CN110591014A - Polycarboxylic acid high-performance water reducing agent and preparation method thereof - Google Patents
Polycarboxylic acid high-performance water reducing agent and preparation method thereof Download PDFInfo
- Publication number
- CN110591014A CN110591014A CN201910854873.1A CN201910854873A CN110591014A CN 110591014 A CN110591014 A CN 110591014A CN 201910854873 A CN201910854873 A CN 201910854873A CN 110591014 A CN110591014 A CN 110591014A
- Authority
- CN
- China
- Prior art keywords
- parts
- reducing agent
- water
- water reducing
- mixture
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
- C04B24/24—Macromolecular compounds
- C04B24/26—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C04B24/2688—Copolymers containing at least three different monomers
- C04B24/2694—Copolymers containing at least three different monomers containing polyether side chains
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F283/00—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G
- C08F283/06—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polyethers, polyoxymethylenes or polyacetals
- C08F283/065—Macromolecular compounds obtained by polymerising monomers on to polymers provided for in subclass C08G on to polyethers, polyoxymethylenes or polyacetals on to unsaturated polyethers, polyoxymethylenes or polyacetals
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
- C04B2103/30—Water reducers, plasticisers, air-entrainers, flow improvers
- C04B2103/302—Water reducers
Abstract
The invention relates to a polycarboxylic acid high-performance water reducing agent and a preparation method thereof, belonging to the technical field of water reducing agents. The polycarboxylic acid high-performance water reducer not only can reduce the 1h time-varying amount of concrete slump through the synergistic effect between the raw materials, but also enables the concrete to have the advantages of higher water reducing rate and higher compressive strength.
Description
Technical Field
The invention relates to the technical field of water reducing agents, in particular to a polycarboxylic acid high-performance water reducing agent and a preparation method thereof.
Background
The water reducing agent is a concrete admixture capable of reducing the water consumption for mixing, has become an indispensable component of concrete due to the advantages of dispersing cement particles and reducing unit water consumption after being added into the concrete, and plays an increasingly important role in improving the performance of the concrete. The water reducing agent can be divided into lignosulfonic acid series, naphthalene series, melamine series, sulfamic acid series, polycarboxylic acid series and the like according to varieties, and the polycarboxylic acid series water reducing agent is a chemically synthesized polycarboxylic acid comb graft copolymer which can be adsorbed on the surface of cement particles, so that the cement particles have high dispersibility and fluidity retentivity through electrostatic repulsion and steric hindrance effects.
When constructing the concrete, the concrete is from mix to the process of pouring, inevitable needs are parked, transit time, always can be along with the change of concrete slump at this in-process, especially to the higher concrete construction of pumping floor, if the loss of slump is too fast, bring the difficulty for the construction, and the water-reducing agent has certain influence to the change of concrete slump, consequently, also provide higher requirement to polycarboxylate water-reducing agent, and need study one kind can reduce the water-reducing agent of concrete slump over-the-time variation, in order to satisfy the market demand.
Disclosure of Invention
The invention aims to provide a polycarboxylic acid high-performance water reducing agent which can reduce the change of concrete slump for 1h with time and also has the advantages of higher water reducing rate and higher compressive strength.
The technical purpose of the invention is realized by the following technical scheme:
a polycarboxylic acid high-performance water reducing agent is characterized in that: the water reducing agent comprises, by weight, 3000-6500 parts of methoxy polyethylene glycol methacrylate, 2-10 parts of an initial initiator, 30-40 parts of a reaction initiator, 1-5 parts of ethanol, 300 parts of acrylic acid, 400 parts of hydroxyethyl acrylate, 0.8-8 parts of vinyl chloride, 70-100 parts of dimethylaminopropyl methacrylamide, 1-12 parts of mercaptopropionic acid, 2000 parts of still bottom water and 2000 parts of softened water, and the water reducing agent has a structural general formula as follows:
wherein a, b, c, d, e and m are the number of the repeating unit chain links of the water reducing agent, and the average molecular weight of the water reducing agent is 80-130 ten thousand.
By adopting the technical scheme, free radical polymerization reaction is carried out among methoxy polyethylene glycol methacrylate, acrylic acid, hydroxyethyl acrylate, vinyl chloride and dimethylamino propyl methacrylamide, a macromolecular copolymer is formed, the water reducing agent is adsorbed on the surface of cement particles, a double electric layer is formed, electrostatic repulsion force is formed among the cement particles, the flocculation structure of the cement particles is damaged, the cement particles are mutually dispersed, free water is released, the fluidity of cement paste is increased, the water reducing rate of concrete is increased, the water reducing agent is a comb graft copolymer and has longer side chains, the cement particles generate larger steric hindrance under the action of the long side chains, the agglomeration among the cement particles is effectively prevented, the fluidity of the cement paste can be improved through the synergistic effect among raw materials, and the 1h time-varying amount of the concrete is reduced, namely, the slump loss of the concrete is reduced, and meanwhile, the concrete has the advantages of higher water reducing rate and higher compressive strength.
