CN101386490B - A kind of allyl polyethylene glycol ether type polycarboxylate water reducing agent and preparation method thereof - Google Patents

Abstract

The invention discloses an allyloxypolyethyleneglycol type polycarboxylate water reducing agent and a method for preparing the same, wherein the water reducing agent is a polymer obtained through polymerization; the polymer comprises the following components in weight percentage: 30 to 50 percent of unsaturated polyoxyalkylene group ether monomer(a), 5 to 20 percent of unsaturated monocarboxylic acid and derivative monomer(b) of unsaturated monocarboxylic acid, 1 to 20 percent of unsaturated dicarboxylic acid(c) and 40 to 60 percent of water; the components undergo polymerization in a water solution at a temperature of between 45 and 70 DEG C in the presence of a redox initiator to form the water reducing agent. The polycarboxylate water reducing agent has the advantages of high conversion rate of reaction product, good cohesiveness and super high dispersibility and excellent performance when applied to high strength concrete.

Description

A kind of allyl polyethylene glycol ether type polycarboxylate water reducing agent and preparation method thereof

technical field

The invention relates to the field of preparation of chemical raw materials, in particular to an allyl polyglycol ether type polycarboxylate water reducer with super strong dispersing effect and a preparation method thereof.

Background technique

In today's concrete industry, it has become a consensus to improve the durability and strength of concrete buildings. It is a common method to use extremely high water-reducing polycarboxylate-based water-reducers to reduce the unit water volume.

Over the years, in order to reduce the unit water volume, polycarboxylate-based water reducers have been replaced, but now it is difficult to meet the increasingly complex requirements for concrete raw materials and workability. In the patent CN1288870A, a method for preparing a polycarboxylate water reducer containing a specific ratio of polyethylene glycol monoallyl ether and maleic acid monomer in an oxidation-reduction system is disclosed, and the reaction temperature is 70 ~110°C, the oxidizing agent is hydrogen peroxide or persulfate, and the reducing agent is hypophosphorous acid or its salt. Practice has proved that the water-reducing performance of the water-reducing agent is insufficient, and a good dispersion ability can only be obtained at a higher solid content. The main reason is the copolymerization of polyethylene glycol monoallyl ether and maleic acid monomers. Sex is very low. In addition, the patent CN1167739A discloses a method for preparing a polycarboxylate cement dispersant. First, alkoxy polyalkylene glycol and (meth)acrylate are subjected to transesterification under the action of a basic catalyst to prepare alkoxy Polyalkylene glycol mono(meth)acrylate is mixed with (meth)acrylic acid, and copolymerized under the action of persulfuric acid to obtain a polycarboxylate water reducer. Such polycarboxylate superplasticizers produced using alkoxy polyalkylene glycol mono(meth)acrylate monomers have unstable product quality and poor adaptability to different sandstone materials and concrete mineral admixtures, often The water-reducing rate fluctuates greatly, and the slump loss of concrete is variable. In addition, the liquid state storage and transportation may cause fluctuations in product quality, exposing some difficult technical problems. Patent CN1343642A discloses a cement dispersant and a cement composition using it, by using allyl polyethylene glycol monomer (a) and unsaturated unit carboxylic acid (b) as essential components, adding other polymerizable monomers The copolymer prepared by this method has a high water-reducing rate, but the cohesive performance of the cement composition is still insufficient. CN101186460A discloses a kind of polycarboxylate water-reducer and its synthetic method with allyl polyethylene glycol as raw material, with allyl polyethylene glycol, maleic anhydride, methyl acrylate, ammonium persulfate, sulfuric acid Stannous and water are synthesized through nitrogen protection and heating reaction. Although this method solves the problem of low copolymerization of polyethylene glycol monoallyl ether and maleic acid monomers, its water reduction rate is still high. It is not high enough, has selectivity to concrete constituent materials, and has poor adaptability. In the field of high water reducing rate, it still cannot meet the requirements of dispersion performance. Patent CN1412175 discloses a preparation method of an allyl ether ester monomer and a method for preparing a water reducer by using the monomer, using the refined allyl ether ester monomer and maleic anhydride at 80°C Azobisisobutyronitrile is used as an initiator to prepare a copolymer with a weight-average molecular weight of 13,500, and then the copolymer is esterified with alkyl polyalkylene glycol at 100°C to obtain a micro-crosslinked cement dispersion agent, so that it has relatively better adaptability to different cements, and the process is more complicated, which makes the cost of the final product very high.

Contents of the invention

The embodiment of the present invention provides an allyl polyethylene glycol ether type polycarboxylate water reducer and its preparation method. Very high dispersibility, especially in the field of high water reducing rate, it has excellent performance in concrete application.

