Water-resistant mildew-proof putty powder as well as preparation method and use method thereof

Abstract

The invention discloses waterproof mildew-proof putty powder as well as a preparation method and a use method thereof, and belongs to the technical field of building materials. The water-resistant and mildew-proof putty powder is prepared by the following steps: firstly carrying out premixing reaction on 8-10 parts of rubber powder and 3.4-3.6 parts of a functionalized molybdenum disulfide composite material, drying, and then mixing with 140-160 parts of white cement, 2-4 parts of water-resistant starch, 3-4 parts of hydroxypropyl methyl cellulose ether, 2-4 parts of bentonite, 2-4 parts of a mildew-proof agent, 0.5-0.6 part of amylase and 809.8-839.1 parts of heavy calcium powder, wherein the water-resistant starch is obtained by modifying starch serving as a raw material, ammonium persulfate serving as an initiator and methacrylic acid dehydrated glyceride serving as a grafting monomer; the functional molybdenum disulfide composite material is obtained by taking mesoporous molybdenum trioxide as a molybdenum source, growing molybdenum sulfide in the mesoporous molybdenum trioxide in situ and then modifying by using aldehyde siloxane, so that the functional molybdenum disulfide composite material has excellent water resistance and mildew resistance, the phenomena that putty powder is easy to absorb moisture, expand, blister, fall off and mildew under the conditions of high temperature and high humidity are solved, and the functional molybdenum disulfide composite material has good water resistance and mildew resistance. And indoor formaldehyde can be removed.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and specifically relates to a water-resistant and mildew-proof putty powder, its preparation method and usage method. Background Art

[0002] In the building decoration industry, putty powder is an important material for wall treatment. Its main function is to fill and level the wall surface, providing a good foundation for subsequent paint construction. However, during the humid season from February to April in the southern regions, the climate is characterized by high temperature and high humidity. In such an environment, not only is it easy for condensation to occur on the wall surface, but it also provides ideal conditions for the growth of mold.

[0003] Due to its composition limitations, traditional putty powder often shows poor water resistance when faced with a humid environment. When the wall surface is in a long-term humid state, the wall treated with ordinary putty powder is prone to moisture absorption, swelling, blistering and even peeling, seriously affecting the aesthetics and service life of the wall. More seriously, these humid conditions are extremely likely to become a hotbed for mold growth. Mold not only affects the indoor air quality and poses a threat to the health of the occupants, but also causes irreversible damage to the wall, such as color spots and peeling, further increasing the maintenance cost and difficulty.

[0004] Therefore, it is particularly important to develop a putty powder with excellent water resistance and mildew resistance. Summary of the Invention

[0005] In view of this, the present invention provides a water-resistant and mildew-proof putty powder, its preparation method and usage method. The water-resistant and mildew-proof putty powder of the present invention has excellent water resistance and mildew resistance, thus solving the problems of putty powder being prone to moisture absorption, swelling, blistering, peeling and mildew under high temperature and high humidity conditions, and can also remove formaldehyde in the room.

[0006] To achieve the above object, the present invention includes the following technical solutions to be realized:

[0007] Technical Solution 1:

[0008] A water-resistant and mildew-proof putty powder, characterized in that it is mainly prepared from the following components according to the following mass ratio:

[0009] 8 - 10 parts of rubber powder,

[0010] 72 - 90 parts of deionized water,

[0011] 0.04 - 0.05 parts of ammonium persulfate,

[0012] 3.4 - 3.6 parts of functionalized molybdenum disulfide composite material,

[0013] 140 - 160 parts of white cement,

[0014] 2 - 4 parts of water - resistant starch,

[0015]

[0016] Further, the rubber powder is polyvinyl alcohol (PVA) rubber powder;

[0017] Further, the acidic pH regulator is hydrochloric acid with a mass concentration of 35 - 38%;

[0018] Further, the basic pH regulator is ammonia water with a concentration of 13.38 - 14.8 mol / L;

[0019] Further, the water - resistant starch is mainly prepared from the following components according to the following mass ratio:

[0020] 20 parts of tapioca starch,

[0021] 37.1 - 37.2 parts of distilled water,

[0022] 0.6 - 1 part of hydrochloric acid solution with a mass concentration of 35 - 38%,

[0023] Appropriate amount of basic pH regulator,

[0024] 0.4 - 0.6 part of ammonium persulfate,

[0025] 3 - 5 parts of glycidyl methacrylate.

[0026] Further, the above - mentioned basic pH regulator is 25 wt% sodium hydroxide solution;

[0027] Further, the preparation method of the above - mentioned water - resistant starch includes the following steps carried out in sequence:

[0028] (1) Mix the dried tapioca starch with distilled water and stir at 48 - 52 °C for 8 - 12 min;

[0029] (2) Then add the hydrochloric acid solution and keep warm and stir for 110 - 130 min;

[0030] (3) Then add the basic pH regulator to adjust the pH to 5.5 - 6;

[0031] (4) Then add ammonium persulfate and keep warm and stir for 55 - 65 min;

[0032] (5) Then add glycidyl methacrylate and stir and react for 80 - 100 min;

[0033] (6) Finally, dry the above solution at 45 - 55 °C for 23 - 25 h, grind it through a sieve with 10 - 14 meshes to obtain water - resistant starch. Further, the above functionalized molybdenum disulfide composite material is mainly prepared from the following components according to the following mass ratio:

[0034] Mesoporous molybdenum trioxide / molybdenum sulfide composite material 0.24 - 0.36 parts,

[0035] Ethanol solution of 2 - 3 wt% aldehyde - group siloxane 122.4 - 123.6 parts,

[0036] Distilled water 4 - 6 parts;

[0037] The mesoporous molybdenum trioxide / molybdenum sulfide composite material is mainly prepared from the following components according to the following mass ratio:

[0038] Hydrochloric acid solution with a mass concentration of 35 - 38% 2500 parts,

[0039] Mesoporous molybdenum trioxide 11 - 13 parts,

[0040] Thiourea 18 - 20 parts.

[0041] Further, the preparation method of the above functionalized molybdenum disulfide composite material includes the following steps carried out in sequence:

[0042] (1) Stir and mix mesoporous molybdenum trioxide with hydrochloric acid solution with a mass concentration of 35 - 38% for 4 - 6 min;

[0043] (2) Then add thiourea and stir and mix for 55 - 65 min;

[0044] (3) Then hydrothermally react the well - stirred and mixed solution in a muffle furnace at 215 - 225 °C for 110 - 130 min;

[0045] (4) Then wash the by - products off the solution after the reaction in a high - speed centrifuge at a rate of 19000 - 21000 rpm successively with ethanol and ultrapure water;

[0046] (5) Then dry it in a vacuum oven at 100 - 110 °C for 10 - 12 h to obtain mesoporous molybdenum trioxide / molybdenum sulfide composite material;

[0047] (6) After that, add the mesoporous molybdenum trioxide / molybdenum sulfide composite material into the ethanol solution of 2 - 3 wt% aldehyde - group siloxane and ultrasonically disperse it for 35 - 45 min;

[0048] (7) Then dropwise add distilled water into the solution at a rate of 2 - 4 drops / min, and stir at 75 - 85 °C for 23 - 25 h;

[0049] (8) Then, the solution was successively washed with ethanol and ultrapure water in a high-speed centrifuge at a rate of 19,000 - 21,000 rpm for multiple times to remove the unreacted aldehyde-functionalized siloxane.

[0050] (9) Finally, freeze-drying was carried out to obtain the functionalized molybdenum disulfide composite material.

