Preparation method of antibacterial waterproof composite board

Abstract

The invention relates to the technical field of boards, and discloses a preparation method of an antibacterial waterproof composite board, which comprises the following steps: taking mercaptopropionic acid and 2, 2-dimethylolpropionic acid as raw materials to prepare a product A, and sequentially reacting with geraniol, nano silver-loaded titanium dioxide and tridecafluorooctanol to obtain the antibacterial waterproof composite board. The preparation method comprises the following steps: adding disulfydryl geranyl ester, disulfydryl nano silver-loaded titanium dioxide and disulfydryl perdecafluorooctyl ester into polyvinyl chloride for reaction to obtain modified polyvinyl chloride, finally adding the modified polyvinyl chloride into polyvinyl chloride, chlorinated polyethylene and dioctyl phthalate, and uniformly mixing to obtain the antibacterial waterproof composite board. The prepared composite board has excellent antibacterial property, waterproof property and mechanical property.

Description

Technical Field

[0001] The present invention relates to the technical field of sheet materials, and particularly to a preparation method of an antibacterial and waterproof composite sheet material. Background Technique

[0002] Polyvinyl chloride (PVC) is a polymer obtained by free radical polymerization of vinyl chloride monomers under the initiation of initiators. It has properties such as chemical corrosion resistance, flame retardancy, and waterproofing. Therefore, it is often used as a sheet material in fields such as bathrooms and floors. However, it is prone to bacterial growth in a long-term humid environment, and long-term contact with water will cause the material to expand or rot, and traditional PVC sheet materials can no longer meet the existing requirements.

[0003] Geraniol, also known as geraniol and citronellol, is an acyclic isoprenoid monoterpene substance, a natural plant-derived alcohol with a sweet rose fragrance. It is one of the main components of clove oil, citronella oil, and rose essential oil, and has the effects of inhibiting bacteria, molds, and treating chronic bronchitis. It is widely used in fields such as food, medicine, and cosmetics. However, geraniol is volatile and unstable under high-temperature heating, which limits its application effect.

[0004] For example, the patent with the application publication number CN 119505443 A discloses a highly antibacterial PVC sheet material and its preparation method. The invention uses PVC resin, multi-effect antibacterial agent, lubricant, etc. as raw materials, and the prepared PVC sheet material has good antibacterial performance, heat resistance performance, etc. However, the PVC sheet material prepared by this method is prone to expansion and rot in a humid environment, affecting the service life of the PVC sheet material and the health and safety of people.

[0005] Therefore, the present invention provides a preparation method of an antibacterial and waterproof composite sheet material. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention provides a preparation method of an antibacterial and waterproof composite sheet material. The composite sheet material prepared by this method has excellent antibacterial performance, waterproof performance, and mechanical properties.

[0007] The object of the present invention can be achieved by the following technical solutions: A preparation method of an antibacterial and waterproof composite sheet material, the preparation method comprising the following steps: Step (1): Add mercaptopropionic acid into toluene solvent, then add 2,2-dimethylolpropionic acid and a catalyst thereto, control the temperature at 100 - 110 °C, react for 6 - 10 h. After the reaction is completed, let it stand and perform vacuum distillation. The obtained product is denoted as product A. Among them, the mass ratio of mercaptopropionic acid to 2,2-dimethylolpropionic acid is 0.7 - 1:1. In this reaction, the carboxyl group contained in mercaptopropionic acid reacts with the hydroxyl group contained in 2,2-dimethylolpropionic acid to carry out an esterification reaction to obtain product A. Its reaction route is: ; Step (2): Add nano silver-loaded titanium dioxide into deionized water, perform ultrasonic dispersion, then add product A thereto, and stir and react at 80 - 95 °C for 1 - 3 h. After the reaction is completed, centrifuge, wash with deionized water, and dry. The obtained product is denoted as double-mercapto nano silver-loaded titanium dioxide. Among them, the mass ratio of nano silver-loaded titanium dioxide to product A is 1:5 - 10. In this reaction, the hydroxyl group on the surface of nano silver-loaded titanium dioxide reacts with the carboxyl group in product A to disperse the nano silver-loaded titanium dioxide, reduce the degree of aggregation, and improve its compatibility with organic substances to obtain double-mercapto nano silver-loaded titanium dioxide. Introducing it into the material can not only improve the antibacterial performance of the material by utilizing the dual antibacterial effects of silver ions antibacterial and photocatalyst antibacterial of silver-loaded nano titanium dioxide, but also, silver-loaded nano titanium dioxide is uniformly dispersed in the material as inorganic particles. When subjected to external impact, it can serve as a stress concentration point, causing an increase in the three-dimensional axial stress around the particles, and then causing the peeling of the particle-matrix interface. This peeling will cause the generation of holes, resulting in a change in the stress condition around the holes and generating shear stress, and this shear stress will absorb the impact force, thereby improving the mechanical properties of the material. Its reaction route is: ; where is nano silver-loaded titanium dioxide.

