Viscosity-reducing surface brightener as well as preparation method and application thereof

Abstract

The invention belongs to the field of concrete admixtures, and particularly relates to a viscosity-reducing surface brightener as well as a preparation method and application thereof. The preparation method of the viscosity-reducing surface brightener comprises the following steps: carrying out polymerization reaction on a polyether macromonomer, unsaturated carboxylic acid, unsaturated carboxylic ester and a modified monomer in water, the polymerization reaction system is converted from initial solution polymerization to soap-free emulsion polymerization by controlling the proportion of unsaturated carboxylic acid, unsaturated carboxylic ester and modified monomer in the polymerization reaction system, and the obtained polymerization reaction product is the viscosity-reducing surface brightener. The viscosity-reducing surface brightener prepared by the method provided by the invention can effectively improve the initial flowability and glossiness of concrete at a lower mixing amount.

Description

Technical Field

[0001] The invention belongs to the field of concrete admixtures, and particularly relates to a viscosity-reducing surface brightener and a preparation method and application thereof. Background Art

[0002] With the rapid development of the construction and materials industries, modern buildings are increasingly trending towards taller, lighter, and longer-span structures. High-grade concrete, with its high overall strength and light weight, is increasingly being used in national infrastructure projects. To achieve high-strength or ultra-high-strength concrete, a large amount of cementitious materials and a low water-binder ratio are required. This results in high viscosity and slow flow in fresh concrete, making construction difficult. Furthermore, with the increasing scarcity of river sand resources, manufactured sand has become the primary fine aggregate in Fujian Province. Compared to natural river sand, manufactured sand particles have a rough, sharp, and angular surface, a large fineness modulus, poor gradation, a high bulk void ratio, and contain a large amount of stone dust. These factors increase viscosity when mixed with concrete. The rough surface and mechanical interlocking increase resistance to concrete flow. The low number of intermediate particles in the manufactured sand gradation makes the prepared concrete susceptible to segregation and bleeding. This is especially true when mixing high-strength concrete. Due to the mix design and inherent viscosity of the cementitious materials, the concrete mix is ​​viscous, difficult to pump, and has a negative impact on the concrete's appearance.

[0003] Currently, the main methods for reducing the viscosity of high-strength concrete are increasing the superplasticizer dosage, using high-quality mineral admixtures, and optimizing particle size distribution. However, increasing the superplasticizer dosage to improve the initial fluidity of concrete can easily lead to adverse effects such as segregation and bleeding in the later stages of concrete construction. Summary of the Invention

[0004] The first object of the present invention is to provide a method for preparing a viscosity-reducing surface brightener capable of improving the initial fluidity and glossiness of concrete.

[0005] The second object of the present invention is to provide a viscosity-reducing surface brightener prepared by the above method.

[0006] The third object of the present invention is to provide application of the above-mentioned viscosity-reducing surface brightener in the field of construction.

[0007] The preparation method of the viscosity-reducing surface brightener provided by the present invention comprises: polymerizing a polyether macromonomer, an unsaturated carboxylic acid, an unsaturated carboxylic acid ester, and a modified monomer in water; controlling the ratio of the unsaturated carboxylic acid, the unsaturated carboxylic acid ester, and the modified monomer in the polymerization reaction system so as to convert the polymerization reaction system from an initial solution polymerization to a soap-free emulsion polymerization; and obtaining a polymerization reaction product, which is the viscosity-reducing surface brightener;

[0008] The modified monomer has a structure shown in formula (1):

[0009] CH3(CH2)nCH=CHCH2(CH=CH)p(CH2)mR1 Formula (1)

[0010] In formula (1), n, m and p are each independently 0 to 7, the sum of n, m and p is 14 or more, R1 is -COOA1 or -SO3A2, and A1 and A2 are each independently H, K or Na.