The purpose of the present invention is achieved through the following technical solutions:

The embodiment of the present invention provides an allyl polyethylene glycol ether type polycarboxylate water reducer, the water reducer is a polymer obtained after polymerization, and the polymer contains The following components:

Unsaturated polyoxyalkylene ether monomer (a) 30～50%

Unsaturated monocarboxylic acid and its derivative monomer (b) 5～20%

Unsaturated dicarboxylic acid (c) 1～20%

Water 40～60%

Wherein, the unsaturated polyoxyalkylene ether monomer (a) is represented by general formula (1):

General formula (1) XO(R ₁ O)nH

In the general formula (1), X represents an alkenyl group containing 2 to 4 carbon atoms, R ₁ O represents an oxyethylene group having 2 to 4 carbon atoms, and n is the average number of added moles of the oxyethylene group, which Represents any number between 20 and 150. In the copolymer, the monomer (a) is one or a mixture of two or more;

The unsaturated monocarboxylic acid and its derivative monomer (b) are represented by general formula (2):

Formula (2)

In general formula (2), R ₂ represents hydrogen, methyl, R ₃ represents OM ₁ , wherein M ₁ represents hydrogen, monovalent metal, divalent metal, ammonium or organic amine, and in the copolymer, monomer (b) is One or a mixture of two or more of them;

The unsaturated dicarboxylic acid (c) is represented by general formula (3):

Formula (3)

In general formula (3), M ₂ represents hydrogen, monovalent metal, divalent metal, ammonium or organic amine, R ₄ represents OM ₃ or O(R ₅ O)mR ₆ , wherein M ₂ represents hydrogen, monovalent metal, divalent Valence metals, ammonium or organic amines, wherein R ₅ O represents an oxyalkylene group with 2 to 4 carbon atoms or a mixture of multiple oxyalkylene groups, and R ₆ represents hydrogen or an alkyl group with 1 to 12 carbon atoms group, phenyl group or organic amine, m is the average addition mole number of oxyalkylene groups, which represents any number between 1 and 35, and in the copolymer, the unsaturated dicarboxylic acid (c) is One or a mixture of two or more of them.

The water reducer also includes: other polymerizable monomers (d) accounting for 1 to 24% of the total weight of the water reducer; the other polymerizable monomers (d) include: unsaturated sulfonic acid or its salt, unsaturated sulfonic acid Any one or a mixture of two or more of saturated amides and vinyl esters.

The unsaturated sulfonic acid or its salt includes any one or a mixture of (meth)allylsulfonic acid or its salt, styrenesulfonic acid or its salt.

The unsaturated amides include any one or a mixture of 2-methacrylamide, 3-propenesulfonic acid or its salts.

The vinyl ester includes: any one or a mixture of vinyl acetate and vinyl propionate.

The embodiment of the present invention also provides a method for preparing an allyl polyethylene glycol ether type polycarboxylate water reducer, the method comprising:

Taking the total weight of the product to be prepared as 100%, each component is taken as a raw material according to the following dosage range, including:

Unsaturated polyoxyalkylene ether monomer (a) 30～50%

Unsaturated monocarboxylic acid and its derivative monomer (b) 5～20%

Unsaturated dicarboxylic acid (c) 1～20%

Water 40～60%

The above-mentioned components are polymerized in an aqueous solution at a temperature of 45-70° C. using a redox initiation system, and the polymer obtained after polymerization is an allyl polyglycol ether type polycarboxylic acid water reducer.

Described method specifically comprises:

After mixing unsaturated polyoxyalkylene ether monomer (a), unsaturated dicarboxylic acid (c), oxidizing agent and 50-80% water according to the total weight of water used, the temperature is raised to 45-70°C;

In the mixed solution after the above reaction, add dropwise the remaining water and the mixed aqueous solution of unsaturated monocarboxylic acid and its derivative monomer (b) and the reducing agent at the same time, dropwise for 2.5 to 3.5 hours, after completion, at the reaction temperature Continue to keep warm for 25-35 minutes under the condition of 45-70°C to complete the polymerization reaction, cool down after the heat preservation is over, add NaOH to neutralize, adjust the concentration of the polymer to 40%-60%, and then obtain allyl polyethylene glycol Alcohol ether type polycarboxylate water reducer.

The method also includes: in the step of mixing the unsaturated polyoxyalkylene ether monomer (a), the unsaturated dicarboxylic acid (c), water and the oxidizing agent, simultaneously adding other polymerizable monomers (d), other Polymerizable monomer (d) includes: unsaturated sulfonic acid or its salt, unsaturated amide, vinyl ester, in the copolymer, other polymerizable monomer (d) is one of them used alone or two or more Mixture; the amount of the other polymerizable monomer (d) is 1-24% of the total weight of the product to be prepared.

