Low-sensitivity air-entraining type polycarboxylate superplasticizer and preparation method thereof

Abstract

The invention belongs to the technical field of additives, and particularly relates to a low-sensitivity air-entraining type polycarboxylate superplasticizer and a preparation method thereof. The low-sensitivity air-entraining type polycarboxylate superplasticizer is prepared from the following components in parts by weight: 60 to 90 parts of polyacrylic acid, 0.5 to 1.5 parts of stabilizer, 60 to 90 parts of maleated rosin modified polyether macromonomer, 12 to 20 parts of air-entraining monomer, 270 to 320 parts of solvent and 0.5 to 0.8 part of sodium hydroxide. The maleated rosin modified polyether macromonomer comprises the following components in parts by weight: 40-50 parts of ethylene glycol monovinyl polyethylene glycol ether, 10-20 parts of an intermediate and 100-200 parts of absolute ethyl alcohol, the intermediate 1 comprises the following components in parts by weight: 10-20 parts of maleated rosin, 5-10 parts of epoxy chloropropane, 50-70 parts of an organic solvent and 0.1-0.5 part of a catalyst. According to the invention, a hydrophobic cyclic structure of rosin and a hydrophilic group of fatty alcohol-polyoxyethylene ether are introduced, so that the air entraining and foam stabilizing capabilities of the water reducing agent are optimized, meanwhile, the dispersity and compatibility in cement paste are improved through a structural complementary design, and the working performance and durability of the water reducing agent are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of admixtures, and in particular to a low-sensitivity air-entraining polycarboxylate water-reducing agent and a preparation method thereof. Background Art

[0002] As an important component of modern concrete admixtures, polycarboxylate superplasticizer is widely used in various concrete projects due to its excellent dispersibility and environmentally friendly characteristics with low dosage. However, in practical applications, the addition of air-entraining agent often has certain compatibility issues with polycarboxylate superplasticizer. Due to the differences in molecular structure and action mechanism between the two, air-entraining agent is easily interfered by the dispersing function of polycarboxylate superplasticizer, resulting in difficulty in forming a stable structure or uneven distribution of bubbles, thus affecting the frost resistance and durability of concrete.

[0003] This compatibility problem is particularly prominent in complex cement systems. For example, in high-mineral admixture or high-sulfate systems, the competitive adsorption effect between polycarboxylate water-reducing agent and air-entraining agent is more obvious, which may cause the air-entraining agent to fail or weaken, and affect the working performance and structural durability of concrete. Based on this, the development of air-entraining polycarboxylate water-reducing agent is particularly important. By introducing functionalized air-entraining groups into the polycarboxylic acid molecular structure, the organic combination of air-entraining function and dispersing function is achieved. This new admixture can solve the problem of insufficient compatibility between traditional water-reducing agent and air-entraining agent at the molecular level, ensure the stability and uniformity of the concrete bubble structure, and maintain efficient water-reducing performance.

[0004] The research and development of air-entraining polycarboxylate water-reducing agent can not only improve the adaptability of concrete in complex environments, but also provide a new solution for improving the frost resistance, durability and overall construction performance of concrete. This technological breakthrough is of great significance to improving project quality, reducing construction costs and extending the life of structures. At the same time, it promotes the development of concrete admixtures from single function to multi-functional synergy.

[0005] CN115073045A combines the effects of multiple components to make the water reducer insensitive to ambient temperature, cement, and machine-made sand, promote the full hydration of cement under low temperature conditions, improve the initial structure of concrete, and strengthen the development of the later structure of concrete; thereby, the stability and adaptability between the water reducer and the concrete components can be increased, and the water reducer has antifreeze, air entraining, collapse prevention, and water reduction effects, which is of great significance to the wide application of water reducers in modern concrete building materials.

[0006] Patent CN117185699A can improve the workability of concrete; without affecting the strength of concrete, it can appropriately increase the viscosity of the cementitious system and introduce a large number of uniform, tiny, closed and stable bubbles, thereby improving the workability of concrete and avoiding segregation, bleeding, aggregate settlement and other phenomena. Summary of the invention

[0007] The present invention aims to overcome the problems of poor compatibility of existing air-entraining agents with water-reducing agents and poor air-entraining effects, and to develop a polycarboxylic acid water-reducing agent with excellent air-entraining performance and high adaptability and a preparation method thereof. The air-entraining polycarboxylic acid water-reducing agent has the advantages of low sensitivity, good air-entraining performance, stable bubbles, etc., and the preparation process is simple.

