CN114057956A - Water-reducing slump-retaining comprehensive polycarboxylic acid water reducer and preparation method thereof - Google Patents
Water-reducing slump-retaining comprehensive polycarboxylic acid water reducer and preparation method thereof Download PDFInfo
- Publication number
- CN114057956A CN114057956A CN202111486110.XA CN202111486110A CN114057956A CN 114057956 A CN114057956 A CN 114057956A CN 202111486110 A CN202111486110 A CN 202111486110A CN 114057956 A CN114057956 A CN 114057956A
- Authority
- CN
- China
- Prior art keywords
- water
- monomer
- water reducing
- diester
- carboxylic acid
- 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
- 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
- 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
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
The invention discloses a water-reducing slump-retaining comprehensive polycarboxylic acid water reducing agent and a preparation method thereof, wherein the water reducing agent comprises an unsaturated polyether macromonomer, an unsaturated carboxylic acid monomer and a functional ester monomer, wherein the molar ratio of the unsaturated polyether macromonomer to the unsaturated carboxylic acid monomer to the functional ester monomer is 1:0.5-3.5: 0.1-2; the functional ester monomer comprises at least one of maleic anhydride-2, 2-dimethylcyclohexanol diester, maleic anhydride-2, 2-dimethylbutyl glycol, maleic anhydride-dimethyl-1-octanol diester, maleic anhydride-2-decanol diester, acrylic acid-2-butyl-2-ethyl-1, 3-propanediol diester, methacrylic acid-ethylene glycol diester and methacrylic acid-propylene glycol diester. The water-reducing slump-retaining comprehensive polycarboxylic acid agent can effectively solve the problem of sensitive effect of the existing water reducing agent.
Description
Technical Field
The invention relates to the technical field of water reducing agents, and particularly relates to a water reducing and slump retaining comprehensive polycarboxylic acid water reducing agent and a preparation method thereof.
Background
A large amount of artificial machine-made sand is applied to concrete, the quality of the current artificial machine-made sand is uneven, the stone gradation is poor, the gradation of the sand and the mud content cannot be effectively controlled, and in addition, the requirement of the transport distance of a mixer truck requires long-time slump retaining of the concrete, which brings great challenge to the polycarboxylic acid water reducing agent. In the concrete mixing plant, the sensitivity of the application of the admixture is hopefully reduced as much as possible under the condition of the existing materials, and the polycarboxylate superplasticizer is required to have a large effective mixing amount floating range and have small influence on the setting time, slump loss resistance and the like of the concrete.
At present, most of polycarboxylic acid admixtures have high water reducing rate and excellent concrete rheological property, but the admixture is sensitive, so that the problems of use are solved, and in order to meet the long-time slump retaining requirement of concrete, a large amount of slump retaining agent is often added in the compounding process of the admixture, which easily causes the defects of reaction lag and the like of the concrete. Therefore, when the concrete slump loss inhibitor is applied to actual engineering, the concrete slump loss is large when the doping amount of the additive is low; at high mixing amount, the concrete has the phenomena of bleeding and segregation, and the production and on-site construction progress of the commercial and hybrid enterprises is influenced.
The concrete admixture has the advantages that the low sensitivity and high adaptability of the water reducing and slump retaining comprehensive water reducing agent are utilized through the synthesis technical means of the admixture, and the continuous maintenance of the stability and the time-lapse state of the concrete state is one of the core technologies of the admixture which are urgently needed to be solved at present.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a water-reducing slump-retaining comprehensive polycarboxylic acid water reducing agent and a preparation method thereof.
In order to achieve the purpose, the technical scheme adopted by the invention for solving the technical problems is as follows:
a water-reducing slump-retaining comprehensive polycarboxylic acid water reducing agent comprises an unsaturated polyether macromonomer, an unsaturated carboxylic acid monomer and a functional ester monomer, wherein the molar ratio of the unsaturated polyether macromonomer to the unsaturated carboxylic acid monomer to the functional ester monomer is 1:0.5-3.5: 0.1-2;
the functional ester monomer comprises at least one of maleic anhydride-2, 2-dimethylcyclohexanol diester, maleic anhydride-2, 2-dimethylbutyl glycol, maleic anhydride-dimethyl-1-octanol diester, maleic anhydride-2-decanol diester, acrylic acid-2-butyl-2-ethyl-1, 3-propanediol diester, methacrylic acid-ethylene glycol diester and methacrylic acid-propylene glycol diester.
