阅读说明：本技术 一种水泥混凝土减水剂的制备方法 (Preparation method of cement concrete water reducing agent ) 是由 王岩 刘宇鑫 于 2021-03-15 设计创作，主要内容包括：本发明公开了一种水泥混凝土减水剂的制备方法,按照重量份数计,包括以下成分：改性硅藻土12～18份、葡糖糖酸钠5～10份、羟丙基纤维素8～12份、分散剂3～6份、聚羧酸减水剂母液18～35份、水解聚马来酸酐7～10份和羟基乙叉二膦酸1.5～3份。本发明水泥混凝土减水剂具有较高的净浆流动度和抗压强度,同时还具有优异的缓蚀效果。(The invention discloses a preparation method of a cement concrete water reducing agent, which comprises the following components in parts by weight: 12-18 parts of modified diatomite, 5-10 parts of sodium gluconate, 8-12 parts of hydroxypropyl cellulose, 3-6 parts of a dispersing agent, 18-35 parts of a polycarboxylic acid water reducing agent mother liquor, 7-10 parts of hydrolyzed polymaleic anhydride and 1.5-3 parts of hydroxyethylidene diphosphonic acid. The cement concrete water reducing agent has higher net paste fluidity and compressive strength, and also has excellent corrosion inhibition effect.)

1. The preparation method of the cement concrete water reducing agent is characterized by comprising the following components in parts by weight: 12-18 parts of modified diatomite, 5-10 parts of sodium gluconate, 8-12 parts of hydroxypropyl cellulose, 3-6 parts of a dispersing agent, 18-35 parts of a polycarboxylic acid water reducing agent mother liquor, 7-10 parts of hydrolyzed polymaleic anhydride and 1.5-3 parts of hydroxyethylidene diphosphonic acid;

the preparation method comprises the following steps:

s1: weighing the raw materials in parts by weight;

s2: adding sodium gluconate and hydrolyzed polymaleic anhydride into a stirring tank, and then adding water, stirring and dissolving to obtain a mixed solution;

s3: adding hydroxypropyl cellulose and hydroxyethylidene diphosphonic acid into the mixed solution obtained in the step S1 during stirring, adding a sodium hydroxide solution during continuous stirring to adjust the pH value to 6.5-7, then sequentially adding modified diatomite, a polycarboxylate superplasticizer mother solution and a dispersing agent, keeping the pH value in the stirring tank within the range by adding a sodium hydroxide solution during continuous stirring, and stirring for 1-2 hours to obtain the cement concrete water reducer.

2. The preparation method of the cement concrete water reducing agent according to claim 1, characterized in that the modified diatomite is prepared by adopting the following method:

(1) dispersing diatomite in distilled water, adding sodium hydroxide to enable the concentration of a sodium hydroxide solution to reach 3-4 mol/L, stirring for 1.5-2 hours, then carrying out suction filtration, washing with distilled water, adding the washed solution into a 5-6 mol/L sulfuric acid solution, stirring for 2-3 hours, carrying out suction filtration, washing with distilled water to be neutral, and then drying;

(2) adding p-aminobenzoic acid and nitrous acid into distilled water, stirring and dissolving, then adding the diatomite product obtained in the step (1), uniformly stirring, transferring into a high-pressure reaction kettle, reacting at 100-110 ℃ for 2-4 h, cooling, filtering, and drying to obtain the modified diatomite, wherein the mass ratio of aminobenzoic acid to nitrous acid to the diatomite product obtained in the step (1) is (0.22-0.39): (0.18-0.34): 1.12-2.35).

