A concrete brightener and preparation method thereof

Abstract

The present invention discloses a concrete brightener and a preparation method thereof, comprising the following components by weight: 100-140 parts of a hydrophilic unsaturated carboxylic acid ester, 70-100 parts of a lipophilic unsaturated carboxylic acid ester, 0.5-2 parts of a modified single-walled carbon nanotube, 8-14 parts of ethylene glycol distearate, 5-9 parts of an imidazoline compound, 2-7 parts of a polyglycerol fatty acid ester, 6-12 parts of a nonionic surfactant, 18-35 parts of a fluorocarbon surfactant, 5-9 parts of a molecular regulator, 3-8 parts of an initiator, and 664-783 parts of water. The present invention can be used in conjunction with an admixture during concrete prefabrication. After use, the concrete brightener has a smooth surface and more uniform color of cement products, can maintain a long-lasting brightening effect, and can achieve strong adsorption and dispersion effects on cement, thereby improving the strength and surface hardness of cement products and enhancing the surface brightness, smoothness, and wear resistance of cement products. Furthermore, the present invention has mild preparation conditions and does not use any organic solvents during the synthesis process, making it safe and environmentally friendly.

Description

Technical Field

[0001] The invention relates to a concrete brightener and a preparation method thereof, belonging to the technical field of concrete building material additives. Background Art

[0002] Cement-based materials are important building materials worldwide, widely used in numerous projects, including housing construction, bridges and tunnels, highways and high-speed railways, ports and airports, and water conservancy projects. With the advancement of cement-based materials and the demand for green development, various projects have placed higher demands on the performance of cement-based materials, such as strength, durability, and workability. At the same time, more stringent standards have been set for the surface appearance of cement-based products, such as finish, brightness, and flatness.

[0003] Patent CN108558321A discloses a high-gloss translucent concrete, its preparation method, and its application. Translucent concrete is first prepared, then subjected to coarse grinding, fine grinding, strengthening with a strengthening agent, and final grinding to enhance the gloss of the translucent concrete, achieving a gloss of 25 to 90 Gu. This invention requires a complex process of coarse grinding, fine grinding, and final grinding to remove impurities from the concrete surface, followed by application of a strengthening agent to fully penetrate the concrete.

[0004] Invention patent CN112645636A discloses a composite high-efficiency brightener and its preparation method. The brightener is primarily composed of the following raw materials in parts by weight: 40-60 parts fatty acid, 700-1130 parts water, 2-5 parts water-soluble carbonate, 9-15 parts potassium hydroxide, 1-3 parts polyol, 0.6-4.5 parts sodium fluoride, 1.5-3 parts cationic surfactant, 1-2 parts defoamer, and 5-10 parts anti-cracking agent. This composite high-efficiency brightener offers the advantages of high surface gloss and hardness for treated concrete. However, this composite high-efficiency brightener only acts on the concrete surface and must be applied to the concrete mold during use.

[0005] Invention patent CN109721275A discloses a concrete brightener and its preparation method. The brightener comprises the following components: a polycarboxylate superplasticizer mother liquor, an anti-UV additive, a sulfonated melamine formaldehyde resin, sodium thiosulfate, caustic soda flakes, and water. This invention enhances the UV radiation resistance and antibacterial properties of concrete treated with the brightener, thereby expanding the concrete's applicability. This concrete brightener can be combined with other admixtures to address concrete surface brightness issues, but the concrete surface hardness is limited.

[0006] Generally speaking, concrete brightener is a concrete admixture used to improve the surface gloss of concrete products. It is usually used in concrete products such as concrete exterior walls, concrete components, sidewalk bricks, and concrete floors. Generally speaking, concrete brighteners are divided into two types according to the method of use. One is internal admixture, which is used in combination with admixtures during concrete prefabrication; the other is external admixture, which is applied to the formwork surface during concrete pouring or after the concrete has hardened. Internal admixture can be added all at once during premixing, avoiding tedious processes, but the added brightener components may have a certain impact on the working condition and performance of the concrete. The focus of external application of brighteners is to eliminate bubbles on the concrete surface and improve the surface strength of the concrete, while the focus of internal admixtures is how to use bubbles and slurry to improve the working condition of the concrete and thus improve the brightness and strength of the concrete surface. This is based on such a contradiction.

[0007] Therefore, it is necessary to develop a concrete brightener and its preparation method that can be used in conjunction with admixtures during concrete prefabrication to simultaneously improve the strength and surface hardness of concrete and enhance the brightness, smoothness and wear resistance of the concrete surface. This is the key to solving the above technical problems. Summary of the Invention

[0008] In view of the many defects and shortcomings in the above-mentioned background technology, the present invention has made improvements and innovations thereto, with the aim of providing a concrete brightener that can be used in combination with admixtures during concrete prefabrication. After using the concrete brightener, the surface of the cement product is smooth, the color is more uniform, and the bright effect can be maintained for a long time.