[0051] Furthermore, the specific surface area of the mesoporous molybdenum trioxide is 194 ㎡ / g. A three-dimensional ordered mesoporous structure carbon template was prepared using the three-dimensional ordered mesoporous molecular sieve KIT-6 as a template agent, and ammonium heptamolybdate tetrahydrate was used as the molybdenum source, and it was prepared by a vacuum impregnation method assisted by ultrasound.

[0052] Furthermore, the aldehyde-functionalized siloxane used is 4-(trimethoxysilyl)butyraldehyde.

[0053] Technical solution two:

[0054] For the preparation method of the water-resistant and mildew-proof putty powder described in Technical solution one, it includes the following steps carried out in sequence:

[0055] (1) Mix the rubber powder with deionized water, heat it up to 94 - 96 °C, and carry out condensation reflux stirring for 110 - 130 min;

[0056] (2) Cool the above solution to 58 - 62 °C, and add an acidic pH regulator to adjust the pH to 1 - 2;

[0057] (3) Add the functionalized molybdenum disulfide composite material. When it is observed that sticky filaments are formed, add a basic pH regulator to adjust the pH to 7 - 7.5;

[0058] (4) Then add ammonium persulfate and stir for reaction for 29 - 31 min;

[0059] (5) Dry the above mixture in an oven at 100 - 120 °C, and after drying, carry out pulverization and sieve through a 20 - 30 mesh sieve to obtain a premix;

[0060] (6) Put white cement, the above premix, water-resistant starch, hydroxypropyl methyl cellulose ether, bentonite, heavy calcium powder, mildew-proof agent, and amylase into a blender and stir for dispersion for 10 - 20 min to make each raw material component evenly dispersed, and obtain the water-resistant and mildew-proof putty powder.

[0061] Technical solution three:

[0062] For the usage method of the water-resistant and mildew-proof putty powder described in Technical solution one, it is characterized in that the usage method of the water-resistant and mildew-proof putty powder is to stir and mix the water-resistant and mildew-proof putty powder and water evenly according to a mass ratio of 100:34 - 36 before use.

[0063] The beneficial technical effects of the present invention:

[0064] In the first technical solution of the present invention, water-resistant starch is prepared. The water-resistant starch is obtained by grafting glycidyl methacrylate with ammonium persulfate as an initiator into starch. Glycidyl methacrylate contains a hydrophobic ester bond and an epoxy group structure. Grafting glycidyl methacrylate into starch can effectively improve the hydrophobicity of starch, and at the same time introduce an epoxy group to ensure the bonding performance of the water-resistant starch, thereby ensuring the bonding strength of the water-resistant and mildew-proof putty powder.

[0065] In the first technical solution of the present invention, a functionalized molybdenum disulfide composite material is also prepared. The functionalized molybdenum disulfide composite material is obtained by using mesoporous molybdenum trioxide as a molybdenum source, in-situ growing molybdenum sulfide outside the mesoporous molybdenum trioxide and then modifying it with aldehyde group-containing siloxane. The functionalized molybdenum disulfide composite material contains a large number of mesopores and has a large specific surface area, which can increase the binding force between other materials and the functionalized molybdenum disulfide composite material. At the same time, under the action of the mesopores, it can adsorb indoor formaldehyde. Under sunlight irradiation, both the conduction band and Fermi level of molybdenum disulfide are higher than those of molybdenum trioxide. In the functionalized molybdenum disulfide composite material, molybdenum trioxide and molybdenum disulfide are in contact, and the Fermi levels reach equilibrium. In this way, the electrons of molybdenum disulfide with a higher Fermi level transfer to molybdenum trioxide, resulting in the loss of electrons on the molybdenum disulfide side, thus becoming positively charged; on the contrary, the molybdenum trioxide side gains electrons and is therefore negatively charged; an upward or downward band bending appears at the interface between molybdenum trioxide and molybdenum disulfide; subsequently, under the action of light, due to the Coulomb attraction between molybdenum trioxide electrons and molybdenum disulfide holes and the influence of band bending, the photo-generated electrons spontaneously transfer from the conduction band of molybdenum trioxide to the valence band of molybdenum disulfide. Similarly, due to the action of Coulomb repulsion, band bending and built-in electric field, the electrons transferred from the conduction band of molybdenum disulfide to the conduction band of molybdenum trioxide are inhibited; under light irradiation, more electrons are retained in the conduction band of molybdenum disulfide, and more holes are retained in the valence band of molybdenum trioxide, forming a typical S-type heterojunction, thereby significantly separating the electron-hole pairs in the composite material, accelerating the separation effect and transfer speed of photo-generated electrons and holes, being beneficial to the generation of reactive oxygen species and the degradation of formaldehyde, and effectively eliminating indoor formaldehyde under light irradiation conditions; the modification of the functionalized molybdenum disulfide composite material with aldehyde group-containing siloxane can effectively increase the dispersibility of the functionalized molybdenum disulfide composite material in the putty powder.

[0066] In the second technical solution of the present invention, the above-mentioned premix is obtained in the 5th step of the preparation process. The premix is prepared by premixing and reacting the rubber powder with the functionalized molybdenum disulfide composite material. After the hydroxyl group of the PVA in the rubber powder loses a hydrogen ion, it reacts with the aldehyde group on the functionalized molybdenum disulfide composite material to form an alkoxy group, increasing the cross-linking degree of PVA and at the same time improving its water resistance, thereby enhancing the water resistance of the water-resistant and mildew-proof putty powder.

[0067] By adopting the above technical solutions, the water-resistant and mildew-proof putty powder of the present invention has improved water resistance and mildew resistance, and thus has a very broad application prospect under high-temperature and high-humidity conditions. Brief Description of the Drawings

[0068] Figure 1 This is the preparation mechanism diagram of the water-resistant starch described in this application.

[0069] Figure 2 This is the preparation mechanism diagram of the functionalized molybdenum disulfide composite material described in this application.

[0070] Figure 3 This is the pre-mixing mechanism diagram of the premix described in this application. Detailed Description of the Invention

[0071] The exemplary embodiments disclosed in the present invention will be described in more detail below. These embodiments are for a more thorough understanding of the present invention and to be able to fully convey the scope of the present invention to those skilled in the art. Although the exemplary embodiments of the present invention are shown, it should be understood that the present invention should not be limited by the embodiments described herein.

[0072] (1) The detailed implementation of the water-resistant and mildew-proof putty powder in the present invention is mainly prepared from the following components according to the following mass ratio:

[0073] 8 - 10 parts of rubber powder,

[0074] 72 - 90 parts of deionized water,

[0075] 0.04 - 0.05 parts of ammonium persulfate,

[0076] 3.4 - 3.6 parts of functionalized molybdenum disulfide composite material,

[0077] 140 - 160 parts of white cement,

[0078] 2 - 4 parts of water-resistant starch,

[0079] 3 - 4 parts of hydroxypropyl methylcellulose ether,

[0080] 2 - 4 parts of bentonite,

[0081] 2 - 4 parts of mildew-proof agent,

[0082] 0.5 - 0.6 parts of amylase,

[0083] 809.8 - 839.1 parts of heavy calcium powder,

[0084] Appropriate amount of acidic pH regulator,

[0085] Appropriate amount of basic pH regulator;

[0086] The above rubber powder uses polyvinyl alcohol rubber powder. The above acidic pH regulator is hydrochloric acid with a mass concentration of 35 - 38%, and the above basic pH regulator is ammonia water with a concentration of 13.38 - 14.8 mol / L;

[0087] The water-resistant starch mentioned above is mainly prepared from the following components according to the following mass fraction ratio:

[0088] 20 parts of tapioca starch,

[0089] 37.1 - 37.2 parts of distilled water,

[0090] 0.6 - 1 part of hydrochloric acid solution with a mass concentration of 35 - 38%,

[0091] Appropriate amount of alkaline pH regulator,

[0092] 0.4 - 0.6 part of ammonium persulfate,

[0093] 3 - 5 parts of glycidyl methacrylate.

