Method for preparing antibacterial and waterproof composite board

Abstract

The invention relates to the technical field of plates and discloses a method for preparing an antibacterial and waterproof composite plate. The method uses mercaptopropionic acid and 2,2-dihydroxymethylpropionic acid as raw materials to prepare a product A, which is reacted with geraniol, nano-silver-loaded titanium dioxide, and tridecafluorooctanol in sequence to obtain bismercaptogeranyl ester, bismercapto nano-silver-loaded titanium dioxide, and bismercapto tridecafluorooctyl ester. The three products are added to polyvinyl chloride for reaction to obtain modified polyvinyl chloride, and the modified polyvinyl chloride is finally added to polyvinyl chloride, chlorinated polyethylene, and dioctyl phthalate and mixed uniformly to obtain an antibacterial and waterproof composite plate. The prepared composite plate has excellent antibacterial properties, waterproof properties, and mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of boards, and in particular to a method for preparing an antibacterial and waterproof composite board. Background Art

[0002] Polyvinyl chloride (PVC) is a polymer obtained by the free polymerization reaction of vinyl chloride monomer under the initiation of an initiator. It has properties such as chemical corrosion resistance, flame retardancy, and waterproofness. Therefore, it is often used as a sheet material in bathrooms, flooring and other fields. However, it is prone to bacterial growth when used in a humid environment for a long time, and prolonged contact with water will cause the material to swell or rot. Traditional PVC sheet materials can no longer meet existing needs.

[0003] Geraniol, also known as geraniol and geranyl alcohol, is an acyclic isoprenoid monoterpenoid substance and a natural plant-derived alcohol with a sweet rose scent. It is one of the main components of martin oil, citronella oil and rose essential oil. It has the effects of inhibiting bacteria and mold and treating chronic bronchitis. It is widely used in food, medicine, cosmetics and other fields. However, geraniol is volatile and unstable when heated at high temperatures, which limits its application effect.

[0004] For example, patent application publication number CN 119505443 A discloses a highly antibacterial PVC sheet and its preparation method. This invention uses PVC resin, a multi-effect antibacterial agent, a lubricant, and the like as raw materials. The resulting PVC sheet has good antibacterial and heat-resistant properties. However, the PVC sheet produced by this method is prone to swelling and rotting in a humid environment, affecting the service life of the PVC sheet and human health and safety.

[0005] Therefore, the present invention provides a method for preparing an antibacterial and waterproof composite board. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides a method for preparing an antibacterial and waterproof composite board. The composite board prepared by the method has excellent antibacterial properties, waterproof properties and mechanical properties.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A method for preparing an antibacterial and waterproof composite board, comprising the following steps:

[0009] Step (1): adding mercaptopropionic acid to a toluene solvent, and then adding 2,2-dimethylolpropionic 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, wherein 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 and the hydroxyl group contained in 2,2-dimethylolpropionic acid are subjected to esterification reaction to obtain product A. The reaction route is:

[0010] ;

[0011] 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 1-3h, centrifuging after the reaction, washing with deionized water, and drying. The obtained product is recorded as bis-thiol nano silver-loaded titanium dioxide, wherein the mass ratio of nano silver-loaded titanium dioxide to product A is 1:5-10. In this reaction, the hydroxyl groups contained on the surface of the nano silver-loaded titanium dioxide react with the carboxyl groups in the product A to disperse the nano silver-loaded titanium dioxide, reduce the degree of agglomeration, and improve its compatibility with organic matter to obtain bis-thiol nano silver-loaded titanium dioxide. Titanium dioxide, when introduced into the material, can not only improve the antibacterial properties of the material by utilizing the dual antibacterial effects of silver ions and photocatalysts, but also, silver-loaded nano-titanium dioxide is uniformly dispersed in the material as inorganic particles. When subjected to external impact, it can act as a stress concentration point, causing an increase in the three-dimensional axial stress around the particles, thereby causing the peeling of the interface between the particles and the matrix. This peeling will cause the generation of cavities, resulting in changes in the stress conditions around the cavities and generating shear stress. This shear stress will absorb the impact force, thereby improving the mechanical properties of the material. The reaction route is:

[0012] ;in It is nano-silver-loaded titanium dioxide.

