CN115960322A - Polycarboxylic acid viscosity reducer and preparation method thereof - Google Patents

Abstract

The invention discloses a polycarboxylic acid viscosity reducer and a preparation method thereof, wherein the viscosity reducer comprises the following components in parts by weight: 30-35 parts of prenyl alcohol polyoxyethylene ether, 1-5 parts of unsaturated carboxylic acid, 0.5-2 parts of unsaturated carboxylic ester, 0.1-2 parts of cationic monomer, 0.1-2 parts of double bond-containing silane coupling agent, 0.1-0.5 part of oxidant, 0.01-0.1 part of reducing agent, 0.05-0.3 part of chain transfer agent and 0.1-2 parts of neutralizer; wherein the mol ratio of the prenyl alcohol polyoxyethylene ether to the unsaturated carboxylic acid is 1:1.0 to 3.0. The viscosity reducer increases the thickness of a water film layer on the surface of cement particles from a self molecular structure, improves the content of free water, reduces the content of a residual water reducer in cement pore liquid, strengthens the surface activity capability of the cement pore liquid, and achieves the purpose of viscosity reduction. The viscosity reducer can obviously reduce the viscosity of concrete, improve the dispersibility, plasticity retention property and workability.

Description

A kind of polycarboxylate viscosity reducer and preparation method thereof

technical field

The invention belongs to the field of building materials, and in particular relates to a polycarboxylic acid-based viscosity reducer and a preparation method thereof.

Background technique

With the rapid development of my country's modern economy, countries all over the world have higher and higher requirements for the construction level and the quality of concrete. As one of the main materials for construction projects, concrete is also developing from ordinary to high-strength and ultra-high-performance. The composition of high-strength and ultra-high-performance concrete is characterized by low water-binder ratio; however, as the water-binder ratio decreases, the viscosity of the concrete mixture gradually increases, causing a series of construction problems such as concrete mixing, transportation, and pumping , which largely limits the promotion and application of high-strength and ultra-high-performance concrete. In addition, due to the shortage of river sand resources, a large amount of machine-made sand has begun to be used in the preparation of concrete. The machine-made sand has many edges and corners and poor gradation, resulting in more prominent viscosity problems, which is not conducive to the pumping and construction of high-performance and ultra-high-performance concrete. Therefore, the high viscosity of high-strength ultra-high performance concrete has become a difficult problem in concrete construction technology. Therefore, it is of great significance to study how to reduce the viscosity of concrete.

Viscosity reduction methods that can be used at this stage are mainly carried out from two aspects of organic admixtures and admixtures. The added organic viscosity reducer is mainly based on air-entraining performance, resulting in the formation of a large number of tiny airtight air bubbles in the concrete mixture, which will weaken the frictional resistance between aggregate particles, thereby reducing the viscosity of concrete; but the air-entraining viscosity-reducing effect Limited and excessive addition will adversely affect the strength of concrete. In terms of admixtures, at present, the working performance of concrete is mainly improved by adding silica fume, fly ash, and microbeads. Very limited and expensive, which increases the cost of concrete and limits its application in concrete. Therefore, it is imminent to develop new polycarboxylate viscosity reducers. CN108299604B discloses a polycarboxylic acid viscosity reducer, its raw material includes basic raw material, modified raw material, oxidizing agent, reducing agent and chain transfer agent; Said basic raw material includes terminal alkenyl polyether monomer and unsaturated carboxylic acid, so The modified raw materials include unsaturated carboxylic acid esters and alkyl carboxylic acid esters. Although this viscosity reducer has a good viscosity reduction effect, its application range is relatively limited, and its adaptability to materials is not obvious, especially for concrete currently dominated by machine-made sand; moreover, machine-made sand contains expansive soil components. It has a great influence on the properties of concrete such as dispersibility and plasticity.