[0094] The above-mentioned alkaline pH regulator is a 25wt% sodium hydroxide solution.

[0095] The preparation method of the above-mentioned water-resistant starch includes the following steps carried out in sequence:

[0096] (1) Mix the dried tapioca starch with distilled water and stir at 48 - 52 °C for 8 - 12 min;

[0097] (2) Then add the hydrochloric acid solution and keep stirring at a constant temperature for 110 - 130 min;

[0098] (3) Then adjust the pH to 5.5 - 6 with the alkaline pH regulator;

[0099] (4) Then add ammonium persulfate and keep stirring at a constant temperature for 55 - 65 min;

[0100] (5) Then add glycidyl methacrylate and stir for reaction for 80 - 100 min;

[0101] (6) Finally, dry the above solution at 45 - 55 °C for 23 - 25 h, grind it through a 10 - 14 - mesh sieve to obtain the water-resistant starch. The above-mentioned functionalized molybdenum disulfide composite material is mainly prepared from the following components according to the following mass fraction ratio:

[0102] 0.24 - 0.36 part of mesoporous molybdenum trioxide / molybdenum disulfide composite material,

[0103] 122.4 - 123.6 parts of ethanol solution of 2 - 3wt% aldehyde group siloxane,

[0104] 4 - 6 parts of distilled water;

[0105] The above-mentioned mesoporous molybdenum trioxide / molybdenum disulfide composite material is mainly prepared from the following components according to the following mass fraction ratio:

[0106] 2500 parts of hydrochloric acid solution with a mass concentration of 35 - 38%,

[0107] 11 - 13 parts of mesoporous molybdenum trioxide,

[0108] 18 - 20 parts of thiourea.

[0109] The above-mentioned aldehyde group siloxane adopts 4-(trimethoxysilyl)butyraldehyde.

[0110] The preparation method of the above functionalized molybdenum disulfide composite material includes the following steps carried out in sequence:

[0111] (1) Stir and mix mesoporous molybdenum trioxide with hydrochloric acid solution with a mass concentration of 35 - 38% for 4 - 6 min;

[0112] (2) Then add thiourea and stir and mix for 55 - 65 min;

[0113] (3) Then hydrothermally react the stirred and mixed solution in a muffle furnace at 215 - 225 °C for 110 - 130 min;

[0114] (4) Then wash the by-products from the solution in a high-speed centrifuge at a rate of 19000 - 21000 rpm successively with ethanol and ultrapure water;

[0115] (5) Then dry in a vacuum oven at 100 - 110 °C for 10 - 12 h to obtain a mesoporous molybdenum trioxide / molybdenum sulfide composite material;

[0116] (6) Then add the mesoporous molybdenum trioxide / molybdenum sulfide composite material into an ethanol solution of 2 - 3 wt% aldehyde group siloxane and ultrasonically disperse for 35 - 45 min;

[0117] (7) Then dropwise add distilled water into the solution at a rate of 2 - 4 drops / min, and stir at 75 - 85 °C for 23 - 25 h;

[0118] (8) Then wash the solution in a high-speed centrifuge at a rate of 19000 - 21000 rpm successively with ethanol and ultrapure water for multiple times to remove the unreacted aldehyde group siloxane;

[0119] (9) Finally, freeze-dry to obtain the functionalized molybdenum disulfide composite material.

[0120] The specific surface area of the above mesoporous molybdenum trioxide is 194 ㎡ / g, which is prepared using three-dimensional ordered mesoporous molecular sieve KIT-6 as a template agent, three-dimensional ordered mesoporous structure carbon template, and ammonium heptamolybdate tetrahydrate as a molybdenum source, and is prepared by ultrasonic-assisted vacuum impregnation method (see Du Yucheng, Zheng Guangwei, Meng Qi, etc. Preparation and catalytic performance of three-dimensional ordered mesoporous structure molybdenum oxide [J]. Journal of Inorganic Materials, 2014, 29(02): 124 - 130).

[0121] (2) Preparation method of the water-resistant and mildew-proof putty powder in the present invention

[0122] It includes the following steps carried out in sequence:

[0123] (1) Mix the rubber powder with deionized water, heat up to 94 - 96 °C, and carry out condensation reflux stirring for 110 - 130 min;

[0124] (2) Cool the above solution to 58 - 62 °C, and add an acidic pH regulator to adjust the pH to 1 - 2;

[0125] (3) Add the functionalized molybdenum disulfide composite material. When it is observed that sticky filaments are formed, add a basic pH regulator to adjust the pH to 7 - 7.5;

[0126] (4) Then add ammonium persulfate and stir for reaction for 29 - 31 min;

[0127] (5) Dry the above mixture in an oven at 100 - 120 °C, and after drying, carry out pulverization and sieve through a 20 - 30 - mesh sieve to obtain a premix;

[0128] (6) Put white cement, the above premix, water - resistant starch, hydroxypropyl methyl cellulose ether, bentonite, heavy calcium powder, mildew - proof agent, and amylase into a blender and stir and disperse for 10 - 20 min to make each raw material component evenly dispersed, thus obtaining the water - resistant and mildew - proof putty powder.

[0129] (3) Usage method of the water - resistant and mildew - proof putty powder in the present invention

[0130] Mix the water - resistant and mildew - proof putty powder in the present invention with water at a mass ratio of 100:34 - 36 and stir evenly, then use it for plastering construction.

[0131] According to the above - mentioned various embodiments, the following 3 examples and 4 comparative examples are set, and the parts in each example are parts by mass ratio.

[0132] Example 1

[0133] First, prepare water - resistant starch according to the following steps:

[0134] (1) Mix 20 parts of dried cassava starch with 37.1 parts of distilled water and stir at 48 °C for 8 min;

[0135] (2) Then add 0.6 part of hydrochloric acid solution with a mass concentration of 38% and keep warm and stir for 110 min;

[0136] (3) Then add 25 wt% sodium hydroxide solution to adjust the pH to 5.5;

[0137] (4) Then add 0.4 part of ammonium persulfate and keep warm and stir for 55 min;

[0138] (5) Then add 3 parts of glycidyl methacrylate and stir for 80 min;

[0139] (6) Finally, dry the above solution at 45 °C for 23 h, grind it through a 10-mesh sieve to obtain the water-resistant starch.

[0140] Next, prepare the functionalized molybdenum disulfide composite material according to the following steps:

[0141] (1) Stir and mix mesoporous molybdenum trioxide with a hydrochloric acid solution with a mass concentration of 38% for 4 min;

[0142] (2) Then add thiourea and stir and mix for 55 min;

[0143] (3) Then hydrothermally react the well-stirred and mixed solution in a muffle furnace at 215 °C for 110 min;

[0144] (4) Then wash the by-products off the solution after the reaction in a high-speed centrifuge at a rate of 19000 rpm successively with ethanol and ultrapure water;

[0145] (5) Then dry it in a vacuum oven at 100 °C for 10 h to obtain the mesoporous molybdenum trioxide / molybdenum sulfide composite material;

[0146] (6) Then add the obtained mesoporous molybdenum trioxide / molybdenum sulfide composite material to an ethanol solution of 2 wt% 4-(trimethoxysilyl)butyraldehyde and ultrasonically disperse for 35 min;

[0147] (7) Then dropwise add distilled water to the solution at a rate of 2 drops / min while stirring at 75 °C for 23 h;

[0148] (8) Then wash the solution in a high-speed centrifuge at a rate of 19000 rpm successively with ethanol and ultrapure water multiple times to remove the unreacted aldehyde group siloxane;

[0149] (9) Finally, freeze-dry to obtain the functionalized molybdenum disulfide composite material;

[0150] Among them, the mass ratio of mesoporous molybdenum trioxide, hydrochloric acid solution, and thiourea in steps (1)-(2) is 11:2500:18; the mass fraction ratio of the mesoporous molybdenum trioxide / molybdenum sulfide composite material, ethanol solution of 4-(trimethoxysilyl)butyraldehyde, and distilled water in steps 6-7 is 0.24:122.4:4.

