Antibacterial halogen-free flame retardant as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of flame retardants, and relates to an antibacterial halogen-free flame retardant as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) enabling hydroquinone and phenylphosphine dichloride to react in a reaction kettle to obtain an intermediate product; (2) reacting the intermediate product with a nitrogen-containing substance to obtain a halogen-free flame retardant; and (3) adding the antibacterial component into the halogen-free flame retardant, and carrying out stirring reaction to obtain the antibacterial halogen-free flame retardant. A halogen-free flame retardant chain is chemically modified through a substitution reaction, specifically, tertiary amine salt and halogenated hydrocarbon are introduced as antibacterial components, and the halogen-free flame retardant is converted into a modified material containing quaternary ammonium cation and pyridine cation groups. After being further blended with a commercial base material, the material is endowed with excellent antibacterial property on the basis of ensuring the mechanical property of the material, and the two-in-one effect of antibacterial property and flame retardance is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of flame retardants and relates to an antibacterial halogen-free flame retardant and a preparation method and application thereof. Background Art

[0002] Fire, as a common natural disaster, poses a serious threat to people's lives and property safety. In modern society, various types of flooring are widely used in various scenarios due to their lightness and durability. However, the flammable nature of such materials also increases the risk of fire, which may lead to significant casualties and economic losses.

[0003] In order to reduce the negative impact of fire, it is particularly important to fireproof the floor. An efficient fire prevention strategy is an important way to prevent fires. Flame retardant materials are added inside these materials to improve their fire resistance. This filler can slow down or prevent the spread of fire, buy people valuable time to escape, and also help reduce property losses. However, in some special environments, a single flame retardant floor cannot meet the requirements. For example, in places with high environmental requirements such as hospitals, extremely high antibacterial properties are also required. Summary of the invention

[0004] The present invention aims at the problems existing in the flame retardant in the prior art and provides an antibacterial halogen-free flame retardant and a preparation method and application thereof.

[0005] One object of the present invention is achieved by the following technical solutions:

[0006] A method for preparing an antibacterial halogen-free flame retardant, the method comprising the following steps:

[0007] (1) reacting hydroquinone and dichlorophenylphosphine in a reactor to obtain an intermediate product;

[0008] (2) then reacting the intermediate product with a nitrogen-containing substance to obtain a halogen-free flame retardant;

[0009] (3) Adding an antibacterial component to the halogen-free flame retardant and stirring the mixture to obtain an antibacterial halogen-free flame retardant.

[0010] Preferably, in step (1), the molar ratio of hydroquinone to dichlorophenylphosphine is (0.1-1.0): (0.5-2.0).

[0011] Preferably, in step (1), hydroquinone is dissolved in a solvent and then added to a reaction kettle, and then dichlorophenylphosphine is added to the reaction kettle using a constant pressure funnel for reaction, and the reaction temperature is 100-150°C.

[0012] Preferably, the solvent mentioned herein includes one or more of xylene, ethyl acetate, tetrahydrofuran, N,N-dimethylformamide, acetone and ethanol.

[0013] Preferably, in step (1), the reaction is terminated when no gas is generated, and the intermediate product is obtained after washing and distillation.

[0014] In the washing operation mentioned herein, the washing agent used includes but is not limited to one or more of water, acetone, ether, ethanol, and ethyl acetate.

[0015] Preferably, in step (1), the preparation steps of the intermediate product are as shown in the following reaction formula I:

[0016]

[0017] Preferably, in step (2), the nitrogen-containing substance includes one or more of cyanuric chloride, chlorohydrin, melamine, and 2-chloro-4,6-diamino-1,3,5-triazine.

[0018] Further preferably, in the step (2), the nitrogen-containing substance comprises one or both of cyanuric chloride and chlorohydrin; wherein the structural formula of cyanuric chloride is as shown in Formula I:

[0019]

[0020] The structural formula of trichlorohydrin is shown in Formula II:

[0021]

[0023] Preferably, in step (2), when the nitrogen-containing substance is cyanuric chloride, the preparation steps of the halogen-free flame retardant are as shown in the following reaction formula II:

[0024]

[0025] When the nitrogen-containing substance is cyanuric chloride, the preparation steps of the halogen-free flame retardant are shown in the following reaction formula III:

[0026]

[0027] Preferably, in step (2), the molar ratio of the intermediate product to the nitrogen-containing substance is (0.1-1.0): (0.1-1.0).

[0028] Preferably, in the step (2), the intermediate product is dissolved in a solvent and then reacted with a nitrogen-containing substance in the presence of a catalyst, the reaction temperature is 60 to 80° C., and the reaction time is 1 to 10 hours.