[0009] Another purpose of the present invention is to achieve strong adsorption and dispersion of cement particles, which can improve the strength and surface hardness of cement products and enhance the surface brightness, smoothness and wear resistance of cement products. At the same time, the preparation conditions of the present invention are mild, and no organic solvents are used in the synthesis process, which is safe and environmentally friendly.

[0010] In order to solve the above problems and achieve the above objectives of the invention, the present invention provides a concrete brightener and a preparation method thereof by adopting the following design structure and the following technical solutions:

[0011] A concrete brightener comprising the following components in parts by weight:

[0012] 100-140 parts of hydrophilic unsaturated carboxylic acid ester, 70-100 parts of lipophilic unsaturated carboxylic acid ester, 0.5-2 parts of modified single-walled carbon nanotubes, 8-14 parts of ethylene glycol distearate, 5-9 parts of pyrazoline compound, 2-7 parts of polyglycerol fatty acid ester, 6-12 parts of nonionic surfactant, 18-35 parts of fluorocarbon surfactant, 5-9 parts of molecular regulator, 3-8 parts of initiator, and 664-783 parts of water.

[0013] Preferably, the hydrophilic unsaturated carboxylic acid ester is a mixture of one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, ethylene glycol dimethacrylate, tert-butyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

[0014] Preferably, the lipophilic unsaturated carboxylic acid ester is a mixture of one or more of methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate and butyl acrylate.

[0015] Preferably, the pyrazoline compound is a mixture of one or more of 1,3-diaryl-2-pyrazoline, 1-(4-dimethylaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, 5-phenyl-1-(4-dimethylaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, 1-(4-diethanolaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, and 1,5-diaryl-3-(2-hydroxy-4,6-dimethoxyphenyl)-2-pyrazoline.

[0016] Preferably, the modified single-walled carbon nanotubes are a mixture of one or more of hydroxylated single-walled carbon nanotubes and carboxylated single-walled carbon nanotubes, wherein the modified single-walled carbon nanotubes have a length of 5-30 μm and a specific surface area of ​​>380 m 2 / g.

[0017] Preferably, the polyglycerol fatty acid ester is a mixture of one or more of polyglyceryl-6 distearate, polyglyceryl-10 stearate, and polyglyceryl-10 dipalmitate.

[0018] Preferably, the nonionic surfactant is a mixture of one or more of octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, alkyl alcohol amide polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0019] Preferably, the fluorocarbon surfactant is DuPont FSK.

[0020] Preferably, the molecular regulator is a mixture of one or more of mercaptoethanol, thioglycolic acid, and sodium methyl propene sulfonate;

[0021] The initiator is a mixture of one or more of potassium persulfate and ammonium persulfate.

[0022] Preferably, a method for preparing a concrete brightener is characterized in that the method comprises the following steps:

[0023] S1. Dissolve a fluorocarbon surfactant in water at 40°C with stirring, then add ethylene glycol distearate, a pyrazoline compound, and polyglycerol fatty acid ester in sequence, stir for 30 minutes, and then cool to room temperature to obtain a solution A, wherein the mass of water is 3 to 6 times the total mass of the fluorocarbon surfactant, ethylene glycol distearate, pyrazoline compound, and polyglycerol fatty acid ester;

[0024] S2, adding a hydrophilic unsaturated carboxylic acid ester, a lipophilic unsaturated carboxylic acid ester, water, a molecular regulator, and an initiator to a reaction kettle at room temperature with stirring, stirring for 30 minutes, stopping stirring, raising the temperature to 60°C, allowing the reaction to proceed for 3 hours, cooling to room temperature, adding modified single-walled carbon nanotubes, and stirring for 30 minutes to obtain solution B, wherein the mass of water is 2 to 3 times the total mass of the hydrophilic unsaturated carboxylic acid ester, the lipophilic unsaturated carboxylic acid ester, the molecular regulator, the initiator, and the modified single-walled carbon nanotubes;

[0025] S3. Under normal temperature and stirring conditions, slowly add the above-mentioned liquid A and non-ionic surfactant into liquid B, and stir for 30 minutes to obtain a concrete brightener.