[0008] Step (3): Under a nitrogen atmosphere, dissolve polyvinyl chloride powder in cyclohexanone solvent, add bis(mercapto)geranyl ester, bis(mercapto)silver-loaded titanium dioxide nanoparticles, bis(mercapto)tridecafluorooctyl ester, and potassium carbonate thereto, and react at 55 - 65 °C for 24 - 30 h. After the reaction, add an aqueous methanol solution with a volume fraction of 67%, stir evenly, dry, then dissolve it in tetrahydrofuran, adjust the pH to 4 with hydrochloric acid, precipitate with methanol, and dry to obtain modified polyvinyl chloride. During this reaction process, through the nucleophilic reaction of the mercapto groups contained in bis(mercapto)geranyl ester, bis(mercapto)silver-loaded titanium dioxide nanoparticles, and bis(mercapto)tridecafluorooctyl ester with the chlorine atoms of polyvinyl chloride, bis(mercapto)geranyl ester, bis(mercapto)silver-loaded titanium dioxide nanoparticles, and bis(mercapto)tridecafluorooctyl ester are introduced into the macromolecular chain of polyvinyl chloride. Firstly, one mercapto group in the bis(mercapto) structure of the three reacts with the chlorine atom in the PVC molecular chain to generate a chemical bond, and the other mercapto group reacts with the chlorine atom in other molecular chains to further generate a chemical bond, increasing the degree of chemical crosslinking between molecular chains. Secondly, bis(mercapto)geranyl ester, bis(mercapto)silver-loaded titanium dioxide nanoparticles, and bis(mercapto)tridecafluorooctyl ester contain more ester group structures, and the carbonyl oxygen therein can interact with the methylene hydrogen in the PVC chain segment to generate hydrogen bonds, further strengthening the degree of chemical crosslinking. Thirdly, due to the branched chain structures contained in bis(mercapto)geranyl ester, bis(mercapto)silver-loaded titanium dioxide nanoparticles, and bis(mercapto)tridecafluorooctyl ester, they can entangle with the main chain and other branched chains to generate more physical crosslinking structures, forming a chemical-physical crosslinking structure. The resulting three-dimensional network structure has more crosslinking sites. On the one hand, when the material is subjected to external stress, the stress can be dispersed to other molecular chains through more crosslinking sites, thereby improving the mechanical properties of the material. On the other hand, due to the more crosslinking structures it contains, it can increase the density of the material, thereby improving the waterproof performance of the material.

[0009] Step (4): Add polyvinyl chloride, modified polyvinyl chloride, calcium-zinc composite stabilizer, stearic acid, polyethylene wax, chlorinated polyethylene, and dioctyl phthalate into the barrel of the extruder, and extrude into a thin sheet at 180 - 190 °C, and obtain an antibacterial and waterproof composite board through a tablet press and a sample making machine.

[0010] Further preferably, in the step (1), the catalyst is any one or several of hypophosphorous acid and p-toluenesulfonic acid, and its dosage is 1 - 3% of the total mass of mercaptopropionic acid and 2,2-dimethylolpropionic acid.

