Flame-retardant modified ms sealant and preparation method thereof

Abstract

The present application relates to the technical field of sealant, in particular to a flame-retardant modified MS sealant and a preparation method thereof.The present application obtains antibacterial fiber by adding chitosan, catechin, luteolin and kaempferol as main raw materials.Then, the present application obtains composite fiber by using silver ammine solution, glucose solution and antibacterial fiber as raw materials.The present application obtains silane modified acrylic resin by adding gamma-methacryloxypropyl trimethoxysilane, acrylic acid, flame-retardant acrylic monomer, antibacterial acrylic monomer, anti-aging vinyl monomer, azobisisobutyronitrile and ethyl acetate.Then, the present application obtains silane modified polyether resin by mixing the silane modified acrylic resin and polytetrahydrofuran and reacting.The present application obtains the finished product by mixing the silane modified polyether resin, composite fiber, plasticizer, filler, water removing agent and catalyst.The finished product prepared by the present application has excellent flame retardancy, antibacterial property and anti-aging property, so the present application has wide application prospect in the technical field of sealant.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealant, in particular to a flame-retardant modified MS sealant and a preparation method thereof. BACKGROUND

[0002] MS sealant, namely modified silane sealant, has unique properties and irreplaceable value in many fields of modern society. In the automobile manufacturing industry, MS sealant can realize the sealing and bonding of parts such as vehicle doors, vehicle windows, and engine compartments. In addition, due to its low VOC (volatile organic compound) emission characteristics, it meets the strict requirements of modern automobile industry for environmental protection, and helps to create a healthy and comfortable indoor environment. In the field of electronics and electrical appliances, MS sealant also shows important value. In the production of mobile phones, computers and other electronic products, MS sealant can seal and protect electronic components, prevent the intrusion of moisture, dust and harmful gases, improve the stability and reliability of electronic equipment, prolong the service life of products, and meet the needs of consumers for high-quality electronic products.

[0003] However, traditional sealants may burn rapidly when a fire occurs, fueling the spread of the fire, while MS sealants with good flame retardant properties can effectively slow down the burning speed when in contact with a fire source, or even self-extinguish, providing valuable time for personnel evacuation and fire rescue in the event of a fire, and reducing fire loss. In addition, in hospitals, food processing plants, kitchens and other places, the growth of bacteria can easily cause health hazards, and antibacterial MS sealant can inhibit the growth and reproduction of bacteria, preventing the pollution of the environment or affecting the quality of products due to the growth of bacteria in the sealed parts. In addition, sealants exposed to natural environment for a long time will be affected by factors such as ultraviolet light, oxygen, and moisture, and will age, crack, harden, and other problems, resulting in a decrease in sealing performance. By improving the anti-aging properties of MS sealant, it can maintain stable performance in different climate conditions, reduce the frequency of replacing sealant due to aging, and reduce maintenance costs.

[0004] In order to overcome the defects of the prior art, the present application provides a flame-retardant modified MS sealant and a preparation method thereof. SUMMARY

[0005] The purpose of the present application is to provide a flame-retardant modified MS sealant and a preparation method thereof to solve the problems in the prior art.

[0006] To achieve the above purpose, the present application provides the following technical solutions:

[0007] A preparation method of a flame-retardant modified MS sealant, comprising the following steps:

[0008] Step one: add chitosan to a mixture of 2.0-2.5wt% acetic acid solution and 2,2,2-trifluoroethanol, stir until uniform, to obtain a shell spinning solution; add catechin, luteolin, and kaempferol to 2,2,2-trifluoroethanol, stir until uniform, to obtain a core spinning solution; coaxially electrospun the shell spinning solution and the core spinning solution, to obtain an antibacterial fiber;

[0009] Step two: add silver nitrate to deionized water, dropwise add 25-28wt% ammonia water until the precipitate disappears, to obtain a silver-ammonia solution; add glucose to deionized water, to obtain a glucose solution; immerse the antibacterial fiber in the silver-ammonia solution for 15-20min, then heat to 50-60℃ for 25-35min, then dropwise add the glucose solution and continue stirring for 4-6h, to obtain a composite fiber;

[0010] Step three: in an argon environment, mix gamma-methacryloxypropyltrimethoxysilane, acrylic acid, flame-retardant acrylic monomer, antibacterial acrylic monomer, anti-aging vinyl monomer, and ethyl acetate, gradually heat to 60-70℃, then dropwise add azobisisobutyronitrile solution, continue to react for 6-8h after the addition is completed, to obtain a silane-modified acrylic resin; in an argon environment, mix the silane-modified acrylic resin and polytetrahydrofuran, gradually heat to 60-70℃, continue to react for 5-7h, to obtain a silane-modified polyether resin;

[0011] Step four: mix the silane-modified polyether resin, the composite fiber, the plasticizer, and the filler until uniform, disperse at high speed for 30-40min at 100-110℃, then add a water removal agent and a catalyst in a nitrogen environment, then uniformly stir under vacuum and seal, to obtain a finished product.