[0151] Next, prepare the water-resistant and mildew-proof putty powder according to the following steps:

[0152] (1) Mix 8 parts of rubber powder with 72 parts of deionized water, heat up to 94 °C, and stir with condensation reflux for 110 min;

[0153] (2) Cool the above solution to 58 °C and adjust the pH to 1 by adding hydrochloric acid with a mass concentration of 38%.

[0154] (3) Add 3.4 parts of the functionalized molybdenum disulfide composite material prepared above. When it is observed that sticky filaments are formed, add ammonia water with a concentration of 13.38 mol / L to adjust the pH to 7.

[0155] (4) Then add 0.04 part of ammonium persulfate and stir for 29 min.

[0156] (5) Dry the above mixture in an oven at 100 °C, pulverize it after drying, and pass through a 20-mesh sieve to obtain a premix.

[0157] (6) Put 140 parts of white cement, the above premix, 2 parts of the water-resistant starch prepared above, 3 parts of hydroxypropyl methylcellulose ether, 2 parts of bentonite, 839.1 parts of heavy calcium powder, 2 parts of mildew preventive, and 0.5 part of amylase into a mixer and stir for 10 - 20 min to make the raw material components disperse evenly, obtaining a water-resistant and mildew-proof putty powder.

[0158] During use, mix the above water-resistant and mildew-proof putty powder with water at a mass ratio of 100:34 and stir evenly for scraping construction.

[0159] Example 2

[0160] First, prepare water-resistant starch according to the following steps:

[0161] (1) Mix 20 parts of dried cassava starch with 37.15 parts of distilled water and stir at 50 °C for 10 min.

[0162] (2) Then add 0.8 part of hydrochloric acid solution with a mass concentration of 35% and stir while keeping warm for 120 min.

[0163] (3) Then add a 25 wt% sodium hydroxide solution to adjust the pH to 5.5.

[0164] (4) Then add 0.5 part of ammonium persulfate and stir while keeping warm for 60 min.

[0165] (5) Then add 4 parts of glycidyl methacrylate and stir for 90 min.

[0166] (6) Finally, dry the above solution at 50 °C for 24 h, grind it, and pass through a 12-mesh sieve to obtain water-resistant starch.

[0167] Then prepare the functionalized molybdenum disulfide composite material according to the following steps:

[0168] (1) Stir and mix mesoporous molybdenum trioxide with hydrochloric acid solution with a mass concentration of 35% for 5 min.

[0169] (2) Then add thiourea and stir and mix for 60 min;

[0170] (3) Then hydrothermally react the stirred and mixed solution in a muffle furnace at 220 °C for 120 min;

[0171] (4) Then wash away the by-products from the solution after the reaction in a high-speed centrifuge at a rate of 20,000 rpm successively with ethanol and ultrapure water;

[0172] (5) Then dry in a vacuum oven at 105 °C for 11 h to obtain a mesoporous molybdenum trioxide / molybdenum disulfide composite;

[0173] (6) Then add 0.3 part of the obtained mesoporous molybdenum trioxide / molybdenum disulfide composite to 123 parts of an ethanol solution of 2.5 wt% 4-(trimethoxysilyl)butyraldehyde and ultrasonically disperse for 40 min;

[0174] (7) Then dropwise add distilled water to the solution at a rate of 3 drops / min while stirring at 80 °C for 24 h;

[0175] (8) Then wash the solution in a high-speed centrifuge at a rate of 20,000 rpm successively with ethanol and ultrapure water multiple times to remove the unreacted aldehyde group siloxane;

[0176] (9) Finally, freeze-dry to obtain a functionalized molybdenum disulfide composite.

[0177] Among them, the mass fraction ratio of mesoporous molybdenum trioxide, hydrochloric acid solution, and thiourea in steps (1)-(2) is 12:2500:19; the mass fraction ratio of the mesoporous molybdenum trioxide / molybdenum disulfide composite, ethanol solution of 4-(trimethoxysilyl)butyraldehyde, and distilled water in steps 6-7 is 0.3:123:5.

[0178] Then prepare a water-resistant and mildew-proof putty powder according to the following steps:

[0179] (1) Mix 9 parts of rubber powder with 81 parts of deionized water, heat up to 95 °C, and stir with condensation reflux for 120 min;

[0180] (2) Cool the above solution to 60 °C and add hydrochloric acid with a mass concentration of 35% to adjust the pH to 1.5;

[0181] (3) Add 3.5 parts of the above-prepared functionalized molybdenum disulfide composite. When sticky filaments are observed to form, add 14.0 mol / L ammonia water to adjust the pH to 7;

[0182] (4) Then add 0.045 part of ammonium persulfate and stir and react for 30 min;

[0183] (5) Dry the above mixture in an oven at 110 °C, pulverize it after drying, and pass through a 25-mesh sieve to obtain a premix;

[0184] (6) Put 150 parts of white cement, the above premix, 3 parts of the water-resistant starch prepared above, 3.5 parts of hydroxypropyl methylcellulose ether, 3 parts of bentonite, 824.45 parts of heavy calcium powder, 3 parts of mildew preventive, and 0.55 parts of amylase into a blender and stir and disperse for 15 min to make the raw material components disperse evenly, obtaining water-resistant and mildew-proof putty powder.

[0185] During use, stir and mix the above water-resistant and mildew-proof putty powder and water in a mass ratio of 100:35 evenly and then use it for scraping construction.

[0186] Example 3

[0187] First, prepare water-resistant starch according to the following steps:

[0188] (1) Mix 20 parts of dried cassava starch with 37.2 parts of distilled water and stir at 52 °C for 12 min;

[0189] (2) Then add 1 part of hydrochloric acid solution with a mass concentration of 36% and keep warm and stir for 130 min;

[0190] (3) Then add 25wt% sodium hydroxide solution to adjust the pH to 6;

[0191] (4) Then add 0.6 part of ammonium persulfate and keep warm and stir for 65 min;

[0192] (5) Then add 5 parts of glycidyl methacrylate and stir and react for 100 min;

[0193] (6) Finally, dry the above solution at 55 °C for 25 h, grind it and pass through a 14-mesh sieve to obtain water-resistant starch.