[0008] The present invention adopts the following technical solutions:

[0009] In a first aspect of the present invention, a low-sensitivity air-entraining polycarboxylate water-reducing agent is provided, wherein the low-sensitivity air-entraining polycarboxylate water-reducing agent comprises, by weight: 60-90 parts of polyacrylic acid, 0.5-1.5 parts of a stabilizer, 60-90 parts of a maleic rosin-modified polyether macromonomer, 12-20 parts of an air-entraining monomer, 270-320 parts of a solvent, and 0.5-0.8 parts of sodium hydroxide.

[0010] Furthermore, the maleated rosin modified polyether macromonomer comprises: 40-50 parts of ethylene glycol monovinyl polyethylene glycol ether, 10-20 parts of intermediate 1, and 100-200 parts of anhydrous ethanol.

[0011] Furthermore, the intermediate 1 comprises: 10-20 parts of maleic rosin, 5-10 parts of epichlorohydrin, 50-70 parts of organic solvent, and 0.1-0.5 parts of catalyst.

[0012] Furthermore, the raw materials for preparing the air entraining monomer include: 80-120 parts of fatty alcohol polyoxyethylene ether with a polymerization degree of 30-50, 200-230 parts of anhydrous toluene, 1.0-1.5 parts of boron trifluoride-ethyl ether, and 15-40 parts of maleic anhydride.

[0013] Furthermore, the stabilizer is at least one of hydroquinone, benzoquinone, tert-butylhydroquinone and resorcinol.

[0014] Furthermore, the solvent is at least one of methoxy polyethylene glycol ether, ethoxy polyethylene glycol ether and polyethylene glycol.

[0015] Furthermore, the organic solvent is at least one of toluene and xylene.

[0016] Furthermore, the catalyst is at least one of p-toluenesulfonic acid and methanesulfonic acid.

[0017] The second aspect of the present invention provides a method for preparing a low-sensitivity air-entraining polycarboxylate water-reducing agent, the method comprising the following steps:

[0018] S1, subjecting maleic rosin and epichlorohydrin to an epoxide ring-opening reaction under the action of a catalyst to obtain an intermediate 1;

[0019] S2, reacting the intermediate 1 obtained in S1 with ethylene glycol monovinyl polyethylene glycol ether to obtain a maleic rosin modified polyether macromonomer;

[0020] S3, reacting the maleic rosin modified polyether macromonomer obtained in S2 with polyacrylic acid and methoxy polyethylene glycol ether under the action of a functional additive to obtain the low-sensitivity air-entraining polycarboxylic acid water-reducing agent.

[0021] The third aspect of the present invention provides a method for preparing an air entraining monomer, which comprises the following steps: dissolving fatty alcohol polyoxyethylene ether in anhydrous toluene, adding boron trifluoride-ethyl ether, stirring at 60-70° C., slowly adding maleic anhydride dropwise, and reacting at 70-80° C. for 3 hours.

[0022] The beneficial effects of the present invention include at least:

[0023] 1) The polycarboxylate water reducer synthesized in this patent, the hydrophobic ring structure and long chain in the rosin structure and the fatty alcohol polyoxyethylene ether structure are introduced into the water reducer through chemical modification, so that the polycarboxylate water reducer has both good air entraining ability and good foam stabilizing ability;

[0024] 2) In the polycarboxylate water-reducing agent of this invention, the benzene ring structure and resin group of rosin provide it with strong hydrophobicity, and can be connected with the hydrophilic group of AEO through esterification reaction. Through this complementary structural design, the compatibility of the air entraining agent with the cement matrix can be enhanced, and its dispersibility in the cement paste can be improved, thereby improving the working performance and durability of the polycarboxylate water-reducing agent. DETAILED DESCRIPTION

[0025] The preferred embodiment of the present invention will be described in detail below in conjunction with specific embodiments. It should be noted that the following specific embodiments are provided only for the purpose of illustration and are not intended to limit the scope of the present invention. Those skilled in the art may make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

[0026] The experimental methods used in the following specific examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following specific examples can be obtained from conventional commercial channels or prepared according to conventional methods in the art unless otherwise specified.