[0012] More preferably, in step one, the mass-volume ratio of chitosan, acetic acid solution, and 2,2,2-trifluoroethanol is (0.9-1.0)g:25mL:25mL; the mass-volume ratio of catechin, luteolin, kaempferol, and 2,2,2-trifluoroethanol is (0.2-0.3)g:0.4g:(0.1-0.2)g:5mL; the coaxial electrospinning parameters are: voltage 10-15kV, injection rate 0.5-0.7mL / h, and temperature 25-30℃.

[0013] More preferably, in step two, the reaction mass ratio of silver nitrate, glucose, and antibacterial fiber is 1:(3.0-3.5):(2.5-3.5).

[0014] More preferably, in step three, the silane-modified acrylic resin contains, by mass fraction, 3-5 parts of γ-methacryloxypropyltrimethoxysilane, 20-25 parts of acrylic acid, 10-13 parts of flame-retardant acrylic monomer, 10-13 parts of antibacterial acrylic monomer, 8-10 parts of anti-aging vinyl monomer, 25-35 parts of ethyl acetate, and 20-23 parts of azobisisobutyronitrile solution; the azobisisobutyronitrile is dissolved in ethyl acetate to obtain the azobisisobutyronitrile solution; the reaction mass ratio of the silane-modified acrylic resin to polytetrahydrofuran is (1.0-1.5):1.

[0015] More preferably, in step four, the finished product contains, by mass fraction, 40-60 parts of silane-modified polyether resin, 8-12 parts of composite fiber, 10-15 parts of plasticizer, 20-30 parts of filler, 1-2 parts of water-removing agent, and 0.5-1.0 parts of catalyst; the plasticizer is diisodecyl phthalate; the filler is talc; the water-removing agent is γ-methacryloxypropyltrimethoxysilane; and the catalyst is dibutyltin dilaurate.

[0016] More preferably, the preparation process of the flame-retardant acrylic monomer is as follows: hydroxyethyl acrylate and triethylamine are added to diethyl ether to obtain reaction liquid 1; hexachlorocyclotriphosphazene is added to diethyl ether to obtain reaction liquid 2; reaction liquid 2 is slowly added to reaction liquid 1, and the reaction is carried out at 0-3°C for 15-18 hours; after the reaction is completed, filtration, extraction, drying, and rotary evaporation are performed to obtain the flame-retardant acrylic monomer; and the reaction molar ratio of hydroxyethyl acrylate to hexachlorocyclotriphosphazene is (6.3-6.5):1.

[0017] More preferably, the preparation process of the antibacterial acrylic monomer is as follows: chitosan is added to a 2.0-2.5 wt% acetic acid solution to obtain a chitosan solution; methyl acrylate is added dropwise to the chitosan solution; after the dropwise addition is completed, the reaction is carried out at 60-70°C for 6-8 hours; after the reaction is completed, pH adjustment and freeze-drying are performed to obtain the antibacterial acrylic monomer.

[0018] More preferably, the mass-volume ratio of chitosan, acetic acid solution, and methyl acrylate is 0.2 g:10 mL:(0.35-0.45) mL.

[0019] More preferably, the preparation process of the anti-aging vinyl monomer is as follows: 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, methylhydroquinone, and triethylamine are added to tetrahydrofuran, and heating and stirring are carried out at 60-65°C until dissolution; then, acryloyl chloride in tetrahydrofuran is added dropwise; after the dropwise addition is completed, the reaction is continued for 12-15 hours; after the reaction is completed, liquid-liquid separation, stirring with deionized water, filtration, rotary evaporation, and recrystallization are performed to obtain the anti-aging vinyl monomer; and the reaction molar ratio of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole to acryloyl chloride is 1:(1.3-1.5).

[0020] The beneficial effects of the present application are:

[0021] The present application is characterized in that, in step one and step two, by adding chitosan, acetic acid solution and 2,2,2-trifluoroethanol, an antibacterial shell layer spinning solution is obtained; by adding catechin, luteolin and kaempferol to 2,2,2-trifluoroethanol, the reaction mass ratio of catechin, luteolin and kaempferol is set to (0.2-0.3):0.4:(0.1-0.2), an antibacterial core layer spinning solution is obtained; the antibacterial shell layer spinning solution and the antibacterial core layer spinning solution are subjected to coaxial electrospinning process treatment to obtain antibacterial fibers. Then by adding silver amine solution, glucose solution and antibacterial fibers, silver particles are coated on the surface of the antibacterial fibers to obtain composite fibers.