[0029] Preferably, the catalyst mentioned herein includes one or more of triethylamine, pyridine, 4-dimethylaminopyridine, 2,6-lutidine, 2,4,6-trimethylpyridine, 4-pyrrolidinylpyridine, and 1-ethyl-(3-dimethylaminopropyl)carbodiimide.

[0030] Preferably, the molar ratio of the catalyst to the intermediate product is (0.1-1.0):(0.1-1.0).

[0031] Preferably, in step (2), the reaction is terminated when no gas is generated, and washing and distillation are performed after cooling.

[0032] Preferably, in step (2), after the reaction is completed, water is added at 85-100° C. for high-temperature reflux for 1-10 hours, and after filtration, the mixture is dried at 60-90° C. to obtain a halogen-free flame retardant.

[0033] Preferably, in step (3), the antibacterial component comprises one or both of tertiary amine salts and halogenated hydrocarbons, and more preferably tertiary amine salts.

[0034] Preferably, the tertiary amine salt includes one or more of N,N-dimethylpropylamine, N,N-dimethyl-1,3-diaminopropane, N,N-dimethylbutylamine, 3-dimethylaminopropylamine, and N,N-dimethylisobutylamine.

[0035] More preferably, the tertiary amine salt includes one or more of N,N-dimethylpropylamine, N,N-dimethyl-1,3-diaminopropane, and N,N-dimethylbutylamine.

[0036] Wherein, the structural formula of N,N-dimethylpropylamine is shown in Formula III:

[0037]

[0038] The structural formula of N,N-dimethylbutylamine is shown in Formula IV:

[0039]

[0040] The structural formula of N,N-dimethyl-1,3-diaminopropane is shown in Formula V:

[0041]

[0042] Preferably, the halogenated hydrocarbon includes one or more of butyl bromide, benzyl bromide, 4-methylbenzyl bromide, propyl bromide, and isobromobutyl.

[0043] More preferably, the halogenated hydrocarbon includes one or more of butyl bromide, benzyl bromide, and 4-methylbenzyl bromide.

[0044] Wherein, the structural formula of bromobutane is shown in Formula VI:

[0045]

[0046] The structural formula of benzyl bromide is shown in Formula VII:

[0047]

[0048] The structural formula of 4-methylbenzyl bromide is shown in Formula VIII:

[0049]

[0050] The present invention introduces tertiary amine salts and / or halogenated hydrocarbon components into the flame retardant, so that the components are converted into quaternary ammonium cations and pyridinium cation groups during the reaction process. Since the bacterial cell membrane usually carries a negative charge, the positively charged groups in the quaternary ammonium cations and pyridinium salt molecules can be adsorbed on the bacterial surface through Coulomb force, penetrate the cell wall, form a quaternary ammonium salt film on the surface, block the metabolism of intracellular substances, thereby causing cell death and achieving an antibacterial effect. After combining this modified flame retardant with a halogen-free flame retardant and then blending it with a substrate (such as polyvinyl chloride, polyurethane, etc.), it can not only retain the original excellent mechanical properties of the substrate, but also give it significant flame retardant and antibacterial properties. .

[0051] Preferably, in step (3), the molar ratio of the halogen-free flame retardant to the antibacterial component is (0.1-1.0): (0.1-1.0).

[0052] Preferably, in step (3), after the halogen-free flame retardant is dissolved in a solvent, the antibacterial component is added, and the reaction temperature is 40 to 90° C. and the reaction time is 10 to 30 hours. More preferably, the reaction temperature is 50 to 80° C. and the reaction time is 12 to 24 hours.

[0053] Preferably, in the step (3), the reaction solution is filtered and then washed, and then dried at 60 to 90° C. to obtain the antibacterial halogen-free flame retardant.

[0054] The second object of the present invention is achieved by the following technical solutions:

[0055] An antibacterial halogen-free flame retardant is prepared by the above preparation method.

[0056] The third object of the present invention is achieved by the following technical solutions:

[0057] An application of an antibacterial halogen-free flame retardant, the application comprising preparing a flame retardant material by blending the antibacterial halogen-free flame retardant with a substrate.

[0058] Preferably, the substrate comprises one or more of polyvinyl chloride, polyurethane, polypropylene, polyethylene, nylon, epoxy resin, and polyester.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] 1. The present invention provides a method for preparing an antibacterial halogen-free flame retardant, which chemically modifies the halogen-free flame retardant chain by substitution reaction. The method converts the halogen-free flame retardant into a modified material containing quaternary ammonium cations and pyridinium cation groups by introducing an antibacterial component. The use of a further preferred tertiary amine salt component for modification can provide more nitrogen elements to the system, thereby significantly improving the flame retardant properties of the material.

