CN107200817A - A kind of preparation method of stable type concrete slump controlling agent - Google Patents

Abstract

The invention discloses a preparation method of a stable concrete slump control agent. An ester group, a benzene ring and a sulfonic acid group structure are introduced into the molecular structure through the esterification product of an unsaturated carboxylic acid and compound A. Initially due to The introduction of sulfonic acid groups with water-reducing effect and benzene ring with steric hindrance effect makes the product have a high initial water-reducing rate, and the introduced ester group structure will gradually hydrolyze under the alkaline condition of concrete, and Since the number of dispersing groups in the molecular structure of the product before and after the hydrolysis of the ester group does not change much, there will be no hysteresis amplification of the concrete slump caused by too fast hydrolysis of the ester group, and there will be no problems due to excessive hydrolysis of the ester group. The problem of too fast loss of concrete slump due to slow speed, so it is not easy to be affected by changes in service conditions during use, and realizes stable control of concrete slump.

Description

A kind of preparation method of stable concrete slump control agent

technical field

The invention belongs to the technical field of building materials, and in particular relates to a preparation method of a stable concrete slump control agent.

Background technique

With the rapid development of concrete technology in the direction of high strength, green and high performance, the water reducing agent as an important part of concrete has also been put forward higher and more comprehensive requirements. In the past, traditional concrete water reducers, such as the first generation of lignin and the second generation of naphthalene sulfonate, sulfonated melamine, sulfamic acid, aliphatic and other water reducers, due to the large amount, The water reducing rate is not high enough, the reinforcement effect is not very significant, and the concrete slump loss is relatively large, which has gradually failed to meet the development of modern concrete technology and modern concrete construction methods. In particular, the use of industrial naphthalene, concentrated sulfuric acid, formaldehyde, liquid caustic soda, phenol and other harmful chemicals in the production process will inevitably cause certain pollution to the environment, and there are disadvantages such as problems that are not conducive to sustainable development, thereby partially restricting other industries. Further promotion and application.

Polycarboxylate superplasticizer has been applied in national key projects such as high-speed rail, hydropower, and nuclear power since 2006 due to its excellent performance, energy saving and environmental protection, and good concrete durability. However, with the shortage of resources and the improvement of concrete performance requirements, polycarboxylate superplasticizers often have problems in the popularization and application of the slump-preserving effect, and the slump-preserving effect is easily affected by factors such as temperature. And the stable concrete slump control agent which is not sensitive to the conditions of use is of great significance.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art and provide a preparation method of a stable concrete slump control agent.

Technical scheme of the present invention is as follows:

A preparation method of a stable concrete slump control agent, comprising the steps of:

(1) Mix unsaturated carboxylic acid, compound A and polymerization inhibitor, under the protection of nitrogen, heat up to 40-60°C, then add catalyst, heat up to 100-140°C, keep warm for 0.5-3h, during which time use vacuum Or the method of logical nitrogen belt water is removed water, after reaction finishes, be down to room temperature, obtain the first mixture that contains esterification product and unreacted unsaturated carboxylic acid, the mol ratio of unsaturated carboxylic acid and compound A is 1.5～6: 1. The amount of catalyst used is 0.5% to 5.0% of the total mass of unsaturated carboxylic acid and compound A, and the amount of polymerization inhibitor is 0.5% to 5.0% of the total mass of unsaturated carboxylic acid and compound A. The structural formula of compound A is as follows:

Wherein R1 is an alkyl group with ₁ to 4 carbons or none, and R2 is an alkyl group with 1 to 4 carbons or none;

(2) Mix the first mixture prepared in step (1) and 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 600 to 5000 in a mass ratio of 1:4 to 30, and add water to dissolve it, Obtain comonomer mixture solution;

(3) Drop the above-mentioned comonomer mixture solution, initiator aqueous solution and molecular weight regulator aqueous solution into water for reaction. The reaction temperature is 10-40°C, the dropping time is 0.2-6.0h, and the temperature is kept for 0-3.0 hours after the dropping is completed. h, to obtain a copolymerization product; the total amount of water used in this step and step (2) makes the mass concentration of the copolymerization product 20 to 80%, and the consumption of the initiator is 0.5 to 3.0 percent of the total mass of the solute in the comonomer mixture solution %, the consumption of the molecular weight modifier is 0.2～3.0% of the total mass of the solute in the comonomer mixture solution;

(4) Adjust the pH of the copolymerization product prepared in step (3) to 5-7 with alkali to obtain the stable concrete slump control agent.