[0026] The beneficial effects of the present invention compared with the prior art are:

[0027] 1. The concrete brightener prepared by the present invention has a strong adsorption and dispersion effect on cement, which can improve the strength and surface hardness of cement products, and enhance the surface brightness, smoothness and wear resistance of cement products;

[0028] 2. The concrete brightener prepared by the present invention can be used in combination with admixtures during concrete prefabrication. After using the concrete brightener, the surface of the cement product is smooth, the color is more uniform, and the bright effect can be maintained for a long time.

[0029] 3. The preparation conditions of the present invention are mild, and no organic solvent is used in the synthesis process, which is safe and environmentally friendly;

[0030] 4. In the present invention, since both the hydrophilic unsaturated carboxylic acid ester and the lipophilic unsaturated carboxylic acid ester are polymerizable monomers, the polymer prepared by temperature and static conditions has a wide molecular weight distribution, a high degree of polymerization, a complex polymerization unit, and contains both hydrophilic and lipophilic chains in the structure. The polymer can effectively disperse the modified single-walled carbon nanotubes through hydrogen bonding and adsorption. During the concrete pouring and vibration process, since the polymer contains a large number of lipophilic segments, the polymer is more inclined to the concrete template where an oil film has been formed. The modified single-walled carbon nanotubes carried along can promote the nucleation of hydrates on the concrete surface, promote hydration, improve the pore structure, and thus enhance the surface strength of the concrete. In addition, the lipophilic groups of the polymer are conducive to the release of free water in the cement slurry, thereby improving the density of the concrete structure;

[0031] 5. The pyrazoline compound used in the present invention can reflect visible light, thereby improving the whiteness and glossiness of concrete;

[0032] 6. The polyglycerol fatty acid ester used in the present invention can enrich the slurry, thereby improving the density of the concrete;

[0033] 7. In the present invention, a large number of bubbles are required for the working state of concrete. Both nonionic surfactants and fluorocarbon surfactants provide bubbles for concrete. However, the bubbles in the concrete will affect the appearance of the concrete to a certain extent. Nonionic surfactants can become unstable as the pH of cement hydration increases, thereby eliminating the impact of bubbles on the appearance of hardened concrete while ensuring the working state of concrete.

[0034] 8. In the present invention, fluorocarbon surfactants can significantly reduce the surface tension of the solvent at extremely low concentrations. They have a stronger tendency to leave the aqueous solution than other surfactant molecules, and are directed to aggregate and arrange into molecular films at the liquid / gas interface (between concrete and formwork). DETAILED DESCRIPTION

[0035] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the technical solutions of the present invention are further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other unless there is a conflict. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0036] A concrete brightener comprising the following components in parts by weight:

[0037] 100-140 parts of hydrophilic unsaturated carboxylic acid ester, 70-100 parts of lipophilic unsaturated carboxylic acid ester, 0.5-2 parts of modified single-walled carbon nanotubes, 8-14 parts of ethylene glycol distearate, 5-9 parts of pyrazoline compound, 2-7 parts of polyglycerol fatty acid ester, 6-12 parts of nonionic surfactant, 18-35 parts of fluorocarbon surfactant, 5-9 parts of molecular regulator, 3-8 parts of initiator, and 664-783 parts of water.

[0038] In the present invention, ethylene glycol distearate is heated and emulsified in a surfactant solution and then crystallized after cooling, thereby producing a strong pearlescent luster.

[0039] Furthermore, the hydrophilic unsaturated carboxylic acid ester is a mixture of one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, ethylene glycol dimethacrylate, tert-butyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

[0040] Furthermore, the lipophilic unsaturated carboxylic acid ester is a mixture of one or more of methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, and butyl acrylate.

[0041] In the present invention, hydrophilic unsaturated carboxylic acid esters and lipophilic unsaturated carboxylic acid esters are both polymerizable monomers. Temperature and static conditions are utilized to prepare a polymer having a wide molecular weight distribution, a high degree of polymerization, complex polymer units, and a structure containing both hydrophilic and lipophilic chains. This polymer can effectively disperse modified single-walled carbon nanotubes through hydrogen bonding and adsorption. During the concrete pouring and vibration process, because the polymer contains a large number of lipophilic segments, the polymer is more likely to form an oil film in the concrete formwork. The modified single-walled carbon nanotubes carried along can promote hydrate nucleation on the concrete surface, promote hydration, improve pore structure, and thus enhance concrete surface strength. In addition, the lipophilic groups of the polymer facilitate the release of free water in the cement slurry, thereby increasing the density of the concrete structure.

[0042] Further, the pyrazoline compound is a mixture of one or more of 1,3-diaryl-2-pyrazoline, 1-(4-dimethylaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, 5-phenyl-1-(4-dimethylaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, 1-(4-diethanolaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, and 1,5-diaryl-3-(2-hydroxy-4,6-dimethoxyphenyl)-2-pyrazoline.