[0011] The key to the present invention lies in the complex polymerization of a polyether macromonomer, an unsaturated carboxylic acid, and an unsaturated carboxylic acid ester, and using a monomer having the structure represented by formula (1) as a modifier, while simultaneously adopting a soap-free emulsion polymerization method. The resulting viscosity-reducing surface brightener can effectively improve the initial fluidity and glossiness of concrete at a relatively low dosage. This is presumably due to the following: compared to other polymerization methods, soap-free emulsion polymerization can significantly reduce the primary particle size of the polymer product. The small primary particle size and the modified monomer with a specific structure can form tiny balls in the concrete mixture, thereby reducing the viscosity of the mixture; and, as the hydration process proceeds, the tiny microbeads formed by the improved method of the present invention tend to aggregate on the surface of the concrete mixture, effectively preventing the formation of pores on the concrete surface, thereby improving the glossiness of the concrete surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The concrete demoulding effect diagrams corresponding to the viscosity-reducing surface brighteners obtained in each example and the reference viscosity-reducing surface brighteners obtained in the comparative example are shown. DETAILED DESCRIPTION

[0013] The preparation method of the viscosity-reducing surface brightener provided by the present invention comprises: carrying out a polymerization reaction of a polyether macromonomer, an unsaturated carboxylic acid, an unsaturated carboxylic acid ester, and a modified monomer in water; controlling the ratio of the unsaturated carboxylic acid, the unsaturated carboxylic acid ester, and the modified monomer in the polymerization reaction system so as to transform the polymerization reaction system from an initial solution polymerization to a soap-free emulsion polymerization; and obtaining the polymerization reaction product, which is the viscosity-reducing surface brightener.

[0014] In the present invention, the mass ratio of the unsaturated carboxylic acid, the unsaturated carboxylic acid ester and the modified monomer is preferably 1: (0.5-1): (0.005-0.015). Specifically, the mass ratio of the unsaturated carboxylic acid to the unsaturated carboxylic acid ester can be 1: 0.5, 1: 0.6, 1: 0.7, 1: 0.8, 1: 0.9, 1: 1 or any value therebetween. The mass ratio of the unsaturated carboxylic acid to the modified monomer can be 1: 0.005, 1: 0.008, 1: 0.01, 1: 0.012, 1: 0.015 or any value therebetween. The mass ratio of the polyether macromonomer to the unsaturated carboxylic acid is preferably (0.5-2): 1, such as 0.5: 1, 0.8: 1, 1: 1, 1.2: 1, 1.5: 1, 1.8: 1, 2: 1 or any value therebetween. The mass ratio of water to polyether macromonomer is preferably (5-23):1, such as 5:1, 8:1, 10:1, 12:1, 15:1, 18:1, 20:1, 22:1, 23:1 or any value therebetween.

[0015] In a preferred embodiment, the polymerization reaction comprises using a mixture of a polyether macromonomer, a portion of an unsaturated carboxylic acid, a portion of an unsaturated carboxylic acid ester, a modifying monomer, an oxidant, and water as a base liquid, and adding a mixture of the remaining unsaturated carboxylic acid, the remaining unsaturated carboxylic acid ester, a reducing agent, a chain transfer agent, and water dropwise to the base liquid under stirring. During the dropwise addition, the reaction liquid changes from colorless to milky white. After the dropwise addition is complete, stirring and the reaction is continued. The resulting reaction product is a viscosity-reducing surface brightener. In this case, the ratio of hydrophilic monomers to lipophilic monomers in the system can be adjusted to allow the polymerization reaction system to transition from an initial solution polymerization to a soap-free emulsion polymerization.

[0016] In the above-mentioned polymerization reaction process, the conditions for the dropwise addition preferably include a temperature of 5°C to 40°C, such as 5°C, 8°C, 10°C, 12°C, 15°C, 18°C, 20°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C, 38°C, 40°C or any value therebetween; a time of 1h to 5h, such as 1h, 2h, 3h, 4h, 5h or any value therebetween. The conditions for the stirring reaction preferably include a temperature of 5°C to 40°C, such as 5°C, 8°C, 10°C, 12°C, 15°C, 18°C, 20°C, 22°C, 25°C, 28°C, 30°C, 32°C, 35°C, 38°C, 40°C or any value therebetween; a time of 0.5h to 5h, such as 0.5h, 1h, 2h, 3h, 4h, 5h or any value therebetween.

