阅读说明：本技术 一种防冻型混凝土复合减水剂及其制备方法 (Antifreezing concrete composite water reducing agent and preparation method thereof ) 是由 符嫦娥 于 2020-12-28 设计创作，主要内容包括：本发明涉及减水剂技术领域,尤其涉及一种防冻型混凝土复合减水剂及其制备方法,该防冻型混凝土复合减水剂由以下组分及质量百分比含量构成：早强型聚羧酸减水剂母液20-30％,保坍型聚羧酸减水剂母液20-30％、复合防冻组分1.5-4％、引气剂0.1-0.3％、稳定剂0.1-0.3％,水为余量；复合防冻组分由甲醇、乙二醇、亚硝酸钠、亚硝酸钙混合而成；引气剂由主引气剂、非离子引气剂和用于调整气液界面分子排列的表面活性剂构成；稳定剂为聚环氧乙烷或聚醚。本发明通过设计早强型、保坍型两种不同的聚羧酸减水剂母液,调整比例满足不同施工对混凝土工作性的要求。(The invention relates to the technical field of water reducing agents, in particular to an antifreezing concrete composite water reducing agent and a preparation method thereof, wherein the antifreezing concrete composite water reducing agent comprises the following components in percentage by mass: 20-30% of mother liquor of an early strength type polycarboxylate superplasticizer, 20-30% of mother liquor of a slump retaining polycarboxylate superplasticizer, 1.5-4% of a composite antifreezing component, 0.1-0.3% of an air entraining agent, 0.1-0.3% of a stabilizer and the balance of water; the composite antifreezing component is formed by mixing methanol, glycol, sodium nitrite and calcium nitrite; the air entraining agent consists of a main air entraining agent, a nonionic air entraining agent and a surfactant for adjusting the molecular arrangement of a gas-liquid interface; the stabilizer is polyethylene oxide or polyether. The invention designs two different polycarboxylic acid water reducing agent mother solutions of early strength type and slump retaining type, and adjusts the proportion to meet the requirements of different constructions on the workability of concrete.)

1. The antifreezing concrete composite water reducing agent is characterized by comprising the following components in percentage by mass: 20-30% of mother liquor of an early strength type polycarboxylate superplasticizer, 20-30% of mother liquor of a slump retaining polycarboxylate superplasticizer, 1.5-4% of a composite antifreezing component, 0.1-0.3% of an air entraining agent, 0.1-0.3% of a stabilizer and the balance of water; the sum of the mass percentages of the components is 100 percent;

the composite antifreezing component is formed by mixing methanol, ethylene glycol, sodium nitrite and calcium nitrite according to the mass ratio of 1:1-3:2-3: 2-4;

the air entraining agent consists of a main air entraining agent, a nonionic air entraining agent and a surfactant for adjusting the molecular arrangement of a gas-liquid interface, wherein the main air entraining agent is rosin soap and accounts for 60-70% of the total amount of the air entraining agent; the nonionic air entraining agent is alkylphenol polyoxyethylene, which accounts for 10-20% of the total amount of the air entraining agent; the surfactant is sodium dodecyl sulfate;

the stabilizer is polyethylene oxide or polyether.

2. The antifreezing concrete composite water reducing agent according to claim 1, wherein: the early-strength polycarboxylate superplasticizer mother liquor is prepared by carrying out free radical copolymerization on a polyether macromonomer, an anionic active monomer, a cationic active monomer, a shrinkage reducing monomer, a chain transfer agent and an initiator; wherein the polyether macromonomer is isopentenyl polyoxyethylene ether; the anion active monomer is acrylic acid, and the mass of the anion active monomer is 5-6% of that of the polyether macromonomer; the cationic active monomer is acryloyloxyethyl trimethyl ammonium chloride, and the mass of the cationic active monomer is 8-15% of that of the polyether macromonomer; the shrinkage reducing monomer is esterification reaction product of benzene alcohol or methyl benzene alcohol and acrylic acid, and the mass of the shrinkage reducing monomer is 5-10% of that of the polyether macromonomer.

3. The antifreezing concrete composite water reducing agent according to claim 2, wherein: the chain transfer agent is sodium methyl propylene sulfonate, thioglycolic acid, mercaptoethanol or mercaptopropionic acid, and the mass of the chain transfer agent is 0.5-1% of that of the polyether macromonomer.

4. The antifreezing concrete composite water reducing agent according to claim 2, wherein: the initiator is ammonium persulfate or vitamin C, and the mass of the initiator is 0.5-1% of that of the polyether macromonomer.