[0022] Chitosan is the key component of the antibacterial shell layer spinning solution. In the acidic environment provided by the acetic acid solution, the amino groups in the chitosan molecules will be protonated and positively charged. The surface of bacteria generally presents a negative charge state. Based on the principle of electrostatic attraction, chitosan will quickly adsorb to the surface of bacteria, destroy the cell membrane structure of bacteria, and then cause the death of bacteria. The antibacterial core layer spinning solution contains catechin, luteolin and kaempferol, and their ratio is (0.2-0.3):0.4:(0.1-0.2). By using this optimized ratio, the best antibacterial synergistic effect can be achieved. Further, the antibacterial fibers with core-shell structure formed by coaxial electrospinning process, the chitosan in the shell layer can quickly capture and adsorb bacteria in the surrounding environment, creating favorable conditions for the antibacterial components in the core layer to work; the antibacterial components in the core layer can be slowly released, achieving sustained inhibition and killing of bacteria, prolonging the time of antibacterial effect, and forming a long-acting antibacterial mechanism. After the action of silver amine solution and glucose solution, silver particles are successfully coated on the surface of the antibacterial fibers. Silver particles and antibacterial components inside the fibers form a synergistic antibacterial effect. Silver ions can quickly kill bacteria adsorbed on the surface of the fibers, while the antibacterial components inside the fibers can continuously exert their effects to inhibit and kill newly contacted bacteria. Through this multi-level and multi-mechanism antibacterial system, the composite fibers have excellent antibacterial performance and can effectively inhibit and kill a variety of bacteria and fungi.

[0023] The application is characterized in that, in step three, by adding hydroxyethyl acrylate, triethylamine, hexachlorocyclotriphosphazene and diethyl ether, a nucleophilic substitution reaction occurs to obtain a flame-retardant acrylic monomer. By adding chitosan, acetic acid solution and methacrylic anhydride, an N-acylation reaction occurs to obtain an antibacterial acrylic monomer. By adding 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, methylhydroquinone, triethylamine, acryloyl chloride and tetrahydrofuran, an esterification reaction occurs to obtain an anti-aging vinyl monomer. Then, the three functional monomers, gamma-methacryloyloxypropyltrimethoxysilane, acrylic acid and ethyl acetate are mixed, and under the initiation of azobisisobutyronitrile solution, a copolymerization reaction occurs to obtain a silane-modified acrylic resin. Then, the silane-modified acrylic resin and polytetrahydrofuran are mixed, and the hydroxyl groups in the end groups or side groups of the polytetrahydrofuran can undergo polycondensation reaction with the hydrolysis product of the silane to produce chemical crosslinking, thereby obtaining a silane-modified polyether resin.

[0024] The flame-retardant acrylic monomer contains flame-retardant elements; the phosphorus element promotes the formation of a dense carbon layer on the surface of the polymer, thereby preventing oxygen from entering the interior of the material and reducing the generation of flammable gases. At the same time, the flame-retardant acrylic monomer also decomposes to produce some non-combustible gases, such as carbon dioxide and nitrogen, when it burns. These gases can dilute the oxygen concentration in the air, reducing the oxygen content in the combustion area and inhibiting combustion. In addition, the chitosan molecules contained in the antibacterial acrylic monomer can be adsorbed on the surface of bacteria through electrostatic action, destroy the cell membrane structure of the bacteria, and cause the leakage of intracellular substances, thereby achieving the purpose of antibiosis. Therefore, the introduction of this antibacterial structure into the silane-modified polyether resin can endow the resin with antibacterial function. The anti-aging vinyl monomer contains a benzotriazole structure, and benzotriazole compounds are a typical class of ultraviolet absorbers that can absorb the energy of ultraviolet light and convert it into heat energy, thereby reducing the damage of ultraviolet light to the molecules of the resin and preventing the resin from degrading, discoloring and other aging phenomena due to ultraviolet irradiation.

[0025] Therefore, the silane-modified polyether resin prepared is mixed with composite fibers, plasticizers, fillers, water removal agents and catalysts to prepare a finished product with excellent flame-retardant properties, antibacterial properties and anti-aging properties, thus having a broad application prospect in the technical field of sealant. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0027] Raw material sources:

[0028] Chitosan, degree of deacetylation is 85%; talc, particle size is 325 mesh, provided by Hebei Hengguang Mineral Products Co., Ltd.; polytetrahydrofuran, model number is

[0029] 216-898-4; in mass fraction, one part is 1 g.

[0030] Example 1: Step one: chitosan is added into a mixture of 2.3wt% acetic acid solution and 2,2,2-trifluoroethanol, and stirred uniformly to obtain a shell spinning solution; catechin, luteolin and kaempferol are added into 2,2,2-trifluoroethanol, and stirred uniformly to obtain a core spinning solution; the shell spinning solution and the core spinning solution are coaxially electrospun to obtain an antibacterial fiber; the mass-volume ratio of chitosan, acetic acid solution and 2,2,2-trifluoroethanol is 0.95g:25mL:25mL; the mass-volume ratio of catechin, luteolin, kaempferol and 2,2,2-trifluoroethanol is 0.25g:0.4g:0.15g:5mL; the coaxial electrospinning parameters are: voltage is 15kV, injection rate is 0.7mL / h, and temperature is 30℃;

[0031] Step two: silver nitrate is added into deionized water, and 28wt% ammonia water is added dropwise until the precipitate disappears to obtain a silver-ammonia solution; glucose is added into deionized water to obtain a glucose solution; the antibacterial fiber is immersed in the silver-ammonia solution for 20min, and then heated to 60℃ for 35min; then the glucose solution is added dropwise and continues to stir for 6h to obtain a composite fiber; the reaction mass ratio of silver nitrate, glucose and antibacterial fiber is 1:3.2:2.7;