3. The preparation method of the cement concrete water reducer according to claim 1, characterized in that the polycarboxylate water reducer mother liquor is prepared by the following method:

the method comprises the following steps: adding polyethylene glycol monomethyl ether and acrylic acid in a molar ratio of (1-2) to (1.15-2.46) into a round-bottom flask, adding p-toluenesulfonic acid as a catalyst, adding a proper amount of a polymerization inhibitor and a solvent toluene, and performing reflux reaction at 130-145 ℃ for 6-9 hours to obtain a precursor;

step two: mixing the precursor, methacrylic acid and sodium allylsulfonate, putting the mixture into a container, raising the reaction temperature to 85-95 ℃, performing magnetic stirring reaction, slowly dropwise adding an initiator in the stirring process, reacting for 4-6 hours after dropwise adding, stopping heating, and adding sodium hydroxide to adjust the pH value to 6.5-7.5 to obtain the polycarboxylic acid water reducer mother liquor.

4. The method for preparing the water reducing agent for cement concrete according to claim 3, wherein the molar ratio of the methyl benzene sulfonic acid to the acrylic acid is (0.012-0.015) to (1-2); the molar ratio of the polymerization inhibitor to the acrylic acid is (0.23-0.36) to (1-2); the molar volume ratio of the acrylic acid to the toluene solvent is (0.8-1.1) mol (30-50) mL.

5. The method for preparing the water reducing agent for cement concrete according to claim 3, wherein the polymerization inhibitor is tert-butyl catechol or p-phenol monobutyl ether; the initiator is ammonium persulfate.

6. The method for preparing the water reducing agent for cement concrete according to claim 3, wherein the mass ratio of the precursor, the methacrylic acid and the sodium allylsulfonate is (0.65-0.8): (0.22-0.28): (0.26-0.38).

7. The preparation method of the cement concrete water reducer according to claim 1, characterized in that the dispersant is any one of sodium polyacrylate, acrylic acid-ethyl acrylate-itaconic acid copolymer, hydrolyzed polymaleic anhydride, maleic acid-acrylic acid copolymer, polyepoxysuccinic acid, polyaspartic acid or glycerol monostearate.

Technical Field

The invention belongs to the technical field of water reducing agents, and particularly relates to a preparation method of a cement concrete water reducing agent.

Background

The cement concrete is the building material with the largest amount in the world, but the cement concrete has the defects of great weight, low strength, brittleness and the like, and researches find that the strength and the flow property of the cement concrete are closely related to the water amount added when the concrete is mixed, the water amount is large, the fluidity is good, and the cement concrete is beneficial to construction, but the strength on the concrete is lower as the water amount is large, so the researches on the water reducing and reinforcing agent of the cement concrete are always hot practical problems. In the field of buildings, the water reducing agents used at present mainly comprise two types, one type is lignosulfonate, and the product only has a water reducing effect on cement and has no obvious enhancing effect. One is high-grade melamine or lignin naphthalene sulfonate, which has excellent performance but high price, so that a treating agent which has low price and excellent performance and has the functions of reducing water and enhancing is urgently needed in the field of buildings.

The water treatment agent is used as a high-efficiency water quality stabilizer, has multiple effects of retarding coagulation, inhibiting corrosion, dispersing and the like, is used as a synergist applied to cement admixtures, and is beneficial to expanding and improving the performance of cement. For example, CN201710158736.5 reports an admixture for improving compatibility of a polycarboxylic acid water reducing agent and concrete constituent materials, and modified lignosulfonic acid and hydroxyethylidene diphosphonic acid are used as mud resistance agents to increase compatibility among concrete materials, with significant effect. CN200510024395.X reports a concrete super-retarding water reducing agent and a preparation method thereof, and the invention uses ethylene polyamine alkyl phosphonic acid and phosphine butane tricarboxylic acid as retarding components to prepare the water reducing agent with super-normal retarding effect.

Disclosure of Invention

The invention aims to provide a preparation method of a cement concrete water reducing agent, which comprises the following components in parts by weight: 12-18 parts of modified diatomite, 5-10 parts of sodium gluconate, 8-12 parts of hydroxypropyl cellulose, 3-6 parts of a dispersing agent, 18-35 parts of a polycarboxylic acid water reducing agent mother liquor, 7-10 parts of hydrolyzed polymaleic anhydride and 1.5-3 parts of hydroxyethylidene diphosphonic acid.