Contents of the invention

In order to solve the above technical problems, the present invention provides a polycarboxylate viscosity reducer. Starting from its own molecular structure, the viscosity reducer increases the thickness of the water film layer on the surface of cement particles, increases the free water content and reduces the residual water reducing agent content in the cement pore fluid, strengthens its surface activity, and achieves the purpose of reducing viscosity.

The present invention is realized through the following technical solutions:

A polycarboxylic acid-based viscosity reducer, characterized in that: the viscosity reducer includes the following components in parts by weight: 30-35 parts of isopentenol polyoxyethylene ether, 1-35 parts of unsaturated carboxylic acid 5 parts, 0.5-2 parts of unsaturated carboxylate, 0.1-2 parts of cationic monomer, 0.1-2 parts of silane coupling agent containing double bond, 0.1-0.5 part of oxidizing agent, 0.01-0.1 part of reducing agent, 0.05-0 part of chain transfer agent 0.3 parts, 0.5-2 parts of neutralizing agent; wherein, the molar ratio of the isopentenol polyoxyethylene ether to the unsaturated carboxylic acid is 1:1.0-3.0.

The weight average molecular weight of the viscosity reducer is 10,000 to 30,000.

The weight average molecular weight of the isopentenol polyoxyethylene ether is 300-1200.

The unsaturated carboxylic acid includes one or more of acrylic acid, methacrylic acid, maleic anhydride and fumaric acid.

The unsaturated carboxylic acid ester includes one or more of methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, monomethyl maleate and monomethyl fumarate.

The cationic monomer includes one or more of tetramethylammonium chloride, methacryloxyethyltrimethylammonium chloride, and dimethyldiallylammonium chloride.

The oxidizing agent includes one or more of hydrogen peroxide, potassium persulfate, ammonium persulfate, and benzoyl peroxide, and the reducing agent includes sodium bisulfite, ferrous sulfate, sodium bisulfite and L-ascorbic acid. One or more of them, the chain transfer agent includes one or more of thioglycolic acid, 3-mercaptopropionic acid, 2-mercaptoethanol, sodium hypophosphite, and dodecanthiol.

The silane coupling agent containing double bonds is vinyltrimethylsilane, 3-(2,3 epoxypropoxy)propylmethyldiethoxysilane, vinyltriethoxysilane, γ-methyl One or several kinds of acryloxypropyltrimethoxysilane.

The neutralizing agent includes one or more of sodium hydroxide, potassium hydroxide, ethanolamine, triethylamine, and AMP-95.

The application of the present invention further provides a kind of preparation method of polycarboxylate viscosity reducer, described method is carried out as follows:

(1) Add the isopentenol polyoxyethylene ether and water weighed according to the formula into the reaction kettle, continue to stir until it is completely dissolved, feed nitrogen into the reaction kettle, remove the air in the reaction kettle, and then add the Double bond silane coupling agent, keep stirring evenly;

(2) Add oxidizing agent in reactor, keep stirring for 5-10 minutes;

(3) First, add the mixed solution A of unsaturated carboxylic acid, unsaturated carboxylic acid ester, cationic monomer and deionized water dropwise at a constant speed in the reactor, and then add reducing agent, chain transfer agent and The mixed solution B of deionized water, the dripping time of solutions A and B are respectively controlled at 2.-3.5h;

(4) Stirring continuously, aging for 1-3h, after the aging is completed, the temperature of the reactor is lowered to 35° C., adding a neutralizing agent, adjusting the pH of the reactant to 5-7, and finally adjusting the concentration of the reactant to 40%-50%, to obtain Polycarboxylate viscosity reducer.

In the present invention, isopentenol polyoxyethylene ether, unsaturated carboxylic acid, unsaturated carboxylic acid ester, cationic monomer, and double bond-containing silane coupling agent are used as polymerization raw materials, through the action of chain transfer agent and redox system, in an inert gas The environment is formed by free radical polymerization.