[0061] 2. The antibacterial halogen-free flame retardant provided by the present invention, after being blended with commercial substrates (such as polyvinyl chloride, polyurethane, etc.), can ensure the mechanical properties of the material, extend its service life, and also give the material excellent antibacterial properties. Compared with conventional materials, the present invention can achieve the two-in-one effect of antibacterial and flame retardant without the need to add additional antibacterial additives or fillers during the blending process. This design not only simplifies the material preparation process and reduces production costs, but also avoids the adverse effects on material properties caused by adding too many additives. In addition, the antibacterial halogen-free flame retardant of the present invention can effectively inhibit bacterial growth while maintaining the original mechanical strength of the substrate, extend the applicability of the material in hygienic sensitive environments, and provide high-performance solutions for medical, household, packaging and other fields.

[0062] 3. The present invention provides a method for preparing an antibacterial halogen-free flame retardant, and successfully synthesizes a multifunctional flame retardant with both excellent antibacterial properties and high-efficiency flame retardant properties. The present invention introduces specific antibacterial groups into the molecular structure of the halogen-free flame retardant, so that the material is endowed with significant antibacterial properties while maintaining the original flame retardant properties. After the modified flame retardant is mixed with a substrate (such as polyvinyl chloride, polyurethane, etc.), the substrate can have excellent flame retardancy and antibacterial effects at the same time, effectively inhibiting the adhesion and growth of bacteria. Compared with traditional flame retardants, the present invention not only avoids the complicated process of adding additional antibacterial additives, but also significantly improves the comprehensive performance of the material, making it have broad application prospects in fields such as medical care, electronics, and home furnishings that have high requirements for hygiene and safety. In addition, the use of the flame retardant can also extend the service life of the material, reduce maintenance costs, and provide a new technical path for the development of multifunctional materials. DETAILED DESCRIPTION

[0063] The technical solution of the present invention is further described below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

[0064] Example 1

[0065] The preparation method of the antibacterial halogen-free flame retardant of this embodiment comprises the following steps:

[0066] (1) dissolving 0.6 mol of hydroquinone in xylene and adding the solution to a reaction kettle equipped with a magnetic stirrer, a reflux condenser and a constant pressure funnel, slowly heating the solution to 130° C., slowly adding 1.0 mol of dichlorophenylphosphine to the reaction kettle using a constant pressure funnel, and reacting until no HCl gas is generated, and then ending the reaction. Excess hydroquinone is removed by washing with deionized water, and xylene is removed by distillation to obtain an intermediate product.

[0067] (2) 0.6 mol of the intermediate product was mixed with 20 mL of ethyl acetate and ultrasonically dissolved, the solution was mixed with 0.5 mol of cyanuric chloride and 0.6 mol of triethylamine and added to a reactor, the reaction was carried out at 70° C. for 5 h until no HCl gas was generated, the reaction was terminated, the intermediate product was removed after cooling to room temperature, and the crude product was washed with ethyl acetate three times, and the ethyl acetate was removed by distillation to obtain a crude product; finally, the crude product and water were added to a reactor, refluxed at 100° C. for 2 h, filtered, and vacuum dried at 80° C. to obtain a halogen-free flame retardant;

[0068] (3) 0.5 mol of N, N-dimethylpropylamine and 50 mL of tetrahydrofuran were mixed and dissolved by ultrasonication. The solution was mixed with 0.5 mol of halogen-free flame retardant and added to a reaction kettle. The mixture was reacted at 65° C. for 24 h. After the reaction was completed, the mixture was washed three times with ethyl acetate, then filtered three times and dried under vacuum at 60° C. to obtain the final product, an antibacterial halogen-free flame retardant, whose structural formula is shown in the following formula IX:

[0069]

[0071] Example 2

[0072] The difference between the preparation method of the antibacterial halogen-free flame retardant of this embodiment and that of embodiment 1 is that the nitrogen-containing substance is trichlorohydrin, and the halogenated hydrocarbon is used in step (3), and the halogenated hydrocarbon is benzyl bromide.