[0043] In the present invention, the pyrazoline compound can reflect visible light, thereby improving the whiteness and glossiness of concrete.

[0044] Furthermore, the modified single-walled carbon nanotubes are a mixture of one or more of hydroxylated single-walled carbon nanotubes and carboxylated single-walled carbon nanotubes, wherein the modified single-walled carbon nanotubes have a length of 5-30 μm and a specific surface area of ​​more than 380 m 2 / g.

[0045] Furthermore, the polyglyceryl fatty acid ester is a mixture of one or more of polyglyceryl-6 distearate, polyglyceryl-10 stearate, and polyglyceryl-10 dipalmitate.

[0046] In the present invention, polyglycerol fatty acid ester can enrich the slurry, thereby improving the density of concrete.

[0047] Furthermore, the nonionic surfactant is a mixture of one or more of octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, alkylolamide polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0048] In the present invention, a large number of bubbles are required for the working state of concrete. Both nonionic surfactants and fluorocarbon surfactants provide bubbles for concrete. However, the bubbles in the concrete will affect the appearance of the concrete to a certain extent. Nonionic surfactants can become unstable as the pH of cement hydration increases, thereby eliminating the influence of bubbles on the appearance of hardened concrete while ensuring the working state of concrete.

[0049] Furthermore, the fluorocarbon surfactant is DuPont FSK.

[0050] In the present invention, fluorocarbon surfactants can significantly reduce the surface tension of the solvent at extremely low concentrations, have a stronger tendency to leave the aqueous solution than other surfactant molecules, and are directed to aggregate and arrange into molecular films at the liquid / gas interface (between concrete and formwork).

[0051] Furthermore, the molecular regulator is a mixture of one or more of mercaptoethanol, thioglycolic acid, and sodium methyl propylene sulfonate;

[0052] The initiator is a mixture of one or more of potassium persulfate and ammonium persulfate.

[0053] Specifically, a method for preparing a concrete brightener comprises the following steps:

[0054] S1. Dissolve a fluorocarbon surfactant in water at 40°C with stirring, then add ethylene glycol distearate, a pyrazoline compound, and polyglycerol fatty acid ester in sequence, stir for 30 minutes, and then cool to room temperature to obtain a solution A, wherein the mass of water is 3 to 6 times the total mass of the fluorocarbon surfactant, ethylene glycol distearate, pyrazoline compound, and polyglycerol fatty acid ester;

[0055] S2. Adding a hydrophilic unsaturated carboxylic acid ester, a lipophilic unsaturated carboxylic acid ester, water, a molecular regulator, and an initiator to a reaction kettle at room temperature with stirring, stirring for 30 minutes, stopping stirring, raising the temperature to 60° C., allowing the reaction to proceed for 3 hours, cooling to room temperature, adding modified single-walled carbon nanotubes, and stirring for 30 minutes to obtain a solution B, wherein the mass of water is 2 to 3 times the total mass of the hydrophilic unsaturated carboxylic acid ester, the lipophilic unsaturated carboxylic acid ester, the molecular regulator, the initiator, and the modified single-walled carbon nanotubes;

[0056] S3. Under normal temperature and stirring conditions, slowly add the above-mentioned liquid A and non-ionic surfactant into liquid B, and stir for 30 minutes to obtain a concrete brightener.

[0057] In summary, a more specific embodiment of the present invention is:

[0058] Example 1

[0059] This embodiment provides a method for preparing a concrete brightener, and the specific steps are as follows:

[0060] S1, under stirring conditions at 40℃, add fluorocarbon surfactant 18 g of FSK was dissolved in 209 g of water, and then 8 g of ethylene glycol distearate, 3 g of 1,3-diaryl-2-pyrazoline, 2 g of 1-(4-dimethylaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, and 7 g of polyglycerol-6 distearate were added in sequence. The mixture was stirred for 30 min and then cooled to room temperature to obtain solution A.

[0061] S2. Add 140 g of hydroxyethyl acrylate, 70 g of butyl acrylate, 455 g of water, 5 g of mercaptoethanol, and 6 g of potassium persulfate to a reaction kettle at room temperature with stirring. Stir for 30 min, then stop stirring, raise the temperature to 60°C, allow to react for 3 h, cool to room temperature, add 1 g of hydroxylated single-walled carbon nanotubes, and stir for 30 min to obtain Solution B.

[0062] S3. At room temperature and stirring conditions, liquid A and 12 g of octylphenol polyoxyethylene ether were slowly added to liquid B. After stirring for 30 min, a concrete brightener was obtained, which was recorded as GG-1.