[0011] Further preferably, in the step (3), the mass ratio of polyvinyl chloride powder, bis(mercapto)geranyl ester, bis(mercapto)silver-loaded titanium dioxide nanoparticles, bis(mercapto)tridecafluorooctyl ester, and potassium carbonate is 1:0.1 - 0.2:0.1 - 0.2:0.1 - 0.2:0.8 - 1.

[0012] Further preferably, in the step (4), the mass ratio of polyvinyl chloride, modified polyvinyl chloride, calcium-zinc composite stabilizer, stearic acid, polyethylene wax, chlorinated polyethylene, and dioctyl phthalate is 100:50 - 80:5 - 8:0.5 - 1:0.6 - 1:5 - 8:3 - 5.

[0013] Further preferably, in the step (3), the preparation method of bis-mercapto geranyl ester includes the following steps: Add product A into dichloromethane solvent, stir and disperse evenly, then add geraniol and triethylamine into it, and react at room temperature for 12 - 16 h. After the reaction is completed, wash it with hydrochloric acid with a volume fraction of 5%, saturated sodium bicarbonate, and brine in sequence until the pH is 7. Use anhydrous sodium sulfate to dry the organic phase, evaporate the solvent, and the obtained product is denoted as bis-mercapto geranyl ester. Among them, the mass ratio of product A, geraniol, and triethylamine is 1:0.5 - 0.6:0.6 - 0.8. Under the catalysis of triethylamine, the carboxyl group contained in product A reacts with the hydroxyl group contained in geraniol to carry out an esterification reaction to obtain bis-mercapto geranyl ester, and then introduce it into the PVC material. On the one hand, since geraniol itself is volatile, grafting it onto the long chain of PVC molecules in the form of a chemical bond can reduce the volatility and increase the antibacterial persistence of geraniol. On the other hand, use the branched structure and ester group contained in it to increase the mechanical properties. Its reaction route is: ; Further preferably, the preparation method of bis-mercapto tridecafluorooctyl ester includes the following steps: Add product A, tridecafluorooctanol, p-toluenesulfonic acid, and hydroquinone into toluene solvent, heat up to 100 - 110 °C, and react for 8 - 12 h. After the reaction is completed, neutralize and wash it with a sodium hydroxide solution with a mass fraction of 5%, wash it with deionized water, dry the organic layer, and perform rotary evaporation. The obtained product is denoted as bis-mercapto tridecafluorooctyl ester. Among them, the mass ratio of product A, tridecafluorooctanol, p-toluenesulfonic acid, and hydroquinone is 1:1.1 - 1.3:0.004 - 0.006:0.01 - 0.02. During this reaction process, the carboxyl group contained in product A reacts with the hydroxyl group contained in tridecafluorooctanol to obtain bis-mercapto tridecafluorooctyl ester. Utilize the lower surface energy of fluorine element, and introducing it into the PVC material can improve the hydrophobic and waterproof performance of the material. Its reaction route is: .

[0014] Compared with the prior art, the beneficial effects of the present invention are: (1) The double-mercapto geranate prepared from geraniol with antibacterial properties as a raw material is introduced into the material in the present invention. It can not only improve the antibacterial performance of the material but also reduce the volatility of geraniol. The double-mercapto silver-loaded titanium dioxide with dual antibacterial effects is used as a raw material in the present invention to prepare double-mercapto silver-loaded titanium dioxide nanoparticles. Due to the use of geraniol and silver-loaded titanium dioxide nanoparticles, the two can synergistically improve the antibacterial performance of the material.