[0017] In the above-mentioned polymerization reaction process, the mass ratio of the unsaturated carboxylic acid contained in the base liquid to the unsaturated carboxylic acid added dropwise is preferably (0.5-2):1, such as 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1, 2:1 or any value therebetween. The mass ratio of the unsaturated carboxylic acid ester contained in the base liquid to the unsaturated carboxylic acid ester added dropwise is preferably (0.05-0.08):1, such as 0.05:1, 0.06:1, 0.07:1, 0.08:1 or any value therebetween. The mass ratio of the water contained in the base liquid to the water added dropwise is preferably (7.1-8):1, such as 7.1:1, 7.2:1, 7.3:1, 7.4:1, 7.5:1, 7.6:1, 7.7:1, 7.8:1, 7.9:1, 8:1 or any value therebetween.

[0018] In the present invention, the modified monomer has a structure shown in formula (1):

[0019] CH3(CH2)nCH=CHCH2(CH=CH)p(CH2)mR1 Formula (1)

[0020] In formula (1), n, m, and p are each independently 0 to 7, the sum of n, m, and p is 14 or greater, R1 is -COOA1 or -SO3A2, and A1 and A2 are each independently H, K, or Na. n, m, and p can each independently be 0, 1, 2, 3, 4, 5, 6, or 7. The sum of n, m, and p can be 14, 15, 16, 17, 18, 19, 20, 21, or any value therebetween.

[0021] The modified monomer is particularly preferably at least one selected from α-olefin sulfonate (AOS), oleic acid and linoleic acid. In this case, the obtained viscosity-reducing surface brightener can reduce the viscosity of the concrete mixture to a lower level and more effectively avoid the formation of surface pores, thereby giving the concrete surface a higher gloss.

[0022] In the present invention, the polyether macromonomer has a structure shown in formula (2):

[0023]

[0024] In formula (2), R 21 、R 22 and R 23 Each independently represents H or a C1-C5 alkylene group, R 24 is a single bond, O or a C1-C5 alkylene group, R 25 is C1-C5 alkylene or C6-C 10 The arylene group, R 26is a single bond, O or a C1-C5 alkylene group, and n is an integer from 1 to 100. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl or neopentyl. Specific examples of C1-C5 alkylene groups include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, tert-pentylene or neopentylene. C6-C 10 Specific examples of the arylene group include, but are not limited to, phenylene, benzylene, benzylene trimethylene or benzylene tetramethylol. n can be 1, 3, 5, 8, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 or any value therebetween. The polyether macromonomer can be specifically selected from at least one of 3-methylbutan-3-yl polyethylene glycol ether, 2-methylprop-2-enyl polyethylene glycol ether, ethylene glycol monovinyl polyethylene glycol ether (EPEG) and 4-hydroxybutyl vinyl polyethylene glycol ether (VPEG). In addition, the number average molecular weight of the polyether macromonomer is preferably 2400-3000, such as 2400, 2500, 2600, 2700, 2800, 2900, 3000 or any value therebetween.

[0025] In the present invention, the unsaturated carboxylic acid preferably has a structure represented by formula (3):

[0026]

[0027] In formula (3), R 31 and R 32 Each independently represents H, C1-C5 alkyl or -R 33 -COOH and R 31 and R 32 At least one of them is -R 33 -COOH, R 33 does not exist or is a C1-C5 alkylene group; when R 31 and R 32 All are -R 33 -COOH, R 31 and R 32 Able to bond into a ring; R 31 ` and R 32`Each independently represents H or a C1-C5 alkyl group. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl. Specific examples of C1-C5 alkylene groups include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, tert-pentylene, or neopentylene. When R 31 and R 32 All are -R 33 -COOH, R 31 and R 32 The unsaturated carboxylic acid can be bonded to form a ring, in which case an acid anhydride is formed. In view of the availability of raw materials, the unsaturated carboxylic acid is particularly preferably selected from at least one of acrylic acid, methacrylic acid, itaconic acid and maleic anhydride.

[0028] In the present invention, the unsaturated carboxylic acid ester preferably has a structure represented by formula (4):

[0029]

[0030] In formula (4), R 41 is H or C1-C5 alkyl; R 42 and R 43 Each independently represents H, C1-C5 alkyl or -R 45 -COOH and R 42 and R 43 At least one of them is -R 45 -COOH, R 45 does not exist or is a C1-C5 alkylene group; when R 42 and R 43 All are -R 45 -COOH, R 42 and R 43 Able to bond into a ring; R 44 is a C1-C5 alkylene group. Specific examples of C1-C5 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl. Specific examples of C1-C5 alkylene groups include, but are not limited to, methylene, ethylene, n-propylene, isopropylene, n-butylene, sec-butylene, isobutylene, tert-butylene, n-pentylene, isopentylene, tert-pentylene, or neopentylene. When R 42 and R 43 All are -R 45 -COOH, R 42 and R 43The unsaturated carboxylic acid ester can be bonded to form a ring, in which case an acid anhydride is formed. In view of the availability of raw materials, the unsaturated carboxylic acid ester is particularly preferably hydroxyethyl acrylate and / or hydroxypropyl acrylate.