[0013] Step (3), under nitrogen atmosphere, dissolving polyvinyl chloride powder in cyclohexanone solvent, adding dithiocarbamate, dithiocarbamate nano-silver-loaded titanium dioxide, dithiocarbamate tridecafluorooctyl ester and potassium carbonate thereto, reacting at 55-65°C for 24-30h, adding methanol aqueous solution with a volume fraction of 67% thereto, stirring evenly, drying, and then adding it to tetrahydrofuran to dissolve, adjusting the pH to 4 with hydrochloric acid, methanol precipitating, and drying to obtain modified polyvinyl chloride. During this reaction process, dithiocarbamate, dithiocarbamate nano-silver-loaded titanium dioxide and dithiocarbamate tridecafluorooctyl ester are introduced into the polyvinyl chloride macromolecular chain through the nucleophilic reaction of the thiol contained in dithiocarbamate, dithiocarbamate nano-silver-loaded titanium dioxide and dithiocarbamate tridecafluorooctyl ester with the chlorine atom of polyvinyl chloride. Firstly, one of the thiol groups in the dithiocarbamate structure of the three reacts with the chlorine atom in the PVC molecular chain to produce a chemical bond, and the other thiol group reacts with the other molecular chain. The chlorine atoms in the PVC react to further produce chemical bonds, thereby increasing the degree of chemical crosslinking between the molecular chains. Secondly, bis-mercaptogeranyl ester, bis-mercapto nano-silver-loaded titanium dioxide, and bis-mercapto tridecafluorooctyl ester contain more ester structures, in which the carbonyl oxygen can interact with the methylene hydrogen in the PVC segment to produce hydrogen bonds, further strengthening the degree of chemical crosslinking. Thirdly, since bis-mercaptogeranyl ester, bis-mercapto nano-silver-loaded titanium dioxide, and bis-mercapto tridecafluorooctyl ester contain branched structures, they can entangle with the main chain and other branched chains to produce 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 large number of crosslinking structures it contains, the density of the material can be increased, thereby improving the waterproof performance of the material.

[0014] 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 thin sheets at 180-190° C., and passing through a tablet press and a sample making machine to obtain an antibacterial and waterproof composite board.

[0015] Further preferably, in the step (1), the catalyst is any one or more of hypophosphorous acid and p-toluenesulfonic acid, and the amount thereof is 1-3% of the total mass of mercaptopropionic acid and 2,2-dihydroxymethylpropionic acid.

[0016] Further preferably, 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.

[0017] Further preferably, in 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.

[0018] Further preferably, in the step (3), the preparation method of bismercaptogeranyl ester comprises the following steps: adding product A to dichloromethane solvent, stirring and dispersing uniformly, then adding geraniol and triethylamine thereto, reacting at room temperature for 12-16 hours, after the reaction is completed, washing with 5% by volume hydrochloric acid, saturated sodium bicarbonate and saline solution to a pH of 7, drying the organic phase with anhydrous sodium sulfate, and evaporating the solvent. The obtained product is recorded as bismercaptogeranyl ester, wherein the product A, geraniol and triethylamine are The mass ratio is 1:0.5-0.6:0.6-0.8. Under the catalysis of triethylamine, the carboxyl group contained in product A and the hydroxyl group contained in geraniol are used to undergo an esterification reaction to obtain bismercaptogeranyl ester, which is then introduced into PVC materials. On the one hand, since geraniol itself is volatile, grafting it to the long chain of PVC molecules in the form of a chemical bond can reduce volatility and increase the antibacterial durability of geraniol. On the other hand, the mechanical properties are improved by utilizing the branched structure and ester group contained in it. The reaction route is:

[0019] ;

[0020] Further preferably, the preparation method of the bis(thio)thiafluorooctyl 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 and washing with a 5% mass fraction sodium hydroxide solution, washing with deionized water, drying the organic layer, and rotary evaporation. The obtained product is recorded as bis(thio)thiafluorooctyl ester, wherein 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 the product A reacts with the hydroxyl group contained in the tridecafluorooctanol to obtain bis(thio)thiafluorooctyl ester. Utilizing the lower surface energy of the fluorine element, its introduction into the PVC material can improve the hydrophobic and waterproof properties of the material. The reaction route is:

[0021] .