5. The antifreezing concrete composite water reducing agent according to claim 1, wherein: the slump-retaining polycarboxylate water reducer mother liquor is obtained by adding a byproduct epoxy compound in the industrial production process of an organosilane coupling agent into a polycarboxylate water reducer prepolymer, preserving heat to enable carboxyl to carry out epoxy ring-opening esterification reaction, adding strong base to adjust pH after the reaction is finished, and adding water.

6. The antifreeze concrete composite water reducing agent according to claim 5, which is characterized in that: the polycarboxylate superplasticizer prepolymer is prepared by carrying out heat preservation on an unsaturated polyether macromonomer and acrylic acid under the action of an initiator, a reducing agent and a chain transfer agent to carry out aqueous phase free radical polymerization reaction; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated polyether macromonomer is 5-6 percent.

7. The antifreeze concrete composite water reducing agent according to claim 6, which is characterized in that: the initiator is ammonium persulfate or sodium persulfate, and the mass of the initiator is 0.5-1% of that of the polyether macromonomer.

8. The antifreeze concrete composite water reducing agent according to claim 6, which is characterized in that: the reducing agent is sodium bisulfite, sodium metabisulfite or ferrous sulfate, and the mass of the reducing agent is 0.1-0.5% of that of the polyether macromonomer.

9. The antifreeze concrete composite water reducing agent according to claim 6, which is characterized in that: the chain transfer agent is sodium methyl propenyl sulfonate or dodecyl mercaptan, and the mass of the chain transfer agent is 0.5-2% of that of the polyether macromonomer.

10. The antifreezing concrete composite water reducing agent of claim 1, wherein the preparation method of the antifreezing concrete composite water reducing agent comprises the following steps:

1) preparing an early strength polycarboxylate superplasticizer mother solution:

adding benzene alcohol or methyl benzene alcohol into polymerization inhibitor and uniformly dispersing, then adding acrylic acid and catalyst, and carrying out esterification reaction at 60-70 ℃, wherein the esterification product is a shrinkage reducing monomer; wherein, the consumption of the polymerization inhibitor is 0.05 percent of the mass of the acrylic acid; dissolving a polyether macromonomer in deionized water to obtain a solution I; dissolving an anion active monomer, a cation active monomer and a chain transfer agent in deionized water to obtain a solution II; dropwise adding an initiator solution into the solution I; dropwise adding the solution II and the shrinkage reducing monomer solution into the solution I, stirring at 55-65 ℃ and carrying out polymerization reaction; adding polyalcohol amine into the polymerization reaction product solution for neutralization to obtain early strength polycarboxylate superplasticizer mother liquor;

2) preparing a slump-retaining polycarboxylic acid water reducer mother solution:

the material is obtained by carrying out water-phase free radical polymerization reaction on unsaturated polyether macromonomer and acrylic acid at the temperature of 40-60 ℃ for 2-4h under the action of an initiator, a reducing agent and a chain transfer agent; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated polyether macromonomer is 5-6 percent of that of the polyether macromonomer; the initiator is ammonium persulfate or sodium persulfate, and the mass of the initiator is 0.5-1% of that of the polyether macromonomer; the reducing agent is sodium bisulfite, sodium metabisulfite or ferrous sulfate, and the mass of the reducing agent is 0.1-0.5 percent of that of the polyether macromonomer; the chain transfer agent is sodium methyl propenyl sulfonate or dodecyl mercaptan, and the mass of the chain transfer agent is 0.5-2% of that of the polyether macromonomer; adding a byproduct epoxy compound in the industrial production process of the organosilane coupling agent into the polycarboxylate superplasticizer prepolymer, preserving heat to perform an epoxy ring-opening esterification reaction on carboxyl, adding strong base to adjust the pH value to 4.2-4.5 after the reaction is finished, and adding water to obtain the slump-retaining polycarboxylate superplasticizer with the mass concentration of 30-50%;

3) compounding:

weighing the early-strength polycarboxylate superplasticizer mother liquor, the slump-retaining polycarboxylate superplasticizer mother liquor, the composite antifreezing component, the air entraining agent, the stabilizing agent and water according to the mass percentage, and stirring and mixing uniformly.

Technical Field

The invention relates to the technical field of water reducing agents, and particularly relates to an antifreezing concrete composite water reducing agent and a preparation method thereof.