[0027] In some embodiments of the present invention, a main chain gas-entraining monomer is used. The main chain gas-entraining monomer includes, by weight, 80-120 parts of fatty alcohol polyoxyethylene ether, 200-230 parts of anhydrous toluene, 1.0-1.5 parts of boron trifluoride-ethyl ether, and 15-40 parts of maleic anhydride;

[0028] Wherein, the polymerization degree of the fatty alcohol polyoxyethylene ether is 30-50.

[0029] Based on the above reaction, the inventors used fatty alcohol polyoxyethylene ether with a polymerization degree of 60. However, it was found through testing that when the polymerization degree of fatty alcohol polyoxyethylene ether becomes higher, the air entraining agent cannot effectively introduce bubbles or the bubble stability decreases.

[0030] One embodiment of the present invention relates to an intermediate 1, which comprises, by weight, 10-20 parts of maleic rosin, 50-70 parts of toluene, 0.1-0.5 parts of p-toluenesulfonic acid, and 5-10 parts of epichlorohydrin.

[0031] The reaction temperature is 60-80°C and the reaction time is 2-3 hours.

[0032] One embodiment of the present invention relates to a maleic rosin modified polyether macromonomer, which comprises, by weight, 40-50 parts of ethylene glycol monovinyl polyethylene glycol ether, 1:10-20 parts of an intermediate, and 100-200 parts of anhydrous ethanol.

[0033] Furthermore, the specific preparation method of the maleated rosin modified polyether macromonomer is as follows:

[0034] Ethylene glycol monovinyl polyethylene glycol ether (molecular weight 1200) was heated to a molten state (about 80°C), and then the intermediate 1 was slowly added dropwise, the reaction temperature was maintained at 80-100°C, and the reaction was carried out for 2 hours. After the reaction was completed, it was cooled to room temperature, anhydrous ethanol and isopropanol mixed solvent was added, and the reaction product was washed to remove unreacted substances and by-products to obtain a maleic rosin modified polyether macromonomer.

[0035] One embodiment of the present invention provides a low-sensitivity air-entraining water-reducing agent, and the preparation method thereof is as follows:

[0036] Nitrogen is continuously introduced into a four-necked flask to remove air in the system, 60-90 g of polyacrylic acid is added, and the mixture is heated to 50-60° C. until the polyacrylic acid is completely dissolved; 0.5-1.5 g of hydroquinone, 60-90 g of maleic rosin-modified polyether macromonomer, 270-320 g of methoxy polyethylene glycol ether (molecular weight 1200) and 0.5-0.8 g of sodium hydroxide with a mass fraction of 30% are then added to the four-necked flask; stirring is started at a speed of 180 r / min, the temperature is raised to 140-150° C., vacuum is evacuated to 0.07 MPa, and the reaction is performed for 5-6 hours to obtain the low-sensitivity air-entraining water-reducing agent.

[0037] The following is a description with reference to specific embodiments.

[0038] Example 1

[0039] This embodiment provides a low-sensitivity air-entraining polycarboxylate water-reducing agent and a preparation method thereof, comprising the following steps:

[0040] Step (1): Main chain gas-entraining monomer 1: 100 g of fatty alcohol polyoxyethylene ether (degree of polymerization: 30) was dissolved in 200 mL of anhydrous toluene, and 1.5 g of boron trifluoride-ether was added. After stirring and dissolving at 70° C., 20 g of maleic anhydride was slowly added, and the temperature was maintained at 70-80° C. for 3 hours. After the reaction was completed, the product was cooled and washed with anhydrous ethanol and isopropanol to remove unreacted substances and by-products, and finally vacuum dried to obtain gas-entraining monomer 1.