More preferably, the raw materials comprise 3600-4800 parts of methoxy polyethylene glycol methacrylate, 5-7 parts of an initial initiator, 33-37 parts of a reaction initiator, 2-4 parts of ethanol, 150-250 parts of acrylic acid, 140-430 parts of hydroxyethyl acrylate, 3-8 parts of vinyl chloride, 80-100 parts of dimethylaminopropyl methacrylamide, 4-8 parts of mercaptopropionic acid, 1300-1700 parts of bottom water and 500-1600 parts of softened water.
More preferably, the weight ratio of the methoxypolyethylene glycol methacrylate to the acrylic acid to the hydroxyethyl acrylate is 50:2: 4.4.
By adopting the technical scheme, the raw material ratio of the water reducing agent is optimized, and the weight ratio of the methoxy polyethylene glycol methacrylate, the acrylic acid and the hydroxyethyl acrylate is optimized, so that the using effect of the water reducing agent is improved, and the water reducing rate and the compressive strength of the concrete are further improved.
More preferably, the initial initiator is 10-15% of hydrogen peroxide solution by weight, and the initial initiator is 3-8% of hydrogen peroxide solution by weight.
By adopting the technical scheme, the primary initiator and the reaction initiator can generate hydroxyl free radicals in the raw materials, the hydroxyl free radicals promote the free radical polymerization reaction between the raw materials and enable the raw materials to form a macromolecular copolymer, the primary initiator accelerates the efficiency of the initial reaction of the raw materials, and the reaction initiator enables the concentration of the hydroxyl free radicals in the raw materials to be kept constant, so that the efficiency of the free radical polymerization reaction of the raw materials is maintained, and the production efficiency of the water reducing agent is improved through the synergistic effect between the primary initiator and the reaction initiator.
More preferably, the pH value of the water reducing agent is 5-6.
By adopting the technical scheme, the water reducing agent is weakly acidic, so that the storage container of the water reducing agent is prevented from being corroded due to high acidity of the water reducing agent, the storage time is shortened due to low acidity of the water reducing agent, the pH value of the water reducing agent is 5-6, and the storage effect of the water reducing agent is improved.
The second purpose of the invention is to provide a method for preparing the polycarboxylic acid high-performance water reducing agent, which not only ensures that the preparation method of the water reducing agent is simple and convenient to control, but also improves the production stability of the water reducing agent.
The technical purpose of the invention is realized by the following technical scheme:
a method for preparing the polycarboxylic acid high-performance water reducing agent comprises the following steps: the method comprises the following steps:
(1) dividing softened water into three parts, namely softened water A, softened water B and softened water C;
(2) adding acrylic acid and hydroxyethyl acrylate into the softened water A, and uniformly mixing to obtain a mixture A for later use;
(3) adding chloroethylene, dimethylamino propyl methacrylamide and mercaptopropionic acid into the softened water B, and uniformly mixing to obtain a mixture B for later use;
(4) under the protection of inert gas, heating kettle bottom water, adding ethanol and methoxy polyethylene glycol methacrylate, uniformly mixing, continuously heating, adding a primary initiator when the temperature reaches 60 ℃, stirring for 5-10min, then respectively dropwise adding the mixture A, the mixture B and a reaction initiator in a dropwise adding mode, wherein the dropwise adding time of the mixture A is 2-2.3h, the dropwise adding time of the mixture B is 2.5-2.8h, the dropwise adding time of the reaction initiator is 2.6-2.9h, the temperature is controlled to be 60-65 ℃, and carrying out heat preservation reaction for 2-4 h;
(5) and cooling to 50 ℃, adding softened water C, uniformly mixing, cooling to room temperature, and filtering to obtain the water reducer.
By adopting the technical scheme, softened water is divided into three parts, so that the preparation of the mixture A and the mixture B is convenient, the control of the concentration of the water reducer is convenient, the acrylic acid and the hydroxyethyl acrylate are prepared into the mixture A, the vinyl chloride, the dimethylamino propyl methacrylamide and the mercaptopropionic acid are prepared into the mixture B, the preparation of the mixture A and the mixture B is convenient, the reaction between the mixture A and the mixture B is reduced, meanwhile, the ethanol is added into the methoxy polyethylene glycol methacrylate, part of the ethanol volatilizes due to heat absorption, a protective layer is formed above the water at the bottom of the kettle, part of the ethanol is remained in the water at the bottom of the kettle, the mixing uniformity among the raw materials is increased, after the dropwise addition of the mixture A and the mixture B is finished, the reaction initiator is continuously dropwise added, and the production stability of the water reducer is.