[0031] In the present invention, specific examples of the oxidizing agent include, but are not limited to, at least one of hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, cumene hydroperoxide, dibenzoyl peroxide, and tert-butyl peroxide, preferably a mixture of two or more. Specific examples of the reducing agent include, but are not limited to, at least one of L-ascorbic acid, azobisisopropylimidazoline hydrochloride, azobiscyclohexylcarbonitrile, sodium bisulfite, sodium sulfite, sodium metabisulfite, bleaching agent, ferrous sulfate heptahydrate, sodium hypophosphite, sodium phosphite, and ferrous ammonium sulfate, preferably a mixture of two or more. The amount of the oxidizing agent is preferably 0.3% to 3.0% by weight of the polyether macromonomer, such as 0.3%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, or any value therebetween. The amount of the reducing agent is preferably 0.3% to 3.0% by mass of the polyether macromonomer, such as 0.3%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3% or any value therebetween.

[0032] In the present invention, the chain transfer agent is preferably a mercaptan chain transfer agent, more preferably selected from the group consisting of mercaptoacetic acid, mercaptopropionic acid, mercaptoethanol, and mercaptopropanol. Furthermore, the amount of the chain transfer agent is preferably 0.1 to 2.0% of the total mass of the polyether macromonomer, unsaturated carboxylic acid, unsaturated carboxylic acid ester, and modifying monomer, such as 0.1%, 0.3%, 0.5%, 1%, 1.5%, 2%, or any value therebetween.

[0033] The present invention also provides a viscosity-reducing surface brightener prepared by the method.

[0034] In addition, the present invention also provides application of the viscosity-reducing surface brightener in the field of construction.

[0035] The present invention will be described in detail below through examples.

[0036] In the following examples and comparative examples, the amounts of each component are in parts by weight.

[0037] In the following examples and comparative examples, the six-carbon polyether monomer (GPEG) was purchased from Jiahua Chemical with the brand name E-60; the five-carbon polyether monomer (TPEG) was purchased from Jiahua Chemical with the brand name TPEG-2400; and sodium α-olefin sulfonate (AOS) was purchased from China National Light Industry Co., Ltd. with the brand name AOS / 92.

[0038] Example 1

[0039] 6 parts of hexacarbonyl polyether monomer (GPEG), 2 parts of acrylic acid (AA), 0.2 parts of methyl methacrylate, 0.04 parts of sodium α-olefin sulfonate (AOS), and 76.64 parts of deionized water were added to a reactor. After stirring for 5 minutes, 0.2 parts of ammonium persulfate was added all at once to form a base solution. At 5°C with constant stirring, 2 parts of acrylic acid, 3 parts of hydroxyethyl acrylate, 0.12 parts of vitamin C (Vc), 0.12 parts of mercaptoethanol, and 10 parts of deionized water were added dropwise to the base solution over a period of 1 hour. During the addition, the reaction solution changed from colorless to milky white, indicating that the polymerization reaction had transitioned from solution polymerization to soap-free emulsion polymerization. After the addition was complete, the reaction was stirred at 5°C for 1 hour to obtain a viscosity-reducing surface brightener, designated J-1.

[0040] Example 2

[0041] 6 parts of five-carbon polyether monomer (TPEG), 2 parts of maleic acid, 0.1 parts of methyl acrylate, 0.02 parts of oleic acid and 79.75 parts of deionized water were added to the reactor. After stirring for 5 minutes, 0.1 parts of sodium persulfate were added at one time to form a base liquid. At a temperature of 40 ° C and under continuous stirring, 2 parts of acrylic acid, 1.9 parts of hydroxypropyl acrylate, 0.05 parts of bleaching powder, 0.08 parts of thioglycolic acid and 10 parts of deionized water were added dropwise to the base liquid, and the addition was controlled to be completed within 4 hours. During the addition, the reaction liquid changed from colorless to milky white, indicating that the polymerization reaction had changed from solution polymerization to soap-free emulsion polymerization. After the addition was completed, the reaction was continued to stir at 40 ° C for 1 hour to obtain a viscosity-reducing surface brightener, which was recorded as J-2.