[0041] Step (2): Maleated rosin modified polyether macromonomer: Dissolve 10g of maleated rosin in 50mL of toluene, stir evenly at 60-80°C, add 0.2g of p-toluenesulfonic acid, and continue stirring until completely dissolved. Slowly drop 6g of epichlorohydrin over 30 minutes, maintain the reaction temperature, and continue stirring the reaction for 2 hours to obtain intermediate 1. Heat 40g of ethylene glycol monovinyl polyethylene glycol ether (molecular weight 1200) to a molten state (about 80°C), then slowly drop 10g of intermediate 1, maintain the reaction temperature at 80-100°C, and react for 2 hours. After the reaction is completed, cool to room temperature, add 100mL of anhydrous ethanol solvent, wash the reaction product to remove unreacted substances and by-products, and obtain maleated rosin modified polyether macromonomer.

[0042] Step (3): continuously introducing nitrogen into a four-necked flask to remove air in the system, adding 70 g of polyacrylic acid, and heating to 60° C. until the polyacrylic acid is completely dissolved; then adding 1.0 g of hydroquinone, 70 g of maleic rosin-modified polyether macromonomer, 290 g of methoxy polyethylene glycol ether (molecular weight 1200), 12 g of air-entraining monomer 1 and 0.8 g of 30% sodium hydroxide into the four-necked flask; starting stirring at a speed of 180 r / min, heating to 140-150° C., evacuating to 0.07 MPa, and reacting for 5-6 hours to obtain the low-sensitivity air-entraining water-reducing agent.

[0043] Embodiment 2:

[0044] This embodiment provides a low-sensitivity air-entraining polycarboxylate water-reducing agent and a preparation method thereof, comprising the following steps:

[0045] Step (1): Main chain gas-entraining monomer 1: 100 g of fatty alcohol polyoxyethylene ether (degree of polymerization: 35) was dissolved in 200 mL of anhydrous toluene, and 1.5 g of boron trifluoride-ether was added. After stirring and dissolving at 70° C., 20 g of maleic anhydride was slowly added, and the temperature was maintained at 70-80° C. for 3 hours. After the reaction was completed, the product was cooled and washed with anhydrous ethanol and isopropanol to remove unreacted substances and by-products, and finally vacuum dried to obtain gas-entraining monomer 1.

[0046] Step (2): Maleated rosin modified polyether macromonomer: Dissolve 10g of maleated rosin in 50mL of toluene, stir evenly at 60-80°C, add 0.2g of p-toluenesulfonic acid, and continue stirring until completely dissolved. Slowly drop 6g of epichlorohydrin over 30 minutes, maintain the reaction temperature, and continue stirring the reaction for 2 hours to obtain intermediate 1. Heat 40g of ethylene glycol monovinyl polyethylene glycol ether (molecular weight 1200) to a molten state (about 80°C), then slowly drop 10g of intermediate 1, maintain the reaction temperature at 80-100°C, and react for 2 hours. After the reaction is completed, cool to room temperature, add 100mL of anhydrous ethanol solvent, wash the reaction product to remove unreacted substances and by-products, and obtain maleated rosin modified polyether macromonomer.

[0047] Step (3): continuously introducing nitrogen into a four-necked flask to remove air in the system, adding 70 g of polyacrylic acid, and heating to 60° C. until the polyacrylic acid is completely dissolved; then adding 1.0 g of hydroquinone, 100 g of maleic rosin-modified polyether macromonomer, 290 g of methoxy polyethylene glycol ether (molecular weight 1200), 18 g of air-entraining monomer 1 and 0.8 g of 30% sodium hydroxide into the four-necked flask; starting stirring at a speed of 180 r / min, heating to 140-150° C., evacuating to 0.07 MPa, and reacting for 5-6 hours to obtain the low-sensitivity air-entraining water-reducing agent.

[0048] Embodiment 3:

[0049] This embodiment provides a low-sensitivity air-entraining polycarboxylate water-reducing agent and a preparation method thereof, comprising the following steps:

[0050] Step (1): Main chain gas-entraining monomer 1: 80 g of fatty alcohol polyoxyethylene ether (degree of polymerization: 40) was dissolved in 200 mL of anhydrous toluene, and 1.5 g of boron trifluoride-ether was added. After stirring and dissolving at 70° C., 40 g of maleic anhydride was slowly added, and the temperature was maintained at 70-80° C. for 3 hours. After the reaction was completed, the product was cooled and washed with anhydrous ethanol and isopropanol to remove unreacted substances and by-products, and finally vacuum dried to obtain gas-entraining monomer 1.