Background

The weather in the vast northern areas of China is usually cold, and the weather is 4-6 months in winter, so that the construction of concrete engineering is greatly influenced. In order to ensure the quality and progress of concrete construction, the most cost-effective method is to use an anti-freezing agent. The concrete antifreezer goes through several stages of chloride salt type, chloride salt rust-resisting type, chlorine-free high-alkali type and chlorine-free low-alkali type. At present, the most used mixing plant is a water reducing component, which mainly comprises a naphthalene water reducing agent, and early strength components comprise sulfate, carbonate and the like, wherein most of the early strength components are sodium salts; the antifreezing component is nitrite, chloride, urea, ammonia water, etc. The water reducing components of the antifreezing agents not only have high alkali content, but also contain residual formaldehyde, and in addition, the water reducing rate is not high, the adaptability to cement and sand stone materials is poor, the requirements of the current high-performance concrete are difficult to meet, and the chloride ion content and the sulfate content in the antifreezing components are very high, so that the antifreezing components are not beneficial to the durability and the environmental protection of the concrete.

The raw materials for preparing the anti-freezing water reducer comprise a main material and an anti-freezing agent accounting for 10 percent of the weight of the main material, wherein the main material comprises 120 parts by weight of an aliphatic water reducer, 150 parts by weight of sodium metaphosphate and 10-20 parts by weight of an early strength agent, and the anti-freezing agent comprises 0.5-1.5 parts by weight of an air entraining agent, 3-8 parts by weight of a calcium magnesium acetate salt, 1-8 parts by weight of a 2-mercaptoethane sulfonic acid sodium salt, 2-5 parts by weight of tetraethyleneglycol monooctyl ether, 10-15 parts by weight of nano kieselguhr and 5-10 parts by weight of a steel fiber; according to the antifreezing water reducing agent and the preparation process thereof, the antifreezing agent and the pine extract are added, so that the water reducing effect is good, the slump retaining strength is increased, bleeding is prevented, the antifreezing effect is good, the slow release effect is strong, the strength of concrete is increased, and the enterprise cost is saved.

But the antifreezing concrete composite water reducing agent still has the defects in use, and firstly, the mother liquor of the water reducing agent is not reasonable enough in design and can not be compounded and adjusted according to requirements; secondly, the requirement of freezing resistance under the environment of-10 ℃, especially-15 ℃ cannot be met. Therefore, optimization improvements are needed.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provides an antifreezing concrete composite water reducing agent and a preparation method thereof.

In order to achieve the technical purpose and achieve the technical effect, the invention is realized by the following technical scheme:

the antifreezing concrete composite water reducing agent comprises the following components in percentage by mass: 20-30% of mother liquor of an early strength type polycarboxylate superplasticizer, 20-30% of mother liquor of a slump retaining polycarboxylate superplasticizer, 1.5-4% of a composite antifreezing component, 0.1-0.3% of an air entraining agent, 0.1-0.3% of a stabilizer and the balance of water; the sum of the mass percentages of the components is 100 percent;

the composite antifreezing component is formed by mixing methanol, ethylene glycol, sodium nitrite and calcium nitrite according to the mass ratio of 1:1-3:2-3: 2-4;

the air entraining agent consists of a main air entraining agent, a nonionic air entraining agent and a surfactant for adjusting the molecular arrangement of a gas-liquid interface, wherein the main air entraining agent is rosin soap and accounts for 60-70% of the total amount of the air entraining agent; the nonionic air entraining agent is alkylphenol polyoxyethylene, which accounts for 10-20% of the total amount of the air entraining agent; the surfactant is sodium dodecyl sulfate;

the stabilizer is polyethylene oxide or polyether.

Further, in the antifreezing concrete composite water reducing agent, the early strength polycarboxylate water reducing agent mother liquor is prepared by carrying out free radical copolymerization on a polyether macromonomer, an anion active monomer, a cation active monomer, a shrinkage reducing monomer, a chain transfer agent and an initiator; wherein the polyether macromonomer is isopentenyl polyoxyethylene ether; the anion active monomer is acrylic acid, and the mass of the anion active monomer is 5-6% of that of the polyether macromonomer; the cationic active monomer is acryloyloxyethyl trimethyl ammonium chloride, and the mass of the cationic active monomer is 8-15% of that of the polyether macromonomer; the shrinkage reducing monomer is esterification reaction product of benzene alcohol or methyl benzene alcohol and acrylic acid, and the mass of the shrinkage reducing monomer is 5-10% of that of the polyether macromonomer.

Further, in the antifreezing concrete composite water reducing agent, the chain transfer agent is sodium methyl acrylate sulfonate, thioglycolic acid, mercaptoethanol or mercaptopropionic acid, and the mass of the chain transfer agent is 0.5-1% of that of the polyether macromonomer.

Further, in the antifreezing concrete composite water reducing agent, the initiator is ammonium persulfate or vitamin C, and the mass of the initiator is 0.5-1% of that of the polyether macromonomer.