In the scheme, a hydrophobic long side chain is introduced through an unsaturated polyether macromonomer, steric hindrance equal resistance repulsion force is provided, and the dispersion and dispersion retention performance of the water reducing agent is determined; strong polar anion groups on a main chain are introduced through unsaturated carboxylic acid monomers, and the effects of anchoring, solubilization, electrostatic repulsion and the like are mainly achieved; by introducing the functional ester monomer, on one hand, the functional ester monomer contains ester groups which hydrolyze to form carboxyl groups, and the carboxyl groups are hydrolyzed in the alkaline environment of the cement paste, so that the carboxyl groups are continuously hydrolyzed in a long time, and the adsorption and dispersion capacity in the later period is improved; on the other hand, the introduction of the functional ester monomer effectively improves the molecular structure (micro-crosslinking) of the polycarboxylate superplasticizer, shows the characteristics of thickening, slurry extraction and the like in concrete, and is beneficial to improving the workability of the concrete; in addition, unsaturated carboxylic acid containing double bonds is introduced into the ester monomer, and can participate in polymerization reaction, and the unsaturated carboxylic acid is continuously generated after the reaction, so that the functions of dispersion and slump retention are achieved. By utilizing the molecular structure of carboxyl strongly polar anionic groups, ester group hydrolysis and micro-crosslinking, the water-reducing slump-retaining comprehensive polycarboxylic acid water reducing agent has the characteristics of high water reducing performance, high slump retaining performance and good workability, and under the conditions that sand is coarse, conventional additives are added, and concrete has poor wrapping performance and quick dispersion and loss, the water-reducing slump-retaining comprehensive polycarboxylic acid water reducing agent can effectively improve the workability of concrete by utilizing the characteristics of thickening and slurry lifting, and can effectively improve the retentivity of concrete, reduce the slump loss and have low sensitivity by utilizing the high water-reducing slump retaining performance and the high slump retaining performance, thereby being beneficial to normal pumping construction and ensuring the quality of the concrete.
The ratio of the unsaturated polyether macromonomer, the unsaturated carboxylic acid monomer and the functional ester monomer has a great influence on the performance of the water reducing agent. The molar ratio of the unsaturated carboxylic acid monomer to the polyether macromonomer (short for acid-ether ratio) is too low, and the water reduction rate is low; the acid ether ratio is too high, the water reducing rate can be large, but bleeding can occur in practical application. The molar ratio (ester ether ratio for short) of the unsaturated carboxylic acid monomer to the functional ester monomer is too low, on one hand, the quantity of carboxyl generated by ester group hydrolysis is less, and the slump retaining performance is poor, and on the other hand, the micro-crosslinking structure is less, so that the improvement of the workability of concrete is not facilitated; the ester-ether ratio is too high, and the water reduction rate may be lowered. Therefore, the acid-ether ratio, the ester-ether ratio, the dosage of the initiating system, the dosage of the bond transfer agent and the like influence the water reducing rate and the slump retaining performance of the water reducing agent and influence the characteristic of improving the workability of the water reducing agent.
According to the application, the characteristics of high water reducing performance and high slump retaining performance can be realized under the specific molar ratio condition of the unsaturated polyether macromonomer, the unsaturated carboxylic acid monomer and the hydrolysis ester monomer, the sensitivity of the water reducing agent is reduced, and the problems of slump loss, segregation and water seepage of concrete are solved. Specifically, the initial adsorption capacity of the polycarboxylate water reducer can be adjusted by fixing the proportion of the unsaturated polyether macromonomer and adjusting the proportion of the unsaturated carboxylic acid monomer; the later adsorption capacity of the polycarboxylate superplasticizer can be adjusted by adjusting the proportion and the type of the functional ester monomers.
Further, the unsaturated polyether macromonomer is at least one of prenyl polyoxyethylene ether, isobutenol polyoxyethylene ether and methallyl alcohol polyoxyethylene ether.
Further, the unsaturated carboxylic acid monomer is at least one of acrylic acid, methacrylic acid and maleic anhydride.