[0015] (2) In the present invention, double-mercapto perfluorooctyl ester is prepared from 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluorooctanol. By using the fluorinated long chain with low surface energy therein and introducing it into the material, it can not only improve the hydrophobic and waterproof effects of the material but also produce physical cross-linking with other long-chain structures and the main-chain structure by using the long-chain structure therein; the double-mercapto geranate, double-mercapto silver-loaded titanium dioxide nanoparticles, and double-mercapto perfluorooctyl prepared in the present invention contain double-mercapto structures, which react with chlorine atoms in the PVC molecular chain to produce chemical cross-linking and form a physical-chemical cross-linking structure with a high cross-linking density. First, due to the dense structure, it can improve the hydrophobic and waterproof effects of the material. Second, more physical cross-linking sites and chemical cross-linking sites are generated. When subjected to external impact, the impact energy can be dispersed along the cross-linking sites to other molecular chains, thereby improving the mechanical properties of the material. Detailed implementation manners

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention. Example 1

[0017] Step (1): Add 10 g of mercaptopropionic acid to a toluene solvent, and then add 10 g of 2,2-bis(hydroxymethyl)propionic acid and 0.2 g of p-toluenesulfonic acid catalyst thereto. Control the temperature at 105 °C and react for 10 h. After the reaction is completed, let it stand and perform vacuum distillation. The obtained product is denoted as product A.

[0018] Step (2): Add 10 g of product A to a dichloromethane solvent, stir and disperse it evenly, and then add 5 g of geraniol and 8 g of triethylamine thereto. React at room temperature for 16 h. After the reaction is completed, wash it successively with 5% (by volume) hydrochloric acid, saturated sodium bicarbonate, and brine until the pH is 7. Dry the organic phase with anhydrous sodium sulfate, evaporate the solvent, and the obtained product is denoted as double-mercapto geranate.

[0019] Step (3): Add 2 g of nano silver-loaded titanium dioxide into deionized water, disperse it by ultrasonic wave, then add 10 g of product A into it, react with stirring at 85 °C for 1 h. After the reaction, centrifuge, wash with deionized water, and dry. The obtained product is denoted as dithiol nano silver-loaded titanium dioxide. Introducing it into the material can, on the one hand, improve the antibacterial performance of the material, on the other hand, disperse the silver-loaded nano titanium dioxide, and on the third hand, use the silver-loaded nano titanium dioxide as inorganic nano particles to be evenly dispersed in the matrix. When subjected to external force, it can absorb external energy as stress concentration points, thereby improving the mechanical properties of the material.

[0020] Step (4): Add 10 g of product A, 11 g of tridecafluorooctanol, 0.04 g of p-toluenesulfonic acid, and 0.1 g of hydroquinone into toluene solvent, heat up to 110 °C, and react for 10 h. After the reaction, neutralize and wash with 5% sodium hydroxide solution by mass, wash with deionized water, dry the organic layer, and rotary evaporate. The obtained product is denoted as dithiol tridecafluorooctyl ester.

[0021] Step (5): Under a nitrogen atmosphere, dissolve 50 g of polyvinyl chloride powder in cyclohexanone solvent, add 5 g of dithiol geranyl ester, 5 g of dithiol nano silver-loaded titanium dioxide, 5 g of dithiol tridecafluorooctyl ester, and 40 g of potassium carbonate into it, react at 65 °C for 26 h. After the reaction, add a methanol aqueous solution with a volume fraction of 67% into it, stir evenly, and dry. Then dissolve it in tetrahydrofuran, adjust the pH to 4 with hydrochloric acid, precipitate with methanol, and dry to obtain modified polyvinyl chloride. In this process, one mercapto group in the structure reacts with the chlorine atom in the PVC molecular chain to generate chemical bonds, and the other mercapto group reacts with the chlorine atom in other molecular chains to further generate chemical bonds, increasing the degree of chemical cross-linking between molecular chains and improving the cross-linking density.

[0022] Step (6): Add 100 g of polyvinyl chloride, 50 g of modified polyvinyl chloride, 5 g of calcium-zinc composite stabilizer, 0.5 g of stearic acid, 1 g of polyethylene wax, 6 g of chlorinated polyethylene, and 5 g of dioctyl phthalate into the extruder barrel, and extrude into a thin sheet at 185 °C. Through a tablet press and a sample preparation machine, an antibacterial and waterproof composite board is obtained. Example 2

[0023] Step (1): Add 7 g of mercaptopropionic acid into toluene solvent, then add 10 g of 2,2-dimethylolpropionic acid and 0.17 g of hypophosphorous acid catalyst into it, control the temperature at 100 °C, and react for 10 h. After the reaction, let it stand and distill under reduced pressure. The obtained product is denoted as product A.