Further, in the anti-freezing concrete composite water reducing agent, the slump-retaining polycarboxylate water reducing agent mother liquor is obtained by adding a byproduct epoxy compound in the industrial production process of the organosilane coupling agent into a polycarboxylate water reducing agent prepolymer, preserving heat to enable carboxyl to carry out epoxy ring-opening esterification reaction, adding strong base to adjust pH after the reaction is finished, and adding water.

Further, in the antifreezing concrete composite water reducing agent, the polycarboxylate water reducing agent prepolymer is obtained by carrying out heat preservation and aqueous phase free radical polymerization on an unsaturated polyether macromonomer and acrylic acid under the action of an initiator, a reducing agent and a chain transfer agent; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated polyether macromonomer is 5-6 percent.

Further, in the antifreezing concrete composite water reducing agent, the initiator is ammonium persulfate or sodium persulfate, and the mass of the initiator is 0.5-1% of that of the polyether macromonomer.

Further, in the antifreezing concrete composite water reducing agent, the reducing agent is sodium bisulfite, sodium metabisulfite or ferrous sulfate, and the mass of the reducing agent is 0.1-0.5% of that of the polyether macromonomer.

Further, in the antifreezing concrete composite water reducing agent, the chain transfer agent is sodium methyl propenyl sulfonate or dodecyl mercaptan, and the mass of the chain transfer agent is 0.5-2% of that of the polyether macromonomer.

Further, in the antifreezing concrete composite water reducing agent, the preparation method of the antifreezing concrete composite water reducing agent comprises the following steps:

1) preparing an early strength polycarboxylate superplasticizer mother solution:

adding benzene alcohol or methyl benzene alcohol into polymerization inhibitor and uniformly dispersing, then adding acrylic acid and catalyst, and carrying out esterification reaction at 60-70 ℃, wherein the esterification product is a shrinkage reducing monomer; wherein, the consumption of the polymerization inhibitor is 0.05 percent of the mass of the acrylic acid; dissolving a polyether macromonomer in deionized water to obtain a solution I; dissolving an anion active monomer, a cation active monomer and a chain transfer agent in deionized water to obtain a solution II; dropwise adding an initiator solution into the solution I; dropwise adding the solution II and the shrinkage reducing monomer solution into the solution I, stirring at 55-65 ℃ and carrying out polymerization reaction; adding polyalcohol amine into the polymerization reaction product solution for neutralization to obtain early strength polycarboxylate superplasticizer mother liquor;

2) preparing a slump-retaining polycarboxylic acid water reducer mother solution:

the material is obtained by carrying out water-phase free radical polymerization reaction on unsaturated polyether macromonomer and acrylic acid at the temperature of 40-60 ℃ for 2-4h under the action of an initiator, a reducing agent and a chain transfer agent; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated polyether macromonomer is 5-6 percent of that of the polyether macromonomer; the initiator is ammonium persulfate or sodium persulfate, and the mass of the initiator is 0.5-1% of that of the polyether macromonomer; the reducing agent is sodium bisulfite, sodium metabisulfite or ferrous sulfate, and the mass of the reducing agent is 0.1-0.5 percent of that of the polyether macromonomer; the chain transfer agent is sodium methyl propenyl sulfonate or dodecyl mercaptan, and the mass of the chain transfer agent is 0.5-2% of that of the polyether macromonomer; adding a byproduct epoxy compound in the industrial production process of the organosilane coupling agent into the polycarboxylate superplasticizer prepolymer, preserving heat to perform an epoxy ring-opening esterification reaction on carboxyl, adding strong base to adjust the pH value to 4.2-4.5 after the reaction is finished, and adding water to obtain the slump-retaining polycarboxylate superplasticizer with the mass concentration of 30-50%;

3) compounding:

weighing the early-strength polycarboxylate superplasticizer mother liquor, the slump-retaining polycarboxylate superplasticizer mother liquor, the composite antifreezing component, the air entraining agent, the stabilizing agent and water according to the mass percentage, and stirring and mixing uniformly.

The invention has the beneficial effects that:

1. by designing two different polycarboxylic acid water reducing agent mother solutions of an early strength type and a slump retaining type, the proportion is adjusted to meet the requirements of different constructions on the workability of concrete, and simultaneously, due to the structural complementarity of the two mother solutions, under the condition of meeting the workability of concrete, the water consumption of the concrete is greatly reduced, the compactness of the concrete is improved, the setting time of the concrete is shortened, and the early strength of the concrete is improved;

2. the composite antifreezing component is formed by mixing methanol, glycol, sodium nitrite and calcium nitrite according to a mass ratio, and effectively reduces the internal freezing point of concrete.