Further, the functional ester monomer is prepared by the following method: adding an alcohol monomer into an unsaturated carboxylic acid monomer, then sequentially adding a catalyst and a polymerization inhibitor into the unsaturated carboxylic acid monomer, and reacting for 3-15h at the temperature of 40-110 ℃ to obtain the unsaturated carboxylic acid monomer, wherein the molar ratio of the unsaturated carboxylic acid monomer to the alcohol monomer is 1: 0.3-3.
Further, the alcohol monomer includes at least one of 2, 2-dimethylcyclohexanol, 2-dimethylbutanol, dimethyl-1-octanol, 2-decanol, 2-butyl-2-ethyl-1, 3-propanediol, ethylene glycol, and propylene glycol.
Furthermore, the catalyst accounts for 0.1-5% of the weight of the functional ester monomer, and the catalyst is at least one of p-toluenesulfonic acid and sodium acetate.
Furthermore, the dosage of the polymerization inhibitor accounts for 0.1-3% of the weight of the functional ester monomer, and the polymerization inhibitor is at least one of hydroquinone and phenothiazine.
The preparation method of the water-reducing slump-retaining comprehensive polycarboxylate superplasticizer comprises the following steps:
(1) dissolving unsaturated polyether macromonomer in water, and then adding an oxidant to obtain a reactant solution;
(2) and respectively dropwise adding a mixed solution of an unsaturated carboxylic acid monomer and a functional ester monomer, a mixed solution of a reducing agent and a chain transfer agent into the obtained reactant solution under the stirring state at 10-60 ℃, preserving heat for reaction after dropwise adding is finished, and then adding alkali to adjust the pH value to 5-7, thus obtaining the water-reducing comprehensive polycarboxylic acid water reducer.
Further, the dropping time of the mixed solution of the unsaturated carboxylic acid monomer and the functional ester monomer is 30-180min, and the dropping time of the mixed solution of the reducing agent and the chain transfer agent is 30-180 min.
Further, the reaction temperature is kept at 20-50 ℃ and the reaction time is 0.5-1.5 h.
Further, the oxidant is at least one of ammonium persulfate, sodium persulfate, potassium persulfate and hydrogen peroxide, and the using amount of the oxidant is 0.1-1.2% of the total mass of the unsaturated polyether macromonomer.
Furthermore, the reducing agent is at least one of vitamin C, ferrous sulfate, sodium methylthiosulfate, sodium sulfite, sodium bisulfite, sodium hypophosphite, sodium formaldehyde sulfoxylate and sodium hydrosulfite, and the dosage of the reducing agent is 0.1-1.8% of the total mass of the unsaturated polyether macromonomer.
Further, the chain transfer agent is at least one of thioglycolic acid, mercaptoethanol, mercaptopropionic acid, aliphatic mercaptan, dodecyl mercaptan and sodium hydrogen phosphite, and the dosage of the chain transfer agent is 0.1-1.2% of the total mass of the unsaturated polyether macromonomer.
The beneficial effect that this application produced does:
functional ester molecular fragments are introduced into a molecular structure through free radical polymerization, and the proportion of unsaturated carboxylic acid monomers is adjusted, so that the micro-crosslinked water-reducing slump-retaining polycarboxylic acid water reducer is synthesized, and the specific crosslinking process is as follows:
r is functional ester.
The polycarboxylate superplasticizer disclosed by the invention has a micro-crosslinking structure and a hydrolytic group, and can effectively improve the workability of concrete, improve the slump retention of the concrete and reduce the sensitivity of the concrete.
Detailed Description
Example 1
A water-reducing slump-retaining comprehensive polycarboxylic acid water reducer comprises an unsaturated polyether macromonomer, an unsaturated carboxylic acid monomer and a functional ester monomer, wherein the molar ratio of the unsaturated polyether macromonomer to the unsaturated carboxylic acid monomer to the functional ester monomer is 1:2:1, and the functional ester monomer is maleic anhydride-dimethyl-1-octanol diester.