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention uses geraniol, which has antibacterial properties, as a raw material to prepare bis-mercaptogeranyl ester, which is introduced into the material, not only improving the antibacterial properties of the material but also reducing the volatility of geraniol. The present invention uses silver-loaded nano-titanium dioxide with dual antibacterial effects as a raw material to prepare bis-mercapto nano-silver-loaded titanium dioxide. Due to the use of geraniol and silver-loaded nano-titanium dioxide, the two can synergistically improve the antibacterial properties of the material.

[0024] (2) The present invention uses tridecafluorooctanol as a raw material to prepare dithiothiothiothioate, and introduces the fluorine-containing long chain with low surface energy into the material, which can not only improve the hydrophobic and waterproof effect of the material, but also use the long chain structure therein to generate physical crosslinking with other long chain structures and the main chain structure; the dithiothiogeranyl ester, dithiothio nano silver-loaded titanium dioxide, and dithiothiothiotride prepared by the present invention contain a dithio structure, which reacts with the chlorine atoms in the PVC molecular chain to generate chemical crosslinking and form a physical-chemical crosslinking structure with a high crosslinking density. Firstly, due to its dense structure, it can improve the hydrophobic and waterproof effect of the material. Secondly, it generates more physical crosslinking sites and chemical crosslinking sites. When subjected to external impact, the impact energy can be dispersed along the crosslinking sites to other molecular chains, thereby improving the mechanical properties of the material. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention. Example 1

[0026] Step (1): add 10 g of mercaptopropionic acid to a toluene solvent, then add 10 g of 2,2-dihydroxymethylpropionic acid and 0.2 g of p-toluenesulfonic acid catalyst thereto, control the temperature to 105°C, react for 10 h, and after the reaction is completed, let it stand and perform vacuum distillation. The obtained product is recorded as product A.

[0027] Step (2): 10 g of product A was added to dichloromethane solvent, stirred and dispersed uniformly, and then 5 g of geraniol and 8 g of triethylamine were added thereto. The mixture was reacted at room temperature for 16 h. After the reaction was completed, the mixture was washed with 5% by volume hydrochloric acid, saturated sodium bicarbonate and brine in sequence until the pH was 7. The organic phase was dried with anhydrous sodium sulfate, and the solvent was evaporated. The obtained product was recorded as bismercaptogeranyl ester.

[0028] Step (3): 2 g of nano silver-loaded titanium dioxide was added to deionized water and ultrasonically dispersed. Then, 10 g of product A was added thereto. The mixture was stirred and reacted at 85° C. for 1 h. After the reaction was completed, the mixture was centrifuged, washed with deionized water, and dried. The obtained product was recorded as dithiol nano silver-loaded titanium dioxide. Introducing it into the material can not only improve the antibacterial properties of the material, but also disperse the silver-loaded nano titanium dioxide. On the other hand, the silver-loaded nano titanium dioxide is used as an inorganic nanoparticle to be uniformly dispersed in the matrix. When subjected to external force, it can act as a stress concentration point to absorb external energy, thereby improving the mechanical properties of the material.

[0029] Step (4): 10 g of product A, 11 g of tridecafluorooctanol, 0.04 g of p-toluenesulfonic acid, and 0.1 g of hydroquinone were added to a toluene solvent, heated to 110° C., and reacted for 10 h. After the reaction, the mixture was neutralized with a 5% by mass sodium hydroxide solution and washed with water, then washed with deionized water. The organic layer was dried and rotary evaporated. The obtained product was recorded as bis(thiol)tridecafluorooctyl ester.