[0194] Then prepare the functionalized molybdenum disulfide composite material according to the following steps:

[0195] (1) Stir and mix 13 parts of mesoporous molybdenum trioxide with 2500 parts of hydrochloric acid solution with a mass concentration of 36% for 6 min;

[0196] (2) Then add 20 parts of thiourea and stir and mix for 65 min;

[0197] (3) Then hydrothermally react the stirred and mixed solution in a muffle furnace at 225 °C for 130 min;

[0198] (4) Then wash the by-products off the solution after the reaction in a high-speed centrifuge at a rate of 21000 rpm successively with ethanol and ultrapure water;

[0199] (5) Then, it was dried in a vacuum oven at 110 °C for 12 h to obtain the mesoporous molybdenum trioxide / molybdenum sulfide composite material;

[0200] (6) Then, 0.36 part of the obtained mesoporous molybdenum trioxide / molybdenum sulfide composite material was added to 123.6 parts of an ethanol solution of 3 wt% 4-(trimethoxysilyl) butyraldehyde, and ultrasonically dispersed for 45 min;

[0201] The ethanol solution of 3 wt% 4-(trimethoxysilyl) butyraldehyde, and ultrasonically dispersed for 45 min;

[0202] (7) Then, distilled water was dropped into the solution at a rate of 4 drops / min, and stirred at 85 °C for 25 h;

[0203] (8) Then, the solution was successively washed with ethanol and ultrapure water in a high-speed centrifuge at a rate of 21000 rpm to remove the unreacted aldehyde group siloxane;

[0204] (9) Finally, it was freeze-dried to obtain the functionalized molybdenum disulfide composite material.

[0205] Among them, the mass ratio of mesoporous molybdenum trioxide, hydrochloric acid solution, and thiourea in steps (1)-(2) is 13:2500:20; the mass ratio of the mesoporous molybdenum trioxide / molybdenum sulfide composite material, ethanol solution of 4-(trimethoxysilyl) butyraldehyde, and distilled water in steps 6-7 is 0.36:123.6:6.

[0206] Then, the water-resistant and mildew-proof putty powder was prepared according to the following steps:

[0207] (1) 10 parts of the rubber powder was mixed with 90 parts of deionized water, heated to 96 °C, and stirred under reflux condensation for 130 min;

[0208] (2) The above solution was cooled to 62 °C, and 36.5% hydrochloric acid was added to adjust the pH to 1.5;

[0209] (3) 3.6 parts of the above-prepared functionalized molybdenum disulfide composite material was added. When sticky filaments were observed to form, 14.8 mol / L ammonia water was added to adjust the pH to 7.5;

[0210] (4) Then, 0.05 part of ammonium persulfate was added and stirred for 30 min;

[0211] (5) The above mixture was dried in an oven at 120 °C, crushed after drying, and passed through a 30-mesh sieve to obtain the premix;

[0212] (6) 160 parts of white cement, the above premix, 4 parts of the above-prepared water-resistant starch, 4 parts of hydroxypropyl methylcellulose ether, 4 parts of bentonite, 809.8 parts of heavy calcium powder, 4 parts of mildew-proof agent, and 0.6 part of amylase were put into a blender and stirred and dispersed for 20 min to make the raw material components disperse evenly, obtaining the water-resistant and mildew-proof putty powder.

[0213] During use, mix the above water-resistant and mildew-proof putty powder with water in a mass ratio of 100:36 and stir evenly, then use it for scraping construction.

[0214] The material sources used in the above embodiments are as follows:

[0215] The white cement is 32.5-strength cement of Alba White Cement;

[0216] The polyvinyl alcohol powder is PVA1788 produced by Chuanwei Chemical Industry;

[0217] The mildew-proof agent uses Mildew-Free Q02, and the manufacturer is Guangzhou Dimei;

[0218] The hydroxypropyl methyl cellulose ether is PMK-40Z of Shanghai Huiguang Fine Chemical Co., Ltd.;

[0219] The bentonite uses Chang'an Renheng PT-02S;

[0220] The aldehyde group siloxane uses 4-(trimethoxysilyl) butyraldehyde;

[0221] The same material sources in the following comparative examples are the same as those in the above embodiments.

[0222] Comparative Example 1

[0223] First, prepare water-resistant starch according to the following steps:

[0224] (1) Mix 20 parts of dried cassava starch with 37.15 parts of distilled water, and stir at 50 °C for 10 min;

[0225] (2) Then add 0.8 part of hydrochloric acid solution with a mass concentration of 35%, and keep stirring for 120 min;

[0226] (3) Then add 25 wt% sodium hydroxide solution to adjust the pH to 5.5;

[0227] (4) Then add 0.5 part of ammonium persulfate, and keep stirring for 60 min;

[0228] (5) Then add 4 parts of glycidyl methacrylate, and stir and react for 90 min;

[0229] (6) Finally, dry the above solution at 50 °C for 24 h, and grind it through a 12-mesh sieve to obtain water-resistant starch.

[0230] Then prepare functionalized molybdenum disulfide according to the following steps:

[0231] (1) Add 0.3 part of molybdenum disulfide to 123 parts of ethanol solution of 2.5 wt% 4-(trimethoxysilyl) butyraldehyde, and ultrasonically disperse for 40 min;

[0232] (2) Then, distilled water was added dropwise to the solution at a rate of 3 drops / min, while stirring at 80 °C for 24 h;

[0233] (3) Then, the solution was successively washed with ethanol and ultrapure water multiple times in a high-speed centrifuge at a rate of 20000 rpm to remove the unreacted aldehyde group siloxane;

[0234] (4) Finally, freeze-drying was carried out to obtain functionalized molybdenum disulfide.

[0235] The water-resistant and mildew-proof putty powder was prepared according to the following steps:

[0236] (1) 9 parts of rubber powder and 81 parts of deionized water were mixed, heated to 95 °C, and stirred under reflux for 120 min;

[0237] (2) The above solution was cooled to 60 °C, and hydrochloric acid with a mass concentration of 35% was added to adjust the pH to 1.5;

[0238] (3) 3.5 parts of the functionalized molybdenum disulfide prepared above was added. When sticky filaments were observed to form, 14.0 mol / L ammonia water was added to adjust the pH to 7;

[0239] (4) Then, 0.045 part of ammonium persulfate was added and stirred for reaction for 30 min;

[0240] (5) The above mixture was dried in an oven at 110 °C, crushed after drying, and passed through a 25-mesh sieve to obtain a premix;

[0241] (6) 150 parts of white cement, the above premix, 3 parts of the water-resistant starch prepared above, 3.5 parts of hydroxypropyl methyl cellulose ether, 3 parts of bentonite, 824.45 parts of heavy calcium powder, 3 parts of mildew-proof agent, and 0.55 part of amylase were put into a blender and stirred and dispersed for 15 min to make the raw material components disperse evenly, obtaining the water-resistant and mildew-proof putty powder.

[0242] During use, the above water-resistant and mildew-proof putty powder was stirred and mixed evenly with water at a mass ratio of 100:35 and then used for scraping construction.

[0243] Comparative Example 2

[0244] First, the water-resistant starch was prepared according to the following steps:

[0245] (1) 20 parts of dried cassava starch and 37.15 parts of distilled water were mixed and stirred at 50 °C for 10 min;

[0246] (2) Then, 0.8 part of hydrochloric acid solution with a mass concentration of 35% was added, and the mixture was stirred and kept warm for 120 min;

[0247] (3) Then, 25 wt% sodium hydroxide solution was added to adjust the pH to 5.5;

[0248] (4) Then add 0.5 part of ammonium persulfate and keep warm and stir for 60 min;

[0249] (5) Then add 4 parts of glycidyl methacrylate and stir and react for 90 min;

[0250] (6) Finally, dry the above solution at 50 °C for 24 h, grind it through a 12-mesh sieve to obtain water-resistant starch.