[0032] Step three: hydroxyethyl acrylate and triethylamine are added into diethyl ether to obtain a reaction liquid 1; hexachlorocyclotriphosphazene is added into diethyl ether to obtain a reaction liquid 2; the reaction liquid 2 is slowly added into the reaction liquid 1, and reacted at 3℃ for 18h; after the reaction is completed, filtration, extraction, drying and rotary evaporation are performed to obtain a flame-retardant acrylic monomer; the reaction molar ratio of hydroxyethyl acrylate and hexachlorocyclotriphosphazene is 6.4:1;

[0033] Chitosan is added into 2.3wt% acetic acid solution, and stirred uniformly to obtain a chitosan solution; methyl acrylate is added dropwise into the chitosan solution, and after the addition is completed, 70℃ reaction is carried out for 8h; after the reaction is completed, pH is adjusted, and freeze-drying is carried out to obtain an antibacterial acrylic monomer; the mass-volume ratio of chitosan, acetic acid solution and methyl acrylate is 0.2g:10mL:0.4mL;

[0034] Add 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, methylhydroquinone, triethylamine into tetrahydrofuran, heat and stir at 65°C until dissolved, then add acryloyl chloride solution in tetrahydrofuran dropwise, continue to react for 15h after the end of dropwise addition, after the reaction is completed, separate the layers, add deionized water, stir, filter, rotary evaporate, recrystallize to obtain the anti-aging vinyl monomer; the reaction molar ratio of 2-(2'-hydroxy-5'-methylphenyl) benzotriazole and acryloyl chloride is 1:1.4;

[0035] Under argon atmosphere, mix 5g γ-methacryloyloxypropyl trimethoxysilane, 25g acrylic acid, 13g flame-retardant acrylic monomer, 13g antibacterial acrylic monomer, 10g anti-aging vinyl monomer, 35g ethyl acetate, gradually heat to 70°C, then add 23g azobisisobutyronitrile solution dropwise, continue to react for 8h after the end of dropwise addition to obtain silane-modified acrylic resin; under argon atmosphere, mix the silane-modified acrylic resin and polytetrahydrofuran, gradually heat to 70°C, and continue to react for 7h to obtain silane-modified polyether resin; the reaction mass ratio of silane-modified acrylic resin and polytetrahydrofuran is 1.3:1;

[0036] Step four: mix 60g silane-modified polyether resin, 12g composite fiber, 15g diisodecyl phthalate, 30g talc uniformly, disperse at high speed for 40min at 110°C, then add 1g γ-methacryloyloxypropyl trimethoxysilane, 0.7g dibutyltin dilaurate under nitrogen atmosphere, then uniformly stir under vacuum, seal to obtain the finished product.

[0037] Example 2: Step one: add chitosan into a mixture of 2.3wt% acetic acid solution and 2,2,2-trifluoroethanol, stir uniformly to obtain a shell spinning solution; add catechin, luteolin, kaempferol into 2,2,2-trifluoroethanol, stir uniformly to obtain a core spinning solution; perform coaxial electrospinning on the shell spinning solution and the core spinning solution to obtain antibacterial fiber; the mass-volume ratio of chitosan, acetic acid solution, and 2,2,2-trifluoroethanol is 0.95g:25mL:25mL; the mass-volume ratio of catechin, luteolin, kaempferol, and 2,2,2-trifluoroethanol is 0.25g:0.4g:0.15g:5mL; the coaxial electrospinning parameters are: voltage is 12kV, injection rate is 0.6mL / h, and temperature is 27°C;

[0038] Step two: add silver nitrate into deionized water, add 26wt% ammonia water dropwise until the precipitate disappears to obtain silver ammine solution; add glucose into deionized water to obtain glucose solution; immerse the antibacterial fiber in the silver ammine solution for 17min, then heat to 55°C and keep for 30min, then add the glucose solution dropwise and continue to stir for 5h to obtain composite fiber; the reaction mass ratio of silver nitrate, glucose, and antibacterial fiber is 1:3.2:2.7;

[0039] Step three: add hydroxyethyl acrylate and triethylamine into ether to obtain reaction liquid 1; add hexachlorocyclotriphosphazene into ether to obtain reaction liquid 2; slowly add reaction liquid 2 into reaction liquid 1, react at 2℃ for 17h, after the reaction is completed, filter, extract, dry, and rotary evaporate to obtain the flame-retardant acrylic monomer; the reaction molar ratio of hydroxyethyl acrylate and hexachlorocyclotriphosphazene is 6.4:1;

[0040] Add chitosan into 2.3wt% acetic acid solution, stir to obtain chitosan solution; dropwise add methacrylic anhydride into the chitosan solution, after the dropwise addition is completed, react at 65℃ for 7h, after the reaction is completed, adjust pH and freeze-dry to obtain the antibacterial acrylic monomer; the mass-volume ratio of chitosan, acetic acid solution, and methacrylic anhydride is 0.2g:10mL:0.4mL;

[0041] Add 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, methylhydroquinone, and triethylamine into tetrahydrofuran, heat and stir at 63℃ until dissolved, then dropwise add acryloyl chloride in tetrahydrofuran, continue to react for 13h after the dropwise addition is completed, after the reaction is completed, separate, add deionized water, stir, filter, rotary evaporate, and recrystallize to obtain the anti-aging vinyl monomer; the reaction molar ratio of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole and acryloyl chloride is 1:1.4;