The preparation method comprises the following steps:

s1: weighing the raw materials in parts by weight.

S2: and (3) adding the sodium gluconate and the hydrolyzed polymaleic anhydride into a stirring tank, and then adding water, stirring and dissolving to obtain a mixed solution.

S3: adding hydroxypropyl cellulose and hydroxyethylidene diphosphonic acid into the mixed solution obtained in the step S1 during stirring, adding a sodium hydroxide solution during continuous stirring to adjust the pH value to 6.5-7, then sequentially adding modified diatomite, a polycarboxylate superplasticizer mother solution and a dispersing agent, keeping the pH value in the stirring tank within the range by adding a sodium hydroxide solution during continuous stirring, and stirring for 1-2 hours to obtain the cement concrete water reducer.

Further, the modified diatomite is prepared by adopting the following method:

(1) dispersing diatomite in distilled water, adding sodium hydroxide to enable the concentration of a sodium hydroxide solution to reach 3-4 mol/L, stirring for 1.5-2 h, carrying out suction filtration, washing with distilled water, adding into a 5-6 mol/L sulfuric acid solution, stirring for 2-3 h, carrying out suction filtration, washing with distilled water to be neutral, and drying.

(2) Adding p-aminobenzoic acid and nitrous acid into distilled water, stirring and dissolving, then adding the diatomite product obtained in the step (1), uniformly stirring, transferring into a high-pressure reaction kettle, reacting at 100-110 ℃ for 2-4 h, cooling, filtering, and drying to obtain the modified diatomite, wherein the mass ratio of aminobenzoic acid to nitrous acid to the diatomite product obtained in the step (1) is (0.22-0.39): (0.18-0.34): 1.12-2.35).

Further, the polycarboxylate superplasticizer mother liquor is prepared by the following method:

the method comprises the following steps: adding polyethylene glycol monomethyl ether and acrylic acid in a molar ratio of (1-2) to (1.15-2.46) into a round-bottom flask, adding p-toluenesulfonic acid as a catalyst, adding a proper amount of a polymerization inhibitor and a solvent toluene, and performing reflux reaction at 130-145 ℃ for 6-9 hours to obtain a precursor.

Step two: mixing the precursor, methacrylic acid and sodium allylsulfonate, putting the mixture into a container, raising the reaction temperature to 85-95 ℃, performing magnetic stirring reaction, slowly dropwise adding an initiator in the stirring process, reacting for 4-6 hours after dropwise adding, stopping heating, and adding sodium hydroxide to adjust the pH value to 6.5-7.5 to obtain the polycarboxylic acid water reducer mother liquor.

Further, the molar ratio of the methyl benzene sulfonic acid to the acrylic acid is (0.012-0.015): 1-2; the molar ratio of the polymerization inhibitor to the acrylic acid is (0.23-0.36) to (1-2); the molar volume ratio of the acrylic acid to the toluene solvent is (0.8-1.1) mol (30-50) mL.

Further, the polymerization inhibitor is tert-butyl catechol or p-phenol monobutyl ether; the initiator is ammonium persulfate.

Furthermore, the mass ratio of the precursor, the methacrylic acid and the sodium allylsulfonate is (0.65-0.8): (0.22-0.28): 0.26-0.38).

Further, the dispersant is any one of sodium polyacrylate, acrylic acid-ethyl acrylate-itaconic acid copolymer, hydrolyzed polymaleic anhydride, maleic acid-acrylic acid copolymer, polyepoxysuccinic acid, polyaspartic acid or glycerol monostearate.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the invention, the hydroxyethylidene diphosphonic acid, the polycarboxylic acid dispersant and the sodium gluconate are combined, so that the stability of the water quality under the alkaline condition of cement is good, the hydroxyethylidene diphosphonic acid has a plurality of functional groups and is a good complexing agent, and the polycarboxylic acid dispersant and the hydroxyethylidene diphosphonic acid are cooperatively used, so that the limit effect of a water treatment agent can be exerted, and the effect of ultra-equivalent metering can be achieved by the amount of PPM.