[0042] Example 3

[0043] 8 parts of a five-carbon polyether monomer (TPEG), 2 parts of acrylic acid (AA), 2 parts of maleic acid, 0.2 parts of methyl methacrylate, 0.06 parts of linoleic acid, and 71.31 parts of deionized water were added to a reactor. After stirring for 5 minutes, 0.2 parts of ammonium persulfate was added all at once to form a base solution. At 20°C with constant stirring, 2 parts of acrylic acid, 3.8 parts of hydroxyethyl acrylate, 0.17 parts of vitamin C (Vc), 0.16 parts of mercaptopropionic acid, and 10 parts of deionized water were added dropwise over a period of 3 hours. During the addition, the reaction solution changed from colorless to milky white, indicating that the polymerization reaction had transitioned from solution polymerization to soap-free emulsion polymerization. After the addition was complete, the reaction was stirred at 20°C for 1 hour to obtain a viscosity-reducing surface brightener, designated J-3.

[0044] Example 4

[0045] 4 parts of hexacarbonyl polyether monomer (GPEG), 1 part of methacrylic acid, 0.2 parts of methyl acrylate, 0.03 parts of sodium α-olefin sulfonate (AOS), and 79.81 parts of deionized water were added to a reactor. After stirring for 5 minutes, 0.2 parts of ammonium persulfate were added all at once to form a base solution. At 15°C with constant stirring, 2 parts of methacrylic acid, 2.5 parts of hydroxyethyl acrylate, 0.12 parts of bleaching powder, 0.14 parts of mercaptoethanol, and 10 parts of deionized water were added dropwise over a period of 2 hours. During the addition, the reaction solution changed from colorless to milky white, indicating that the polymerization reaction had transitioned from solution polymerization to soap-free emulsion polymerization. After the addition was complete, the reaction was stirred at 15°C for 1 hour to obtain a viscosity-reducing surface brightener, designated J-4.

[0046] Comparative Example 1

[0047] A viscosity-reducing surface brightener was prepared according to the method of Example 1, except that the sodium α-olefin sulfonate was replaced by the same weight portion of methyl methacrylate. The other conditions were the same as in Example 1 to obtain a reference viscosity-reducing surface brightener, which was recorded as DJ-1.

[0048] Comparative Example 2

[0049] A viscosity-reducing surface brightener was prepared according to the method of Example 1, except that the amount of acrylic acid in the base liquid was adjusted from 2 parts to 4 parts, and the acrylic acid in the dropping liquid was removed to ensure that the total amount of acrylic acid was 4 parts by weight. However, at this time, the polymerization reaction system was always in solution polymerization and could not be converted into soap-free emulsion polymerization. The remaining conditions were the same as in Example 1, and a reference viscosity-reducing surface brightener was obtained, which was recorded as DJ-2.

[0050] Test Case

[0051] The viscosity reducing surface brighteners obtained in the above examples and the reference viscosity reducing surface brighteners obtained in the comparative examples were tested for viscosity reducing performance of the mixtures according to the group standard "Concrete Viscosity Regulator" T / CECS10157-2021. The total amount of cementitious materials used was 390 kg / m 3 The cement used is PO42.5 grade Conch Cement, with a sand content of 44.5%. The solid content of the viscosity reducing surface brightener is 0.01%, and a steel mold is used to test the apparent performance of the concrete. The viscosity reducing performance (emptying time) is shown in Table 1, and the apparent performance is shown in Tables 1 and Figure 1 .from Figure 1 It can be seen that the concrete added with the present invention has a smooth surface and few pores after molding; while the blank concrete and the comparative samples DJ-1 and DJ-2 have more pores after molding, and the concrete added with DJ-2 has a certain color difference.