[0042] Under an argon environment, mix 5g γ-methacryloyloxypropyltrimethoxysilane, 25g acrylic acid, 13g flame-retardant acrylic monomer, 13g antibacterial acrylic monomer, 10g anti-aging vinyl monomer, and 35g ethyl acetate, gradually heat to 65℃, then dropwise add 23g azobisisobutyronitrile solution, continue to react for 7h after the dropwise addition is completed to obtain silane-modified acrylic resin; under an argon environment, mix the silane-modified acrylic resin and polytetrahydrofuran, gradually heat to 65℃, and continue to react for 6h to obtain silane-modified polyether resin; the reaction mass ratio of silane-modified acrylic resin and polytetrahydrofuran is 1.3:1;

[0043] Step four: mix 60g silane-modified polyether resin, 12g composite fiber, 15g diisodecyl phthalate, and 30g talc uniformly, disperse at 105℃ for 35min at high speed, then under a nitrogen environment, add 1g γ-methacryloyloxypropyltrimethoxysilane and 0.7g dibutyltin dilaurate, then uniformly stir under vacuum, seal, and obtain the finished product.

[0044] Example 3: Step one: add chitosan to a mixture of 2.3wt% acetic acid solution and 2,2,2-trifluoroethanol, stir until uniform, to obtain a shell spinning solution; add catechin, luteolin, kaempferol to 2,2,2-trifluoroethanol, stir until uniform, to obtain a core spinning solution; coaxial electrospinning the shell spinning solution and the core spinning solution to obtain an antibacterial fiber; the mass-volume ratio of chitosan, acetic acid solution, 2,2,2-trifluoroethanol is 0.95g:25mL:25mL; the mass-volume ratio of catechin, luteolin, kaempferol, 2,2,2-trifluoroethanol is 0.25g:0.4g:0.15g:5mL; the coaxial electrospinning parameters are: voltage 10kV, injection rate 0.5mL / h, temperature 25℃;

[0045] Step two: add silver nitrate to deionized water, dropwise add 25wt% ammonia water until the precipitate disappears, to obtain a silver-ammonia solution; add glucose to deionized water to obtain a glucose solution; immerse the antibacterial fiber in the silver-ammonia solution for 15min, then heat to 50℃ for 25min, then dropwise add the glucose solution and continue stirring for 4h, to obtain a composite fiber; the reaction mass ratio of silver nitrate, glucose, antibacterial fiber is 1:3.2:2.7;

[0046] Step three: add hydroxyethyl acrylate and triethylamine to diethyl ether to obtain reaction liquid 1; add hexachlorocyclotriphosphazene to diethyl ether to obtain reaction liquid 2; slowly add reaction liquid 2 to reaction liquid 1, react at 0℃ for 15h, after the reaction is completed, filter, extract, dry, and rotary evaporate to obtain a flame-retardant acrylic monomer; the reaction molar ratio of hydroxyethyl acrylate and hexachlorocyclotriphosphazene is 6.4:1;

[0047] Add chitosan to a 2.3wt% acetic acid solution, stir until uniform to obtain a chitosan solution; dropwise add methacrylic anhydride to the chitosan solution, after the dropwise addition is completed, react at 60℃ for 6h, after the reaction is completed, adjust the pH, and freeze-dry to obtain an antibacterial acrylic monomer; the mass-volume ratio of chitosan, acetic acid solution, methacrylic anhydride is 0.2g:10mL:0.4mL;

[0048] Add 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, methylhydroquinone, and triethylamine to tetrahydrofuran, heat and stir at 60℃ until dissolved, then dropwise add acryloyl chloride in tetrahydrofuran, after the dropwise addition is completed, continue to react for 12h, after the reaction is completed, separate the liquid, add deionized water and stir to filter, rotary evaporate, and recrystallize to obtain an anti-aging vinyl monomer; the reaction molar ratio of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole and acryloyl chloride is 1:1.4;

[0049] In an argon environment, 5 g of γ-methacryloxypropyl trimethoxysilane, 25 g of acrylic acid, 13 g of flame-retardant acrylic monomer, 13 g of antibacterial acrylic monomer, 10 g of anti-aging vinyl monomer, 35 g of ethyl acetate were mixed, gradually heated to 60°C, and then 23 g of azobisisobutyronitrile solution was added dropwise. After the dropwise addition was completed, the reaction was continued for 6 h to obtain a silane-modified acrylic resin; in an argon environment, the silane-modified acrylic resin and polytetrahydrofuran were mixed, and gradually heated to 60°C, and the reaction was continued for 5 h to obtain a silane-modified polyether resin; the reaction mass ratio of the silane-modified acrylic resin and polytetrahydrofuran was 1.3:1;

[0050] Step four: 60 g of silane-modified polyether resin, 12 g of composite fiber, 15 g of diisodecyl phthalate, and 30 g of talc powder were uniformly mixed, and then dispersed at 100°C for 30 min. Then, 1 g of γ-methacryloxypropyl trimethoxysilane and 0.7 g of dibutyltin dilaurate were added under a nitrogen environment, and then uniformly stirred under vacuum, sealed, and obtained as a finished product.