[0051] Step (2): Maleated rosin modified polyether macromonomer: Dissolve 10g of maleated rosin in 50mL of toluene, stir evenly at 60-80°C, add 0.2g of p-toluenesulfonic acid, and continue stirring until completely dissolved. Slowly drop 6g of epichlorohydrin over 30 minutes, maintain the reaction temperature, and continue stirring the reaction for 2 hours to obtain intermediate 1. Heat 40g of ethylene glycol monovinyl polyethylene glycol ether (molecular weight 1200) to a molten state (about 80°C), then slowly drop 10g of intermediate 1, maintain the reaction temperature at 80-100°C, and react for 2 hours. After the reaction is completed, cool to room temperature, add 100mL of anhydrous ethanol solvent, wash the reaction product to remove unreacted substances and by-products, and obtain maleated rosin modified polyether macromonomer.

[0052] Step (3): continuously introducing nitrogen into a four-necked flask to remove air in the system, adding 70 g of polyacrylic acid, and heating to 60° C. until the polyacrylic acid is completely dissolved; then adding 1.0 g of hydroquinone, 90 g of maleic rosin-modified polyether macromonomer, 290 g of methoxy polyethylene glycol ether (molecular weight 1200), 15 g of air-entraining monomer 1 and 0.8 g of 30% sodium hydroxide into the four-necked flask; starting stirring at a speed of 180 r / min, heating to 140-150° C., evacuating to 0.07 MPa, and reacting for 5-6 hours to obtain the low-sensitivity air-entraining water-reducing agent.

[0053] Comparative Example 1: Compared with Example 1, except that the fatty alcohol polyoxyethylene ether (with a polymerization degree of 30) in step (1) is replaced by fatty alcohol polyoxyethylene ether (with a polymerization degree of 60), the rest are the same.

[0054] Comparative Example 2, compared with Example 1, except that ethylene glycol monovinyl polyethylene glycol ether (molecular weight 1200) in step (2) is replaced by ethylene glycol monovinyl polyethylene glycol ether (molecular weight 3000), the rest are the same.

[0055] Comparative Example 3: Compared with Example 1, except that methoxy polyethylene glycol ether (molecular weight 1200) in step (3) is replaced by methoxy polyethylene glycol ether (molecular weight 2400), the other steps are the same.

[0056] Comparative Example 4: Commercially available air-entraining polycarboxylate water reducer PCE-YQ, having the same solid content as the water reducer in the example.

[0057] Minfu P.042.5 cement was used to test the slump of concrete. The mix ratio of the experimental concrete was designed according to JGJ55 “Code for Design of Ordinary Concrete Mix Ratio”. The concrete mix ratio is shown in Table 1.

[0058] Table 1 Concrete mix ratio / m 3

[0059]

[0060] The concrete performance test refers to GB / T 50080-2016 "Test methods for properties of ordinary concrete mixtures" and GB / T50081-2016 "Test methods for mechanical properties of ordinary concrete". The test data are shown in Table 2.

[0061] Table 2 Performance test results

[0062]

[0063]

[0064] It can be seen from Table 2 that the products of Examples 1-3 have low sensitivity and good adaptability to sulfate. Even at a sulfate concentration of 50 mmol / L, they can still maintain good slump (≥200 mm) and expansion (≥510 mm), while maintaining a high air content. This shows that the products of Examples 1-3 can exert excellent dispersibility, fluidity and air entrainment performance in concrete with different sulfate contents.

[0065] Compared with Example 1, in Comparative Example 1, the fatty alcohol polyoxyethylene ether (polymerization degree of 30) in the air entraining monomer 1 was replaced with fatty alcohol polyoxyethylene ether (polymerization degree of 60), resulting in a significant decrease in the initial air content, expansion, and slump. This indicates that the increase in the polymerization degree of fatty alcohol polyoxyethylene ether significantly weakens the air entrainment and dispersion properties of the material.