[0063] Example 2

[0064] This embodiment provides a method for preparing a concrete brightener, and the specific steps are as follows:

[0065] S1, under stirring conditions at 40℃, add fluorocarbon surfactant 35 g of FSK was dissolved in 265 g of water, and then 14 g of ethylene glycol distearate, 9 g of 5-phenyl-1-(4-dimethylaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, and 2 g of polyglycerol-10 stearate were added in sequence. The mixture was stirred for 30 min and then cooled to room temperature to obtain solution A.

[0066] S2, under normal temperature and stirring conditions, add 100 g of hydroxypropyl acrylate, 20 g of 4-hydroxybutyl acrylate, 85 g of methyl acrylate, 427 g of water, 5 g of thioglycolic acid, and 3 g of ammonium persulfate to a reaction kettle, stir for 30 min, then stop stirring, raise the temperature to 60°C, let it react for 3 h, cool to room temperature, add 0.5 g of carboxylated single-walled carbon nanotubes, and stir for 30 min to obtain solution B;

[0067] S3. At room temperature and stirring conditions, liquid A and 9 g of nonylphenol polyoxyethylene ether were slowly added to liquid B. After stirring for 30 min, a concrete brightener was obtained, which was recorded as GG-2.

[0068] Example 3

[0069] This embodiment provides a method for preparing a concrete brightener, and the specific steps are as follows:

[0070] S1, under stirring conditions at 40℃, add fluorocarbon surfactant Dissolve 27 g of FSK in 150 g of water, then add 14 g of ethylene glycol distearate, 7 g of 1-(4-diethanolaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, and 2 g of polyglycerol-10 dipalmitate in sequence. Stir for 30 min and cool to room temperature to obtain solution A.

[0071] S2, under normal temperature and stirring conditions, add 100 g of ethylene glycol dimethacrylate, 60 g of methyl methacrylate, 25 g of butyl methacrylate, 527 g of water, 9 g of sodium methacrylic acid, and 4.5 g of potassium persulfate to a reactor, stir for 30 min, then stop stirring, raise the temperature to 60°C, let it react for 3 h, cool to room temperature, add 2 g of hydroxylated single-walled carbon nanotubes, and stir for 30 min to obtain solution B;

[0072] S3, under normal temperature and stirring conditions, slowly add liquid A and 12g of fatty alcohol polyoxyethylene ether into liquid B, and stir for 30min to obtain a concrete brightener, which is recorded as GG-3.

[0073] Example 4

[0074] This embodiment provides a method for preparing a concrete brightener, and the specific steps are as follows:

[0075] S1, under stirring conditions at 40℃, add fluorocarbon surfactant 35 g of FSK was dissolved in 261 g of water, and then 11 g of ethylene glycol distearate, 3 g of 1,3-diaryl-2-pyrazoline, 5 g of 1,5-diaryl-3-(2-hydroxy-4,6-dimethoxyphenyl)-2-pyrazoline, 3 g of polyglycerol-6 distearate, and 1.5 g of polyglycerol-10 stearate were added in sequence. The mixture was stirred for 30 min and then cooled to room temperature to obtain solution A.

[0076] S2, under normal temperature and stirring conditions, add 70 g of tert-butyl acrylate, 70 g of hydroxyethyl methacrylate, 100 g of ethyl methacrylate, 504 g of water, 3 g of mercaptoethanol, 4 g of thioglycolic acid, and 3 g of potassium persulfate to a reaction kettle, stir for 30 min, then stop stirring, raise the temperature to 60°C, let it stand for 3 h, cool to room temperature, add 1 g of hydroxylated single-walled carbon nanotubes and 1 g of carboxylated single-walled carbon nanotubes, and stir for 30 min to obtain solution B;

[0077] S3. At room temperature and stirring conditions, liquid A and 6 g of lauryl alcohol polyoxyethylene ether were slowly added to liquid B. After stirring for 30 min, a concrete brightener was obtained, which was recorded as GG-4.

[0078] Comparative Example 1

[0079] This embodiment provides a method for preparing a concrete brightener, and the specific steps are as follows:

[0080] At 40℃ and under stirring conditions, the fluorocarbon surfactant 18 g of FSK was dissolved in 209 g of water, and then 8 g of ethylene glycol distearate, 3 g of 1,3-diaryl-2-pyrazoline, 2 g of 1-(4-dimethylaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, and 7 g of polyglycerol-6 distearate were added in sequence. The mixture was stirred for 30 min and then cooled to room temperature to obtain a concrete brightener, which was recorded as DB-1.