[0073] The preparation method of the antibacterial halogen-free flame retardant of this embodiment comprises the following steps:

[0074] (1) Same as step (1) in Example 1;

[0075] (2) 0.6 mol of the intermediate product was mixed with 20 mL of ethyl acetate and ultrasonically dissolved, the solution was mixed with 0.5 mol of trichlorohydrin and 0.6 mol of triethylamine and added to a reactor, reacted at 70° C. for 5 h until no HCl gas was generated, the reaction was terminated, cooled to room temperature, washed three times with ethyl acetate to remove the intermediate product, and then distilled to remove the ethyl acetate to obtain a crude product; finally, the crude product and water were added to a reactor, refluxed at 100° C. for 2 h, filtered, and vacuum dried at 80° C. to obtain a halogen-free flame retardant;

[0076] (3) 0.5 mol of benzyl bromide was mixed with 50 mL of tetrahydrofuran, and the solution was mixed with 0.5 mol of halogen-free flame retardant and added to a reaction kettle, and reacted at 80° C. for 12 h. After the reaction was completed, the mixture was washed three times with ether, and then filtered three times and dried in vacuum at 60° C. to obtain the final product, an antibacterial halogen-free flame retardant, whose structural formula is shown in the following formula X:

[0077]

[0078] Example 3

[0079] The difference between the preparation method of the antibacterial halogen-free flame retardant in this embodiment and that in Embodiment 2 is that the halogenated hydrocarbon in step (3) is butyl bromide.

[0080] The preparation method of the antibacterial halogen-free flame retardant of this embodiment comprises the following steps:

[0081] (1) to (2) are the same as steps (1) to (2) in Example 2;

[0082] (3) 0.5 mol of bromobutyl and 50 mL of ethyl acetate were mixed and dissolved by ultrasonication, and the solution was mixed with 0.5 mol of halogen-free flame retardant and added to a reactor, and reacted at 60° C. for 12 h. After the reaction was completed, the mixture was washed three times with ether, and then filtered three times and dried in vacuum at 60° C. to obtain the final product, an antibacterial halogen-free flame retardant, whose structural formula is shown in the following formula XI:

[0083]

[0084] Comparative Example 1

[0085] This comparative example uses the halogen-free flame retardant prepared in step (2) of Example 1 as the final product.

[0086] Comparative Example 2

[0087] This comparative example uses the halogen-free flame retardant prepared in step (2) of Example 2 as the final product.

[0088] The flame retardants of the examples and comparative examples were co-cultured with E. coli and S. aureus for 3 days, and their surface antibacterial properties were studied by counting the bacterial density. The specific results are shown in Table 1.

[0089] Table 1 Antibacterial performance results of examples and comparative examples

[0090]

[0091] As shown in Table 1, the halogen-free flame retardant was modified by introducing quaternary ammonium salt and cationic pyridine components in Examples 1 to 3, and its bacterial density was significantly lower than that of the halogen-free flame retardant without introducing antibacterial components in Comparative Examples 1 to 2. This result fully demonstrates that the modified flame retardant can effectively inhibit the growth and reproduction of bacteria and exhibit excellent antibacterial properties. The realization of this antibacterial effect is mainly attributed to the positive charge characteristics of the quaternary ammonium salt cation and the pyridine group, which can adsorb and destroy the negatively charged bacterial cell membrane through electrostatic action, thereby inhibiting bacterial activity.

[0092] The flame retardants of the embodiment and the comparative example were respectively blended into commercial polyurethane, with the flame retardant accounting for 20wt% of the total mass fraction, and then the mechanical properties and flame retardant properties of the materials were tested. The specific test results are shown in Table 2.

[0093] Table 2 Mechanical and flame retardant performance test results of examples and comparative examples

[0094] Tensile strengthMpa Elongation at break % Flame retardant Example 1 36.7 602 V-0 Example 2 38.7 567 V-1 Example 3 35.2 612 V-1 Comparative Example 1 36.2 542 V-0 Comparative Example 2 34.5 610 V-1

[0095] As shown in Table 2, by comparing Examples 1 to 3 with Comparative Examples 1 to 2, it can be seen that the flame-retardant polyurethane material prepared by the technical solution of the present invention shows good levels in mechanical properties and flame retardant properties. Specifically, although antibacterial components are introduced in Examples 1 to 3, the materials can still maintain high mechanical properties during the blending process with polyurethane, indicating that the modification process has little effect on the mechanical properties of the material. In terms of flame retardant properties, in Example 1, quaternary ammonium salt cations are formed by introducing the preferred tertiary ammonium salt component of the present invention, providing more nitrogen elements for the system, showing excellent flame retardant effects. In Examples 2 to 3, the preferred antibacterial component is not used for modification, so no additional nitrogen element is introduced, and its flame retardant properties are slightly poor.