[0066] Compared with Example 1, Comparative Example 2 replaces ethylene glycol monovinyl polyethylene glycol ether (molecular weight 1200) with ethylene glycol monovinyl polyethylene glycol ether (molecular weight 3000), and Comparative Example 3 replaces methoxy polyethylene glycol ether (molecular weight 1200) with methoxy polyethylene glycol ether (molecular weight 2400). Both replacements lead to a decrease in initial slump and initial air content at a sulfate concentration of 50 mmol / L. Due to the low slump, the dispersibility of the water reducer is very weak, and measuring the dilatation is meaningless. This shows that monomers with too large a molecular weight cause a significant decrease in the dispersibility and air entraining properties of the water reducer, especially at high sulfate concentrations, the fluidity is worse and the dilatation cannot be effectively maintained.

[0067] Comparative Example 4 uses a commercially available water reducer. When the sulfate concentration increases to 50 mmol / L, the air entrainment performance and flowability significantly decrease. In contrast, the products of Examples 1-3 can still maintain excellent performance under the same conditions, which is significantly better than the commercially available water reducer.

[0068] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A low-sensitivity air-entraining polycarboxylate water-reducing agent, characterized in that: The low-sensitivity air-entraining polycarboxylic acid water-reducing agent comprises, by weight: 60-90 parts of polyacrylic acid, 0.5-1.5 parts of stabilizer, 60-90 parts of maleic rosin-modified polyether macromonomer, 12-20 parts of air-entraining monomer, 270-320 parts of solvent and 0.5-0.8 parts of sodium hydroxide.

2. The low-sensitivity air-entraining polycarboxylate water-reducing agent according to claim 1, characterized in that: In parts by weight, the maleic rosin modified polyether macromonomer comprises: 40-50 parts of ethylene glycol monovinyl polyethylene glycol ether, 10-20 parts of intermediate 1, and 100-200 parts of anhydrous ethanol.

3. The low-sensitivity air-entraining polycarboxylate water-reducing agent according to claim 2, characterized in that: The intermediate 1 comprises: 10-20 parts of maleic rosin, 5-10 parts of epichlorohydrin, 50-70 parts of an organic solvent, and 0.1-0.5 parts of a catalyst.

4. The low-sensitivity air-entraining polycarboxylate water-reducing agent according to claim 1, characterized in that: The raw materials for preparing the air entraining monomer include: 80-120 parts of fatty alcohol polyoxyethylene ether with a polymerization degree of 30-50, 200-230 parts of anhydrous toluene, 1.0-1.5 parts of boron trifluoride-ethyl ether, and 15-40 parts of maleic anhydride.

5. The low-sensitivity air-entraining polycarboxylate water-reducing agent according to claim 1, characterized in that: The stabilizer is at least one of hydroquinone, benzoquinone, tert-butylhydroquinone and resorcinol.

6. The low-sensitivity air-entraining polycarboxylate water-reducing agent according to claim 1, characterized in that: The solvent is at least one of methoxy polyethylene glycol ether, ethoxy polyethylene glycol ether and polyethylene glycol.

7. The low-sensitivity air-entraining polycarboxylate water-reducing agent according to claim 2, characterized in that: The organic solvent is at least one of toluene and xylene.

8. The low-sensitivity air-entraining polycarboxylate water-reducing agent according to claim 2, characterized in that: The catalyst is at least one of p-toluenesulfonic acid and methanesulfonic acid.

9. A method for preparing a low-sensitivity air-entraining polycarboxylate water-reducing agent, characterized in that: The preparation method comprises the following steps: S1, subjecting maleic rosin and epichlorohydrin to an epoxide ring-opening reaction under the action of a catalyst to obtain an intermediate 1; S2, reacting the intermediate 1 obtained in S1 with ethylene glycol monovinyl polyethylene glycol ether to obtain a maleic rosin modified polyether macromonomer; S3, reacting the maleic rosin modified polyether macromonomer obtained in S2 with polyacrylic acid and methoxy polyethylene glycol ether under the action of a functional additive to obtain the low-sensitivity air-entraining polycarboxylic acid water-reducing agent.

10. A method for preparing an air-entraining monomer, characterized in that: The preparation method comprises the following steps: dissolving fatty alcohol polyoxyethylene ether in anhydrous toluene, adding boron trifluoride-ethyl ether, stirring at 60-70° C., slowly dropping maleic anhydride, and reacting at 70-80° C. for 3 hours.

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