[0024] Step (2): Add 10 g of product A into dichloromethane solvent, stir and disperse evenly, then add 5 g of geraniol and 7 g of triethylamine thereto, react at room temperature for 14 h. After the reaction is completed, wash successively with hydrochloric acid with a volume fraction of 5%, saturated sodium bicarbonate and brine until the pH is 7. Use anhydrous sodium sulfate to dry the organic phase, evaporate the solvent, and the obtained product is denoted as bis-mercapto geranyl ester.

[0025] Step (3): Add 2 g of nano silver-loaded titanium dioxide into deionized water, disperse by ultrasonic wave, then add 14 g of product A thereto, react with stirring at 85 °C for 2 h. After the reaction is completed, centrifuge, wash with deionized water, and dry. The obtained product is denoted as bis-mercapto nano silver-loaded titanium dioxide.

[0026] Step (4): Add 10 g of product A, 11 g of tridecafluorooctanol, 0.05 g of p-toluenesulfonic acid, and 0.2 g of hydroquinone into toluene solvent, heat up to 100 °C, react for 10 h. After the reaction is completed, neutralize and wash with a sodium hydroxide solution with a mass fraction of 5%, wash with deionized water, dry the organic layer, and rotary evaporate. The obtained product is denoted as bis-mercapto tridecafluorooctyl ester.

[0027] Step (5): Under a nitrogen atmosphere, dissolve 50 g of polyvinyl chloride powder in cyclohexanone solvent, add 6 g of bis-mercapto geranyl ester, 7 g of bis-mercapto nano silver-loaded titanium dioxide, 6 g of bis-mercapto tridecafluorooctyl ester, and 45 g of potassium carbonate thereto, react at 65 °C for 24 h. After the reaction is completed, add a methanol aqueous solution with a volume fraction of 67%, stir evenly, dry, then dissolve it in tetrahydrofuran, adjust the pH to 4 with hydrochloric acid, precipitate with methanol, and dry to obtain modified polyvinyl chloride.

[0028] Step (6): Add 100 g of polyvinyl chloride, 60 g of modified polyvinyl chloride, 6 g of calcium-zinc composite stabilizer, 1 g of stearic acid, 0.8 g of polyethylene wax, 8 g of chlorinated polyethylene, and 3 g of dioctyl phthalate into the barrel of an extruder, extrude into a thin sheet at 180 °C, and obtain an antibacterial and waterproof composite board through a tablet press and a sample making machine. Example 3

[0029] Step (1): Add 10 g of mercaptopropionic acid into toluene solvent, then add 10 g of 2,2-dimethylolpropionic acid, 0.1 g of hypophosphorous acid, and 0.1 g of p-toluenesulfonic acid thereto, control the temperature at 110 °C, react for 6 h. After the reaction is completed, let it stand and distill under reduced pressure. The obtained product is denoted as product A.

[0030] Step (2): Add 10 g of product A into dichloromethane solvent, stir and disperse evenly, then add 6 g of geraniol and 6 g of triethylamine thereto. React at room temperature for 12 h. After the reaction is completed, wash successively with 5% (by volume) hydrochloric acid, saturated sodium bicarbonate and brine until the pH is 7. Dry the organic phase with anhydrous sodium sulfate, evaporate the solvent, and the obtained product is denoted as dithiol geranyl ester.

[0031] Step (3): Add 2 g of silver-loaded titanium dioxide nanoparticles into deionized water, disperse ultrasonically, then add 18 g of product A thereto. React with stirring at 95 °C for 2 h. After the reaction is completed, centrifuge, wash with deionized water, and dry. The obtained product is denoted as dithiol silver-loaded titanium dioxide nanoparticles.