3. The air entraining agent consists of a main air entraining agent, a nonionic air entraining agent and a surfactant for adjusting the molecular arrangement of a gas-liquid interface, improves the pore structure of the concrete, enables air pores in the concrete to be micro-air pores which are uniformly distributed, closed and independent, and can effectively consume frost heaving stress in the concrete.

4. The stabilizer is polyethylene oxide or polyether, can improve the sensitivity of the polycarboxylate superplasticizer to the water adding amount, the admixture mixing amount and the temperature in the concrete mixing construction process, improves the compatibility among the components, and synergistically generates the early strength and antifreezing effect.

Of course, it is not necessary for any one product that embodies the invention to achieve all of the above advantages simultaneously.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The antifreezing concrete composite water reducing agent comprises the following components in percentage by mass: 25% of an early strength type polycarboxylate superplasticizer mother liquor, 25% of a slump retaining polycarboxylate superplasticizer mother liquor, 3% of a composite antifreezing component, 0.2% of an air entraining agent, 0.2% of a stabilizing agent and the balance of water; the sum of the mass percentages of the components is 100 percent.

In the embodiment, the early strength polycarboxylate superplasticizer mother liquor is prepared by carrying out free radical copolymerization on a polyether macromonomer, an anion active monomer, a cation active monomer, a shrinkage reducing monomer, a chain transfer agent and an initiator; wherein the polyether macromonomer is isopentenyl polyoxyethylene ether; the anion active monomer is acrylic acid, and the mass of the anion active monomer is 5 percent of that of the polyether macromonomer; the cationic active monomer is acryloyloxyethyl trimethyl ammonium chloride, and the mass of the cationic active monomer is 12% of that of the polyether macromonomer; the shrinkage reducing monomer is an esterification reaction product of benzene alcohol and acrylic acid, and the mass of the shrinkage reducing monomer is 8% of that of the polyether macromonomer. The chain transfer agent is sodium methyl propylene sulfonate, and the mass of the chain transfer agent is 0.7 percent of that of the polyether macromonomer. The initiator is ammonium persulfate, and the mass of the initiator is 0.6 percent of that of the polyether macromonomer.

In the embodiment, the slump-retaining polycarboxylate water reducer mother liquor is obtained by adding a byproduct epoxy compound in the industrial production process of an organosilane coupling agent into a polycarboxylate water reducer prepolymer, preserving heat to enable carboxyl to perform an epoxy ring-opening esterification reaction, adding strong base to adjust the pH after the reaction is finished, and adding water. The polycarboxylate water reducing agent prepolymer is prepared by carrying out water-phase free radical polymerization reaction on an unsaturated polyether macromonomer and acrylic acid under the action of an initiator, a reducing agent and a chain transfer agent in a heat preservation manner; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated acid is 5 percent of that of the polyether macromonomer; the initiator is sodium persulfate, and the mass of the initiator is 0.6 percent of that of the polyether macromonomer; the reducing agent is sodium bisulfite, and the mass of the reducing agent is 0.3 percent of that of the polyether macromonomer. The chain transfer agent is sodium methyl propenyl sulfonate, and the mass of the chain transfer agent is 0.7 percent of that of the polyether macromonomer.

In the embodiment, the composite antifreezing component is formed by mixing methanol, ethylene glycol, sodium nitrite and calcium nitrite according to the mass ratio of 1:2:2: 3;

in the embodiment, the air entraining agent is composed of a main air entraining agent, a nonionic air entraining agent and a surfactant for adjusting the molecular arrangement of a gas-liquid interface, wherein the main air entraining agent is rosin soap, and accounts for 65% of the total amount of the air entraining agent; the nonionic air entraining agent is alkylphenol polyoxyethylene, which accounts for 15% of the total amount of the air entraining agent; the surfactant is sodium dodecyl sulfate;

in this example, the stabilizer is polyethylene oxide.