In a preferred embodiment of the present invention, the step (1) is: mix unsaturated carboxylic acid, compound A, and polymerization inhibitor, under the protection of nitrogen, heat up to 50-60°C, then add catalyst, and heat up to 105-130°C, heat preservation reaction for 1-3 hours, during which the water is removed by vacuuming or nitrogen with water, and after the reaction is completed, it is lowered to room temperature to obtain the first mixture containing esterification products and unreacted unsaturated carboxylic acids. The molar ratio of unsaturated carboxylic acid and compound A is 1.5～5:1, the consumption of catalyst is 0.5%～4.0% of the total mass of unsaturated carboxylic acid and compound A, and the consumption of polymerization inhibitor is the total mass of unsaturated carboxylic acid and compound A. 0.5% to 4.0% of the mass.

In a preferred embodiment of the present invention, the step (2) is: the first mixture prepared in the step (1), 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 600-5000 in a ratio of 1: 5-20 mass ratio, and adding water to dissolve it, to obtain a comonomer mixture solution.

In a preferred embodiment of the present invention, the step (3) is: drop the above-mentioned comonomer mixture solution, initiator aqueous solution and molecular weight modifier aqueous solution into water for reaction, the reaction temperature is 10-30° C., dropwise The time is 0.2～5.0h, after the dropwise addition is completed, it is incubated for 0～3.0h to obtain the copolymerization product; the total amount of water used in this step and step (2) makes the mass concentration of the copolymerization product 20～70%, and the consumption of initiator The amount of the molecular weight regulator is 0.5-2.0% of the total mass of the solute in the comonomer mixture solution, and the dosage of the molecular weight regulator is 0.2-2.0% of the total mass of the solute in the comonomer mixture solution.

Further preferably, the unsaturated carboxylic acid is at least one of acrylic acid and methacrylic acid.

Further preferably, the catalyst is at least one of ethylsulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid and 98% concentrated sulfuric acid.

Further preferably, the polymerization inhibitor is at least one of hydroquinone, phenothiazine and diphenylamine.

Further preferably, the initiator is a water-soluble redox initiator system or a water-soluble azo initiator.

Further preferably, the molecular weight regulator is at least one of mercaptoacetic acid, mercaptopropionic acid, mercaptoethanol, isopropanol, sodium hypophosphite, trisodium phosphate, sodium formate, sodium acetate and dodecanethiol.

Beneficial effects of the present invention:

1. The present invention introduces an ester group, a benzene ring and a sulfonic acid group structure in the molecular structure through the esterification product of an unsaturated carboxylic acid and compound A. Initially, due to the introduction of a sulfonic acid group with a water-reducing effect and a space The benzene ring with steric hindrance effect makes the product have a higher initial water reduction rate.

2. When the stable concrete slump control agent prepared by the preparation method of the present invention is used in concrete, under the alkaline environment of concrete, the ester bond in the molecular structure will be gradually hydrolyzed, and the carboxyl group with water-reducing effect will be released to realize Excellent slump retention effect, and because the number of dispersing groups in the molecular structure of the product does not change much before and after ester group hydrolysis, there will be no problem of lagging magnification of concrete slump caused by too fast ester group hydrolysis. There will also be no problem of too fast loss of concrete slump due to too slow hydrolysis of ester groups, so it is not easily affected by changes in service conditions during use, and stable control of concrete slump can be achieved.

detailed description

The technical solutions of the present invention will be further illustrated and described below through specific embodiments.