[0081] Comparative Example 2

[0082] This embodiment provides a method for preparing a concrete brightener, and the specific steps are as follows:

[0083] Under normal temperature and stirring conditions, 140 g of hydroxyethyl acrylate, 70 g of butyl acrylate, 455 g of water, 5 g of mercaptoethanol, and 6 g of potassium persulfate were added to the reactor. After stirring for 30 minutes, stirring was stopped, the temperature was raised to 60°C, and the reaction was allowed to stand for 3 hours. After cooling to room temperature, 1 g of hydroxylated single-walled carbon nanotubes was added, and the mixture was stirred for 30 minutes to obtain a concrete brightener, which was recorded as DB-2.

[0084] Comparative Example 3

[0085] This embodiment provides a method for preparing a concrete brightener, and the specific steps are as follows:

[0086] S1, under stirring conditions at 40℃, add fluorocarbon surfactant Dissolve 27 g of FSK in 150 g of water, then add 14 g of ethylene glycol distearate, 7 g of 1-(4-diethanolaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, and 2 g of polyglycerol-10 dipalmitate in sequence. Stir for 30 min and cool to room temperature to obtain solution A.

[0087] S2, under normal temperature and stirring conditions, add 100 g of ethylene glycol dimethacrylate, 60 g of methyl methacrylate, 25 g of butyl methacrylate, 527 g of water, 9 g of sodium methacrylic acid, and 4.5 g of potassium persulfate to a reactor, stir for 30 min, then stop stirring, raise the temperature to 60°C, let it react for 3 h, cool to room temperature, add 2 g of hydroxylated single-walled carbon nanotubes, and stir for 30 min to obtain solution B;

[0088] S3: At room temperature and stirring conditions, liquid A was slowly added to liquid B and stirred for 30 minutes to obtain a concrete brightener, which was recorded as DB-3.

[0089] Comparative Example 4

[0090] This embodiment provides a method for preparing a concrete brightener, and the specific steps are as follows:

[0091] S1, dissolve 14 g of ethylene glycol distearate, 7 g of 1-(4-diethanolaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, and 2 g of polyglycerol-10 dipalmitate in 150 g of water at 40°C with stirring, stir for 30 min, and then cool to room temperature to obtain solution A;

[0092] S2. At room temperature and with stirring, solution A and 2 g of hydroxylated single-walled carbon nanotubes were slowly added into 527 g of water and stirred for 30 min to obtain a concrete brightener, which was designated as DB-4.

[0093] The ingredients and quantities of comparative examples 5-10 are matched

[0094]

[0095] Performance test examples

[0096] In the application examples, unless otherwise specified, the cement used is ordinary Portland cement (Dongjun 42.5), and the sand has a fineness modulus of M x =2.6 Zone II sand, gravel with continuously graded particle size of 5 to 20 mm, water-cement ratio of 0.3, and sand rate of 42%.

[0097] The air content, slump and slump loss over time of concrete were tested with reference to GB / T50080-2016 “Standard for Test Methods of Performance of Ordinary Concrete Mixtures”. The admixture dosage was fixed at 2.0% of the adhesive dosage. The concrete working performance test results are shown in Table 1.

[0098]

[0099] Note: PT-0 is a common water-reducing agent produced by a domestic company; in Example 1 to Comparative Example 3, a concrete brightener accounting for 0.5% of the total adhesive was added while adding the same amount of PT-0.

[0100] As can be seen from the data in Table 1, the concrete brightener Examples 1-4 prepared by the present invention can be used in conjunction with admixtures during concrete precasting. Their initial expansion is slightly smaller than the benchmark, their air content is higher than the benchmark, and their flow rate is faster than the benchmark, indicating that the addition of the brightener helps to improve the concrete's encapsulation and has a positive effect on the concrete's working state. At the same time, the 28-day compressive strength of brightener Examples 1-4 is higher than the benchmark, indicating that the concrete brightener can improve concrete strength. The comparative data of Comparative Examples 1-3 and Example 1 show that nonionic surfactants help improve the concrete's state through bubbles, and hydrophilic and lipophilic polymers and modified single-walled carbon nanotubes have a significant effect on strength. The comparative data of Comparative Example 4 with Comparative Examples 1-3 and Example 1 show that the modified single-walled carbon nanotubes, ethylene glycol distearate, pyrazoline compounds, and polyglycerol fatty acid esters alone have no significant effect on the concrete's working performance and mechanical properties.

[0101] Rebound tests were conducted on concrete specimens using a standard rebound hammer, in accordance with JGJ / T 232-2011, "Technical Specification for Testing Concrete Compressive Strength by Rebound Method." Gloss testing was also conducted using an 85° low-gloss meter, in accordance with GB / T 9754. The results are shown in Table 2.