The oxidant in the redox initiation system is one of hydroperoxide, persulfate or their mixture; the amount of the oxidant is 0.2%-10% of the total weight of the monomers used.

The reducing agent in the redox initiation system is one of low-valent sulfur compounds, L-ascorbic acid or their mixture; the amount of the reducing agent is 0.1-5% of the total weight of the monomers used.

It can be seen from the technical solutions provided by the above-mentioned embodiments of the present invention that the embodiments of the present invention combine unsaturated polyoxyalkylene ether monomer (a), unsaturated monocarboxylic acid and its derivative monomer (b) and unsaturated Dibasic carboxylic acid (c) is polymerized under redox initiation system to form allyl polyglycol ether type polycarboxylate water reducer. One of the most important features of this water reducer is that its molecular Excellent with super dispersing effect. When a small amount is added to the concrete (generally 0.5% to 1.5% of the total weight of the cement), it has a high water-reducing rate and good slump retention, which can meet higher construction requirements and greatly improve the concrete. strength and durability.

Detailed ways

The embodiment of the present invention provides an allyl polyethylene glycol ether type polycarboxylate water reducer and its preparation method. The water reducer has a super strong dispersion effect. The water reducer is made of the following components: Redox initiation system, a polymer formed by copolymerization in aqueous solution, based on the percentage of the total weight of the polymer, the polymer contains various components and the content is: unsaturated polyoxyalkylene ether monomer (a) 30-50%, unsaturated monocarboxylic acid and its derivative monomer (b) 5-20%, unsaturated dicarboxylic acid (c) 1-20%, water 40-60%.

In actual preparation, each component is also taken according to the above weight ratio, and each component is polymerized in an aqueous solution using a redox initiation system at a temperature of 45-70 ° C. The polymer obtained after polymerization is a water reducer. The water reducer has a high conversion rate of reaction products, and can exhibit high dispersibility with a small amount of addition, especially in the field of high water reducing rate, and its performance is excellent when it is applied in concrete.

For ease of understanding, the present invention will be further described below through specific examples.

Embodiment one

This embodiment provides an allyl polyglycol ether type polycarboxylate water reducer with super strong dispersing effect. Compared with the water-reducing agent, the conversion rate of the reaction product of the water-reducing agent is high, and it can show high dispersibility with a small amount of addition. Especially in the field of high water-reducing rate, it has excellent performance when applied in concrete. The water-reducing agent It is a polymer formed by copolymerization of the following components in an aqueous solution using a redox initiation system. The polymer water reducer contains:

Unsaturated polyoxyalkylene ether monomer (a) 30-50% (accounting for the percentage of total polymer weight)

Unsaturated monocarboxylic acid and its derivative monomer (b) 5-20% (accounting for the percentage of the total weight of the polymer)

Unsaturated dicarboxylic acid (c) 1～20% (accounting for the percentage of the total weight of the polymer)

Water 40-60% (accounting for the percentage of the total weight of the polymer)

Wherein, the unsaturated polyoxyalkylene ether monomer (a) is represented by general formula (1):

General formula (1) X0(R ₁ O)nH

In the general formula (1), X represents an alkenyl group containing 2 to 4 carbon atoms, R ₁ O represents an oxyethylene group having 2 to 4 carbon atoms, and n is the average number of added moles of the oxyethylene group, which Represents any number between 20 and 150. In the copolymer, the monomer (a) is one or a mixture of two or more;

The unsaturated monocarboxylic acid and its derivative monomer (b) are represented by general formula (2):

Formula (2)

In general formula (2), R ₂ represents hydrogen, methyl, R ₃ represents OM ₁ , wherein M ₁ represents hydrogen, monovalent metal, divalent metal, ammonium or organic amine, and in the copolymer, monomer (b) is One or a mixture of two or more of them;

The unsaturated dicarboxylic acid (c) is represented by general formula (3):

Formula (3)

In general formula (3), M ₂ represents hydrogen, monovalent metal, divalent metal, ammonium or organic amine, R ₄ represents OM ₃ or O(R ₅ O)mR ₆ , wherein M ₂ represents hydrogen, monovalent metal, divalent Valence metal, ammonium or organic amine, R ₅ O represents an oxyalkylene group with 2 to 4 carbon atoms or a mixture of multiple oxyalkylene groups, R ₆ represents hydrogen or an alkyl group with 1 to 12 carbon atoms , phenyl group or organic amine, m is the average addition mole number of oxyalkylene groups, which represents any number between 1 and 35, and in the copolymer, unsaturated dicarboxylic acid (c) is one of them species or a mixture of two or more.