The preparation method of the antifreezing concrete composite water reducing agent comprises the following steps:

1) preparing an early strength polycarboxylate superplasticizer mother solution:

adding benzene alcohol into polymerization inhibitor and uniformly dispersing, then adding acrylic acid and catalyst, and carrying out esterification reaction at 65 ℃ to obtain an esterification product, namely a shrinkage reducing monomer; wherein, the consumption of the polymerization inhibitor is 0.05 percent of the mass of the acrylic acid; dissolving a polyether macromonomer in deionized water to obtain a solution I; dissolving an anion active monomer, a cation active monomer and a chain transfer agent in deionized water to obtain a solution II; dropwise adding an initiator solution into the solution I; dropwise adding the solution II and the shrinkage reducing monomer solution into the solution I, stirring at 60 ℃ and carrying out polymerization reaction; adding polyalcohol amine into the polymerization reaction product solution for neutralization to obtain early strength polycarboxylate superplasticizer mother liquor;

2) preparing a slump-retaining polycarboxylic acid water reducer mother solution:

the material is obtained by carrying out water-phase free radical polymerization reaction on unsaturated polyether macromonomer and acrylic acid at the temperature of 40-60 ℃ for 2-4h under the action of an initiator, a reducing agent and a chain transfer agent; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated acid is 5 percent of that of the polyether macromonomer; the initiator is sodium persulfate, and the mass of the initiator is 0.6 percent of that of the polyether macromonomer; the reducing agent is sodium bisulfite, and the mass of the reducing agent is 0.3 percent of that of the polyether macromonomer. The chain transfer agent is sodium methyl propenyl sulfonate, and the mass of the chain transfer agent is 0.7 percent of that of the polyether macromonomer; adding a byproduct epoxy compound in the industrial production process of the organosilane coupling agent into the polycarboxylate superplasticizer prepolymer, preserving heat to perform epoxy ring-opening esterification reaction on carboxyl, adding strong base to adjust the pH to 4.3 after the reaction is finished, and adding water to obtain the slump-retaining polycarboxylate superplasticizer with the mass concentration of 40%;

3) compounding:

weighing the early-strength polycarboxylate superplasticizer mother liquor, the slump-retaining polycarboxylate superplasticizer mother liquor, the composite antifreezing component, the air entraining agent, the stabilizing agent and water according to the mass percentage, and stirring and mixing uniformly.

Example 2

The antifreezing concrete composite water reducing agent comprises the following components in percentage by mass: 20% of an early strength type polycarboxylate superplasticizer mother liquor, 30% of a slump retaining polycarboxylate superplasticizer mother liquor, 1.5% of a composite antifreezing component, 0.3% of an air entraining agent, 0.1% of a stabilizing agent and the balance of water; the sum of the mass percentages of the components is 100 percent;

in the embodiment, the early strength polycarboxylate superplasticizer mother liquor is prepared by carrying out free radical copolymerization on a polyether macromonomer, an anion active monomer, a cation active monomer, a shrinkage reducing monomer, a chain transfer agent and an initiator; wherein the polyether macromonomer is isopentenyl polyoxyethylene ether; the anion active monomer is acrylic acid, and the mass of the anion active monomer is 5 percent of that of the polyether macromonomer; the cationic active monomer is acryloyloxyethyl trimethyl ammonium chloride, and the mass of the cationic active monomer is 9% of that of the polyether macromonomer; the shrinkage reducing monomer is an esterification reaction product of benzene alcohol and acrylic acid, and the mass of the shrinkage reducing monomer is 10% of that of the polyether macromonomer. The chain transfer agent is thioglycolic acid, and the mass of the chain transfer agent is 0.5 percent of that of the polyether macromonomer. The initiator is vitamin C, and the mass of the initiator is 0.5 percent of that of the polyether macromonomer.

In the embodiment, the slump-retaining polycarboxylate water reducer mother liquor is obtained by adding a byproduct epoxy compound in the industrial production process of an organosilane coupling agent into a polycarboxylate water reducer prepolymer, preserving heat to enable carboxyl to perform an epoxy ring-opening esterification reaction, adding strong base to adjust the pH after the reaction is finished, and adding water. The polycarboxylate water reducing agent prepolymer is prepared by carrying out water-phase free radical polymerization reaction on an unsaturated polyether macromonomer and acrylic acid under the action of an initiator, a reducing agent and a chain transfer agent in a heat preservation manner; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated acid is 5 percent of that of the polyether macromonomer; the initiator is sodium persulfate, and the mass of the initiator is 1 percent of that of the polyether macromonomer; the reducing agent is sodium bisulfite, and the mass of the reducing agent is 0.5 percent of that of the polyether macromonomer. The chain transfer agent is sodium methyl propenyl sulfonate or dodecyl mercaptan, and the mass of the chain transfer agent is 0.5 percent of that of the polyether macromonomer.

In the embodiment, the composite antifreezing component is formed by mixing methanol, ethylene glycol, sodium nitrite and calcium nitrite according to the mass ratio of 1:3:2: 4;

in the embodiment, the air entraining agent is composed of a main air entraining agent, a nonionic air entraining agent and a surfactant for adjusting the molecular arrangement of a gas-liquid interface, wherein the main air entraining agent is rosin soap, and accounts for 60% of the total amount of the air entraining agent; the nonionic air entraining agent is alkylphenol polyoxyethylene, which accounts for 20% of the total amount of the air entraining agent; the surfactant is sodium dodecyl sulfate. The balance of surfactant;

in this example, the stabilizer is polyethylene oxide or polyether.