More preferably, the weight ratio of the softened water A to the softened water B to the softened water C is 3:3: 2.
By adopting the technical scheme, the softened water A is used for preparing the mixture A, the softened water B is used for preparing the mixture B, the softened water C is used for controlling the concentration of the water reducing agent, and the proportion of the softened water A, the softened water B and the softened water C is limited, so that the preparation of the water reducing agent is controlled conveniently, and the production of the water reducing agent is more stable.
More preferably, the water reducing agent adopts 5% by weight of sodium hydroxide solution to adjust the pH value.
By adopting the technical scheme, the pH value of the water reducing agent is adjusted, the raw material of sodium hydroxide is easy to obtain, and the production cost of the water reducing agent is reduced.
Preferably, the mixture A, the mixture B, the primary initiator and the reaction initiator are prepared in situ and within 3min before use.
By adopting the technical scheme, after the mixture A and the mixture B are prepared, firstly, the raw materials are easily oxidized and deteriorated due to the existence of oxygen, partial polymerization can also occur between the raw materials, a small amount of hydroxyl free radicals are immediately generated in the initial initiator and the reaction initiator after the preparation is completed, the hydroxyl free radicals move freely and are easily collided and eliminated, the preparation completion time of the mixture A, the mixture B, the initial initiator and the reaction initiator is limited, and the influence on the performance and the production stability of the water reducing agent due to deterioration is reduced.
In conclusion, the invention has the following beneficial effects:
firstly, the polycarboxylic acid high-performance water reducing agent disclosed by the invention can reduce the change of the concrete slump for 1h with the time, and also has the advantages of higher water reducing rate and higher compressive strength.
And secondly, limiting the primary initiator and the reaction initiator, and improving the production efficiency of the water reducer through the synergistic effect of the primary initiator and the reaction initiator.
Thirdly, the method for preparing the polycarboxylic acid high-performance water reducing agent not only ensures that the preparation method of the water reducing agent is simple and convenient to control, but also improves the production stability of the water reducing agent.
And fourthly, the time for finishing the preparation of the mixture A, the mixture B, the primary initiator and the reaction initiator is limited, so that the influence on the performance and the production stability of the water reducer caused by deterioration is reduced.
Detailed Description
The present invention will be described in further detail with reference to examples. It should be understood that the preparation methods described in the examples are only for illustrating the present invention and are not to be construed as limiting the present invention, and that the simple modifications of the preparation methods of the present invention based on the concept of the present invention are within the scope of the present invention as claimed.
The structural general formula of the water reducing agent is as follows:
wherein a, b, c, d, e and m are the number of repeating unit links of the water reducing agent, and m is an integer of 23 to 35, preferably 25.
Table 1 examples the water reducing agent contained in each raw material (unit: Kg)
| Examples | 1 | 2 | 3 | 4 | 5 |
| Methoxy polyethylene glycol methacrylate | 3000 | 4800 | 4750 | 3600 | 6500 |
| Initial initiator | 2 | 10 | 6 | 5 | 7 |
| Reaction initiator | 37 | 30 | 35 | 40 | 33 |
| Ethanol | 4 | 5 | 3 | 1 | 2 |
| Acrylic acid | 150 | 100 | 190 | 300 | 250 |
| Acrylic acid hydroxy ethyl ester | 420 | 430 | 418 | 410 | 400 |
| Vinyl chloride | 8 | 3 | 4 | 0.8 | 5 |
| Dimethylamino propyl methacrylamide | 100 | 80 | 84 | 70 | 90 |
| Mercaptopropionic acid | 4 | 12 | 6 | 8 | 1 |
| Kettle bottom water | 2000 | 1300 | 1500 | 1700 | 1000 |
| Softened water | 2000 | 500 | 1200 | 1600 | 300 |
Example 1
The raw material proportion of the polycarboxylic acid high-performance water reducing agent is shown in table 1;
(1) the softened water is divided into three parts, namely softened water A, softened water B and softened water C for later use, wherein the weight ratio of the softened water A to the softened water B to the softened water C is 3:3: 2;
(2) adding softened water A into a batching tank A, then adding acrylic acid and hydroxyethyl acrylate into the softened water A, uniformly mixing to obtain a mixture A, and pumping the mixture A into a dripping tank A for later use;