2. In the invention, sodium allylsulfonate is added into the mother liquor of the polycarboxylic acid water reducing agent in the preparation process, wherein the sulfonic group is beneficial to improving the water reducing rate of the polymer, thereby further improving the tax reducing efficiency of the concrete water reducing agent; and the modified diatomite modified by aminobenzoic acid and nitrous acid has better dispersion performance and water retention effect, and can play a role in improving the wrapping performance of concrete and the anti-carbonization capacity of concrete.

Detailed Description

The following embodiments of the present invention are described in detail, and the embodiments are implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, it should be noted that, for those skilled in the art, a plurality of modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Example 1

The preparation method of the cement concrete water reducer comprises the following components in parts by weight: 12 parts of modified diatomite, 5 parts of sodium gluconate, 8 parts of hydroxypropyl cellulose, 3 parts of a dispersing agent, 18 parts of polycarboxylic acid water reducing agent mother liquor, 7 parts of hydrolyzed polymaleic anhydride and 1.5 parts of hydroxyethylidene diphosphonic acid.

The modified diatomite is prepared by the following method:

(1) dispersing diatomite in distilled water, adding sodium hydroxide to enable the concentration of a sodium hydroxide solution to reach 3mol/L, stirring for 1.5 hours, then carrying out suction filtration, washing with distilled water, then adding the washed solution into a 5mol/L sulfuric acid solution, stirring for 2 hours, carrying out suction filtration, then washing with distilled water to be neutral, and then drying.

(2) Adding p-aminobenzoic acid and nitrous acid into distilled water, stirring and dissolving, then adding the product diatomite in the step (1), stirring uniformly, transferring into a high-pressure reaction kettle, reacting at 100 ℃ for 2 hours, cooling, filtering, and drying to obtain the modified diatomite, wherein the mass ratio of aminobenzoic acid to nitrous acid to the product diatomite in the step (1) is 0.22:0.18: 1.12.

The polycarboxylate superplasticizer mother liquor is prepared by the following method:

the method comprises the following steps: adding polyethylene glycol monomethyl ether and acrylic acid in a molar ratio of 1:1.15 into a round-bottom flask, then adding p-toluenesulfonic acid as a catalyst, adding a proper amount of tert-butyl catechol and a solvent toluene, and performing reflux reaction at 130 ℃ for 6 hours to obtain a precursor; wherein the molar ratio of the methyl benzene sulfonic acid to the acrylic acid is 0.012: 1; the molar ratio of the p-phenol monobutyl ether to the acrylic acid is 0.23: 1; the molar volume ratio of the acrylic acid to the toluene solvent is 0.8mol:30 mL.

Step two: mixing the precursor, methacrylic acid and sodium allylsulfonate, putting the mixture into a container, raising the reaction temperature to 85 ℃, performing magnetic stirring reaction, slowly dropwise adding ammonium persulfate in the stirring process, reacting for 4 hours after dropwise adding, stopping heating, and adding sodium hydroxide to adjust the pH value to 6.5 to obtain a polycarboxylic acid water reducer mother liquor; wherein the mass ratio of the precursor, the methacrylic acid and the sodium allylsulfonate is 0.65:0.22: 0.26.

The preparation method comprises the following steps:

s1: weighing the raw materials in parts by weight.

S2: and (3) adding the sodium gluconate and the hydrolyzed polymaleic anhydride into a stirring tank, and then adding water, stirring and dissolving to obtain a mixed solution.

S3: adding hydroxypropyl cellulose and hydroxyethylidene diphosphonic acid into the mixed solution obtained in the step S1 during stirring, adding a sodium hydroxide solution during continuous stirring to adjust the pH value to 6.5, then sequentially adding modified diatomite, a polycarboxylate water reducer mother solution and a dispersing agent, keeping the pH value in the stirring tank within the range by adopting a sodium hydroxide solution during continuous stirring, and stirring for 1h to obtain the cement concrete water reducer.