[0051] Comparative Example 1: The composite fiber was removed, and the remaining steps were the same as in Example 1, and the specific steps were as follows: Step one: hydroxyethyl acrylate and triethylamine were added to diethyl ether to obtain reaction liquid 1; hexachlorocyclotriphosphazene was added to diethyl ether to obtain reaction liquid 2; reaction liquid 2 was slowly added to reaction liquid 1, and reacted at 3°C for 18 h. After the reaction was completed, filtration, extraction, drying, and rotary evaporation were performed to obtain a flame-retardant acrylic monomer; the reaction molar ratio of hydroxyethyl acrylate and hexachlorocyclotriphosphazene was 6.4:1;

[0052] Chitosan was added to a 2.3wt% acetic acid solution and stirred to obtain a chitosan solution; methacrylic anhydride was added dropwise to the chitosan solution, and after the dropwise addition was completed, the reaction was continued at 70°C for 8 h. After the reaction was completed, the pH was adjusted, and freeze-drying was performed to obtain an antibacterial acrylic monomer; the mass-volume ratio of chitosan, acetic acid solution, and methacrylic anhydride was 0.2g:10mL:0.4mL;

[0053] 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, methylhydroquinone, and triethylamine were added to tetrahydrofuran, heated and stirred at 65°C until dissolved, and then acryloyl chloride in tetrahydrofuran was added dropwise. After the dropwise addition was completed, the reaction was continued for 15 h. After the reaction was completed, liquid-liquid separation was performed, deionized water was added and stirred, filtered, rotary evaporated, and recrystallized to obtain an anti-aging vinyl monomer; the reaction molar ratio of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole and acryloyl chloride was 1:1.4;

[0054] In an argon environment, 5 g of γ-methacryloxypropyl trimethoxysilane, 25 g of acrylic acid, 13 g of flame-retardant acrylic monomer, 13 g of antibacterial acrylic monomer, 10 g of anti-aging vinyl monomer, and 35 g of ethyl acetate were mixed, gradually heated to 70°C, and then 23 g of azobisisobutyronitrile solution was added dropwise. After the dropwise addition was completed, the reaction was continued for 8 h to obtain a silane-modified acrylic resin; in an argon environment, the silane-modified acrylic resin and polytetrahydrofuran were mixed, gradually heated to 70°C, and the reaction was continued for 7 h to obtain a silane-modified polyether resin; the reaction mass ratio of the silane-modified acrylic resin and polytetrahydrofuran was 1.3:1;

[0055] Step two: 60 g of silane-modified polyether resin, 15 g of diisodecyl phthalate, and 30 g of talc powder were mixed uniformly, dispersed at a high speed for 40 min at 110°C, and then 1 g of γ-methacryloxypropyl trimethoxysilane and 0.7 g of dibutyltin dilaurate were added under a nitrogen environment. After being uniformly stirred under vacuum and sealed, the finished product was obtained.

[0056] Comparative Example 2: The flame-retardant acrylic monomer, the antibacterial acrylic monomer, and the anti-aging vinyl monomer were removed, and the remaining steps were the same as in Example 1. The specific steps are as follows: Step one: chitosan was added to a mixture of 2.3 wt% acetic acid solution and 2,2,2-trifluoroethanol, and stirred uniformly to obtain a shell spinning solution; catechin, luteolin, and kaempferol were added to 2,2,2-trifluoroethanol and stirred uniformly to obtain a core spinning solution; the shell spinning solution and the core spinning solution were subjected to coaxial electrospinning to obtain an antibacterial fiber; the mass-volume ratio of chitosan, acetic acid solution, and 2,2,2-trifluoroethanol was 0.95 g:25 mL:25 mL; the mass-volume ratio of catechin, luteolin, kaempferol, and 2,2,2-trifluoroethanol was 0.25 g:0.4 g:0.15 g:5 mL; the coaxial electrospinning parameters were: voltage 15 kV, injection rate 0.7 mL / h, and temperature 30°C;

[0057] Step two: silver nitrate was added to deionized water, and 28 wt% ammonia water was added dropwise until the precipitate disappeared to obtain a silver-ammonia solution; glucose was added to deionized water to obtain a glucose solution; the antibacterial fiber was immersed in the silver-ammonia solution for 20 min, then heated to 60°C and kept for 35 min, and then the glucose solution was added dropwise and stirred for 6 h to obtain a composite fiber; the reaction mass ratio of silver nitrate, glucose, and antibacterial fiber was 1:3.2:2.7;

[0058] Step three: under argon environment, 5g γ-methacryloxypropyl trimethoxysilane, 25g acrylic acid, 35g ethyl acetate were mixed, gradually heated to 70℃, then 23g azobisisobutyronitrile solution was added drop by drop, after the end of dropwise addition, the reaction was continued for 8h, to obtain silane modified acrylic resin; under argon environment, the silane modified acrylic resin and polytetrahydrofuran were mixed, gradually heated to 70℃, and the reaction was continued for 7h, to obtain silane modified polyether resin; the reaction mass ratio of silane modified acrylic resin and polytetrahydrofuran was 1.3:1;

[0059] Step four: 60g silane modified polyether resin, 12g composite fiber, 15g diisodecyl phthalate, 30g talc were mixed uniformly, and dispersed at high speed for 40min at 110℃, then 1g γ-methacryloxypropyl trimethoxysilane, 0.7g dibutyltin dilaurate were added under nitrogen environment, and then uniformly stirred under vacuum, sealed to obtain the finished product.