(3) adding softened water B into a batching tank B, adding vinyl chloride, dimethylamino propyl methacrylamide and mercaptopropionic acid into the softened water B, uniformly mixing to obtain a mixture B, and pumping the mixture B into a dripping tank B for later use;
(4) preparing a hydrogen peroxide solution with the mass fraction of 10% in a mixing barrel to obtain a primary initiator for later use, preparing a hydrogen peroxide solution with the weight fraction of 6% in a mixing tank C to obtain a reaction initiator, and adding the reaction initiator into a dripping tank C for later use;
(5) adding kettle bottom water into a reaction kettle, heating the kettle bottom water under the protection of nitrogen, adding ethanol and methoxy polyethylene glycol methacrylate, uniformly mixing, continuously heating, adding a primary initiator into the reaction kettle when the temperature reaches 60 ℃, wherein the primary initiator is prepared in situ, stirring for 5min is completed 3min before use, then respectively dropwise adding a mixture A, a mixture B and a reaction initiator in a dropwise adding mode, wherein the mixture A, the mixture B and the reaction initiator are prepared in situ, the preparation is completed 3min before use, the dropwise adding time of the mixture A is 2h, the dropwise adding time of the mixture B is 2.5h, the dropwise adding time of the reaction initiator is 2.6h, the temperature is controlled to be 60 ℃, and carrying out heat preservation reaction for 4 h;
(6) cooling the temperature in the reaction kettle to 50 ℃, adding softened water C, uniformly mixing, cooling to room temperature, and filtering to obtain a water reducing agent, wherein the average molecular weight of the water reducing agent is 80 ten thousand;
(7) then adding a sodium hydroxide solution with the weight fraction of 5% into the reaction kettle, adjusting the pH value of the sodium hydroxide solution to ensure that the pH value of the water reducing agent is 5, and sampling and detecting to ensure that the fluidity of the cement paste is 280 mm.
Example 2
The raw material proportion of the polycarboxylic acid high-performance water reducing agent is shown in table 1;
(1) the softened water is divided into three parts, namely softened water A, softened water B and softened water C for later use, wherein the weight ratio of the softened water A to the softened water B to the softened water C is 3:3: 2;
(2) adding softened water A into a batching tank A, then adding acrylic acid and hydroxyethyl acrylate into the softened water A, uniformly mixing to obtain a mixture A, and pumping the mixture A into a dripping tank A for later use;
(3) adding softened water B into a batching tank B, adding vinyl chloride, dimethylamino propyl methacrylamide and mercaptopropionic acid into the softened water B, uniformly mixing to obtain a mixture B, and pumping the mixture B into a dripping tank B for later use;
(4) preparing a hydrogen peroxide solution with the mass fraction of 13% in a mixing barrel to obtain a primary initiator for later use, preparing a hydrogen peroxide solution with the weight fraction of 8% in a mixing tank C to obtain a reaction initiator, and adding the reaction initiator into a dripping tank C for later use;
(5) adding kettle bottom water into a reaction kettle, heating the kettle bottom water under the protection of nitrogen, adding ethanol and methoxy polyethylene glycol methacrylate, uniformly mixing, continuously heating, adding a primary initiator into the reaction kettle when the temperature reaches 60 ℃, wherein the primary initiator is prepared in situ, stirring for 8min is completed 3min before use, then respectively dropwise adding a mixture A, a mixture B and a reaction initiator in a dropwise adding mode, wherein the mixture A, the mixture B and the reaction initiator are prepared in situ, the preparation is completed 3min before use, the dropwise adding time of the mixture A is 2.1h, the dropwise adding time of the mixture B is 2.6h, the dropwise adding time of the reaction initiator is 2.7h, the temperature is controlled to be 63 ℃, and carrying out heat preservation reaction for 2 h;
(6) cooling the temperature in the reaction kettle to 50 ℃, adding softened water C, uniformly mixing, cooling to room temperature, and filtering to obtain a water reducing agent, wherein the average molecular weight of the water reducing agent is 90 ten thousand;
(7) then adding a sodium hydroxide solution with the weight fraction of 5% into the reaction kettle, adjusting the pH value of the sodium hydroxide solution to ensure that the pH value of the water reducing agent is 5.5, and sampling and detecting to obtain the cement paste with the fluidity of 285 mm.