[0102] 28-day rebound value MPa Glossiness Gu Concrete surface PT-0 62.07 45.7 There are few large bubbles on the concrete surface, but many small bubbles are dense. Example 1 66.18 63.9 There are no large or small bubbles or color difference on the concrete surface Example 2 66.80 64.3 There are no large or small bubbles or color difference on the concrete surface Example 3 67.10 64.5 There are no large or small bubbles or color difference on the concrete surface Example 4 67.05 62.7 There are no large or small bubbles or color difference on the concrete surface Comparative Example 1 62.13 56.2 There are no large bubbles, a small number of small bubbles, and no color difference on the concrete surface Comparative Example 2 66.58 51.3 A small amount of large bubbles and a small amount of small bubbles on the concrete surface Comparative Example 3 65.94 59.6 There are no large bubbles, a small number of small bubbles, and no color difference on the concrete surface Comparative Example 4 61.19 48.1 There are few large bubbles on the concrete surface, but many small bubbles are dense.

[0103] Comparison of Examples 1-4 with the blank sample PT-0 demonstrates that the concrete brightener prepared by the present invention can enhance the surface strength, surface brightness, and smoothness of concrete, making the concrete's apparent color more uniform and maintaining a long-lasting bright effect. Comparison of Comparative Examples 1-3 with Example 1 demonstrates that fluorocarbon surfactants can effectively emulsify or disperse ethylene glycol distearate, pyrazoline compounds, and polyglycerol fatty acid esters. During the concrete vibration process, the active ingredients are transported to the concrete surface via bubbles, thereby improving the concrete's surface brightness. Furthermore, the polymer synthesized from hydrophilic and lipophilic chain segments transports modified single-walled carbon nanotubes to the concrete surface, thereby improving the concrete's rebound strength. Comparative Example 4 demonstrates that the modified single-walled carbon nanotubes, ethylene glycol distearate, pyrazoline compounds, and polyglycerol fatty acid esters alone cannot fully demonstrate their properties without the aid of a carrier.

[0104] In order to verify the effects of the ingredients and components of the concrete synergist of the present invention, comparative examples 5 to 10 were designed and synthesized, and their properties are shown in Table 3.

[0105]

[0106] Comparative Example 5, compared to Example 1, replaces the hydrophilic and lipophilic unsaturated carboxylates with methyl glycolate and 2-hydroxybutyl propylene, which do not contain double bonds. This results in the initiator failing to form free radicals and, consequently, polymers, leading to solution instability. This indirectly suggests that the broadly distributed polymer formed by the hydrophilic and lipophilic unsaturated carboxylates contributes to the longitudinal dispersion of the cement paste.

[0107] Comparative Example 6, compared to Example 1, replaces hydroxylated single-walled carbon nanotubes with hydroxylated multi-walled carbon nanotubes. Compared to multi-walled carbon nanotubes, single-walled carbon nanotubes have a smaller diameter, a relatively larger specific surface area, a higher aspect ratio, and no inter-walled carbon nanotube slip. Furthermore, when added as nanoreinforcements to a cement matrix, single-walled carbon nanotubes can strongly interact with the crystalline dislocations of the cement components, thereby achieving reinforcement. In terms of mechanical behavior, multi-walled carbon nanotubes are composed of multiple concentric layers of carbon atoms, and the forces between the layers are very weak.

[0108] Comparative Example 7 Compared with Example 1, the nonionic surfactant and fluorocarbon surfactant were replaced with sodium dodecylbenzenesulfonate (anionic surfactant). The data showed that sodium dodecylbenzenesulfonate brought too many bubbles to the concrete. Although it helped the state of the concrete, it affected the concrete strength and the appearance of the formed concrete.

[0109] Compared with Example 1, in Comparative Example 8, the content of the hydrophilic unsaturated carboxylate was increased to 190 parts (100-140 parts of the hydrophilic unsaturated carboxylate), and the content of the lipophilic unsaturated carboxylate was reduced to 20 parts (70-100 parts of the lipophilic unsaturated carboxylate). The 28-day rebound value of the concrete was significantly reduced, which may be due to the hydrophilic-lipophilic ratio causing the surface strength to be affected.

[0110] Compared with Example 1, Comparative Example 9 increases the amount of hydroxyl single-walled carbon nanotubes, ethylene glycol distearate, and polyglycerol fatty acid. However, the dispersibility of these three substances is limited. If the amount is too high, not only will there be no positive effect, but it will also cause negative effects due to the inability to disperse.