[0060] Flame retardant performance test: the finished product prepared by the present application was added to a polytetrafluoroethylene mold, and cured at 25℃ for 10h in a natural environment to obtain a test sample. According to GB / T 2406.2-2009 "Plastics-Determination of the burning behavior of plastics-Part 2: Guidance on the measurement of flame properties under specified test conditions-Method using a 50Watt horizontal and vertical flame", the size of the test sample was 80x10x10mm, and a JF-20 type limiting oxygen index analyzer was used to test the test sample, and the oxygen index value was recorded.

[0061] Antibacterial performance test: the finished product prepared by the present application was added to a polytetrafluoroethylene mold, and cured at 25℃ for 10h in a natural environment to obtain a test sample. Escherichia coli was used as the experimental strain, and the Escherichia coli was inoculated, cultured and diluted in turn to obtain a bacterial solution with a concentration of 1x10 6 CFU / mL. The bacterial solution with a concentration of 1x10 6 CFU / mL and buffer were added to the well plate, and then the test sample was placed on the well plate, and incubated at 35℃ for 10h. The mixed solution in the well plate after incubation was taken out, and the mixed solution was cultured on a solid agar medium, and incubated at 35℃ for 30h. After incubation, the number of colonies in the culture medium was counted. Under the same conditions, a blank group was set, and the corresponding data was introduced into the formula to calculate the antibacterial rate.

[0062] Anti-aging performance test: the finished product prepared by the present application was added to a polytetrafluoroethylene mold, and cured at 25℃ for 10h in a natural environment to obtain a test sample. The test sample was placed in an ultraviolet aging oven for artificial accelerated aging, a 1KW iodine gallium lamp was used, the ultraviolet radiation intensity was 5W / m 2 , and the aging test was carried out at 60℃ for 1000h. The tensile strength of the test sample before and after the aging test was tested, and the tensile strength data was introduced into the formula to calculate the tensile strength change rate. The results are as follows:

[0063]

[0064] Conclusion: The amount of Example 1-Example 3 is unchanged, only modify part of the reaction parameters. From the experimental data, the performance of the sample has no obvious fluctuation.

[0065] Comparative Example 1: Remove the composite fiber, the rest is the same as Example 1, from the experimental data, compared with Example 1, the antibacterial rate is reduced to 79.6%, the analysis reason is: the composite fiber has a multi-level, multi-mechanism antibacterial system, so it has excellent antibacterial performance, so after removing it, the antibacterial rate is reduced.

[0066] Comparative Example 2: Remove the flame-retardant acrylic monomer, antibacterial acrylic monomer, and anti-aging vinyl monomer, the rest is the same as Example 1, from the experimental data, compared with Example 1, the oxygen index is reduced to 21.5%, the antibacterial rate is reduced to 89.3%, and the tensile strength change rate before and after aging test is-48.6%, the analysis reason is: the addition of the three functional monomers can effectively improve the flame retardance, antibacterial property and anti-aging property of the main resin silane modified polyether resin, so after removing them, the oxygen index is reduced, the antibacterial rate is reduced, and the tensile strength change rate before and after aging test is improved.

[0067] It should be noted that the relational terms herein such as first and second and the like are used only to differentiate one entity or action from another, and do not necessarily require or imply that any such actual relationship or order exists between or among the entities or actions. Also, the terms "comprising", "having", or any other variant thereof are intended to cover non-exclusive inclusion, so that the process method article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or other elements inherent to such process method article or equipment.

[0068] Finally, it should be noted that: the above only describes the preferred embodiments of the present application, and is not intended to limit the present application, although the above embodiments of the present application are described in detail, those skilled in the art can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement for part of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a flame-retardant modified MS sealant, characterized in that: Comprising the following steps: Step one: add chitosan to a mixture of 2.0-2.5wt% acetic acid solution and 2,2,2-trifluoroethanol, stir evenly to obtain a shell spinning solution; add catechin, luteolin and kaempferol to 2,2,2-trifluoroethanol, stir evenly to obtain a core spinning solution; coaxially electrospun the shell spinning solution and the core spinning solution to obtain an antibacterial fiber; Step two: add silver nitrate to deionized water, dropwise add 25-28wt% ammonia water until the precipitate disappears to obtain a silver-ammonia solution; add glucose to deionized water to obtain a glucose solution; Immerse the antibacterial fiber in the silver-ammonia solution for 15-20min, then heat to 50-60℃ for 25-35min, then dropwise add the glucose solution and continue stirring for 4-6h to obtain a composite fiber; Step three: under argon environment, mix gamma-methacryloxypropyltrimethoxysilane, acrylic acid, flame-retardant acrylic monomer, antibacterial acrylic monomer, anti-aging vinyl monomer and ethyl acetate, gradually heat to 60-70℃, then dropwise add azobisisobutyronitrile solution, continue to react for 6-8h after the end of dropping to obtain silane-modified acrylic resin; under argon environment, mix the silane-modified acrylic resin and polytetrahydrofuran, gradually heat to 60-70℃, continue to react for 5-7h to obtain silane-modified polyether resin; Step four: mix the silane-modified polyether resin, composite fiber, plasticizer and filler evenly, disperse at high speed for 30-40min at 100-110℃, then add water removal agent and catalyst under nitrogen environment, then uniformly stir under vacuum and seal to obtain the finished product.