Compared with the prior art, the present invention has the following advantages:

1. The viscosity reducer of the present invention has low energy consumption, small dosage and wide adaptability, and can significantly reduce concrete viscosity, improve dispersibility, plastic retention and workability. Hydrophobic groups gather on the surface of the water film layer and arrange in a direction on the liquid-air interface of the air bubbles, reducing the surface tension and making it easy to form many tiny air bubbles in the concrete mixture. The relative sliding between cement particles and aggregate particles in concrete improves the workability of concrete mixture.

2. The present invention introduces functional group molecules containing double bond siloxane structure into the main chain of polycarboxylic acid molecule, and carries out copolymerization reaction with unsaturated carboxylic acid, polyoxyethylene ether, etc., and the silane coupling agent containing double bond is currently a A good chemical bonding monomer, the hydrolyzed silicic acid oligomer can chemically bond with the silicate in cement, which has a stronger surface bonding ability than adsorption, and improves the dispersion of low-activity cement. And significantly improve the anchoring capacity;

3. The present invention introduces a cationic group, and methacryloyloxyethyltrimethylammonium chloride is a cationic functional monomer with both a quaternary ammonium group and an unsaturated vinyl group, and grafts it In the molecular structure, the prepared polymer has the characteristics of low dosage, good dispersion, excellent plastic retention effect, and early strength;

4. The hydrophobic group monomers introduced in the present invention work synergistically with hydrophilic groups to keep the water film stable, prevent the water film from penetrating into the cement particles, delay the hydration process to a certain extent, and make the concrete have Good condition retention ability.

5. The preparation method of the viscosity reducer of the present invention is easy to operate, simple and easy to implement, strong in operability, high in production efficiency, safe and pollution-free in the production process, and easy for industrialized production.

Detailed ways

The present invention will be described in detail below, and the technical solutions in the embodiments of the present invention will be clearly and completely described. Apparently, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1.

A polycarboxylate viscosity reducer, comprising the following components by mass: isopentenol polyoxyethylene ether TPEG-400: 300g, 43.1g of acrylic acid, 8g of methyl methacrylate, methacryloxy Ethyltrimethylammonium chloride 15g, vinyltrimethylsilane 3.33g, hydrogen peroxide 1.8g, L-ascorbic acid 0.47g, mercaptoethanol 1.5g, sodium hydroxide 10g, deionized water 270g.

Example 2.

A polycarboxylate viscosity reducer, comprising the following components by mass: isopentenol polyoxyethylene ether TPEG-600: 300g, vinyltrimethylsilane 2.22g, hydrogen peroxide 1.77g (concentration 27.5% ), 42.7g of acrylic acid, 8g of methyl methacrylate, 15g of methacryloxyethyltrimethylammonium chloride, 0.45g of L-ascorbic acid, 1.6g of mercaptoethanol, 10g of sodium hydroxide, and 270g of deionized water.

Example 3.

A preparation method of polycarboxylate viscosity reducer, carried out according to the following steps:

(1.) Add 300g of prenol polyoxyethylene ether TPEG-800 and 200g of deionized water into the reactor, blow in nitrogen gas, remove the air in the reactor, control the temperature of the reactor at 40°C, and stir until it is completely Dissolve, then add 1.66g vinyltrimethylsilane, keep stirring;

(2) Add 1.8g hydrogen peroxide (concentration 27.5%) into the reaction kettle and stir for 5min;

(3) Add 42.7g of acrylic acid, 8g of methyl methacrylate, 15g of methacryloyloxyethyltrimethylammonium chloride, and 20g of deionized water into the reactor dropwise at a constant speed, and drop it at a constant speed after 10 minutes. Add 0.45g L-ascorbic acid, 1.65g mercaptoethanol, 50g deionized water mixed solution B, and the solution A and solution B are added dropwise for 2.5h and 3h respectively.

(4) After the dropwise addition, keep at 60°C for 1 hour of continuous aging. After the aging is completed, turn on the circulating water to cool down to 35°C, add 10g of sodium hydroxide (concentration 32%) to neutralize the solution to 6±1, and adjust the concentration to 50% with water. That is, a polycarboxylic acid viscosity reducer is obtained.

