (1) at 80°C for 10 hours. (3) after the reaction, removing the ramie fabric and soaking it in N,N-dimethylformamide solution for several minutes to remove the TD@Cl adhering to the fiber surface. The treated ramie fibers are washed with deionized water and dried in a 50°C oven to constant weight to obtain ramie fabric. (4) The ramie fabric obtained in step (3) is soaked in a 10 wt% sodium hypochlorite solution (pH=7) for 0.5 hours, then taken out and washed with a large amount of light water, and placed in an oven to dry to obtain a highly effective antibacterial and flame-retardant twill ramie fabric.

[0034] The antibacterial properties of the obtained ramie fabric were tested as follows: Figure 7 As shown, the limiting oxygen index test results indicate that the ramie fabric increased from 22±1 to 27±1. Experiments have proven that the antibacterial and flame-retardant properties of ramie fabric treated with TD@Cl were effectively improved.

[0035] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and inclusions made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A multifunctional molecule (TD@Cl) with a terminal chlorine group, consisting of a triazole-haloamine-DOPO group, characterized in that... It is prepared from p-hydroxybenzaldehyde, bromochloroalkyl, triazole and DOPO.

2. The multifunctional molecule with a terminal chlorine group of triazole-haloamine-DOPO according to claim 1, characterized in that, The structural formula of the bromochloroane is as follows: .

3. A multifunctional molecule with a terminal chlorine group, consisting of a triazole-haloamine-DOPO group, characterized in that... Includes the following steps: (1) Dissolve p-hydroxybenzaldehyde, 1-bromo-3-chloropropane and anhydrous potassium carbonate as an acid-binding agent in acetonitrile solvent and reflux at 60-90℃ for 10-48 h to obtain mixture A. The molar ratio of p-hydroxybenzaldehyde to 1-bromo-3-chloropropane and anhydrous potassium carbonate is 1:1:1-2.

4. (2) Add acidic catalytic solution glacial acetic acid and 1,2,4-triazole to mixture A, and reflux at 60-90℃ for 10-48 h to obtain solid powder B. The molar ratio of 1,2,4-triazole to p-hydroxybenzaldehyde is 1:1-1.

2.

5. (3) Add DOPO to the reaction flask and reflux at 60-90℃ for 12-48 h. After the reaction is complete, filter and wash with acetonitrile solution at 60-90℃ to remove unreacted raw materials to obtain solid powder C, which is the triazole-haloamine-DOPO multifunctional molecule with terminal chlorine group.

6. The method for preparing the terminal chlorine-terminated triazole-haloamine-DOPO multifunctional molecule according to any one of claims 1-3 is applied to the preparation of antibacterial and flame-retardant multifunctional materials.

7. The application according to claim 3, characterized in that, The preparation method of the antibacterial and flame-retardant multifunctional textile material includes: (1) Dissolve TD@Cl in N,N-dimethylformamide solution and add a small amount of strong base to prepare a reaction solution. The concentration ratio of TD@Cl to N,N-dimethylformamide solution is 0.3-0.7 g / mL, and the strong base is sodium hydroxide, potassium hydroxide, sodium hydride, etc.

8. (2) The washed cotton fabric with a bath ratio of 1:20-30 to the reaction solution is reacted at 60-95℃ for 6-19h. After the reaction is completed, it is washed with deionized water and dried to obtain antibacterial flame retardant finishing material (COTD).

9. (3) COTD with a bath ratio of 1:20-30 to sodium hypochlorite solution was immersed in a 10 wt% sodium hypochlorite solution and reacted for 1 hour. After washing and drying, a high-efficiency antibacterial and flame-retardant material (COTD-Cl) was obtained. The sodium hypochlorite solution was adjusted to neutral with glacial acetic acid.

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