[0030] Step (5), under a nitrogen atmosphere, dissolve 50g of polyvinyl chloride powder in cyclohexanone solvent, add 5g of bis-mercaptogeranyl ester, 5g of bis-mercapto nano-silver-loaded titanium dioxide, 5g of bis-mercapto tridecafluorooctyl ester, and 40g of potassium carbonate thereto, react at 65°C for 26h, and after the reaction is completed, add a 67% volume fraction methanol aqueous solution thereto, stir evenly, dry, and then add it to tetrahydrofuran to dissolve, adjust the pH to 4 with hydrochloric acid, precipitate with methanol, and dry to obtain modified polyvinyl chloride. During this process, one thiol group in the structure reacts with the chlorine atoms in the PVC molecular chain to produce a chemical bond, and the other thiol group reacts with the chlorine atoms in other molecular chains to further produce a chemical bond, thereby increasing the degree of chemical crosslinking between the molecular chains and improving the crosslinking density.

[0031] Step (6): 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 are added to the extruder barrel, and thin sheets are extruded at 185° C. The sheets are passed through a tablet press and a sample making machine to obtain an antibacterial and waterproof composite board. Example 2

[0032] Step (1): 7 g of mercaptopropionic acid was added to a toluene solvent, and then 10 g of 2,2-dihydroxymethylpropionic acid and 0.17 g of hypophosphorous acid catalyst were added thereto. The temperature was controlled at 100° C. and the reaction was carried out for 10 h. After the reaction was completed, the mixture was allowed to stand and distilled under reduced pressure. The obtained product was recorded as product A.

[0033] Step (2): 10 g of product A was added to dichloromethane solvent, stirred and dispersed uniformly, and then 5 g of geraniol and 7 g of triethylamine were added thereto. The mixture was reacted at room temperature for 14 h. After the reaction was completed, the mixture was washed with 5% by volume hydrochloric acid, saturated sodium bicarbonate and brine in sequence until the pH was 7. The organic phase was dried with anhydrous sodium sulfate, and the solvent was evaporated. The obtained product was recorded as bismercaptogeranyl ester.

[0034] Step (3): 2 g of nano silver-loaded titanium dioxide was added to deionized water and ultrasonically dispersed. Then, 14 g of product A was added thereto. The mixture was stirred and reacted at 85° C. for 2 h. After the reaction was completed, the mixture was centrifuged, washed with deionized water, and dried. The obtained product was recorded as bisthiol nano silver-loaded titanium dioxide.

[0035] Step (4): 10 g of product A, 11 g of tridecafluorooctanol, 0.05 g of p-toluenesulfonic acid, and 0.2 g of hydroquinone were added to a toluene solvent, heated to 100° C., and reacted for 10 h. After the reaction, the mixture was neutralized with a 5% by mass sodium hydroxide solution and washed with water, then washed with deionized water. The organic layer was dried and rotary evaporated. The obtained product was recorded as bis(thiol)tridecafluorooctyl ester.

[0036] Step (5), under a nitrogen atmosphere, dissolve 50g of polyvinyl chloride powder in cyclohexanone solvent, add 6g of bismercaptogeranyl ester, 7g of bismercapto nano-silver-loaded titanium dioxide, 6g of bismercaptotridecafluorooctyl ester, and 45g of potassium carbonate thereto, react at 65°C for 24h, and after the reaction is completed, add a 67% by volume methanol aqueous solution thereto, stir evenly, dry, and then add it to tetrahydrofuran to dissolve, adjust the pH to 4 with hydrochloric acid, precipitate with methanol, and dry to obtain modified polyvinyl chloride.

[0037] Step (6): 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 are added to the extruder barrel, and thin sheets are extruded at 180° C., and the sheets are passed through a tablet press and a sample making machine to obtain an antibacterial and waterproof composite board. Example 3

[0038] Step (1): add 10 g of mercaptopropionic acid to a toluene solvent, and then add 10 g of 2,2-dihydroxymethylpropionic acid, 0.1 g of hypophosphorous acid, and 0.1 g of p-toluenesulfonic acid thereto. Control the temperature to 110° C. and react for 6 h. After the reaction is completed, let it stand and perform vacuum distillation. The obtained product is recorded as product A.