Example 3
The raw material proportion of the polycarboxylic acid high-performance water reducing agent is shown in table 1;
(1) the softened water is divided into three parts, namely softened water A, softened water B and softened water C for later use, wherein the weight ratio of the softened water A to the softened water B to the softened water C is 3:3: 2;
(2) adding softened water A into a batching tank A, then adding acrylic acid and hydroxyethyl acrylate into the softened water A, uniformly mixing to obtain a mixture A, and pumping the mixture A into a dripping tank A for later use;
(3) adding softened water B into a batching tank B, adding vinyl chloride, dimethylamino propyl methacrylamide and mercaptopropionic acid into the softened water B, uniformly mixing to obtain a mixture B, and pumping the mixture B into a dripping tank B for later use;
(4) preparing a hydrogen peroxide solution with the mass fraction of 13% in a mixing barrel to obtain a primary initiator for later use, preparing a hydrogen peroxide solution with the weight fraction of 5% in a mixing tank C to obtain a reaction initiator, and adding the reaction initiator into a dripping tank C for later use;
(5) adding kettle bottom water into a reaction kettle, heating the kettle bottom water under the protection of nitrogen, adding ethanol and methoxy polyethylene glycol methacrylate, uniformly mixing, continuously heating, adding a primary initiator into the reaction kettle when the temperature reaches 60 ℃, wherein the primary initiator is prepared in situ, stirring for 8min is completed 3min before use, then respectively dropwise adding a mixture A, a mixture B and a reaction initiator in a dropwise adding mode, wherein the mixture A, the mixture B and the reaction initiator are prepared in situ, the preparation is completed 3min before use, the dropwise adding time of the mixture A is 2.1h, the dropwise adding time of the mixture B is 2.6h, the dropwise adding time of the reaction initiator is 2.7h, the temperature is controlled to be 63 ℃, and carrying out heat preservation reaction for 3 h;
(6) cooling the temperature in the reaction kettle to 50 ℃, adding softened water C, uniformly mixing, cooling to room temperature, and filtering to obtain a water reducing agent, wherein the average molecular weight of the water reducing agent is 110 ten thousand;
(7) then adding a sodium hydroxide solution with the weight fraction of 5% into the reaction kettle, adjusting the pH value of the sodium hydroxide solution to ensure that the pH value of the water reducing agent is 5.5, and sampling and detecting to obtain the cement paste with the fluidity of 290 mm.
Example 4
The raw material proportion of the polycarboxylic acid high-performance water reducing agent is shown in table 1;
(1) the softened water is divided into three parts, namely softened water A, softened water B and softened water C for later use, wherein the weight ratio of the softened water A to the softened water B to the softened water C is 3:3: 2;
(2) adding softened water A into a batching tank A, then adding acrylic acid and hydroxyethyl acrylate into the softened water A, uniformly mixing to obtain a mixture A, and pumping the mixture A into a dripping tank A for later use;
(3) adding softened water B into a batching tank B, adding vinyl chloride, dimethylamino propyl methacrylamide and mercaptopropionic acid into the softened water B, uniformly mixing to obtain a mixture B, and pumping the mixture B into a dripping tank B for later use;
(4) preparing a hydrogen peroxide solution with the mass fraction of 11% in a mixing barrel to obtain a primary initiator for later use, preparing a hydrogen peroxide solution with the weight fraction of 4% in a mixing tank C to obtain a reaction initiator, and adding the reaction initiator into a dripping tank C for later use;
(5) adding kettle bottom water into a reaction kettle, heating the kettle bottom water under the protection of nitrogen, adding ethanol and methoxy polyethylene glycol methacrylate, uniformly mixing, continuously heating, adding a primary initiator into the reaction kettle when the temperature reaches 60 ℃, wherein the primary initiator is prepared in situ, stirring for 5min is completed 3min before use, then respectively dropwise adding a mixture A, a mixture B and a reaction initiator in a dropwise adding mode, wherein the mixture A, the mixture B and the reaction initiator are prepared in situ, the preparation is completed 3min before use, the dropwise adding time of the mixture A is 2.3h, the dropwise adding time of the mixture B is 2.8h, the dropwise adding time of the reaction initiator is 2.9h, the temperature is controlled to be 60 ℃, and carrying out heat preservation reaction for 3.5 h;
(6) cooling the temperature in the reaction kettle to 50 ℃, adding softened water C, uniformly mixing, cooling to room temperature, and filtering to obtain a water reducing agent, wherein the average molecular weight of the water reducing agent is 90 ten thousand;
(7) then adding a sodium hydroxide solution with the weight fraction of 5% into the reaction kettle, adjusting the pH value of the sodium hydroxide solution to ensure that the pH value of the water reducing agent is 6, and sampling and detecting to ensure that the fluidity of the cement paste is 280 mm.