[0032] Step (4): Add 10 g of product A, 12 g of tridecafluorooctanol, 0.06 g of p-toluenesulfonic acid, and 0.1 g of hydroquinone into toluene solvent. Heat up to 105 °C and react for 8 h. After the reaction is completed, neutralize with 5% (by mass) sodium hydroxide solution, wash with water, wash with deionized water, dry the organic layer, and rotary evaporate. The obtained product is denoted as dithiol tridecafluorooctyl ester.

[0033] Step (5): Under a nitrogen atmosphere, dissolve 50 g of polyvinyl chloride powder in cyclohexanone solvent, add 8 g of dithiol geranyl ester, 8 g of dithiol silver-loaded titanium dioxide nanoparticles, 8 g of dithiol tridecafluorooctyl ester, and 50 g of potassium carbonate thereto. React at 55 °C for 30 h. After the reaction is completed, add 67% (by volume) methanol aqueous solution thereto, stir evenly, and dry. Then dissolve it in tetrahydrofuran, adjust the pH to 4 with hydrochloric acid, precipitate with methanol, and dry to obtain modified polyvinyl chloride.

[0034] Step (6): Add 100 g of polyvinyl chloride, 70 g of modified polyvinyl chloride, 6 g of calcium-zinc composite stabilizer, 0.7 g of stearic acid, 0.8 g of polyethylene wax, 8 g of chlorinated polyethylene, and 3 g of dioctyl phthalate into the barrel of an extruder, and extrude into a thin sheet at 180 °C. Pass through a tablet press and a sample making machine to obtain an antibacterial and waterproof composite board. Example 4

[0035] Step (1): Add 10 g of mercaptopropionic acid into toluene solvent, then add 10 g of 2,2-dimethylolpropionic acid and 0.2 g of hypophosphorous acid catalyst thereto. Control the temperature at 105 °C and react for 8 h. After the reaction is completed, let it stand and distill under reduced pressure. The obtained product is denoted as product A.

[0036] Step (2): Add 10 g of product A into dichloromethane solvent, stir and disperse evenly, then add 6 g of geraniol and 6 g of triethylamine into it. React at room temperature for 15 h. After the reaction is completed, wash it successively with 5% (volume fraction) hydrochloric acid, saturated sodium bicarbonate and brine until the pH is 7. Use anhydrous sodium sulfate to dry the organic phase, evaporate the solvent, and the obtained product is denoted as bis-mercapto geranyl ester.

[0037] Step (3): Add 2 g of nano silver-loaded titanium dioxide into deionized water, disperse it by ultrasonic wave, then add 20 g of product A into it. React with stirring at 80 °C for 3 h. After the reaction is completed, centrifuge, wash with deionized water, and dry. The obtained product is denoted as bis-mercapto nano silver-loaded titanium dioxide.

[0038] Step (4): Add 10 g of product A, 13 g of tridecafluorooctanol, 0.06 g of p-toluenesulfonic acid, and 0.1 g of hydroquinone into toluene solvent, heat up to 100 °C, and react for 12 h. After the reaction is completed, neutralize and wash with 5% (mass fraction) sodium hydroxide solution, wash with deionized water, dry the organic layer, and rotary evaporate. The obtained product is denoted as bis-mercapto tridecafluorooctyl ester.

[0039] Step (5): Under a nitrogen atmosphere, dissolve 50 g of polyvinyl chloride powder in cyclohexanone solvent, add 10 g of bis-mercapto geranyl ester, 10 g of bis-mercapto nano silver-loaded titanium dioxide, 10 g of bis-mercapto tridecafluorooctyl ester, and 40 g of potassium carbonate into it. React at 60 °C for 30 h. After the reaction is completed, add 67% (volume fraction) methanol aqueous solution into it, stir evenly, and dry. Then dissolve it in tetrahydrofuran, adjust the pH to 4 with hydrochloric acid, precipitate with methanol, and dry to obtain modified polyvinyl chloride.