In the above-mentioned polymer water reducing agent, it may also contain unsaturated polyoxyalkylene ether monomer (a), unsaturated monocarboxylic acid and its derivative monomer (b) and unsaturated dicarboxylic acid (c) 1-25% of other polymerizable monomers (d) by total weight, the other polymerizable monomers (d) specifically include: unsaturated sulfonic acid or its salt, unsaturated amide, vinyl ester, in the copolymer, other The polymerizable monomer (d) is one kind or a mixture of two or more kinds thereof.

Among the above-mentioned other polymerizable monomers (d), the unsaturated sulfonic acid or its salt includes any one of (meth)allylsulfonic acid or its salt, styrenesulfonic acid or its salt, or A mixture of the two; the unsaturated amides include: 2-methacrylamide, 3-propenesulfonic acid or a salt thereof, or a mixture of the two; the vinyl ester includes: vinyl acetate , vinyl propionate, or a mixture of both.

When actually preparing the above-mentioned water reducer, the raw material components used are specifically: the unsaturated polyoxyalkylene ether monomer (a) is: allyl polyethylene glycol ether with a molecular weight of 600-5000; the monomer (b ) is: (meth)acrylic acid and its carboxylic acid derivative monomers, such as: (meth)acrylic acid, (meth)acrylamide, (meth)methyl acrylate, (meth)hydroxyethyl acrylate, ( Meth) hydroxypropyl acrylate, etc.; monomer (c) is: maleic anhydride, fumaric acid, itaconic acid, citraconic acid and other dicarboxylic acids and their esterified monomers; monomer (d) is: other Alkenyl and carboxylic acid derivative monomers, etc., including: unsaturated sulfonic acid or its salt, such as: (meth) allyl sulfonic acid or its salt, styrene sulfonic acid or its salt, sodium methacrylic acid etc.; Vinyl esters, such as vinyl acetate, vinyl propionate, etc. The initiators in the redox initiation system used include: ammonium persulfate, hydrogen peroxide, etc., and the reducing agents include: sodium thiosulfate, sodium bisulfite, stannous sulfate, L-ascorbic acid, etc.; neutralization with sodium hydroxide and water etc. In the preparation process, the monomer (a) can be added in whole or in part at the beginning of the reaction, and the monomers (b), (c), and (d) can be added at the beginning of the reaction, or in batches or continuously after the reaction begins. join, or use a combination of these join methods.

The preparation of polycarboxylate water reducer is based on the following components as essential components, and the total weight of the final prepared polymer is 100%, and the consumption of each component is given as a percentage of the total weight of the final polymer product out:

The amount of allyl polyethylene glycol monomer (a) with a molecular weight of 1000-6000 accounts for 30-50% of the total product weight, and the amount of (meth)acrylic unsaturated carboxylic acid and its derivative monomer (b) accounts for 5-20% of the total weight of the product, the amount of unsaturated dicarboxylic acid and its derivative monomer (c) accounts for 1-20% of the total weight of the product, and the amount of water accounts for 40-60% of the total weight of the product, At a temperature of 45-70°C, a redox initiation system is used as an initiator to polymerize each monomer component in an aqueous solution, and the copolymer obtained after copolymerization is the water reducer of the embodiment of the present invention.

The specific preparation method is: after mixing the unsaturated polyoxyalkylene ether monomer (a), the unsaturated dicarboxylic acid (c), the oxidizing agent and the water of 50-80% of the total weight of the water used above, the temperature is raised to 45-80%. 70°C, react for 2.5 to 3.5 hours;

In the mixed solution after the above reaction, add dropwise the remaining water and unsaturated monocarboxylic acid and its derivative monomer (b) mixed aqueous solution and reducing agent at the same time, the reaction temperature is 45 ~ 70 ° C, after the dropwise addition, Continue to keep warm at the reaction temperature for 25 to 35 minutes to complete the polymerization reaction. After the heat preservation is over, cool down, add NaOH to neutralize, and adjust the concentration of the polymer to 40% to 60%. Carboxylic acid water reducer.

In the step of mixing unsaturated polyoxyalkylene ether monomer (a), unsaturated dicarboxylic acid (c), water and oxidizing agent, simultaneously add other polymerizable monomers (d), other polymerizable monomers (d ) includes: unsaturated sulfonic acid or its salt, unsaturated amide, vinyl ester, in the copolymer, other polymerizable monomers (d) are used alone or in mixture of two or more; the other polymerizable The amount of monomer (d) is 1-24% of the total weight of the final product.