[0052] Table 1

[0053] serial number Emptying time ratio Apparent performance J-1 63％ Smooth surface, few pores J-2 70％ Smooth surface, few pores J-3 75％ Smooth surface and few pores J-4 72％ Smooth surface and few pores DJ-1 95％ Many pores DJ-2 96％ Many pores and color difference blank -- Many pores

[0054] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A method for preparing a viscosity-reducing surface brightener, characterized in that: The method comprises: carrying out a polymerization reaction of a polyether macromonomer, an unsaturated carboxylic acid, an unsaturated carboxylic acid ester and a modified monomer in water; controlling the ratio of the unsaturated carboxylic acid, the unsaturated carboxylic acid ester and the modified monomer in the polymerization reaction system so as to convert the polymerization reaction system from an initial solution polymerization to a soap-free emulsion polymerization; and obtaining a polymerization reaction product which is a viscosity-reducing surface brightener; The modified monomer has a structure shown in formula (1): CH3(CH2)nCH=CHCH2(CH=CH)p(CH2)mR1 Formula (1) In formula (1), n, m and p are each independently 0 to 7, the sum of n, m and p is 14 or more, R1 is -COOA1 or -SO3A2, and A1 and A2 are each independently H, K or Na.

2. The method for preparing the viscosity reducing surface brightener according to claim 1, wherein: The polymerization reaction method includes using a mixture of a polyether macromonomer, a portion of an unsaturated carboxylic acid, a portion of an unsaturated carboxylic acid ester, a modifying monomer, an oxidant and water as a base liquid, and dropping a mixture of the remaining unsaturated carboxylic acid, the remaining unsaturated carboxylic acid ester, a reducing agent, a chain transfer agent and water into the base liquid under stirring conditions. During the dropwise addition, the reaction liquid changes from colorless to milky white. After the dropwise addition is completed, the stirring reaction is continued, and the resulting reaction product is a viscosity-reducing surface brightener.

3. The method for preparing the viscosity reducing surface brightener according to claim 2, wherein: The conditions for the dropwise addition include a temperature of 5° C. to 40° C. and a time of 1 h to 5 h.

4. The method for preparing the viscosity reducing surface brightener according to claim 2, wherein: The stirring reaction conditions include a temperature of 5° C. to 40° C. and a time of 0.5 h to 5 h.

5. The method for preparing the viscosity-reducing surface brightener according to any one of claims 1 to 4, characterized in that: The mass ratio of the unsaturated carboxylic acid, unsaturated carboxylic acid ester and modified monomer is 1:(0.5-1):(0.005-0.015); the mass ratio of the polyether macromonomer and unsaturated carboxylic acid is (0.5-2):1; the mass ratio of water and polyether macromonomer is (5-23):

1.

6. The method for preparing the viscosity-reducing surface brightener according to any one of claims 1 to 4, characterized in that: The polyether macromonomer has a structure shown in formula (2): In formula (2), R 21 、R 22 and R 23 Each independently represents H or a C1-C5 alkylene group, R 24 is a single bond, O or a C1-C5 alkylene group, R 25 is C1-C5 alkylene or C6-C 10 The arylene group, R 26 is a single bond, O or a C1-C5 alkylene group, and n is an integer of 1-100.

7. The method for preparing the viscosity-reducing surface brightener according to any one of claims 1 to 4, characterized in that: The unsaturated carboxylic acid has a structure shown in formula (3): In formula (3), R 31 and R 32 Each independently represents H, C1-C5 alkyl or -R 33 -COOH and R 31 and R 32 At least one of them is -R 33 -COOH, R 33 does not exist or is a C1-C5 alkylene group; when R 31 and R 32 All are -R 33 -COOH, R 31 and R 32 Able to bond into a ring; R 31 ` and R 32 ` are each independently H or a C1-C5 alkyl group.

8. The method for preparing the viscosity-reducing surface brightener according to any one of claims 1 to 4, characterized in that: The unsaturated carboxylic acid ester has a structure shown in formula (4): In formula (4), R 41 is H or C1-C5 alkyl; R 42 and R 43 Each independently represents H, C1-C5 alkyl or -R 45 -COOH and R 42 and R 43 At least one of them is -R 45 -COOH, R 45 does not exist or is a C1-C5 alkylene group; when R 42 and R 43 All are -R 45 -COOH, R 42 and R 43 Able to bond into a ring; R 44 It is a C1-C5 alkylene group.

9. A viscosity-reducing surface brightener prepared by the method according to any one of claims 1 to 8.

10. Use of the viscosity-reducing surface brightener according to claim 9 in the field of construction.

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