The preparation method of the water-reducing slump-retaining comprehensive polycarboxylate superplasticizer comprises the following steps:
(1) sequentially adding 200.2g of prenyl alcohol polyoxyethylene ether and 175g of deionized water into a glass reactor provided with a thermometer and a mechanical stirrer, stirring at a low speed for dissolving for 20min, and then adding 0.62g of hydrogen peroxide to obtain a reactant solution;
(2) stirring and dispersing 20g of deionized water, 12g of acrylic acid and 29g of maleic anhydride-dimethyl-1-octanol diester uniformly to obtain a solution A; stirring and dissolving 80g of water, 0.68g of mercaptoethanol and 0.35g of 0.35gVc to obtain a solution B;
(3) and respectively dripping the solution A and the solution B into the obtained reactant solution under the stirring state at the temperature of 30 ℃, dripping the material A for 100min, dripping the material B for 120min, keeping the temperature at 40 ℃ for reaction for 1h after dripping is finished, and then adding alkali to adjust the pH value to 6, thus obtaining the water-reducing comprehensive polycarboxylic acid water reducer.
Example 2
A water-reducing slump-retaining comprehensive polycarboxylic acid water reducer comprises an unsaturated polyether macromonomer, an unsaturated carboxylic acid monomer and a functional ester monomer, wherein the molar ratio of the unsaturated polyether macromonomer to the unsaturated carboxylic acid monomer to the functional ester monomer is 1:3:1, and the functional ester monomer is acrylic acid-2-butyl-2-ethyl-1, 3-propylene glycol diester.
The preparation method of the water-reducing slump-retaining comprehensive polycarboxylate superplasticizer comprises the following steps:
(1) sequentially adding 200.2g of methallyl alcohol polyoxyethylene ether and 175g of deionized water into a glass reactor provided with a thermometer and a mechanical stirrer, stirring at a low speed for dissolving for 20min, and then adding 0.62g of hydrogen peroxide to obtain a reactant solution;
(2) 20g of deionized water, 21g of methacrylic acid and 17.28g of acrylic acid-2-butyl-2-ethyl-1, 3-propanediol diester are stirred and dispersed uniformly to obtain a solution A; stirring and dissolving 80g of water, 0.68g of mercaptopropionic acid and 0.35gVc to obtain a solution B;
(3) respectively dripping the solution A and the solution B into the obtained reactant solution under the stirring state at 18 ℃, dripping the material A for 100min, dripping the material B for 120min, keeping the temperature at 35 ℃ for reaction for 0.5h after dripping is finished, and then adding alkali to adjust the pH value to 7, thus obtaining the water-reducing comprehensive polycarboxylic acid water reducer.
Example 3
A water-reducing slump-retaining comprehensive polycarboxylic acid water reducer comprises an unsaturated polyether macromonomer, an unsaturated carboxylic acid monomer and a functional ester monomer, wherein the molar ratio of the unsaturated polyether macromonomer to the unsaturated carboxylic acid monomer to the functional ester monomer is 1:1.8:2, and the functional ester monomer is methacrylic acid-ethylene glycol diester.
The preparation method of the water-reducing slump-retaining comprehensive polycarboxylate superplasticizer comprises the following steps:
(1) sequentially adding 200.2g of prenyl alcohol polyoxyethylene ether and 175g of deionized water into a glass reactor provided with a thermometer and a mechanical stirrer, stirring at a low speed for dissolving for 20min, and then adding 0.62g of hydrogen peroxide to obtain a reactant solution;
(2) stirring and dispersing 20g of deionized water, 10.8g of methacrylic acid and 33g of methacrylic acid-ethylene glycol diester uniformly to obtain a solution A; stirring and dissolving 80g of water, 0.68g of thioglycolic acid and 0.35gVc to obtain a solution B;
(3) and respectively dripping the solution A and the solution B into the obtained reactant solution under the stirring state at 25 ℃, dripping the material A for 100min and dripping the material B for 120min, keeping the temperature at 43 ℃ for reaction for 1.5h after dripping is finished, and then adding alkali to adjust the pH value to 7, thus obtaining the water-reducing comprehensive polycarboxylic acid water reducer.
Example 4
A water-reducing slump-retaining comprehensive polycarboxylic acid water reducer comprises an unsaturated polyether macromonomer, an unsaturated carboxylic acid monomer and a functional ester monomer, wherein the molar ratio of the unsaturated polyether macromonomer to the unsaturated carboxylic acid monomer to the functional ester monomer is 1:2:0.8, and the functional ester monomer is maleic anhydride-dimethyl-1-octanol diester and methacrylic acid-propylene glycol diester.