In the above-mentioned preparation method, the oxidizing agent in redox initiation system can adopt hydroperoxide, as hydrogen peroxide, t-butyl hydroperoxide etc.; Ascorbic acid, such as sodium bisulfite, sodium thiosulfate, sodium hydroxymethyl bisulfite, sodium dithionite, etc. During the preparation, the amount of the oxidizing agent is 0.2%-10% of the total weight of the monomers used, and the amount of the reducing agent is 0.1-5% of the total weight of the monomers used. The amount of NaOH added for neutralization is based on adjusting the concentration of the polymer to 40% to 60%.

The prepared synthetic product is a light colorless or light yellow transparent liquid with a concentration of 40% to 60%. A small amount (generally 0.5% to 1.5% of the total weight of cement) is added to the concrete, which has a high water reducing rate and good The slump is maintained, which can meet higher construction requirements and greatly improve the strength and durability of concrete.

Embodiment two

This embodiment provides an allyl polyglycol ether type polycarboxylic acid-based water reducer. The amounts of the following components used to prepare the water reducer are by weight, including:

1200g allyl polyglycol ether 1200

105g acrylic acid monomer

49g maleic anhydride

25g sodium methacrylate

1095g deionized water (add in two times, add 700g for the first time, add 395g and 105g of acrylic acid monomer for the second time to form an aqueous solution of acrylic acid monomer)

30g 27.5% hydrogen peroxide

250g concentration is 5% sodium hydroxymethyl bisulfite solution

360g30%NaOH;

Add 1200g allyl polyglycol ether 1200, 700g deionized water, 49g maleic anhydride, 25g sodium methacrylate, 30g in a glass flask equipped with a stirrer, thermometer, dropping device, and reflux cooler Mix hydrogen peroxide with a concentration of 27.5%, and after heating up to 65°C, add dropwise monomer aqueous solution mixed with 395g deionized water and 105g acrylic acid and 250g concentration of 5% methylol Sodium bisulfite solution, the reaction temperature is controlled at 65°C. After the dropwise addition, continue to insulate at 65°C for 30 minutes to complete the polymerization reaction. After the heat preservation is completed, cool down, add 360g of 30% NaOH to neutralize, and adjust the polymerization The concentration of the compound was 45%, and the polycarboxylate water-reducer of the embodiment of the present invention was obtained. For the convenience of description in the subsequent comparison experiment, the water-reducer was named PC-1.

Embodiment three

This embodiment provides an allyl polyglycol ether type polycarboxylic acid-based water reducer. The amounts of the following components used to prepare the water reducer are by weight, including:

2100g allyl polyglycol ether 2400

129g methacrylic acid

249g polyethylene glycol 400 monoester maleate (98:400)

1771g deionized water (1300g is added for the first time in two uses, and the remaining 471g deionized water is used to mix with 129g methacrylic acid to form a methacrylic acid solution)

30g of 27.5% hydrogen peroxide

250 g of 5% L-ascorbic acid solution

360g of 30% NaOH

Add 2100g allyl polyethylene glycol ether 2400, 1300g deionized water, 249g polyethylene glycol maleate 400 monoester (98: 400), 30g concentration is 27.5% hydrogen peroxide, after being warmed up to 65 ℃, dropwise in above-mentioned glass flask simultaneously in 3 hours the monomer aqueous solution that has mixed 129g methacrylic acid, 471g deionized water and 250g concentration is 5 % of L-ascorbic acid solution, the reaction temperature is controlled at 65°C, after the dropwise addition is completed, it is incubated at 65°C for about 30 minutes to complete the polymerization reaction, after the insulation is completed, cool, add 36 parts of 30% NaOH to neutralize, Concentration to 45%, to obtain the polycarboxylate water reducer of this example, for the convenience of description in subsequent comparison experiments, the water reducer is named PC-2.

Embodiment four

This embodiment provides an allyl polyglycol ether type polycarboxylic acid-based water reducer. The amounts of the following components used to prepare the water reducer are by weight, including:

2000g allyl polyglycol ether 3600

95g sodium acrylate

100g acrylic acid

45g itaconic acid

41g sodium methacrylate

1745g deionized water (add in two times, add 1350g for the first time, and mix the remaining 395g deionized water with 95g sodium acrylate and 100g acrylic acid to form a monomer aqueous solution)

13g ammonium persulfate

250g concentration is 5% sodium hydroxymethyl bisulfite solution

360g of 30% NaOH

Add 2000g allyl polyglycol ether 3600, 1350g deionized water, 45g itaconic acid, 41g sodium methacrylate, 13g in a glass flask equipped with a stirrer, thermometer, dropping device, and reflux cooler ammonium persulfate, after heating up to 65°C, within 3 hours, add dropwise the monomer aqueous solution formed by mixing 95g sodium acrylate, 100g acrylic acid and 395g deionized water and 250g concentration of 5% methylol Base sodium bisulfite solution, the reaction temperature is controlled at 65°C. After the dropwise addition, keep the temperature at 65°C for about 30 minutes to make the polymerization reaction complete. The concentration was 45%, and the polycarboxylate water reducer of this example was obtained. For the convenience of description in subsequent comparison experiments, the water reducer was named PC-3.