Example 5
The raw material proportion of the polycarboxylic acid high-performance water reducing agent is shown in table 1;
(1) the softened water is divided into three parts, namely softened water A, softened water B and softened water C for later use, wherein the weight ratio of the softened water A to the softened water B to the softened water C is 3:3: 2;
(2) adding softened water A into a batching tank A, then adding acrylic acid and hydroxyethyl acrylate into the softened water A, uniformly mixing to obtain a mixture A, and pumping the mixture A into a dripping tank A for later use;
(3) adding softened water B into a batching tank B, adding vinyl chloride, dimethylamino propyl methacrylamide and mercaptopropionic acid into the softened water B, uniformly mixing to obtain a mixture B, and pumping the mixture B into a dripping tank B for later use;
(4) preparing a hydrogen peroxide solution with the mass fraction of 15% in a mixing barrel to obtain a primary initiator for later use, preparing a hydrogen peroxide solution with the weight fraction of 3% in a mixing tank C to obtain a reaction initiator, and adding the reaction initiator into a dripping tank C for later use;
(5) adding kettle bottom water into a reaction kettle, heating the kettle bottom water under the protection of nitrogen, adding ethanol and methoxy polyethylene glycol methacrylate, uniformly mixing, continuously heating, adding a primary initiator into the reaction kettle when the temperature reaches 60 ℃, wherein the primary initiator is prepared in situ, stirring for 10min after the preparation is completed 3min before use, then respectively dropwise adding a mixture A, a mixture B and a reaction initiator in a dropwise adding mode, wherein the mixture A, the mixture B and the reaction initiator are prepared in situ, the preparation is completed 3min before use, the dropwise adding time of the mixture A is 2h, the dropwise adding time of the mixture B is 2.5h, the dropwise adding time of the reaction initiator is 2.6h, the temperature is controlled to be 65 ℃, and carrying out heat preservation reaction for 2.5 h;
(6) cooling the temperature in the reaction kettle to 50 ℃, adding softened water C, uniformly mixing, cooling to room temperature, and filtering to obtain a water reducing agent, wherein the average molecular weight of the water reducing agent is 130 ten thousand;
(7) then adding a sodium hydroxide solution with the weight fraction of 5% into the reaction kettle, adjusting the pH value of the sodium hydroxide solution to ensure that the pH value of the water reducing agent is 6, and sampling and detecting to obtain the cement paste with the fluidity of 285 mm.
Comparative example 1
Adopts a commercial common polycarboxylic acid high-performance water reducing agent.
Comparative example 2
The difference between this comparative example and example 3 is that vinyl chloride was not added to the raw material of the water reducing agent.
Comparative example 3
The difference between this comparative example and example 3 is that mercaptopropionic acid was not added to the raw materials of the water-reducing agent.
Comparative example 4
The difference between the comparative example and the example 3 is that no dimethylaminopropyl methacrylamide was added to the raw materials of the water reducing agent.
Comparative example 5
The difference between the comparative example and the example 3 is that the raw materials of the water reducing agent are not added with vinyl chloride, mercaptopropionic acid and dimethylaminopropyl methacrylamide.
According to GB/T8076-2008 concrete admixture and GB/T8077-2012 concrete admixture homogeneity test method, the following performance tests are carried out on the water reducing agents obtained in examples 1-5 and comparative examples 1-5, and the test results are shown in Table 2.
TABLE 2 test results
As can be seen from Table 2, the water reducing agent of the invention can improve the water reducing rate and the compressive strength of concrete, the water reducing rate is 32% at most, the compressive strength ratio of 1d is 203% at most, and the compressive strength ratio of 28d is 153% at most, and the time variation and the shrinkage ratio of slump constant 1h are reduced, the time variation of slump constant 1h is 10mm at least, and the shrinkage ratio is 96% at least.
By comparing the example 3 with the comparative example 1, the water reducer disclosed by the invention has the advantages that the water reducing rate and the compressive strength ratio of concrete are obviously improved, and the time-dependent change amount and the shrinkage ratio of the slump constant of 1h are obviously reduced, mainly due to the synergistic effect of the raw materials, the raw materials are subjected to free radical polymerization reaction to generate a comb graft copolymer, the agglomeration of the concrete is effectively prevented, and the concrete shows good water reducing rate and compressive strength.
By comparing the example 3 with the comparative examples 2 to 4, it can be seen that the efficiency of the initial reaction of the raw materials accelerated by the initial initiator, the reaction initiator enables the raw materials to maintain mutually constant hydroxyl radical concentration, thereby maintaining the efficiency of the raw material free radical polymerization reaction, the methoxy polyethylene glycol methacrylate, the acrylic acid, the hydroxyethyl acrylate, the vinyl chloride and the dimethylaminopropyl methacrylamide undergo the free radical polymerization reaction, the mercaptopropionic acid improves the stability of the free radical polymerization reaction, through the mutual matching of the raw materials, not only the raw materials undergo the polymerization reaction to form the comb graft copolymer, but also the average molecular weight of the comb graft copolymer is maintained between 80 and 130 ten thousand, the stability of the water reducing agent is improved, the fluidity of cement paste can be improved, and the water reducing agent has good using effect, and the 1h time change of the concrete is reduced, namely the slump loss of the concrete is reduced, and meanwhile, the concrete has the advantages of higher water reducing rate and higher compressive strength.