[0039] Step (2): 10 g of product A was added to dichloromethane solvent, stirred and dispersed uniformly, and then 6 g of geraniol and 6 g of triethylamine were added thereto. The mixture was reacted at room temperature for 12 h. After the reaction was completed, the mixture was washed with 5% by volume hydrochloric acid, saturated sodium bicarbonate and brine in sequence until the pH was 7. The organic phase was dried with anhydrous sodium sulfate, and the solvent was evaporated. The obtained product was recorded as bismercaptogeranyl ester.

[0040] Step (3): 2 g of nano silver-loaded titanium dioxide was added to deionized water and ultrasonically dispersed. Then, 18 g of product A was added thereto. The mixture was stirred and reacted at 95° C. for 2 h. After the reaction was completed, the mixture was centrifuged, washed with deionized water, and dried. The obtained product was recorded as bisthiol nano silver-loaded titanium dioxide.

[0041] Step (4): 10 g of product A, 12 g of tridecafluorooctanol, 0.06 g of p-toluenesulfonic acid, and 0.1 g of hydroquinone were added to a toluene solvent, heated to 105° C., and reacted for 8 h. After the reaction, the mixture was neutralized with a 5% by mass sodium hydroxide solution and washed with water, then washed with deionized water. The organic layer was dried and rotary evaporated. The obtained product was recorded as dithiothiafluorooctyl ester.

[0042] Step (5), under a nitrogen atmosphere, dissolve 50g of polyvinyl chloride powder in cyclohexanone solvent, add 8g of bis-mercaptogeranyl ester, 8g of bis-mercapto nano-silver-loaded titanium dioxide, 8g of bis-mercapto tridecafluorooctyl ester, and 50g of potassium carbonate thereto, react at 55°C for 30h, after which a 67% by volume methanol aqueous solution is added thereto, stirred evenly, dried, and then added to tetrahydrofuran to dissolve, hydrochloric acid adjusted to pH 4, methanol precipitated, and dried to obtain modified polyvinyl chloride.

[0043] Step (6): 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 are added to the extruder barrel, and thin sheets are extruded at 180° C. The sheets are passed through a tablet press and a sample making machine to obtain an antibacterial and waterproof composite board. Example 4

[0044] Step (1): add 10 g of mercaptopropionic acid to a toluene solvent, then add 10 g of 2,2-dihydroxymethylpropionic acid and 0.2 g of hypophosphorous acid catalyst thereto, control the temperature to 105°C, react for 8 h, and after the reaction is completed, let it stand and perform vacuum distillation. The obtained product is recorded as product A.

[0045] Step (2): 10 g of product A was added to a dichloromethane solvent and stirred to disperse uniformly. 6 g of geraniol and 6 g of triethylamine were then added thereto. The mixture was reacted at room temperature for 15 h. After the reaction, the mixture was washed with 5% by volume hydrochloric acid, saturated sodium bicarbonate, and brine to a pH of 7. The organic phase was dried with anhydrous sodium sulfate, and the solvent was evaporated. The obtained product was recorded as bismercaptogeranyl ester.

[0046] Step (3): 2 g of nano silver-loaded titanium dioxide was added to deionized water and ultrasonically dispersed. Then, 20 g of product A was added thereto. The mixture was stirred and reacted at 80° C. for 3 h. After the reaction was completed, the mixture was centrifuged, washed with deionized water, and dried. The obtained product was recorded as bisthiol nano silver-loaded titanium dioxide.

[0047] Step (4): 10 g of product A, 13 g of tridecafluorooctanol, 0.06 g of p-toluenesulfonic acid, and 0.1 g of hydroquinone were added to a toluene solvent, heated to 100° C., and reacted for 12 h. After the reaction, the mixture was neutralized with a 5% by mass sodium hydroxide solution and washed with water, then washed with deionized water. The organic layer was dried and rotary evaporated. The obtained product was recorded as dithiothiafluorooctyl ester.