Example 4.

A preparation method of polycarboxylate viscosity reducer, carried out according to the following steps:

(1.) Add 300g isopentenol polyoxyethylene ether TPEG-1000 and 200g deionized water into the reactor, feed nitrogen, stir until it is completely dissolved, remove the air in the reactor, and control the temperature of the reactor to 40 ℃, then add 2.23g γ-methacryloxypropyl trimethoxysilane, and keep stirring;

(2) Add 1.8g hydrogen peroxide (concentration 27.5%) into the reaction kettle and stir for 5min;

(3) Add 34g of acrylic acid, 6g of methyl methacrylate, 13g of methacryloyloxyethyltrimethylammonium chloride, and 20g of deionized water into the reaction kettle dropwise at a constant speed, and the time is controlled to be 2.5 drops. After 10 minutes, a mixed solution of 0.55g L-ascorbic acid, 1.72g mercaptoethanol, and 50g deionized water was added dropwise to the reactor at a constant speed, and the addition was completed in 3 hours;

(4) After the dropwise addition, keep at 60°C for 1 hour of continuous aging, turn on the circulating water and cool down to 40°C, then add 10g of sodium hydroxide (concentration 32%) solution to neutralize to 6±1, replenish water to adjust the concentration to 50%, and obtain Polycarboxylate viscosity reducer.

Example 5.

A preparation method of polycarboxylate viscosity reducer, carried out according to the following steps:

(1.) Add 300g isopentenol polyoxyethylene ether TPEG-1200 and 200g deionized water into the reactor, feed nitrogen, stir until it is completely dissolved, remove the air in the reactor, and control the temperature of the reactor to 40 ℃, then add 2.23g γ-methacryloxypropyl trimethoxysilane, and keep stirring;

(2) Add 1.84g hydrogen peroxide (concentration 27.5%) into the reaction kettle and stir for 5min;

(3) Add 34g of acrylic acid, 6g of methyl methacrylate, 13g of methacryloyloxyethyltrimethylammonium chloride, and 20g of deionized water into the reaction kettle dropwise at a constant speed, and the time is controlled to be 2.5 drops. After 10 minutes, add a mixed solution of 0.5g L-ascorbic acid, 1.2g mercaptoethanol, and 50g deionized water dropwise at a constant speed in the reaction kettle, and the addition is completed in 3 hours;

(4) After the dropwise addition, keep at 60°C for 1 hour of continuous aging, turn on the circulating water and cool down to 40°C, then add 10g of sodium hydroxide (concentration 32%) solution to neutralize to 6±1, replenish water to adjust the concentration to 50%, and obtain Polycarboxylate viscosity reducer.

Example 6.

(1.) Add 300g isopentenol polyoxyethylene ether TPEG-800 and 200g deionized water into the reactor, feed nitrogen, stir until it is completely dissolved, remove the air in the reactor, and control the temperature of the reactor to 40 ℃, then add 2.79g γ-methacryloxypropyltrimethoxysilane, and keep stirring;

(2) 2.6g ammonium persulfate was added into the reaction kettle, stirred for 5min;

(3) Add 42.7g of acrylic acid, 8g of methyl methacrylate, 15g of methacryloyloxyethyltrimethylammonium chloride, and 20g of deionized water into the reaction kettle dropwise at a constant speed, and the time is controlled at 2.5h After the dropwise addition was completed, 10 minutes later, a mixed solution of 0.48g L-ascorbic acid, 1.8g mercaptopropionic acid, and 50g deionized water was added dropwise to the reactor at a constant speed, and the dropwise addition was completed within 3 hours;

(4) After the dropwise addition, keep at 60°C for 1 hour of continuous aging, turn on the circulating water and cool down to 40°C, then add 10g of sodium hydroxide (concentration 32%) solution to neutralize to 6±1, replenish water to adjust the concentration to 50%, and obtain Polycarboxylate viscosity reducer.

Comparative example 1

In this comparative example, on the basis of Example 3, no cationic monomer was added to prepare the polycarboxylic acid viscosity reducer.