Example 1

(1) Mix 240.00g of acrylic acid, 200.00g of p-hydroxybenzenesulfonic acid, and 6.50g of phenothiazine. Under the protection of nitrogen, heat up to 60°C, add 8.23g of p-toluenesulfonic acid, heat up to 110°C, and keep the temperature for 2 hours. During the period, the water is removed by vacuumizing or nitrogen-carrying water, and the reaction is cooled to room temperature after the end of the reaction to obtain the first mixture containing the esterification product and unreacted acrylic acid;

(2) Mix 20.00 g of the first mixture prepared in step (1), 185.00 g of 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 2400, and add 120.00 g of water to dissolve it to obtain a comonomer mixture solution;

(3) Mix the above-mentioned comonomer mixture solution with hydrogen peroxide aqueous solution (wherein, hydrogen peroxide 1.20g, water 20.00g), ascorbic acid aqueous solution (wherein, ascorbic acid 0.40g, water 20.00g), ferrous sulfate solution (wherein, ferrous sulfate 0.40g g, water 10.00g), thioglycolic acid aqueous solution (among them, thioglycolic acid 1.20g, water 20.00g) was dripped into 60.00g water for reaction, the reaction temperature was 30°C, the dropping time was 2.0h, and the temperature was kept for 0.5h after the dropping was completed , to obtain copolymerization products;

(4) Adjust the pH of the copolymerization product prepared in step (3) to 5-7 with alkali to obtain the stable concrete slump control agent KZJ-1.

Example 2

(1) Mix 247.00g of methacrylic acid, 200.00g of p-hydroxymethylbenzenesulfonic acid, 5.60g of hydroquinone, and 2.00g of phenothiazine. Under the protection of nitrogen, the temperature is raised to 50°C, and 8.20g of mass fraction is added. 98% concentrated sulfuric acid, heat up to 115°C, keep warm for 3 hours, remove water by vacuuming or blowing nitrogen with water, and cool down to room temperature after the reaction to obtain the first product containing esterification products and unreacted methacrylic acid. a mixture;

(2) Mix 20.00 g of the first mixture prepared in step (1) with 260.00 g of 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 2400, and add 150.00 g of water to dissolve it to obtain a comonomer mixture solution;

(3) Mix the above-mentioned comonomer mixture solution with hydrogen peroxide aqueous solution (wherein, hydrogen peroxide 1.10g, water 20.00g), dimple aqueous solution (wherein, dimple 0.70g, water 20.00g), ferrous sulfate solution (wherein, Ferrous sulfate 0.50g, water 10.00g), mercaptopropionic acid aqueous solution (among them, mercaptopropionic acid 1.50g, water 20.00g) were dropped into 60.00g water for reaction, the reaction temperature was 20°C, and the dropping time was 1.0h. After the addition, keep warm for 1 hour to obtain the copolymerized product;

(4) Adjust the pH of the copolymerization product prepared in step (3) to 5-7 with alkali to obtain the stable concrete slump control agent KZJ-2.

Example 3

(1) Mix 156g of acrylic acid, 86g of methacrylic acid, 200.00g of p-hydroxyethylbenzenesulfonic acid, and 4.20g of hydroquinone. Under nitrogen protection, heat up to 60°C, add 6.30g of ethylsulfonic acid, and heat up to 110 ° C, heat preservation reaction for 2 hours, during which the water was removed by vacuuming or nitrogen with water, and after the reaction was completed, it was lowered to room temperature to obtain the first mixture containing the esterification product and unreacted acrylic acid and methacrylic acid;

(2) Mix 20.00 g of the first mixture prepared in step (1) with 233.00 g of 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 2400, and add 150.00 g of water to dissolve it to obtain a comonomer mixture solution;

(3) Mix the above-mentioned comonomer mixture solution with hydrogen peroxide aqueous solution (wherein, hydrogen peroxide 1.30g, water 20.00g), ascorbic acid aqueous solution (wherein, ascorbic acid 0.30g, water 20.00g), ferrous sulfate solution (wherein, ferrous sulfate 0.50g) g, water 10.00g), trisodium phosphate aqueous solution (among them, trisodium phosphate 2.00g, water 20.00g) was dropped into 60.00g of water for reaction, the reaction temperature was 10°C, and the dropping time was 1.5h. 1h, obtain copolymerization product;

(4) Adjust the pH of the copolymerization product prepared in step (3) to 5-7 with alkali to obtain the stable concrete slump control agent KZJ-3.