[0040] Step (6): Add 100 g of polyvinyl chloride, 80 g of modified polyvinyl chloride, 8 g of calcium-zinc composite stabilizer, 0.8 g of stearic acid, 0.6 g of polyethylene wax, 5 g of chlorinated polyethylene, and 4 g of dioctyl phthalate into the barrel of the extruder, and extrude into a thin sheet at 190 °C. Through a tablet press and a sample making machine, an antibacterial and waterproof composite board is prepared.

[0041] Comparative Example 1 The difference between this comparative example and Example 1 is that: bis-mercapto geranyl ester is not contained in step (5).

[0042] Comparative Example 2 The difference between this comparative example and Example 1 is that: bis-mercapto nano silver-loaded titanium dioxide is not contained in step (5).

[0043] Comparative Example 3 The difference between this comparative example and Example 1 is that: bis-mercapto tridecafluorooctyl ester is not contained in step (5).

[0044] Refer to GB / T 1040.1-2006 to test the tensile properties of the sheet, and the tensile speed is 2 mm / min.

[0045] Refer to QB / T 2591-2003 to test the antibacterial properties of the sheet, and the test strain is Escherichia coli.

[0046] Table 1: Tensile strength / MPa Antibacterial rate / % Example 1 23.9 85.8 Example 2 25.0 91.1 Example 3 28.9 98.4 Example 4 27.8 99.9 Comparative Example 1 22.1 77.6 Comparative Example 2 19.4 75.4 Comparative Example 3 21.6 85.4 It can be seen from Example 1 and Comparative Examples 1-3 that the mechanical properties of the composite containing dithiol geranyl ester, dithiol silver-loaded titanium dioxide nanoparticles, and dithiol perfluorooctyl ester are better, and as the dosage of the three increases, the mechanical properties increase. This is because it contains physical-chemical crosslinking sites and uniformly dispersed inorganic nanomaterials. Therefore, the composite sheet prepared by the present invention has excellent mechanical properties.

[0047] Comparative Example 1 does not contain dithiol geranyl ester, and dithiol geranyl ester contains an antibacterial structure. Comparative Example 2 does not contain dithiol silver-loaded titanium dioxide nanoparticles, and dithiol silver-loaded titanium dioxide nanoparticles have a dual antibacterial structure. Comparative Example 3 does not contain dithiol perfluorooctyl ester, and contains dithiol geranyl ester and dithiol silver-loaded titanium dioxide nanoparticles. Therefore, the antibacterial effect of Comparative Example 3 is higher than that of Comparative Example 1 and Comparative Example 2. It can be seen from Examples 1-4 that as the dosage of the antibacterial structure increases, the antibacterial rate increases, and the highest antibacterial rate can reach 99.9%.

[0048] According to ISO 15989-2004, test the contact angle of the sheet.

[0049] Table 2: Contact angle / ° Example 1 108.7 Example 2 112.6 Example 3 117.4 Example 4 119.0 Comparative Example 1 101.4 Comparative Example 2 104.7 Comparative Example 3 98.7 The larger the contact angle, the better the hydrophobicity. It can be seen from the table that the sheet prepared by the present invention has excellent hydrophobic and waterproof effects.

[0050] The above content is only an example and explanation of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution. As long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should fall within the protection scope of the present invention.