Embodiment five

This embodiment provides an allyl polyglycol ether type polycarboxylic acid-based water reducer. The amounts of the following components used to prepare the water reducer are by weight, including:

1800g allyl polyglycol ether 4800

105g acrylic acid

43g methacrylic acid

40g maleic anhydride

1662g deionized water (add in two times, add 1300g for the first time, and mix the remaining 362g deionized water with 105g acrylic acid and 43g methacrylic acid to form a monomer aqueous solution)

13g ammonium persulfate

250g concentration is 5% sodium hydroxymethyl bisulfite solution

360g of 30% NaOH

Add 1800g allyl polyglycol ether 4800, 1300g deionized water, 250g maleic anhydride, ammonium persulfate of 130g in the glass flask that is equipped with stirrer, thermometer, dropping device, reflux cooler, be warming up to 65 After ℃, in 3 hours, in 3 hours, add dropwise simultaneously the monomer aqueous solution that is mixed into by 105g acrylic acid, 43g methacrylic acid and remaining 362g deionized water and 250g concentration be 5% sodium hydroxymethyl bisulfite solution, The reaction temperature was controlled at 65°C. After the dropwise addition was completed, it was incubated at 65°C for about 30 minutes to complete the polymerization reaction. After the insulation was completed, it was cooled, and 360g of NaOH with a concentration of 30% was added for neutralization, and the concentration was adjusted to 45%. The polycarboxylate water-reducer of the embodiment is named PC-4 for the convenience of description in subsequent comparison experiments.

Comparative Example 1

This example provides a water-reducer for comparison. The amounts of the following components used to prepare the water-reducer are all by weight, and the amounts of the raw materials used below are all by weight. Add 120 parts of allyl polyglycol ether 1200, 7.5 parts of acrylic acid, 70 parts of deionized water, and 3.0 parts of 27.5% hydrogen peroxide into the glass flask of the device, thermometer, dropping device, and reflux cooler, and heat up to 65 After 10°C, the monomer aqueous solution mixed with 10.5 parts of acrylic acid and 39.5 parts of deionized water and 25 parts of 5% sodium hydroxymethyl bisulfite solution were added dropwise to the reaction vessel at the same time within 3 hours, and the reaction temperature was controlled at 65°C. After the dropwise addition, keep the temperature at 65°C for 30 minutes, cool after the heat preservation is over, add 15 parts of 30% NaOH to neutralize, adjust to a concentration of 45%, and obtain a comparative polycarboxylate water reducer for subsequent comparative experiments used, the water reducer was named C-1.

Comparative Example Two

This example provides a water-reducer for comparison. The additions of the following components used to prepare the water-reducer are all by weight. Add 240 parts of allyl polyethylene glycol ether 2400, 130 parts of deionized water in the glass flask, 49.8 parts of polyethylene glycol 400 monoester maleate (9.8:40), 3.0 parts of 27.5% hydrogen peroxide, heat up After reaching 65°C, within 3 hours, a monomer aqueous solution mixed with 19.5 parts of hydroxypropyl acrylate and 30.5 parts of deionized water and 25 parts of 5% L-ascorbic acid solution were added dropwise to the reaction vessel, and the reaction temperature was controlled at 65°C. After the dropwise addition, keep the temperature at 65°C for about 30 minutes to complete the polymerization reaction, cool down after the heat preservation, add 36 parts of 30% NaOH for neutralization, and adjust the concentration to 45% to obtain a comparative polycarboxylate water reducer. For subsequent comparative experiments, the water reducer was named C-2.

Comparative Example Three

This example provides a water-reducer for comparison. The additions of the following components used to prepare the water-reducer are all by weight. Add 240 parts of allyl polyethylene glycol ether 3600, 130 parts of deionized water, 9.1 parts of sodium acrylate, 4.5 parts of sodium methacrylate, and 1.3 parts of ammonium persulfate into the glass flask. Within 3 hours, the monomer aqueous solution mixed with 12.9 parts of methacrylic acid, 37.1 parts of deionized water and 25 parts of 5% sodium hydroxymethyl bisulfite solution were added dropwise to the reaction vessel at the same time, and the reaction temperature was controlled at 65°C. After the dropwise addition, keep the temperature at 65°C for about 30 minutes to complete the polymerization reaction, cool down after the heat preservation, add 36 parts of 30% NaOH for neutralization, and adjust the concentration to 45% to obtain a comparative polycarboxylate water reducer. For subsequent comparative experiments, the water reducer was named C-3.