[0251] Then prepare the molybdenum disulfide composite material according to the following steps:

[0252] (1) Stir and mix 12 parts of mesoporous molybdenum trioxide with 2500 parts of hydrochloric acid solution with a mass concentration of 35% for 5 min;

[0253] (2) Then add 19 parts of thiourea and stir and mix for 60 min;

[0254] (3) Then hydrothermally react the well-stirred and mixed solution in a muffle furnace at 220 °C for 120 min;

[0255] (4) Then wash the by-products off the solution after the reaction in a high-speed centrifuge at a rate of 20000 rpm successively with ethanol and ultrapure water;

[0256] (5) Then dry it in a vacuum oven at 105 °C for 11 h to obtain the molybdenum disulfide composite material;

[0257] Then prepare the water-resistant and mildew-proof putty powder according to the following steps:

[0258] (1) Mix 9 parts of rubber powder with 81 parts of deionized water, heat it up to 95 °C, and carry out condensation reflux and stir for 120 min;

[0259] (2) Cool the above solution to 60 °C and add hydrochloric acid with a mass concentration of 35% to adjust the pH to 1.5;

[0260] (3) Add 3.5 parts of the molybdenum disulfide composite material prepared above. When sticky filaments are observed to form, add 14.0 mol / L ammonia water to adjust the pH to 7;

[0261] (4) Then add 0.045 part of ammonium persulfate and stir and react for 30 min;

[0262] (5) Dry the above mixture in a drying oven at 110 °C, and after drying, carry out pulverization and pass through a 25-mesh sieve to obtain the premix;

[0263] (6) Put 150 parts of white cement, the above-mentioned premix, 3 parts of the water-resistant starch prepared above, 3.5 parts of hydroxypropyl methyl cellulose ether, 3 parts of bentonite, 824.45 parts of heavy calcium powder, 3 parts of mildew preventive, and 0.55 part of amylase into a blender and stir and disperse for 15 min to make the raw material components disperse evenly, obtaining water-resistant and mildew-proof putty powder.

[0264] During use, stir and mix the above-mentioned water-resistant and mildew-proof putty powder with water at a mass ratio of 100:35 evenly and then use it for scraping construction.

[0265] Comparative Example 3

[0266] First, prepare the functionalized molybdenum disulfide composite material according to the following steps:

[0267] (1) Stir and mix mesoporous molybdenum trioxide with a hydrochloric acid solution with a mass concentration of 35% for 5 min;

[0268] (2) Then add thiourea and stir and mix for 60 min;

[0269] (3) Then hydrothermally react the stirred and mixed solution in a muffle furnace at 220 °C for 120 min;

[0270] (4) Then wash the by-products off the solution after the reaction in a high-speed centrifuge at a rate of 20000 rpm successively with ethanol and ultrapure water;

[0271] (5) Then dry in a vacuum oven at 105 °C for 11 h to obtain a mesoporous molybdenum trioxide / molybdenum sulfide composite material;

[0272] (6) Then add the obtained mesoporous molybdenum trioxide / molybdenum sulfide composite material into an ethanol solution of 2.5 wt% 4-(trimethoxysilyl)butyraldehyde and ultrasonically disperse for 40 min;

[0273] (7) Then drop distilled water into the solution at a rate of 3 drops / min while stirring at 80 °C for 24 h;

[0274] (8) Then wash the solution in a high-speed centrifuge at a rate of 20000 rpm successively with ethanol and ultrapure water multiple times to remove the unreacted aldehyde group siloxane;

[0275] (9) Finally, freeze-dry to obtain the functionalized molybdenum disulfide composite material.

[0276] Among them, the mass parts ratio of mesoporous molybdenum trioxide, hydrochloric acid solution, and thiourea in steps (1)-(2) is 12:2500:19; the mass fraction ratio of the mesoporous molybdenum trioxide / molybdenum sulfide composite material, ethanol solution of 4-(trimethoxysilyl)butyraldehyde, and distilled water in steps 6-7 is 0.3:123:5.

[0277] Then, prepare the water-resistant and mildew-proof putty powder according to the following steps:

[0278] (1) Mix 9 parts of rubber powder with 81 parts of deionized water, heat up to 95 °C, and stir with condensation reflux for 120 min;

[0279] (2) Cool the above solution to 60 °C, and add hydrochloric acid with a mass concentration of 35% to adjust the pH to 1.5;

[0280] (3) Add 3.5 parts of the functionalized molybdenum disulfide composite material prepared above. When sticky filaments are observed to form, add 14.0 mol / L ammonia water to adjust the pH to 7;

[0281] (4) Then add 0.045 parts of ammonium persulfate and stir for reaction for 30 min;

[0282] (5) Dry the above mixture in an oven at 110 °C, pulverize after drying, and pass through a 25-mesh sieve to obtain a premix;

[0283] (6) Put 150 parts of white cement, the above premix, 3 parts of tapioca starch, 3.5 parts of hydroxypropyl methylcellulose ether, 3 parts of bentonite, 824.45 parts of heavy calcium powder, 3 parts of mildew-proof agent, and 0.55 parts of amylase into a blender and stir for dispersion for 15 min to make each raw material component evenly dispersed, thus obtaining the water-resistant and mildew-proof putty powder.

[0284] During use, mix the above water-resistant and mildew-proof putty powder with water at a mass ratio of 100:35 and stir evenly, then use it for scraping construction.

[0285] Comparative Example 4

[0286] First, prepare the water-resistant starch according to the following steps:

[0287] (1) Mix 20 parts of dried tapioca starch with 37.15 parts of distilled water and stir at 50 °C for 10 min;

[0288] (2) Then add 0.8 part of hydrochloric acid solution with a mass concentration of 35% and stir while keeping warm for 120 min;

[0289] (3) Then add 25 wt% sodium hydroxide solution to adjust the pH to 5.5;

[0290] (4) Then add 0.5 part of ammonium persulfate and stir while keeping warm for 60 min;

[0291] (5) Then add 4 parts of glycidyl methacrylate and stir for reaction for 90 min;

[0292] (6) Finally, dry the above solution at 50 °C for 24 h, grind it, and pass through a 12-mesh sieve to obtain the water-resistant starch.

[0293] Next, prepare the functionalized molybdenum disulfide composite material according to the following steps:

[0294] (1) Stir and mix mesoporous molybdenum trioxide with a hydrochloric acid solution with a mass concentration of 35% for 5 min;

[0295] (2) Then add thiourea and stir and mix for 60 min;

[0296] (3) Then hydrothermally react the well-stirred and mixed solution in a muffle furnace at 220 °C for 120 min;

[0297] (4) Then wash the solution after the reaction in a high-speed centrifuge at a rate of 20000 rpm successively with ethanol and ultrapure water to remove by-products;

[0298] (5) Then dry it in a vacuum oven at 105 °C for 11 h to obtain a mesoporous molybdenum trioxide / molybdenum sulfide composite material;

[0299] (6) Then add the obtained mesoporous molybdenum trioxide / molybdenum sulfide composite material to an ethanol solution of 2.5 wt% 4-(trimethoxysilyl)butyraldehyde and ultrasonically disperse for 40 min;

[0300] (7) Then drop distilled water into the solution at a rate of 3 drops / min while stirring at 80 °C for 24 h;

[0301] (8) Then wash the solution in a high-speed centrifuge at a rate of 20000 rpm successively with ethanol and ultrapure water multiple times to remove unreacted aldehyde group siloxane;

[0302] (9) Finally, freeze-dry to obtain the functionalized molybdenum disulfide composite material.

[0303] Among them, the mass fraction ratio of mesoporous molybdenum trioxide, hydrochloric acid solution, and thiourea in steps (1)-(2) is 12:2500:19; the mass fraction ratio of mesoporous molybdenum trioxide / molybdenum sulfide composite material, ethanol solution of 4-(trimethoxysilyl)butyraldehyde, and distilled water in steps 6-7 is 0.3:123:5.