The preparation method of the antifreezing concrete composite water reducing agent comprises the following steps:

1) preparing an early strength polycarboxylate superplasticizer mother solution:

adding benzene alcohol into polymerization inhibitor and dispersing uniformly, then adding acrylic acid and catalyst, and carrying out esterification reaction at 60 ℃ to obtain an esterification product, namely a shrinkage reducing monomer; wherein, the consumption of the polymerization inhibitor is 0.05 percent of the mass of the acrylic acid; dissolving a polyether macromonomer in deionized water to obtain a solution I; dissolving an anion active monomer, a cation active monomer and a chain transfer agent in deionized water to obtain a solution II; dropwise adding an initiator solution into the solution I; dropwise adding the solution II and the shrinkage reducing monomer solution into the solution I, stirring at 65 ℃ and carrying out polymerization reaction; adding polyalcohol amine into the polymerization reaction product solution for neutralization to obtain early strength polycarboxylate superplasticizer mother liquor;

2) preparing a slump-retaining polycarboxylic acid water reducer mother solution:

the material is obtained by carrying out water-phase free radical polymerization reaction on unsaturated polyether macromonomer and acrylic acid for 2 hours at the temperature of 60 ℃ under the action of an initiator, a reducing agent and a chain transfer agent; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated acid is 5 percent of that of the polyether macromonomer; the initiator is sodium persulfate, and the mass of the initiator is 1 percent of that of the polyether macromonomer; the reducing agent is sodium bisulfite, and the mass of the reducing agent is 0.5 percent of that of the polyether macromonomer. The chain transfer agent is sodium methyl propenyl sulfonate or dodecyl mercaptan, and the mass of the chain transfer agent is 0.5 percent of that of the polyether macromonomer; adding a byproduct epoxy compound in the industrial production process of the organosilane coupling agent into the polycarboxylate superplasticizer prepolymer, preserving heat to perform epoxy ring-opening esterification reaction on carboxyl, adding strong base to adjust the pH to 4.5 after the reaction is finished, and adding water to obtain the slump-retaining polycarboxylate superplasticizer with the mass concentration of 32%;

3) compounding:

weighing the early-strength polycarboxylate superplasticizer mother liquor, the slump-retaining polycarboxylate superplasticizer mother liquor, the composite antifreezing component, the air entraining agent, the stabilizing agent and water according to the mass percentage, and stirring and mixing uniformly.

Example 3

The antifreezing concrete composite water reducing agent comprises the following components in percentage by mass: 30% of an early strength type polycarboxylate superplasticizer mother liquor, 20% of a slump retaining polycarboxylate superplasticizer mother liquor, 4% of a composite antifreezing component, 0.1% of an air entraining agent, 0.3% of a stabilizer and the balance of water; the sum of the mass percentages of the components is 100 percent.

In the embodiment, the early strength polycarboxylate superplasticizer mother liquor is prepared by carrying out free radical copolymerization on a polyether macromonomer, an anion active monomer, a cation active monomer, a shrinkage reducing monomer, a chain transfer agent and an initiator; wherein the polyether macromonomer is isopentenyl polyoxyethylene ether; the anion active monomer is acrylic acid, and the mass of the anion active monomer is 5 percent of that of the polyether macromonomer; the cationic active monomer is acryloyloxyethyl trimethyl ammonium chloride, and the mass of the cationic active monomer is 15% of that of the polyether macromonomer; the shrinkage reducing monomer is an esterification reaction product of methyl benzene alcohol and acrylic acid, and the mass of the shrinkage reducing monomer is 5% of that of the polyether macromonomer. The chain transfer agent is sodium methyl propylene sulfonate, thioglycolic acid, mercaptoethanol or mercaptopropionic acid, and the mass of the chain transfer agent is 1 percent of that of the polyether macromonomer. The initiator is vitamin C, and the mass of the initiator is 1% of that of the polyether macromonomer.