Comparative Example Four

This example provides a water-reducer for comparison. The additions of the following components used to prepare the water-reducer are all by weight. Add 240 parts of allyl polyglycol ether 4800, 130 parts of deionized water, 14.7 parts of maleic anhydride, 6.5 parts of vinyl acetate, and 5.0 parts of 27.5% hydrogen peroxide into the glass flask, and heat up to 65°C. In 3 hours, in the reaction vessel, drip simultaneously the monomer aqueous solution that has mixed 7.2 parts of acrylic acid, 4.3 parts of methacrylic acid, 38.5 parts of deionized water and 25 parts of 5% sodium hydroxymethyl bisulfite solution, and the reaction temperature is controlled at 65°C. After the dropwise addition, keep the temperature at 65°C for about 30 minutes to complete the polymerization reaction, cool down after the heat preservation, add 36 parts of 30% NaOH for neutralization, and adjust the concentration to 45% to obtain a comparative polycarboxylate water reducer. For use in subsequent experiments, it was named C-4.

Through corresponding experiments, the water reducers PC-1 to PC-4 obtained in the above-mentioned Examples 2 to 5 are compared with the water reducers C-1 to C-4 obtained in Comparative Examples 1 to 4, and the The performance of the water reducer prepared in the examples of the invention will be further elaborated.

(1) Clean pulp test

Clean slurry fluidity test (GB/T8077-2000): Using benchmark cement, test the clean slurry fluidity of cement according to GB8077-87, the results are shown in Table 1.

Table 1 Fluidity Test of Clean Pulp

It can be seen from Table 1 that the preparation of water reducers in Comparative Examples 1 to 4 cannot meet the conditions of (a), (b), (c), and (d) at the same time, resulting in insufficient dispersion performance and retention performance, while the present invention The polycarboxylate water reducer prepared in Examples 2 to 5 has a lower dosage, and has better dispersion and dispersion retention stability.

(2) C45 concrete test:

Ordinary Portland cement P.O42.5, medium sand (fineness modulus 2.65, mud content 2%), gravel (particle size 5-25mm, continuous particle size), etc. are used. The concrete mix ratio is shown in Table 2. The concrete was mixed under the above conditions, and the slump, air content, slump retention value, etc. of the concrete were measured, and the results are shown in Table 3.

Table 2 concrete test mix ratio

Table 3 Concrete Tests

Note: slump retention value: slump after standing for 60min/initial slump*100%

Tests have shown that, compared to the water reducing agents in Comparative Examples 1 to 4, the polycarboxylate cement dispersant prepared in Examples 2 to 5 of the present invention can obtain higher slump at a lower dosage , and has excellent slump holding capacity.

(3) C100 concrete test:

Ordinary Portland cement P.O42.5, medium sand (river sand, fineness modulus 2.65, mud content 0%), crushed granite (particle size 5-15mm, continuous particle size), etc., concrete mix ratio See Table 4. Mix concrete under the above conditions, and measure the initial slump and 1-hour slump of the concrete. The results are shown in Table 5.

Table 4 concrete test mix ratio

Table 5 concrete test results

Polycarboxylate superplasticizer Solid content (%) Initial slump (mm) 1 hour slump (mm) PC-1 0.6 225 225 PC-2 0.6 235 240 PC-3 0.6 236 220 PC-4 0.6 228 225 C-1 0.9 195 / C2 1.05 180 / C-3 0.95 205 / C-4 0.95 190 /

Tests have shown that in the field of ultra-high water reduction, using the polycarboxylate cement dispersant prepared in Examples 2 to 5 of the present invention can obtain higher slump and have excellent slump retention capabilities, while the comparative implementation The water reducer in the example is difficult to meet the requirements.

In summary, the water-reducing agent prepared in the examples of the present invention has a small amount of mixing in concrete (generally 0.5% to 1.5% of the total weight of cement) when used, and has a high water-reducing rate and good slump The strength can be maintained, which can meet the higher construction requirements and greatly improve the strength and durability of concrete.