[0096] In summary, the technical solution of the present invention can not only enable the flame-retardant polyurethane material to maintain good mechanical properties, but also significantly improve its flame retardant properties by optimizing the introduction of antibacterial components and nitrogen elements, providing a reliable technical path for the development of high-performance multifunctional polyurethane materials.

[0097] The various aspects, embodiments, and features of the present invention should be considered to be illustrative in all aspects and not limiting of the present invention, the scope of which is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

[0098] In the preparation method of the present invention, the order of each step is not limited to the order listed. For those skilled in the art, without creative work, the order of each step is also within the protection scope of the present invention. In addition, two or more steps or actions can be performed simultaneously.

[0099] Finally, it should be noted that the specific embodiments described herein are merely examples of the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art of the present invention may make various modifications or supplements to the specific embodiments described, or replace them in a similar manner. It is not necessary and impossible to provide all examples of all implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the scope of protection of the present invention, and interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A method for preparing an antibacterial halogen-free flame retardant, characterized in that: The preparation method comprises the following steps: (1) reacting hydroquinone and dichlorophenylphosphine in a reactor to obtain an intermediate product; (2) then reacting the intermediate product with a nitrogen-containing substance to obtain a halogen-free flame retardant; (3) adding an antibacterial component to the halogen-free flame retardant and stirring the mixture to obtain an antibacterial halogen-free flame retardant; In the step (3), the antibacterial component includes one or two of tertiary amine salts and halogenated hydrocarbons.

2. The preparation method according to claim 1, characterized in that: In the step (1), the molar ratio of hydroquinone to dichlorophenylphosphine is (0.1-1.0): (0.5-2.0); And / or, in the step (1), hydroquinone is dissolved in a solvent and then added to a reaction kettle, and then dichlorophenylphosphine is added to the reaction kettle using a constant pressure funnel for reaction, and the reaction temperature is 100-150° C.; And / or, in the step (1), the reaction is terminated when no gas is generated, and the intermediate product is obtained after washing and distillation.

3. The preparation method according to claim 1, characterized in that: In the step (2), the nitrogen-containing substance includes one or more of cyanuric chloride, chlorohydrin, melamine, and 2-chloro-4,6-diamino-1,3,5-triazine.

4. The preparation method according to claim 1, characterized in that: In the step (2), the nitrogen-containing substance includes one or both of cyanuric chloride and trichlorohydrin.

5. The preparation method according to claim 1, characterized in that: In the step (2), the molar ratio of the intermediate product to the nitrogen-containing substance is (0.1-1.0): (0.1-1.0); And / or, in the step (2), the intermediate product is dissolved in a solvent and then reacted with a nitrogen-containing substance in the presence of a catalyst, the reaction temperature is 60 to 80° C., and the reaction time is 1 to 10 hours; And / or, in step (2), the reaction is terminated when no gas is generated, and washing and distillation are performed after cooling; And / or, in the step (2), after the reaction is completed, water is added at 85-100° C. for high-temperature reflux for 1-10 hours, and after filtering, the mixture is dried at 60-90° C. to obtain a halogen-free flame retardant.

6. The preparation method according to claim 1, characterized in that: The tertiary amine salt includes one or more of N,N-dimethylpropylamine, N,N-dimethyl-1,3-diaminopropane, N,N-dimethylbutylamine, 3-dimethylaminopropylamine, and N,N-dimethylisobutylamine; And / or, the halogenated hydrocarbon includes one or more of butyl bromide, benzyl bromide, 4-methylbenzyl bromide, propyl bromide, and isobromobutyl.

7. The preparation method according to claim 1, characterized in that: The antibacterial component adopts tertiary amine salt, and the tertiary amine salt includes one or more of N, N-dimethylpropylamine, N, N-dimethyl-1, 3-diaminopropane, and N, N-dimethylbutylamine.

8. The preparation method according to claim 1, characterized in that: In the step (3), the molar ratio of the halogen-free flame retardant to the antibacterial component is (0.1-1.0): (0.1-1.0); And / or, in the step (3), after the halogen-free flame retardant is dissolved in a solvent, an antibacterial component is added, the reaction temperature is 40 to 90° C., and the reaction time is 10 to 30 hours; And / or, in the step (3), the reaction solution is filtered, washed, and dried at 60-90° C. to obtain the antibacterial halogen-free flame retardant.

9. An antibacterial halogen-free flame retardant, characterized in that: The method is prepared according to any one of claims 1 to 8.

10. An application of an antibacterial halogen-free flame retardant, characterized in that: The application includes preparing a flame retardant material by blending an antibacterial halogen-free flame retardant as claimed in claim 9 with a substrate.

Images