Example 2

The preparation method of the cement concrete water reducer comprises the following components in parts by weight: 18 parts of modified diatomite, 10 parts of sodium gluconate, 12 parts of hydroxypropyl cellulose, 6 parts of a dispersing agent, 35 parts of polycarboxylic acid water reducing agent mother liquor, 10 parts of hydrolyzed polymaleic anhydride and 3 parts of hydroxyethylidene diphosphonic acid.

The modified diatomite is prepared by the following method:

(1) dispersing diatomite in distilled water, adding sodium hydroxide to enable the concentration of a sodium hydroxide solution to reach 4mol/L, stirring for 2 hours, carrying out suction filtration, washing with distilled water, adding into a 6mol/L sulfuric acid solution, stirring for 3 hours, carrying out suction filtration, washing with distilled water to be neutral, and drying.

(2) Adding p-aminobenzoic acid and nitrous acid into distilled water, stirring and dissolving, then adding the product diatomite in the step (1), stirring uniformly, transferring into a high-pressure reaction kettle, reacting at 110 ℃ for 4 hours, cooling, filtering, and drying to obtain the modified diatomite, wherein the mass ratio of aminobenzoic acid to nitrous acid to the product diatomite in the step (1) is 0.39:0.34: 2.35.

The polycarboxylate superplasticizer mother liquor is prepared by the following method:

the method comprises the following steps: adding polyethylene glycol monomethyl ether and acrylic acid in a molar ratio of 2:2.46 into a round-bottom flask, adding p-toluenesulfonic acid as a catalyst, adding a proper amount of tert-butyl catechol and a solvent toluene, and performing reflux reaction at 145 ℃ for 9 hours to obtain a precursor; wherein the molar ratio of the methyl benzene sulfonic acid to the acrylic acid is 0.015: 2; the molar ratio of the tert-butyl catechol to the acrylic acid is 0.36: 2; the molar volume ratio of the acrylic acid to the toluene solvent is 1.1mol:50 mL.

Step two: mixing the precursor, methacrylic acid and sodium allylsulfonate, putting the mixture into a container, raising the reaction temperature to 95 ℃, performing magnetic stirring reaction, slowly dropwise adding ammonium persulfate in the stirring process, reacting for 6 hours after dropwise adding, stopping heating, and adding sodium hydroxide to adjust the pH value to 7.5 to obtain a polycarboxylic acid water reducer mother liquor; wherein the mass ratio of the precursor, the methacrylic acid and the sodium allylsulfonate is 0.8:0.28: 0.38.

The preparation method comprises the following steps:

s1: weighing the raw materials in parts by weight.

S2: and (3) adding the sodium gluconate and the hydrolyzed polymaleic anhydride into a stirring tank, and then adding water, stirring and dissolving to obtain a mixed solution.

S3: adding hydroxypropyl cellulose and hydroxyethylidene diphosphonic acid into the mixed solution obtained in the step S1 during stirring, adding a sodium hydroxide solution during continuous stirring to adjust the pH value to 7, then sequentially adding modified diatomite, a polycarboxylate water reducer mother solution and a dispersing agent, keeping the pH value in the stirring tank within the range by adopting a sodium hydroxide solution during continuous stirring, and stirring for 2 hours to obtain the cement concrete water reducer.

Example 3

The preparation method of the cement concrete water reducer comprises the following components in parts by weight: 15 parts of modified diatomite, 7 parts of sodium gluconate, 10 parts of hydroxypropyl cellulose, 5 parts of a dispersing agent, 26 parts of polycarboxylic acid water reducing agent mother liquor, 9 parts of hydrolyzed polymaleic anhydride and 2 parts of hydroxyethylidene diphosphonic acid.

The modified diatomite is prepared by the following method:

(1) dispersing diatomite in distilled water, adding sodium hydroxide to enable the concentration of a sodium hydroxide solution to reach 3.6mol/L, stirring for 2 hours, carrying out suction filtration, washing with distilled water, adding into a 5-6 mol/L sulfuric acid solution, stirring for 2.5 hours, carrying out suction filtration, washing with distilled water to be neutral, and drying.