The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, nor does the sequence of each embodiment cause any limitation to the present invention. Within the technical scope disclosed in the present invention, changes or substitutions that can be easily conceived by personnel shall be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (10)

1. An allyl polyglycol ether type polycarboxylate water-reducer, characterized in that the water-reducer is a polymer obtained after polymerization, and as a percentage of the total weight of the polymer, in the polymer Contains the following components:

Wherein, the unsaturated polyoxyalkylene ether monomer (a) is represented by general formula (1): General formula (1) XO(R ₁ O)nH In the general formula (1), X represents an alkenyl group containing 2 to 4 carbon atoms, R ₁₀ represents an oxyethylene group having 2 to 4 carbon atoms, and n is the average addition mole number of the oxyethylene group, which Represents any number between 20 and 150. In the copolymer, the monomer (a) is one or a mixture of two or more; The unsaturated monocarboxylic acid and its derivative monomer (b) are represented by general formula (2): Formula (2)

In general formula (2), R ₂ represents hydrogen, methyl, R ₃ represents OM ₁ , wherein M ₁ represents hydrogen, monovalent metal, divalent metal, ammonium or organic amine, and in the copolymer, monomer (b) is One or a mixture of two or more of them; The unsaturated dicarboxylic acid (c) is represented by general formula (3): Formula (3)

In general formula (3), M ₂ represents hydrogen, monovalent metal, divalent metal, ammonium or organic amine, R ₄ represents OM ₃ or O(R ₅ O)mR ₆ , wherein M ₃ represents hydrogen, monovalent metal, divalent Valence metals, ammonium or organic amines, wherein R ₅ O represents an oxyalkylene group with 2 to 4 carbon atoms or a mixture of multiple oxyalkylene groups, and R ₆ represents hydrogen or an alkyl group with 1 to 12 carbon atoms group, phenyl group or organic amine, m is the average addition mole number of oxyalkylene groups, which represents any number between 1 and 35, and in the copolymer, the unsaturated dicarboxylic acid (c) is One or a mixture of two or more of them. 2. The water-reducing agent according to claim 1, characterized in that, the water-reducing agent further comprises: other polymerizable monomers (d) accounting for 1-24% of the total weight of the water-reducing agent; Polymer (d) includes any one or a mixture of two or more of unsaturated sulfonic acid or its salt, unsaturated amide, and vinyl ester. 3. The water reducing agent according to claim 2, characterized in that, the unsaturated sulfonic acid or its salt comprises: (meth) allylsulfonic acid or its salt, styrenesulfonic acid or its salt Either or a mixture of both. 4. The water reducer according to claim 2, wherein the unsaturated amide comprises: 2-methacrylamide. 5. The water reducer according to claim 2, wherein the vinyl ester comprises: any one or a mixture of vinyl acetate and vinyl propionate. 6. A preparation method of an allyl polyglycol ether type polycarboxylate water reducer, characterized in that the method comprises: Taking the total weight of the product to be prepared as 100%, each component is taken as a raw material according to the following dosage range, including:

The above-mentioned components are polymerized in an aqueous solution at a temperature of 45-70° C. using a redox initiation system, and the polymer obtained after polymerization is an allyl polyglycol ether type polycarboxylic acid water reducer. 7. The method according to claim 6, characterized in that, the method specifically comprises: After mixing unsaturated polyoxyalkylene ether monomer (a), unsaturated dicarboxylic acid (c), oxidizing agent and 50-80% water according to the total weight of water used, the temperature is raised to 45-70°C; In the mixed solution after the above reaction, add dropwise the remaining water and the mixed aqueous solution of unsaturated monocarboxylic acid and its derivative monomer (b) and the reducing agent at the same time, dropwise for 2.5 to 3.5 hours, after completion, at the reaction temperature Continue to keep warm for 25-35 minutes under the condition of 45-70°C to complete the polymerization reaction, cool down after the heat preservation is over, add NaOH to neutralize, adjust the concentration of the polymer to 40%-60%, and then obtain allyl polyethylene glycol Alcohol ether type polycarboxylate water reducer. 8. The method according to claim 6, characterized in that, the method also comprises: mixing unsaturated polyoxyalkylene ether monomer (a), unsaturated dicarboxylic acid (c), water and oxidizing agent In the step, other polymerizable monomers (d) are added at the same time, and other polymerizable monomers (d) include: unsaturated sulfonic acid or its salt, unsaturated amide, vinyl ester, in the copolymer, other polymerizable monomers (d) is used alone or in mixture of two or more; the amount of other polymerizable monomers (d) is 1-24% of the total weight of the product to be prepared. 9. according to the described method of claim 6 or 7, it is characterized in that, the oxidizing agent in described oxidation-reduction initiation system is one or their mixture in hydroperoxide, persulfate; The consumption of described oxidizing agent is 0.2% to 10% of the total weight of the monomers used. 10. The method according to claim 6 or 7, characterized in that, the reducing agent in the redox initiation system is one of low-valent compounds of sulfur, L-ascorbic acid or their mixture; The amount of used is 0.1 to 5% of the total weight of the monomers used.