A preparation method of polycarboxylate viscosity reducer, carried out according to the following steps:

(1.) Add 300g of prenol polyoxyethylene ether TPEG-800 and 200g of deionized water into the reactor, blow in nitrogen gas, remove the air in the reactor, control the temperature of the reactor at 40°C, and stir until it is completely Dissolve, then add 1.72g vinyltrimethylsilane, keep stirring;

(2) Add 1.85g hydrogen peroxide (concentration 27.5%) into the reaction kettle and stir for 5min;

(3) Add 40.3g of acrylic acid, 16g of methyl methacrylate, and 20g of deionized water into the reaction kettle dropwise at a constant speed. After 10 minutes, add 0.48g of L-ascorbic acid, 1.62g of mercaptoethanol, and 50g of deionized water dropwise at a constant speed. The mixing solution B, solution A and solution B dropping time are 2.5h and 3h respectively.

(4) After the dropwise addition, keep at 60°C for 1 hour of continuous aging. After the aging is completed, turn on the circulating water to cool down to 35°C, add 10g of sodium hydroxide (concentration 32%) to neutralize the solution to 6±1, and adjust the concentration to 50% with water. That is, a polycarboxylic acid viscosity reducer is obtained.

Comparative example 2

In this comparative example, on the basis of Example 3, a polycarboxylic acid viscosity reducer was prepared without adding a double bond-containing silane coupling agent.

A preparation method of polycarboxylate viscosity reducer, carried out according to the following steps:

(1.) Add 300g of prenol polyoxyethylene ether TPEG-800 and 200g of deionized water into the reactor, blow in nitrogen gas, remove the air in the reactor, control the temperature of the reactor at 40°C, and stir until it is completely Dissolve, stirring continuously;

(2) Add 1.83g hydrogen peroxide (concentration 27.5%) into the reaction kettle and stir for 5min;

(3) Add 41.5g of acrylic acid, 7.2g of methyl methacrylate, 15.3g of methacryloxyethyltrimethylammonium chloride, and 20g of deionized water into the reaction kettle dropwise at a constant speed. After 10 minutes, A mixed solution B of 0.5g L-ascorbic acid, 1.61g mercaptoethanol, and 50g deionized water was added dropwise at a constant speed, and the dropping time of solution A and solution B was 2.5h and 3h, respectively.

(4) After the dropwise addition, keep at 60°C for 1 hour of continuous aging. After the aging is completed, turn on the circulating water to cool down to 35°C, add 10g of sodium hydroxide (concentration 32%) to neutralize the solution to 6±1, and adjust the concentration to 50% with water. That is, a polycarboxylic acid viscosity reducer is obtained.

Comparative example 3

In this comparative example, on the basis of Example 3, no double bond-containing silane coupling agent and cationic monomer were added to prepare a polycarboxylic acid viscosity reducer.

A preparation method of polycarboxylate viscosity reducer, carried out according to the following steps:

(1.) Add 300g of prenol polyoxyethylene ether TPEG-800 and 200g of deionized water into the reactor, blow in nitrogen gas, remove the air in the reactor, control the temperature of the reactor at 40°C, and stir until it is completely Dissolve, stirring continuously;

(2) Add 1.8g hydrogen peroxide (concentration 27.5%) into the reaction kettle and stir for 5min;

(3) Add 41.9g of acrylic acid, 13.8g of methyl methacrylate, and 20g of deionized water into the reaction kettle dropwise at a constant speed. After 10 minutes, add 0.52g of L-ascorbic acid, 1.63g of mercaptoethanol, and 50g of deionized water at a constant speed. Water mixed solution B, solution A and solution B are added dropwise for 2.5h and 3h respectively.

(4) After the dropwise addition, keep at 60°C for 1 hour of continuous aging. After the aging is completed, turn on the circulating water to cool down to 35°C, add 10g of sodium hydroxide (concentration 32%) to neutralize the solution to 6±1, and adjust the concentration to 50% with water. That is, a polycarboxylic acid viscosity reducer is obtained.