[0304] Next, prepare the water-resistant and mildew-proof putty powder according to the following method:

[0305] Put 9 parts of rubber powder, 3.5 parts of the above-prepared functionalized molybdenum disulfide composite material, 150 parts of white cement, 3 parts of the above-prepared water-resistant starch, 3.5 parts of hydroxypropyl methyl cellulose ether, 3 parts of bentonite, 824.45 parts of heavy calcium powder, 3 parts of mildew-proof agent, and 0.55 parts of amylase into a mixer and stir and disperse for 15 min to make each raw material component evenly dispersed, obtaining the water-resistant and mildew-proof putty powder.

[0306] During use, stir and mix the above water-resistant and mildew-proof putty powder with water at a mass ratio of 100:35 evenly and then use it for scraping construction.

[0307] The difference between Comparative Example 1 and Example 2 is as follows: In Comparative Example 1, molybdenum disulfide was directly modified with aldehyde group siloxane. The water-resistant and mildew-proof putty powder prepared in Comparative Example 1 could hardly eliminate formaldehyde, and the reduction of formaldehyde concentration might be due to the sealing problem of the reaction chamber and the adsorption effect of the putty powder.

[0308] The difference between Comparative Example 2 and Example 2 is as follows: In Comparative Example 2, a molybdenum disulfide composite material obtained by directly using mesoporous molybdenum trioxide as the molybdenum source and in-situ growing molybdenum sulfide in the mesoporous molybdenum trioxide was used, and aldehyde group siloxane was not used for modification. The dispersibility of the molybdenum disulfide composite material in the putty powder was affected, directly affecting the workability, water resistance, bond strength before and after immersion, and formaldehyde elimination performance of the putty powder.

[0309] The difference between Comparative Example 3 and Example 2 is as follows: In Comparative Example 3, tapioca starch was directly used instead of starch modified with glycerol methacrylate, directly affecting the water resistance and bond strength before and after immersion of the putty powder.

[0310] The difference between Comparative Example 4 and Example 2 is as follows: In Comparative Example 4, the rubber powder and the functionalized molybdenum disulfide composite material were not pre-mixed and reacted first, but the raw material components were directly mixed. The water resistance and bond strength before and after immersion of the prepared putty powder were weaker than those in Example 2.

[0311] After the water-resistant and mildew-proof putty powder samples obtained from all the above examples and comparative examples were used, the following indicators and methods were used for testing:

[0312] Antibacterial and mildew-proof performance: The antibacterial rate against Escherichia coli AS1.90 and Staphylococcus aureus AS1.89 of the samples was tested with reference to the antibacterial property determination method and antibacterial effect of antibacterial coatings (paint films) in GB / T21866-2008, and the mildew-proof effect was tested at level 0 according to the "Mildew Resistance of Paint Films" standard in JB / T1741-2020.

[0313] Workability, water resistance, and bond strength before and after immersion: The water-resistant and mildew-proof putty powders of the examples and comparative examples were tested with reference to the standard of type N in JG / T298-2010.

[0314] Formaldehyde elimination performance: The volume of the experimental reaction chamber is approximately 6 liters (20 cm × 20 cm × 15 cm). The distance between the surface of the sample and the quartz window at the top of the reaction chamber is about 10 cm. The reaction gas can only pass between the surface of the sample and the air inlet and outlet of the reaction chamber. During the photocatalytic reaction process, simulated sunlight will be provided vertically outside the reaction chamber. After uniformly stirring and mixing the water-resistant and mold-proof putty powder of the examples and comparative examples with water at a mass ratio of 100:35, scrape and construct it on a 150 mm * 70 mm * 5 mm asbestos-free fiber cement plate and dry it to obtain a water-resistant and mold-proof putty powder layer with a thickness of 1 mm. Then, put it into the reaction chamber and introduce gaseous formaldehyde with a concentration of about 100 ppm. Turn on the xenon lamp and use a formaldehyde detector to measure the change in formaldehyde concentration within 30 minutes, measuring once every 10 seconds on average. The formaldehyde concentration is estimated according to the following formula:

[0315]

[0316] Among them, ρ represents the density of formaldehyde, v1 is the volume of the liquid formaldehyde solution initially added (in milliliters), c(wt)% is the concentration of formaldehyde, k = 1.25 is the conversion coefficient, and v2 is the volume of the container (in cubic meters).

[0317] The following table shows the sample performance test results of the water-resistant and mold-proof putty powder of the above examples and comparative examples:

[0318]

[0319] From the comparison of the data in Table 1, it can be seen that the water-resistant and mold-proof putty powder of Examples 1-3 has good antibacterial and mold-proof properties, workability, water resistance, bond strength before and after immersion, and formaldehyde elimination performance.

[0320] The above conclusion can also be supported theoretically:

[0321] In the present invention, water-resistant starch is prepared as a raw material. As Figure 1 shown, this water-resistant starch is obtained by grafting glycidyl methacrylate with ammonium persulfate as an initiator into starch. Glycidyl methacrylate contains a hydrophobic ester bond and an epoxy group structure. Grafting glycidyl methacrylate into starch can effectively improve the hydrophobicity of starch, and at the same time introduce epoxy groups, ensuring the bonding performance of the water-resistant starch, and thus ensuring the bond strength of the water-resistant and mold-proof putty powder.

[0322] In the present invention, a functionalized molybdenum disulfide composite material is also prepared as a raw material. As Figure 2As shown in the figure, the functionalized molybdenum disulfide composite material is obtained by using mesoporous molybdenum trioxide as the molybdenum source, in-situ growing molybdenum disulfide outside the mesoporous molybdenum trioxide and then modifying it with aldehyde group siloxane. The functionalized molybdenum disulfide composite material contains a large number of mesopores and has a large specific surface area, which can increase the binding force between other materials and the functionalized molybdenum disulfide composite material. At the same time, under the action of mesopores, it can adsorb indoor formaldehyde. Under sunlight irradiation, the conduction band and Fermi level of molybdenum disulfide are both higher than those of molybdenum trioxide. In the functionalized molybdenum disulfide composite material, molybdenum trioxide and molybdenum disulfide are in contact, and the Fermi level reaches equilibrium. In this way, the electrons of molybdenum disulfide with a higher Fermi level transfer to molybdenum trioxide, resulting in the loss of electrons on the molybdenum disulfide side, thus becoming positively charged; on the contrary, the molybdenum trioxide side gains electrons and is therefore negatively charged; an upward or downward band bending appears at the interface between molybdenum trioxide and molybdenum disulfide; subsequently, under the action of light, due to the Coulomb attraction between molybdenum trioxide electrons and molybdenum disulfide holes and the influence of band bending, the photo-generated electrons spontaneously transfer from the conduction band of molybdenum trioxide to the valence band of molybdenum disulfide. Similarly, due to the action of Coulomb repulsion, band bending and built-in electric field, the electrons transferred from the conduction band of molybdenum disulfide to the conduction band of molybdenum trioxide are inhibited; under light irradiation, more electrons are retained in the conduction band of molybdenum disulfide, and more holes are retained in the valence band of molybdenum trioxide, forming a typical S-type heterojunction. Thus, the electron-hole pairs in the composite material are significantly separated, accelerating the separation effect and transfer speed of photo-generated electrons and holes, which is beneficial to the generation of reactive oxygen species and the degradation of formaldehyde, and can effectively eliminate indoor formaldehyde under light irradiation conditions; the aldehyde group siloxane modification of the functionalized molybdenum disulfide composite material can effectively increase the dispersibility of the functionalized molybdenum disulfide composite material in putty powder.