Claims

1. A method for preparing an antibacterial and waterproof composite board, characterized in that: The preparation method comprises the following steps: Step (1), adding mercaptopropionic acid to toluene solvent, and then adding 2,2-dihydroxymethylpropionic acid and a catalyst thereto, controlling the temperature to 100-110° C., reacting for 6-10 hours, and after the reaction is completed, standing, and distilling under reduced pressure, the obtained product is recorded as product A; Step (2), adding nano silver-loaded titanium dioxide to deionized water, ultrasonically dispersing, then adding product A thereto, stirring and reacting at 80-95° C. for 1-3 hours, centrifuging after the reaction, washing with deionized water, and drying. The obtained product is recorded as bis-thiol nano silver-loaded titanium dioxide; Step (3), under a nitrogen atmosphere, dissolving polyvinyl chloride powder in cyclohexanone solvent, adding dithiocarbazol geranyl ester, dithiocarbazol nano silver-loaded titanium dioxide, dithiocarbazol tridecafluorooctyl ester and potassium carbonate thereto, reacting at 55-65° C. for 24-30 hours, adding a 67% by volume methanol aqueous solution thereto after the reaction, stirring evenly, drying, and then adding it to tetrahydrofuran to dissolve, adjusting the pH to 4 with hydrochloric acid, precipitating with methanol, and drying to obtain modified polyvinyl chloride; Step (4), adding polyvinyl chloride, modified polyvinyl chloride, calcium zinc composite stabilizer, stearic acid, polyethylene wax, chlorinated polyethylene, and dioctyl phthalate into the extruder barrel, extruding a thin sheet at 180-190° C., and passing through a tablet press and a sample making machine to obtain an antibacterial and waterproof composite sheet.

2. The method for preparing the antibacterial and waterproof composite board according to claim 1, characterized in that: In the step (1), the mass ratio of mercaptopropionic acid to 2,2-dihydroxymethylpropionic acid is 0.7-1:

1.

3. The method for preparing the antibacterial and waterproof composite board according to claim 1, characterized in that: In the step (1), the catalyst is any one or more of hypophosphorous acid and p-toluenesulfonic acid, and the amount used is 1-3% of the total mass of mercaptopropionic acid and 2,2-dihydroxymethylpropionic acid.

4. The method for preparing the antibacterial and waterproof composite board according to claim 1, characterized in that: In the step (2), the mass ratio of nano silver-loaded titanium dioxide to product A is 1:5-10.

5. The method for preparing the antibacterial and waterproof composite board according to claim 1, characterized in that: In the step (3), the mass ratio of polyvinyl chloride powder, bismercaptogeranyl ester, bismercapto nano silver-loaded titanium dioxide, bismercapto tridecafluorooctyl ester and potassium carbonate is 1:0.1-0.2:0.1-0.2:0.1-0.2:0.8-1.

6. The method for preparing the antibacterial and waterproof composite board according to claim 1, characterized in that: In the step (4), the mass ratio of polyvinyl chloride, modified polyvinyl chloride, calcium zinc composite stabilizer, stearic acid, polyethylene wax, chlorinated polyethylene, and dioctyl phthalate is 100:50-80:5-8:0.5-1:0.6-1:5-8:3-5.

7. The method for preparing the antibacterial and waterproof composite board according to claim 1, characterized in that: In the step (3), the preparation method of bis-mercaptogeranyl ester comprises the following steps: adding product A to a dichloromethane solvent, stirring and dispersing the product evenly, adding geraniol and triethylamine thereto, reacting at room temperature for 12-16 hours, and after the reaction is completed, washing with 5% by volume hydrochloric acid, saturated sodium bicarbonate and brine in sequence until the pH value is 7, drying the organic phase with anhydrous sodium sulfate, and evaporating the solvent. The obtained product is recorded as bis-mercaptogeranyl ester.

8. The method for preparing the antibacterial and waterproof composite board according to claim 7, characterized in that: The mass ratio of the product A, geraniol and triethylamine is 1:0.5-0.6:0.6-0.

8.

9. The method for preparing the antibacterial and waterproof composite board according to claim 1, characterized in that: In the step (3), the preparation method of bis(thio)thridecafluorooctyl ester comprises the following steps: adding product A, tridecafluorooctanol, p-toluenesulfonic acid and hydroquinone to a toluene solvent, heating to 100-110° C., reacting for 8-12 hours, and after the reaction, neutralizing with a 5% by mass sodium hydroxide solution and washing with water, washing with deionized water, drying the organic layer, and rotary evaporating. The obtained product is recorded as bis(thio)thridecafluorooctyl ester.

10. The method for preparing the antibacterial and waterproof composite board according to claim 9, characterized in that: The mass ratio of the product A, tridecafluorooctanol, p-toluenesulfonic acid and hydroquinone is 1:1.1-1.3:0.004-0.006:0.01-0.02.

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