(2) Adding p-aminobenzoic acid and nitrous acid into distilled water, stirring and dissolving, then adding the product diatomite in the step (1), uniformly stirring, transferring into a high-pressure reaction kettle, reacting at 105 ℃ for 3 hours, cooling, filtering, and drying to obtain the modified diatomite, wherein the mass ratio of aminobenzoic acid to nitrous acid to the product diatomite in the step (1) is 0.29:0.27: 1.96.

The polycarboxylate superplasticizer mother liquor is prepared by the following method:

the method comprises the following steps: adding polyethylene glycol monomethyl ether and acrylic acid in a molar ratio of 1.6:2.24 into a round-bottom flask, adding p-toluenesulfonic acid as a catalyst, adding a proper amount of p-phenol monobutyl ether and a solvent toluene, and performing reflux reaction at 140 ℃ for 8 hours to obtain a precursor; wherein the molar ratio of the methyl benzene sulfonic acid to the acrylic acid is 0.013: 1.6; the molar ratio of the p-phenol monobutyl ether to the acrylic acid is 0.29: 1.5; the molar volume ratio of the acrylic acid to the toluene solvent is 0.9mol:40 mL.

Step two: mixing the precursor, methacrylic acid and sodium allylsulfonate, putting the mixture into a container, raising the reaction temperature to 85-95 ℃, performing magnetic stirring reaction, slowly dropwise adding ammonium persulfate in the stirring process, reacting for 4-6 hours after dropwise adding, stopping heating, and adding sodium hydroxide to adjust the pH value to 7 to obtain a polycarboxylic acid water reducer mother liquor; wherein the mass ratio of the precursor, the methacrylic acid and the sodium allylsulfonate is 0.77:0.26: 0.34.

The preparation method comprises the following steps:

s1: weighing the raw materials in parts by weight.

S2: and (3) adding the sodium gluconate and the hydrolyzed polymaleic anhydride into a stirring tank, and then adding water, stirring and dissolving to obtain a mixed solution.

S3: adding hydroxypropyl cellulose and hydroxyethylidene diphosphonic acid into the mixed solution obtained in the step S1 during stirring, adding a sodium hydroxide solution during continuous stirring to adjust the pH value to 7, then sequentially adding modified diatomite, a polycarboxylate water reducer mother solution and a dispersing agent, keeping the pH value in the stirring tank within the range by adopting a sodium hydroxide solution during continuous stirring, and stirring for 1.5 hours to obtain the cement concrete water reducer.

Comparative example 1

Prepared according to the preparation described in example 7 in chinese patent document CN 102199015A.

Examples of the experiments

Performance test experiment, the performance of the cement concrete water reducing agent prepared in examples 1 to 3 and comparative example 1 in concrete is detected, a coupon test is adopted as a corrosion test, and the tests are all carried out under the same conditions. Wherein: the cementing material adopts P.O42.5 reference cement, the cement is the reference cement P.O42.5, the sand is ISO standard sand, and the water is distilled water. The water reducing agent product accounting for 1.5 percent (folded solid content) of the total weight of the cementing material is added into concrete, the initial and 1-hour performances of cement paste fluidity, water reducing rate, setting time, compressive strength, corrosion rate and the like are measured according to the method specified in GB/T8077-2012 test method for concrete admixture homogeneity, GB/T17671-1999 test method for cement mortar strength (ISO method), GB/T18175-2000 test method for water treatment corrosion inhibition performance by rotating hanging sheet method, the test results are shown in Table 1,

table 1. results of performance testing:

as can be seen from Table 1, compared with the water reducing agent in the comparative example 1, the cement water reducing agent in the examples 1-3 of the invention has obviously increased net slurry fluidity and compressive strength, and has certain improvement on the early strength and the later strength of the cement; meanwhile, the initial fluidity is obviously increased, basically no loss is caused after 1h, the initial setting time and the final setting time are greatly increased, and the corrosion inhibition effect is better.