[0323] In the present invention, a premix is also prepared first in the preparation of the water-resistant and mildew-proof putty powder, as Figure 3 shown. This premix pre-mixes and reacts the rubber powder with the functionalized molybdenum disulfide composite material. After the hydroxyl group of the PVA in the rubber powder loses a hydrogen ion, it reacts with the aldehyde group on the functionalized molybdenum disulfide composite material to form an alkoxy group, increasing the cross-linking degree of PVA and improving its water resistance, thereby enhancing the water resistance of the water-resistant and mildew-proof putty powder.

[0324] In summary, the water-resistant and mildew-proof putty powder of the present invention is prepared by first pre-mixing and reacting the rubber powder with the functionalized molybdenum disulfide composite material, drying, and then mixing with the remaining raw material components; among them, the water-resistant starch is modified with starch as the raw material, ammonium persulfate as the initiator, and glycidyl methacrylate as the graft monomer; the functionalized molybdenum disulfide composite material is obtained by using mesoporous molybdenum trioxide as the molybdenum source, in-situ growing molybdenum disulfide in the mesoporous molybdenum trioxide and then modifying it with aldehyde group siloxane; the rubber powder uses PVA rubber powder. The prepared water-resistant and mildew-proof putty powder has good water resistance, mildew resistance, and the performance of removing indoor formaldehyde.

[0325] The specific embodiments described above further elaborate on the objectives, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc., made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A water-resistant and mildew-proof putty powder, characterized in that: It is mainly prepared by the following components in the following mass ratios: 8-10 parts of rubber powder, 72-90 parts of deionized water, 0.04-0.05 parts of ammonium persulfate, Functionalized molybdenum disulfide composite material 3.4-3.6 parts, 140-160 parts of white cement, 2-4 parts of water-resistant starch, 3-4 parts of hydroxypropyl methylcellulose ether, 2-4 parts of bentonite, 2-4 parts of mildew inhibitor, Amylase 0.5-0.6 parts, 809.8-839.1 parts of heavy calcium powder, Acidic pH adjuster, Alkaline pH adjuster.

2. The water-resistant and mildew-proof putty powder according to claim 1, characterized in that: The rubber powder is polyvinyl alcohol rubber powder.

3. The water-resistant and mildew-proof putty powder according to claim 1, characterized in that: The acidic pH regulator is hydrochloric acid with a mass concentration of 35-38%, and the alkaline pH regulator is ammonia water with a concentration of 13.38-14.8 mol / L.

4. The water-resistant and mildew-proof putty powder according to claim 1, characterized in that: The water-resistant starch is prepared from the following components in the following mass ratios: 20 parts of tapioca starch, 37.1-37.2 parts of distilled water, 0.6-1 part of hydrochloric acid solution with a mass concentration of 35-38%, Alkaline pH adjuster, 0.4-0.6 parts of ammonium persulfate, 3-5 parts of dehydrated glyceryl methacrylate.

5. The water-resistant and mildew-proof putty powder according to claim 4, characterized in that: The water-resistant starch is prepared by the following preparation method: (1) mixing the dried cassava starch with distilled water and stirring at 48-52° C. for 8-12 minutes; (2) Then add hydrochloric acid solution and stir at the temperature for 110-130 minutes; (3) then adding an alkaline pH regulator to adjust the pH to 5.5-6; (4) then adding ammonium persulfate and stirring for 55-65 minutes; (5) then adding dehydrated methacrylate and stirring the reaction for 80-100 minutes; (6) Finally, the solution is dried at 45-55°C for 23-25 ​​hours and ground through a 10-14 mesh sieve to obtain water-resistant starch.

6. The water-resistant and mildew-proof putty powder according to claim 1, characterized in that: The functionalized molybdenum disulfide composite material is mainly prepared from the following components in the following mass ratios: Mesoporous molybdenum trioxide / molybdenum sulfide composite material 0.24-0.36 parts, 122.4-123.6 parts of ethanol solution of 2-3wt% aldehyde siloxane, 4-6 parts of distilled water; The mesoporous molybdenum trioxide / molybdenum sulfide composite material is mainly prepared from the following components in the following mass proportions: 2500 parts of hydrochloric acid solution with a mass concentration of 35-38%, Mesoporous molybdenum trioxide 11-13 parts, Thiourea 18-20 parts.

7. The water-resistant and mildew-proof putty powder according to claim 6, characterized in that: The functionalized molybdenum disulfide composite material is prepared by the following preparation method: (1) stirring and mixing mesoporous molybdenum trioxide and a hydrochloric acid solution with a mass concentration of 35-38% for 4-6 minutes; (2) Then add thiourea and stir and mix for 55-65 minutes; (3) The stirred and mixed solution is then subjected to a hydrothermal reaction in a muffle furnace at 215-225° C. for 110-130 min; (4) The solution after the reaction was completed was then centrifuged at a speed of 19000-21000 rpm to wash away the by-products with ethanol and ultrapure water; (5) then baking in a vacuum oven at a temperature of 100-110° C. for 10-12 h to obtain a mesoporous molybdenum trioxide / molybdenum sulfide composite material; (6) adding the mesoporous molybdenum trioxide / molybdenum sulfide composite material to a 2-3 wt % ethanol solution of aldehyde-based siloxane and ultrasonically dispersing for 35-45 min; (7) Then, distilled water was added to the solution at a rate of 2-4 drops / min while stirring at 75-85°C for 23-25h; (8) The solution is then washed multiple times with ethanol and then ultrapure water at a speed of 19000-21000 rpm in a high-speed centrifuge to remove unreacted aldehyde siloxane; (9) Finally, freeze-drying is performed to obtain a functionalized molybdenum disulfide composite material.

8. The water-resistant and mildew-proof putty powder according to claim 7, characterized in that: The specific surface area of ​​the mesoporous molybdenum trioxide is 194 m2 / g. The three-dimensional ordered mesoporous carbon template is prepared by taking the three-dimensional ordered mesoporous molecular sieve KIT-6 as the template agent, and ammonium heptamolybdate tetrahydrate is used as the molybdenum source. It is prepared by the vacuum impregnation method assisted by ultrasound. The aldehyde siloxane is 4-(trimethoxysilane)butyraldehyde.

9. The method for preparing a water-resistant and mildew-proof putty powder according to any one of claims 1 to 8, characterized in that: Follow these steps in order: (1) Mix the rubber powder and deionized water, heat to 94-96°C, condense and reflux with stirring for 110-130 minutes; (2) cooling the above solution to 58-62° C., and adding an acidic pH adjuster to adjust the pH to 1-2; (3) adding the functionalized molybdenum disulfide composite material, and when sticky filaments are observed to form, adding an alkaline pH regulator to adjust the pH to 7-7.5; (4) then adding ammonium persulfate and stirring the reaction for 29-31 minutes; (5) drying the mixture in a drying oven at 100-120° C., crushing the mixture after drying, and passing it through a 20-30 mesh sieve to obtain a premix; (6) Put white cement, the above premix, water-resistant starch, hydroxypropyl methylcellulose ether, bentonite, heavy calcium powder, mildew inhibitor, and amylase into a blender, and stir and disperse for 10-20 minutes to evenly disperse the raw material components to obtain a water-resistant and mildew-resistant putty powder.

10. The method for using the water-resistant and mildew-proof putty powder according to any one of claims 1 to 8, characterized in that: The method for using the water-resistant and mildew-proof putty powder is to stir and mix the water-resistant and mildew-proof putty powder and water in a mass ratio of 100:34-36 and then use the mixture.

Images