In the embodiment, the slump-retaining polycarboxylate water reducer mother liquor is obtained by adding a byproduct epoxy compound in the industrial production process of an organosilane coupling agent into a polycarboxylate water reducer prepolymer, preserving heat to enable carboxyl to perform an epoxy ring-opening esterification reaction, adding strong base to adjust the pH after the reaction is finished, and adding water. The polycarboxylate water reducing agent prepolymer is prepared by carrying out water-phase free radical polymerization reaction on an unsaturated polyether macromonomer and acrylic acid under the action of an initiator, a reducing agent and a chain transfer agent in a heat preservation manner; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated acid is 5 percent of that of the polyether macromonomer; the initiator is ammonium persulfate, and the mass of the initiator is 0.5 percent of that of the polyether macromonomer; the reducing agent is sodium pyrosulfite, and the mass of the reducing agent is 0.1 percent of that of the polyether macromonomer. The chain transfer agent is sodium methyl propenyl sulfonate or dodecyl mercaptan, and the mass of the chain transfer agent is 2% of that of the polyether macromonomer.

In the embodiment, the composite antifreezing component is formed by mixing methanol, ethylene glycol, sodium nitrite and calcium nitrite according to the mass ratio of 1:1:2: 2;

in the embodiment, the air entraining agent is composed of a main air entraining agent, a nonionic air entraining agent and a surfactant for adjusting the molecular arrangement of a gas-liquid interface, wherein the main air entraining agent is rosin soap, and accounts for 70% of the total amount of the air entraining agent; the nonionic air entraining agent is alkylphenol polyoxyethylene, which accounts for 10% of the total amount of the air entraining agent; the surfactant is sodium dodecyl sulfate;

in this example, the stabilizer is polyethylene oxide or polyether.

The preparation method of the antifreezing concrete composite water reducing agent comprises the following steps:

1) preparing an early strength polycarboxylate superplasticizer mother solution:

adding a polymerization inhibitor into the methyl benzene alcohol, uniformly dispersing, then adding acrylic acid and a catalyst, and carrying out esterification reaction at 70 ℃ to obtain an esterification product, namely a shrinkage-reducing monomer; wherein, the consumption of the polymerization inhibitor is 0.05 percent of the mass of the acrylic acid; dissolving a polyether macromonomer in deionized water to obtain a solution I; dissolving an anion active monomer, a cation active monomer and a chain transfer agent in deionized water to obtain a solution II; dropwise adding an initiator solution into the solution I; dropwise adding the solution II and the shrinkage reducing monomer solution into the solution I, stirring at 55 ℃ and carrying out polymerization reaction; adding polyalcohol amine into the polymerization reaction product solution for neutralization to obtain early strength polycarboxylate superplasticizer mother liquor;

2) preparing a slump-retaining polycarboxylic acid water reducer mother solution:

the material is obtained by carrying out aqueous phase free radical polymerization reaction on unsaturated polyether macromonomer and acrylic acid at 40 ℃ for 4h under the action of an initiator, a reducing agent and a chain transfer agent; wherein the unsaturated polyether macromonomer is allyl polyethylene glycol, the unsaturated acid is acrylic acid, and the mass of the unsaturated acid is 5 percent of that of the polyether macromonomer; the initiator is ammonium persulfate, and the mass of the initiator is 0.5 percent of that of the polyether macromonomer; the reducing agent is sodium pyrosulfite, and the mass of the reducing agent is 0.1 percent of that of the polyether macromonomer. The chain transfer agent is sodium methyl propenyl sulfonate or dodecyl mercaptan, and the mass of the chain transfer agent is 2% of that of the polyether macromonomer; adding a byproduct epoxy compound in the industrial production process of the organosilane coupling agent into the polycarboxylate superplasticizer prepolymer, preserving heat to perform an epoxy ring-opening esterification reaction on carboxyl, adding strong base to adjust the pH to 4.2 after the reaction is finished, and adding water to obtain a slump-retaining polycarboxylate superplasticizer with the mass concentration of 47%;

3) compounding:

weighing the early-strength polycarboxylate superplasticizer mother liquor, the slump-retaining polycarboxylate superplasticizer mother liquor, the composite antifreezing component, the air entraining agent, the stabilizing agent and water according to the mass percentage, and stirring and mixing uniformly.

And (3) antifreezing test:

the test is carried out by taking the anti-freezing requirement at minus 10 ℃ as a reference, the mixing amount of the anti-freezing concrete composite water reducing agent obtained in the example 1-3 is designed to be 2.5 percent of the cement gel material, and the test results are shown in the table 1:

TABLE 1-10 ℃ Freeze protection requirement test and results

The test is carried out by taking the anti-freezing requirement at 15 ℃ below zero as a reference, the mixing amount of the anti-freezing concrete composite water reducing agent obtained in the example 1-3 is designed to be 3.5 percent of the cement gel material, and the test results are shown in the table 2:

TABLE 2-10 ℃ Freeze protection requirement test and results

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.