1. Clean pulp test example 1

The polycarboxylate viscosity-reducing agent that adopts embodiment 1-6 of the present invention, comparative example 1-3 to provide, is 50% viscosity-reducing agent PC-1, viscosity-reducing agent PC-2 with two kinds of concentrations on the market A comparative test was carried out to measure their pulp fluidity, time loss and Marsh time. The specific test method is as follows:

The cement used in the experiment is Esheng 42.5 ordinary silicate cement. Refer to GB 8077 to test the initial fluidity and time-dependent fluidity of the cement paste.

Test sample: water cement ratio 0.20

Mixing ratio of clean slurry: 500g cement + 100g water + 1g polycarboxylate superplasticizer + viscosity reducer.

Marsh time automatic measuring instrument method:

Pour the well-stirred cement slurry into the Marsh barrel, make sure it is full and use a scraper to scrape the mouth of the barrel, and then turn on the working switch to the working position. When the slurry flows out of the lower nozzle for 200mL, the timer will stop automatically, and the time on the display will That is Marsh time, read and record. The time loss of 60 minutes is from the time of adding water for the first time. After 60 minutes, re-stir, load, and test the fluidity and Marsh time of the slurry again; the shorter the Marsh time, the better the flow performance of the slurry.

Result judgment:

1. Fix the amount of water reducer, adjust the amount of viscosity reducer, under the condition that the initial fluidity is basically the same, the shorter the Marsh time, it shows that the viscosity reducer with a small amount is better than the viscosity reducer with a large amount .

2. At the same dosage, under the condition that the initial fluidity is basically the same, the shorter the Marsh time, the better the effect of the viscosity reducer. The test results are shown in Table 1.

Table 1 Fluidity test results and Marsh time of cement slurry with different viscosity reducers

in conclusion:

1. From the results in Table 1, it can be seen that by adjusting the amount of viscosity reducer, the initial fluidity of the designed pulp is basically the same. The plastic retention is obviously better than that of Comparative Examples 1-3 and the viscosity reducers PC-1 and PC-2 on the market; it shows that the simultaneous introduction of double bond-containing silane coupling agents and cationic groups into the molecular structure can significantly reduce the viscosity of cement paste , and obtain excellent plastic retention effect.

2. Concrete Test Example 1

The polycarboxylate viscosity-reducing agent that adopts embodiment 1～6 of the present invention, comparative example 1-3 to provide, carries out comparative test with viscosity-reducing agent PC-1 on the market, viscosity-reducing agent PC-2, and test adopts water-cement ratio of 0.2 ultra-high performance concrete mix ratio, see Table 2.

Test method: The cement used in the test is Esheng P·O42.5 ordinary silicon cement, according to the relevant provisions of the national standard GB/T50080-2019 "General Concrete Mixture Performance Test Method", mix 20L concrete; keep polycarboxylate water reducing The amount of the agent remains unchanged, and the initial state of the concrete is basically the same by adjusting the amount of the viscosity reducer. The slump time of the mixture, the initial and 60min time loss of the slump, the degree of expansion, and the parameters of the 500mm expansion time are tested respectively. The results are shown in the table. 3

Table 2 Ultra-high performance concrete mix ratio (Kg/m ³ )

Table 3 performance results of concrete mixture

Conclusion: It can be seen from Table 3 that by adjusting the amount of viscosity reducer, the slump and expansion of the designed concrete mixture are basically the same, and the amount of viscosity reducer in Examples 1 to 6 is lower than that of the comparative example; combined with comparative example 1 Through comparison with 3, it is found that through the orthogonal test, it is proved that the simultaneous introduction of double bond-containing silane coupling agent and cationic group in the viscosity reducer of the embodiment can significantly reduce the viscosity of concrete, improve dispersibility and good plastic retention.