Claims (9)
1. A polycarboxylic acid high-performance water reducing agent is characterized in that: the water reducing agent comprises, by weight, 3000-6500 parts of methoxy polyethylene glycol methacrylate, 2-10 parts of an initial initiator, 30-40 parts of a reaction initiator, 1-5 parts of ethanol, 300 parts of acrylic acid, 400 parts of hydroxyethyl acrylate, 0.8-8 parts of vinyl chloride, 70-100 parts of dimethylaminopropyl methacrylamide, 1-12 parts of mercaptopropionic acid, 2000 parts of still bottom water and 2000 parts of softened water, and the water reducing agent has a structural general formula as follows:
wherein a, b, c, d, e and m are the number of the repeating unit chain links of the water reducing agent, and the average molecular weight of the water reducing agent is 80-130 ten thousand.
2. The polycarboxylic acid high-performance water reducing agent according to claim 1, characterized in that: the raw materials comprise 3600-4800 parts of methoxy polyethylene glycol methacrylate, 5-7 parts of an initial initiator, 33-37 parts of a reaction initiator, 2-4 parts of ethanol, 150-250 parts of acrylic acid, 430 parts of hydroxyethyl acrylate, 3-8 parts of vinyl chloride, 80-100 parts of dimethylaminopropyl methacrylamide, 4-8 parts of mercaptopropionic acid, 1300 parts of kettle bottom water, 1700 parts of softened water and 1600 parts of ethylene glycol methacrylate.
3. The polycarboxylic acid high-performance water reducing agent according to claim 1, characterized in that: the weight ratio of the methoxy polyethylene glycol methacrylate to the acrylic acid to the hydroxyethyl acrylate is 50:2: 4.4.
4. The polycarboxylic acid high-performance water reducing agent according to claim 1, characterized in that: the initial initiator is hydrogen peroxide solution with the weight fraction of 10-15%, and the initial initiator is hydrogen peroxide solution with the weight fraction of 3-8%.
5. The polycarboxylic acid high-performance water reducing agent according to claim 1, characterized in that: the pH value of the water reducing agent is 5-6.
6. A method for preparing a polycarboxylic acid high performance water reducing agent according to any one of claims 1 to 5, characterized in that: the method comprises the following steps:
(1) dividing softened water into three parts, namely softened water A, softened water B and softened water C;
(2) adding acrylic acid and hydroxyethyl acrylate into the softened water A, and uniformly mixing to obtain a mixture A for later use;
(3) adding chloroethylene, dimethylamino propyl methacrylamide and mercaptopropionic acid into the softened water B, and uniformly mixing to obtain a mixture B for later use;
(4) under the protection of inert gas, heating kettle bottom water, adding ethanol and methoxy polyethylene glycol methacrylate, uniformly mixing, continuously heating, adding a primary initiator when the temperature reaches 60 ℃, stirring for 5-10min, then respectively dropwise adding the mixture A, the mixture B and a reaction initiator in a dropwise adding mode, wherein the dropwise adding time of the mixture A is 2-2.3h, the dropwise adding time of the mixture B is 2.5-2.8h, the dropwise adding time of the reaction initiator is 2.6-2.9h, the temperature is controlled to be 60-65 ℃, and carrying out heat preservation reaction for 2-4 h;
(5) and cooling to 50 ℃, adding softened water C, uniformly mixing, cooling to room temperature, and filtering to obtain the water reducer.
7. The method for preparing the polycarboxylic acid high-performance water reducing agent according to claim 6, characterized by comprising the following steps: the weight ratio of the softened water A to the softened water B to the softened water C is 3:3: 2.
8. The method for preparing the polycarboxylic acid high-performance water reducing agent according to claim 6, characterized by comprising the following steps: the pH value of the water reducing agent is adjusted by adopting a sodium hydroxide solution with the weight percentage of 5%.