[0048] Step (5), under a nitrogen atmosphere, dissolve 50g of polyvinyl chloride powder in cyclohexanone solvent, add 10g of bis-mercaptogeranyl ester, 10g of bis-mercapto nano-silver-loaded titanium dioxide, 10g of bis-mercapto tridecafluorooctyl ester, and 40g of potassium carbonate thereto, react at 60°C for 30h, after which a 67% by volume methanol aqueous solution is added thereto, stirred evenly, dried, and then added to tetrahydrofuran to dissolve, hydrochloric acid adjusted to pH 4, methanol precipitated, and dried to obtain modified polyvinyl chloride.

[0049] Step (6): 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 are added to the extruder barrel, and thin sheets are extruded at 190° C. The antibacterial and waterproof composite board is prepared by a tablet press and a sample making machine.

[0050] Comparative Example 1

[0051] The difference between this comparative example and Example 1 is that step (5) does not contain bismercaptogeranyl ester.

[0052] Comparative Example 2

[0053] The difference between this comparative example and Example 1 is that step (5) does not contain bis-mercapto nano-silver-loaded titanium dioxide.

[0054] Comparative Example 3

[0055] The difference between this comparative example and Example 1 is that step (5) does not contain bis(thio)thridecafluorooctyl ester.

[0056] With reference to GB / T1040.1-2006, the tensile properties of the plate were tested at a tensile speed of 2 mm / min.

[0057] Refer to QB / T2591-2003 to test the antibacterial properties of the board, and the test bacteria is Escherichia coli.

[0058] Table 1:

[0059] 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

[0060] It can be seen from Example 1 and Comparative Examples 1-3 that the mechanical properties of the composite board containing bismercaptogeranyl ester, bismercapto nano-silver-loaded titanium dioxide, and bismercapto tridecafluorooctyl ester are better, and as the amount of the three increases, the mechanical properties increase. This is because they contain physical-chemical crosslinking sites and uniformly dispersed inorganic nanomaterials. Therefore, the composite board prepared by the present invention has excellent mechanical properties.

[0061] Comparative Example 1 does not contain bismercaptogeranyl, but bismercaptogeranyl contains an antibacterial structure. Comparative Example 2 does not contain bismercapto nano-silver-loaded titanium dioxide, but bismercapto nano-silver-loaded titanium dioxide has a dual antibacterial structure. Comparative Example 3 does not contain bismercaptotridecylfluorooctyl but contains bismercaptogeranyl and bismercapto nano-silver-loaded titanium dioxide. Therefore, the antibacterial effect of Comparative Example 3 is higher than that of Comparative Examples 1 and 2. As can be seen from Examples 1-4, as the amount of the antibacterial structure increases, the antibacterial rate increases, and the antibacterial rate can reach up to 99.9%.

[0062] According to ISO15989-2004, the contact angle of the plate was tested.

[0063] Table 2:

[0064] 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

[0065] The larger the contact angle, the better the hydrophobicity. It can be seen from the table that the plate prepared by the present invention has excellent hydrophobic and waterproof effects.

[0066] The above contents are merely examples and illustrations of the present invention. Persons skilled in the art may make various modifications, additions, or substitute similar methods to the described specific embodiments. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall fall within the scope of protection 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 a toluene solvent, and then adding 2,2-dihydroxymethylpropionic acid and a catalyst thereto, controlling the temperature to be 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 dithiocarbamate, dithiocarbamate nano-silver-loaded titanium dioxide, dithiocarbamate 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; The structural formula of the bismercaptogeranyl ester is: ； The structural formula of the bis(thio)thridecafluorooctyl ester is: ； 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 thin sheets at 180-190° C., and passing through a tablet press and a sample making machine to obtain an antibacterial and waterproof composite board.

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 thereof 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, wherein: 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 step (3), the preparation method of bismercaptogeranyl ester includes the following steps: adding product A to a dichloromethane solvent, stirring and dispersing the mixture uniformly, then 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 to a pH of 7, drying the organic phase with anhydrous sodium sulfate, and evaporating the solvent. The obtained product is recorded as bismercaptogeranyl 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 the mixture to 100-110° C., reacting the mixture for 8-12 hours, and after the reaction is completed, neutralizing the mixture with a 5% by mass sodium hydroxide solution, washing the mixture with water, washing the mixture with deionized water, drying the organic layer, and rotary evaporating the mixture. 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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