Claims (10)

1. A polycarboxylic viscosity reducer is characterized in that: the viscosity reducer comprises the following components in parts by weight: 30-35 parts of prenyl alcohol polyoxyethylene ether, 1-5 parts of unsaturated carboxylic acid, 0.5-2 parts of unsaturated carboxylic ester, 0.1-2 parts of cationic monomer, 0.1-2 parts of double bond-containing silane coupling agent, 0.1-0.5 part of oxidant, 0.01-0.1 part of reducing agent, 0.05-0.3 part of chain transfer agent and 0.1-2 parts of neutralizer; wherein the mole ratio of the prenyl polyoxyethylene ether to the unsaturated carboxylic acid is 1:1.0 to 3.0.

2. The polycarboxylic acid-based viscosity reducer according to claim 1, having a weight average molecular weight of 1 to 3 ten thousand.

3. The polycarboxylic acid-based viscosity reducer according to claim 1 or 2, wherein the prenyl polyoxyethylene ether has a weight average molecular weight of 300 to 1200.

4. The polycarboxylic acid viscosity reducer according to claim 1 or 2, wherein the unsaturated carboxylic acid comprises one or more of acrylic acid, methacrylic acid, maleic anhydride and fumaric acid.

5. The polycarboxylic acid viscosity reducer according to claim 1 or 2, wherein the unsaturated carboxylic acid ester comprises one or more of methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, monomethyl maleate and monomethyl fumarate.

6. The viscosity reducer according to claim 1 or 2, wherein the cationic monomer comprises one or more of tetramethylammonium chloride, methacryloyloxyethyl trimethylammonium chloride, and dimethyldiallylammonium chloride.

7. The polycarboxylic acid-based viscosity reducer according to claim 1 or 2, characterized in that: the oxidant comprises one or more of hydrogen peroxide, potassium persulfate, ammonium persulfate and benzoyl peroxide, the reducing agent comprises one or more of sodium bisulfite, ferrous sulfate, sodium bisulfite and L-ascorbic acid, and the chain transfer agent comprises one or more of thioglycolic acid, 3-mercaptopropionic acid, 2-mercaptoethanol, sodium hypophosphite and dodecyl mercaptan.

8. The viscosity reducer of claim 1 or 2, wherein the double bond-containing silane coupling agent is one or more of vinyltrimethylsilane, 3- (2, 3 glycidoxy) propylmethyldiethoxysilane, vinyltriethoxysilane, and γ -methacryloxypropyltrimethoxysilane.

9. The polycarboxylic acid viscosity reducer according to claim 1 or 2, wherein the neutralizing agent comprises one or more of sodium hydroxide, potassium hydroxide, ethanolamine, triethylamine, and AMP-95.

10. A process for producing a polycarboxylic acid viscosity reducer according to claim 1, characterized in that: the method comprises the following steps:

(1) Adding prenyl alcohol polyoxyethylene ether and water weighed according to the formula into a reaction kettle, continuously stirring until the prenyl alcohol polyoxyethylene ether and the water are completely dissolved, introducing nitrogen into the reaction kettle, then adding a silane coupling agent containing double bonds, and continuously stirring uniformly;

(2) Adding an oxidant into the reaction kettle, and continuously stirring for 5-10 minutes;

(3) Firstly, dropwise adding a mixed solution A of unsaturated carboxylic acid, unsaturated carboxylic ester, cationic monomer and deionized water into a reaction kettle at a constant speed, dropwise adding a mixed solution B of a reducing agent, a chain transfer agent and deionized water into the reaction kettle at a constant speed after 10min, and controlling the dropwise adding time of the solution A and the dropwise adding time of the solution B to be 2-3.5 h respectively;

(4) And (3) continuously stirring after the dropwise adding is finished, curing for 1-3h, cooling the temperature of the reaction kettle to 35 ℃ after the curing is finished, adding a neutralizing agent, adjusting the pH of the reactant to 5-7, and finally adjusting the concentration of the reactant to 40% -50% to obtain the polycarboxylic acid viscosity reducer.