[0111] Compared with Example 1, Comparative Example 10 reduced the content of the hydrophilic unsaturated carboxylate to 50 parts (100-140 parts of the hydrophilic unsaturated carboxylate), and increased the content of the lipophilic unsaturated carboxylate to 160 parts (70-100 parts of the lipophilic unsaturated carboxylate). In the water-soluble initiation system (potassium persulfate, ammonium persulfate), the lipophilic unsaturated carboxylate could not be completely converted into free radicals, resulting in incomplete polymerization.

[0112] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and does not limit the present invention in any other form. Any person skilled in the art may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any modification of the above description according to the technical essence of the present invention without departing from the technical solution of the present invention is not possible.

[0113] Any simple modification, equivalent change and modification made to the embodiment still belongs to the technical aspects of the present invention.

[0114] The scope of protection of the case.

Claims

1. A concrete brightener, characterized in that: The composition comprises the following components in parts by weight: 100-140 parts of hydrophilic unsaturated carboxylic acid ester, 70-100 parts of lipophilic unsaturated carboxylic acid ester, 0.5-2 parts of modified single-walled carbon nanotubes, 8-14 parts of ethylene glycol distearate, 5-9 parts of pyrazoline compound, 2-7 parts of polyglycerol fatty acid ester, 6-12 parts of nonionic surfactant, 18-35 parts of fluorocarbon surfactant, 5-9 parts of molecular regulator, 3-8 parts of initiator, and 664-783 parts of water.

2. A concrete brightener according to claim 1, characterized in that: The hydrophilic unsaturated carboxylic acid ester is a mixture of one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, ethylene glycol dimethacrylate, tert-butyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

3. A concrete brightener according to claim 1, characterized in that: The lipophilic unsaturated carboxylic acid ester is a mixture of one or more of methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate and butyl acrylate.

4. A concrete brightener according to claim 1, characterized in that: The pyrazoline compound is a mixture of one or more of 1,3-diaryl-2-pyrazoline, 1-(4-dimethylaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, 5-phenyl-1-(4-dimethylaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, 1-(4-diethanolaminoethylsulfonylphenyl)-3-(4-chlorophenyl)-2-pyrazoline, and 1,5-diaryl-3-(2-hydroxy-4,6-dimethoxyphenyl)-2-pyrazoline.

5. A concrete brightener according to claim 1, characterized in that: The modified single-walled carbon nanotubes are a mixture of one or more of hydroxylated single-walled carbon nanotubes and carboxylated single-walled carbon nanotubes, wherein the modified single-walled carbon nanotubes have a length of 5-30 μm and a specific surface area of ​​more than 380 m 2 / g.

6. A concrete brightener according to claim 1, characterized in that: The polyglycerol fatty acid ester is a mixture of one or more of polyglycerol-6 distearate, polyglycerol-10 stearate and polyglycerol-10 dipalmitate.

7. A concrete brightener according to claim 1, characterized in that: The nonionic surfactant is a mixture of one or more of octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, alkyl alcohol amide polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

8. A concrete brightener according to claim 1, characterized in that: The fluorocarbon surfactant is DuPont 9. A concrete brightener according to claim 1, characterized in that: The molecular regulator is a mixture of one or more of mercaptoethanol, thioglycolic acid, and sodium methyl propylene sulfonate; The initiator is a mixture of one or more of potassium persulfate and ammonium persulfate.

10. The method for preparing a concrete brightener according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: S1. Dissolve a fluorocarbon surfactant in water at 40°C with stirring, then add ethylene glycol distearate, a pyrazoline compound, and polyglycerol fatty acid ester in sequence, stir for 30 minutes, and then cool to room temperature to obtain a solution A, wherein the mass of water is 3 to 6 times the total mass of the fluorocarbon surfactant, ethylene glycol distearate, pyrazoline compound, and polyglycerol fatty acid ester; S2. Adding a hydrophilic unsaturated carboxylic acid ester, a lipophilic unsaturated carboxylic acid ester, water, a molecular regulator, and an initiator to a reaction kettle at room temperature with stirring, stirring for 30 minutes, stopping stirring, raising the temperature to 60° C., allowing the reaction to proceed for 3 hours, cooling to room temperature, adding modified single-walled carbon nanotubes, and stirring for 30 minutes to obtain a solution B, wherein the mass of water is 2 to 3 times the total mass of the hydrophilic unsaturated carboxylic acid ester, the lipophilic unsaturated carboxylic acid ester, the molecular regulator, the initiator, and the modified single-walled carbon nanotubes; S3. Under normal temperature and stirring conditions, slowly add the above-mentioned liquid A and non-ionic surfactant into liquid B, and stir for 30 minutes to obtain a concrete brightener.

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