Example 4

(1) Mix 177.00g of acrylic acid, 200.00g of 4-hydroxyphenylmethanesulfonic acid, and 6.60g of diphenylamine. Under nitrogen protection, heat up to 60°C, add 5.50g of concentrated sulfuric acid with a mass fraction of 98%, and heat up to 105°C , heat preservation reaction 3h, remove water with the method of evacuating or nitrogen-carrying water during, after the reaction finishes, drop to room temperature, obtain the first mixture that contains esterification product and unreacted acrylic acid;

(2) Mix 244.00 g of the first mixture obtained in step (1) with 20.00 g of 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 3000, and add 150.00 g of water to dissolve it to obtain a comonomer mixture solution;

(3) Mix the above-mentioned comonomer mixture solution with hydrogen peroxide aqueous solution (wherein, hydrogen peroxide 2.00g, water 20.00g), dichotoma aqueous solution (wherein, dichotoma 1.20g, water 20.00g), ferrous sulfate solution (wherein, Ferrous sulfate 0.70g, water 10.00g), isopropanol aqueous solution (wherein, isopropanol 1.50g, water 20.00g) drop into 60.00g water to react, the reaction temperature is 25 ℃, the time of dropping is 0.5h, dropwise After the addition, keep warm for 1.5h to obtain the copolymerized product;

(4) Adjust the pH of the copolymerization product prepared in step (3) to 5-7 with alkali to obtain the stable concrete slump control agent KZJ-4.

Example 5

(1) Mix 140.00g of acrylic acid, 87.00g of p-hydroxybenzenesulfonic acid, 113g of p-hydroxymethylbenzenesulfonic acid, and 3.40g of hydroquinone. Under nitrogen protection, heat up to 50°C, add 4.60g of benzenesulfonic acid, Raise the temperature to 120°C and keep the reaction for 2 hours. During this period, remove the water by vacuuming or blowing nitrogen with water. After the reaction, cool down to room temperature to obtain the first mixture containing the esterification product and unreacted acrylic acid;

(2) Mix 20.00 g of the first mixture prepared in step (1) with 220.00 g of 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 3000, and add 150.00 g of water to dissolve it to obtain a comonomer mixture solution;

(3) The above-mentioned comonomer mixture solution is mixed with azobisisobutylamidine hydrochloride aqueous solution (wherein azobisisobutylamidine hydrochloride 1.80g, water 30.00g), dodecanethiol aqueous solution (wherein, 2.30 g of dodecanethiol, 30.00 g of water) were dropped into 70.00 g of water for reaction, the reaction temperature was 30° C., the dropping time was 3.0 h, and after the dropping was completed, the temperature was kept for 1.0 h to obtain a copolymerized product;

(4) Adjust the pH of the copolymerization product prepared in step (3) to 5-7 with alkali to obtain the stable concrete slump control agent KZJ-5.

The stable concrete slump control agent (KZJ-1, KZJ-2, KZJ-3, KZJ-4 and KZJ-5) and commercially available slump-preserving type polycarboxylate prepared from embodiment 1 to embodiment 5 Acid superplasticizer (PCE) was used to compare the performance of concrete with different materials and different temperatures. Minfu cement (P.O42.5R) is used, and the concrete mix ratio is: cement 280kg/m ³ , fly ash 80kg/m ³ , sand 770kg/m ³ , gravel 1040kg/m ³ , water 160kg/m ³ , respectively The properties of concrete mixed with KZJ-1, KZJ-2, KZJ-3, KZJ-4, KZJ-5 and PCE were tested respectively under the conditions of sand and mud content of 1%, 5% and temperature of 5°C and 35°C, in order to observe The slump loss control ability of different admixtures, by adjusting the dosage, the initial expansion of the concrete is within the range of 550±10mm, and the slump (TL) and expansion (TK) of each admixture are tested for 1h, 2h and 3h , the results are shown in Table 1 and Table 2:

Table 1 Concrete properties of various admixtures under different sand and mud contents

Table 2 Concrete performance of each admixture under different temperature conditions

As can be seen from the above results, the initial water-reducing rate of the commercially available slump-preserving polycarboxylate superplasticizer (PCE) is lower than that of the embodiment synthesized by this patent under different experimental conditions, and the sand silt content and temperature When changing, the slump loss of the commercially available slump-preserving polycarboxylate superplasticizer (PCE) changes more than the embodiment synthesized by this patent, that is, its ability to control the slump of concrete is relatively large when the experimental conditions change. The synthetic embodiment of this patent is weak.