9. The method for preparing the polycarboxylic acid high-performance water reducing agent according to claim 6, characterized by comprising the following steps: the mixture A, the mixture B, the primary initiator and the reaction initiator are prepared in situ and are prepared within 3min before use.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910854873.1A CN110591014A (en) | 2019-09-10 | 2019-09-10 | Polycarboxylic acid high-performance water reducing agent and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910854873.1A CN110591014A (en) | 2019-09-10 | 2019-09-10 | Polycarboxylic acid high-performance water reducing agent and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110591014A true CN110591014A (en) | 2019-12-20 |
Family
ID=68858655
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910854873.1A Pending CN110591014A (en) | 2019-09-10 | 2019-09-10 | Polycarboxylic acid high-performance water reducing agent and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110591014A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101585900A (en) * | 2009-06-18 | 2009-11-25 | 西安建筑科技大学 | Method for synthesizing polycarboxylic acid concrete high-performance water reducing agent |
| US20150291716A1 (en) * | 2012-12-05 | 2015-10-15 | Sobute New Materials Co., Ltd. | Slump retaining polycarboxylic acid superplasticizer |
| CN108275941A (en) * | 2018-01-25 | 2018-07-13 | 四川通德商品混凝土有限公司 | Clear-water concrete compound additive and clear-water concrete |
| CN109369859A (en) * | 2018-08-16 | 2019-02-22 | 武汉源锦建材科技有限公司 | A kind of concrete thickening type viscosity modifier and preparation method thereof |
-
2019
- 2019-09-10 CN CN201910854873.1A patent/CN110591014A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101585900A (en) * | 2009-06-18 | 2009-11-25 | 西安建筑科技大学 | Method for synthesizing polycarboxylic acid concrete high-performance water reducing agent |
| US20150291716A1 (en) * | 2012-12-05 | 2015-10-15 | Sobute New Materials Co., Ltd. | Slump retaining polycarboxylic acid superplasticizer |
| CN108275941A (en) * | 2018-01-25 | 2018-07-13 | 四川通德商品混凝土有限公司 | Clear-water concrete compound additive and clear-water concrete |
| CN109369859A (en) * | 2018-08-16 | 2019-02-22 | 武汉源锦建材科技有限公司 | A kind of concrete thickening type viscosity modifier and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109312032B (en) | Rapid low-temperature preparation method of low-doping-amount sensitive polycarboxylic acid | |
| EP2937321B1 (en) | Slump retaining polycarboxylic acid superplasticizer | |
| CN105924592B (en) | Viscosity-reducing polycarboxylic acid water reducer and preparation method thereof | |
| CN106432628B (en) | A kind of muting sensitive induction reactance mud ether-ether copoly type polycarboxylate water-reducer and preparation method thereof | |
| CN112708045B (en) | Low-sensitivity super-early-strength polycarboxylate superplasticizer and preparation method thereof | |
| CN112707674B (en) | High-adsorption dispersion type polycarboxylate superplasticizer and preparation method thereof | |
| CN103897116A (en) | Mud-resistant polycarboxylic acid water reducer and preparation method thereof | |
| CN104672401A (en) | Preparation method for slump retaining agent for polycarboxylate superplasticizer | |
| CN104861125A (en) | Slump retaining type polyether polycarboxylic acid reducing agent and preparation method thereof | |
| CN107200839B (en) | Methallyl alcohol random polyether and preparation method thereof | |
| CN109608082B (en) | Anti-mud polycarboxylate superplasticizer, preparation method and application | |
| CN108047390B (en) | Preparation method of anti-mud-reduction type polycarboxylate superplasticizer | |
| CN110627972A (en) | Novel mud-resistant polyether polycarboxylic acid water reducer and normal-temperature synthesis process thereof | |
| CN104961866B (en) | A kind of more amido fibre modification carboxylic acid type water reducing agents and preparation method thereof | |
| CN114316289A (en) | Seed crystal type polycarboxylate superplasticizer for prefabricated parts and preparation method thereof | |
| CN110591014A (en) | Polycarboxylic acid high-performance water reducing agent and preparation method thereof | |
| CN109721271B (en) | Polycarboxylate water reducing agent composition for self-compacting high-workability concrete | |
| CN107602775A (en) | A kind of high-performance protects the anti-chamotte mould polycarboxylic acids and preparation method thereof that collapses | |
| CN112708065B (en) | Polyhydroxy air entraining retarding water reducing agent and preparation method thereof | |
| CN113512154B (en) | Method for synthesizing solid polycarboxylate superplasticizer | |
| CN112708048B (en) | Ester anti-mud type super-early-strength polycarboxylate superplasticizer and preparation method thereof | |
| CN113278112A (en) | Polycarboxylate superplasticizer miscible with defoaming agent and preparation method thereof | |
| CN114044858A (en) | Comprehensive polycarboxylic acid water reducing agent and preparation method thereof | |
| CN112708047B (en) | Mud-blocking super-early-strength polycarboxylate superplasticizer and preparation method thereof | |
| CN112661916A (en) | Preparation method of early-strength polycarboxylate superplasticizer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20191220 |
|
| RJ01 | Rejection of invention patent application after publication |