2. The preparation method of the fire-retardant modified MS sealant according to claim 1, characterized in that: In step one, the mass-volume ratio of chitosan, acetic acid solution and 2,2,2-trifluoroethanol is (0.9-1.0)g:25mL:25mL; the mass-volume ratio of catechin, luteolin, kaempferol and 2,2,2-trifluoroethanol is (0.2-0.3)g:0.4g:(0.1-0.2)g:5mL; the coaxial electrospinning parameters are: voltage 10-15kV, injection rate 0.5-0.7mL / h, temperature 25-30℃.

3. The preparation method of the flame-retardant modified MS sealant according to claim 1, characterized in that: In step two, the reaction mass ratio of silver nitrate, glucose and antibacterial fiber is 1:(3.0-3.5):(2.5-3.5).

4. The preparation method of the flame-retardant modified MS sealant according to claim 1, characterized in that: In step three, the content of each component of the silane-modified acrylic resin is: 3-5 parts of gamma-methacryloxypropyltrimethoxysilane, 20-25 parts of acrylic acid, 10-13 parts of flame-retardant acrylic monomer, 10-13 parts of antibacterial acrylic monomer, 8-10 parts of anti-aging vinyl monomer, 25-35 parts of ethyl acetate, and 20-23 parts of azobisisobutyronitrile solution; dissolve azobisisobutyronitrile in ethyl acetate to obtain azobisisobutyronitrile solution; the reaction mass ratio of silane-modified acrylic resin and polytetrahydrofuran is (1.0-1.5):

1.

5. The preparation method of the flame-retardant modified MS sealant according to claim 1, characterized in that: In step four, the content of each component of the finished product is as follows: 40-60 parts of silane modified polyether resin, 8-12 parts of composite fiber, 10-15 parts of plasticizer, 20-30 parts of filler, 1-2 parts of water removing agent, and 0.5-1.0 parts of catalyst; the plasticizer is diisodecyl phthalate; the filler is talc; the water removing agent is gamma-methacryloxypropyltrimethoxysilane; and the catalyst is dibutyltin dilaurate.

6. The preparation method of the fire-retardant modified MS sealant according to claim 4, characterized in that: The preparation process of the flame-retardant acrylic monomer is as follows: adding hydroxyethyl acrylate and triethylamine into diethyl ether to obtain reaction liquid 1; adding hexachlorocyclotriphosphazene into diethyl ether to obtain reaction liquid 2; slowly adding reaction liquid 2 into reaction liquid 1, and reacting at 0-3℃ for 15-18h; after the reaction is completed, filtering, extracting, drying, and rotary evaporation are performed to obtain the flame-retardant acrylic monomer; and the reaction molar ratio of hydroxyethyl acrylate to hexachlorocyclotriphosphazene is (6.3-6.5):

1.

7. The preparation method of the fire-retardant modified MS sealant according to claim 4, characterized in that: The preparation process of the antibacterial acrylic monomer is as follows: adding chitosan into a 2.0-2.5wt% acetic acid solution, and stirring uniformly to obtain a chitosan solution; dropwise adding methyl methacrylate into the chitosan solution, and reacting at 60-70℃ for 6-8h after the dropwise addition is completed; and after the reaction is completed, adjusting the pH and freeze-drying to obtain the antibacterial acrylic monomer.

8. The preparation method of the flame-retardant modified MS sealant according to claim 7, characterized in that: The mass-volume ratio of chitosan, acetic acid solution, and methyl methacrylate is 0.2g:10mL:(0.35-0.45)mL.

9. The preparation method of the flame-retardant modified MS sealant according to claim 4, characterized in that: The preparation process of the anti-aging vinyl monomer is as follows: adding 2-(2'-hydroxy-5'-methylphenyl) benzotriazole, methylhydroquinone, and triethylamine into tetrahydrofuran, heating and stirring at 60-65℃ until dissolution, then dropwise adding an acryloyl chloride tetrahydrofuran solution, continuing to react for 12-15h after the dropwise addition is completed, and then performing liquid separation, adding deionized water to stir and filter, rotary evaporation, and recrystallization to obtain the anti-aging vinyl monomer; the reaction molar ratio of 2-(2'-hydroxy-5'-methylphenyl) benzotriazole to acryloyl chloride is 1:(1.3-1.5).

10. A fire-retardant modified MS sealant, characterized by, Prepared according to the preparation method in any one of claims 1-9.

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