Those of ordinary skill in the art will know that when the technical parameters and raw material components of the present invention are changed within the following ranges, the same or similar technical effects as those of the above-mentioned examples can still be obtained, and still belong to the protection scope of the present invention:

A preparation method of a stable concrete slump control agent, comprising the steps of:

(1) Mix unsaturated carboxylic acid, compound A and polymerization inhibitor, under the protection of nitrogen, heat up to 40-60°C, then add catalyst, heat up to 100-140°C, keep warm for 0.5-3h, during which time use vacuum Or the method of logical nitrogen belt water is removed water, after reaction finishes, be down to room temperature, obtain the first mixture that contains esterification product and unreacted unsaturated carboxylic acid, the mol ratio of unsaturated carboxylic acid and compound A is 1.5～6: 1. The amount of catalyst used is 0.5% to 5.0% of the total mass of unsaturated carboxylic acid and compound A, and the amount of polymerization inhibitor is 0.5% to 5.0% of the total mass of unsaturated carboxylic acid and compound A. The structural formula of compound A is as follows:

Wherein R1 is an alkyl group with ₁ to 4 carbons or none, and R2 is an alkyl group with ₁ to 4 carbons or none;

(2) Mix the first mixture prepared in step (1) and 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 600 to 5000 in a mass ratio of 1:4 to 30, and add water to dissolve it, Obtain comonomer mixture solution;

(3) Drop the above-mentioned comonomer mixture solution, initiator aqueous solution and molecular weight regulator aqueous solution into water for reaction. The reaction temperature is 10-40°C, the dropping time is 0.2-6.0h, and the temperature is kept for 0-3.0 hours after the dropping is completed. h, to obtain a copolymerization product; the total amount of water used in this step and step (2) makes the mass concentration of the copolymerization product 20 to 80%, and the consumption of the initiator is 0.5 to 3.0 percent of the total mass of the solute in the comonomer mixture solution %, the consumption of the molecular weight modifier is 0.2～3.0% of the total mass of the solute in the comonomer mixture solution;

(4) Adjust the pH of the copolymerization product prepared in step (3) to 5-7 with alkali to obtain the stable concrete slump control agent.

The unsaturated carboxylic acid is at least one of acrylic acid and methacrylic acid. The catalyst is at least one of ethylsulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid and 98% concentrated sulfuric acid. The polymerization inhibitor is at least one of hydroquinone, phenothiazine and diphenylamine. The initiator is a water-soluble redox initiator system or a water-soluble azo initiator. The molecular weight regulator is at least one of mercaptoacetic acid, mercaptopropionic acid, mercaptoethanol, isopropanol, sodium hypophosphite, trisodium phosphate, sodium formate, sodium acetate and dodecanethiol.

The above is only a preferred embodiment of the present invention, so the scope of the present invention cannot be limited accordingly, that is, equivalent changes and modifications made according to the patent scope of the present invention and the content of the specification should still be covered by the present invention In the range.

Claims (9)

1. a preparation method of stable concrete slump control agent, is characterized in that: comprise the steps: (1) Mix unsaturated carboxylic acid, compound A and polymerization inhibitor, under the protection of nitrogen, heat up to 40-60°C, then add catalyst, heat up to 100-140°C, keep warm for 0.5-3h, during which time use vacuum Or the method of logical nitrogen belt water is removed water, after reaction finishes, be down to room temperature, obtain the first mixture that contains esterification product and unreacted unsaturated carboxylic acid, the mol ratio of unsaturated carboxylic acid and compound A is 1.5～6: 1. The amount of catalyst used is 0.5% to 5.0% of the total mass of unsaturated carboxylic acid and compound A, and the amount of polymerization inhibitor is 0.5% to 5.0% of the total mass of unsaturated carboxylic acid and compound A. The structural formula of compound A is as follows: Wherein R1 is an alkyl group with ₁ to 4 carbons or none, and R2 is an alkyl group with ₁ to 4 carbons or none; (2) Mix the first mixture prepared in step (1) and 4-hydroxybutyl vinyl polyoxyethylene ether with a molecular weight of 600 to 5000 in a mass ratio of 1:4 to 30, and add water to dissolve it, Obtain comonomer mixture solution; (3) Drop the above-mentioned comonomer mixture solution, initiator aqueous solution and molecular weight regulator aqueous solution into water for reaction. The reaction temperature is 10-40°C, the dropping time is 0.2-6.0h, and the temperature is kept for 0-3.0 hours after the dropping is completed. h, to obtain a copolymerization product; the total amount of water used in this step and step (2) makes the mass concentration of the copolymerization product 20 to 80%, and the consumption of the initiator is 0.5 to 3.0 percent of the total mass of the solute in the comonomer mixture solution %, the consumption of the molecular weight modifier is 0.2～3.0% of the total mass of the solute in the comonomer mixture solution; (4) Adjust the pH of the copolymerization product prepared in step (3) to 5-7 with alkali to obtain the stable concrete slump control agent. 2. The preparation method according to claim 1, characterized in that: said step (1) is: mixing unsaturated carboxylic acid, compound A, and polymerization inhibitor, and heating up to 50-60°C under nitrogen protection, Then add the catalyst, raise the temperature to 105-130°C, and keep the temperature for 1-3 hours. During this period, the water is removed by vacuuming or nitrogen with water. The first mixture of acids, the molar ratio of unsaturated carboxylic acid and compound A is 1.5～5:1, the consumption of catalyst is 0.5%～4.0% of the total mass of unsaturated carboxylic acid and compound A, and the consumption of polymerization inhibitor is unsaturated 0.5%-4.0% of the total mass of carboxylic acid and compound A. 3. The preparation method according to claim 1, characterized in that: the step (2) is: the first mixture prepared in the step (1), 4-hydroxybutyl vinyl polyoxyethylene with a molecular weight of 600-5000 Vinyl ethers are mixed at a mass ratio of 1:5-20, and water is added to dissolve them to obtain a comonomer mixture solution. 4. preparation method as claimed in claim 1, is characterized in that: described step (3) is: above-mentioned comonomer mixture solution and initiator aqueous solution and molecular weight regulator aqueous solution are dropped into water and react, and reaction temperature is 10 ~ 30°C, the dropping time is 0.2 ~ 5.0h, and after the dropping is completed, the insulation is kept for 0 ~ 3.0h to obtain the copolymerization product; the total amount of water used in this step and step (2) makes the mass concentration of the copolymerization product 20 ~ 70 %, the amount of the initiator is 0.5-2.0% of the total mass of the solute in the comonomer mixture solution, and the amount of the molecular weight regulator is 0.2-2.0% of the total mass of the solute in the comonomer mixture solution. 5. The preparation method according to any one of claims 1 to 4, wherein the unsaturated carboxylic acid is at least one of acrylic acid and methacrylic acid. 6. The preparation method according to any one of claims 1 to 4, characterized in that: the catalyst is at least one of ethylsulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid and 98% concentrated sulfuric acid kind. 7. The preparation method according to any one of claims 1 to 4, wherein the polymerization inhibitor is at least one of hydroquinone, phenothiazine and diphenylamine. 8. The preparation method according to any one of claims 1 to 4, characterized in that: the initiator is a water-soluble redox initiator system or a water-soluble azo initiator. 9. The preparation method according to any one of claims 1 to 4, wherein the molecular weight regulator is mercaptoacetic acid, mercaptopropionic acid, mercaptoethanol, isopropanol, sodium hypophosphite, trisodium phosphate , sodium formate, sodium acetate and at least one of dodecanethiol.