The preparation method of the water-reducing slump-retaining comprehensive polycarboxylate superplasticizer comprises the following steps:
(1) sequentially adding 200.2g of prenyl alcohol polyoxyethylene ether and 175g of deionized water into a glass reactor provided with a thermometer and a mechanical stirrer, stirring at a low speed for dissolving for 20min, and then adding 0.62g of hydrogen peroxide to obtain a reactant solution;
(2) stirring and dispersing 20g of deionized water, 12g of methacrylic acid, 11.6g of maleic anhydride-dimethyl-1-octanol diester and 6.68g of methacrylic acid-propylene glycol diester uniformly to obtain a solution A; stirring and dissolving 80g of water, 0.68g of thioglycolic acid and 0.35gVc to obtain a solution B;
(3) respectively dripping the solution A and the solution B into the obtained reactant solution under the stirring state at 25 ℃, dripping the material A for 100min, dripping the material B for 120min, keeping the temperature at 50 ℃ for reaction for 0.8h after dripping is finished, and then adding alkali to adjust the pH value to 6, thus obtaining the water-reducing comprehensive polycarboxylic acid water reducer.
Comparative example 1
A water-reducing slump-retaining comprehensive polycarboxylic acid water reducer comprises an unsaturated polyether macromonomer, an unsaturated carboxylic acid monomer and a functional ester monomer, wherein the molar ratio of the unsaturated polyether macromonomer to the unsaturated carboxylic acid monomer to the functional ester monomer is 1:1.8:2, and the functional ester monomer is hydroxyethyl acrylate.
The preparation method of the water-reducing slump-retaining comprehensive polycarboxylate superplasticizer comprises the following steps:
(1) sequentially adding 200.2g of prenyl alcohol polyoxyethylene ether and 175g of deionized water into a glass reactor provided with a thermometer and a mechanical stirrer, stirring at a low speed for dissolving for 20min, and then adding 0.62g of hydrogen peroxide to obtain a reactant solution;
(2) stirring and dispersing 20g of deionized water, 10.8g of methacrylic acid and 19.38g of hydroxyethyl acrylate uniformly to obtain a solution A; stirring and dissolving 80g of water, 0.68g of thioglycolic acid and 0.35gVc to obtain a solution B;
(3) and respectively dripping the solution A and the solution B into the obtained reactant solution under the stirring state at 25 ℃, dripping the material A for 100min, dripping the material B for 120min, keeping the temperature at 40 ℃ for reaction for 1.2h after dripping is finished, and then adding alkali to adjust the pH value to 7, thus obtaining the water-reducing comprehensive polycarboxylic acid water reducer.
Comparative example 2
A water-reducing slump-retaining comprehensive polycarboxylic acid water reducer comprises an unsaturated polyether macromonomer, an unsaturated carboxylic acid monomer and a functional ester monomer, wherein the molar ratio of the unsaturated polyether macromonomer to the unsaturated carboxylic acid monomer to the functional ester monomer is 1:2.5:2.5, and the functional ester monomer is methacrylic acid-ethylene glycol diester.
The preparation method of the water-reducing slump-retaining comprehensive polycarboxylate superplasticizer comprises the following steps:
(1) sequentially adding 200.2g of prenyl alcohol polyoxyethylene ether and 175g of deionized water into a glass reactor provided with a thermometer and a mechanical stirrer, stirring at a low speed for dissolving for 20min, and then adding 0.62g of hydrogen peroxide to obtain a reactant solution;
(2) 20g of deionized water, 15.03g of methacrylic acid and 41.25g of methacrylic acid-ethylene glycol diester are stirred and dispersed uniformly to obtain a solution A; stirring and dissolving 80g of water, 0.68g of thioglycolic acid and 0.35gVc to obtain a solution B;
(3) and respectively dripping the solution A and the solution B into the obtained reactant solution under the stirring state at 25 ℃, dripping the material A for 100min and dripping the material B for 120min, keeping the temperature at 40 ℃ for reaction for 0.8h after dripping is finished, and then adding alkali to adjust the pH value to 7, thus obtaining the water-reducing comprehensive polycarboxylic acid water reducer.
Comparative example 3
The existing comprehensive polycarboxylic acid water reducing agent is 3A 02.
Test examples
The water reducing agents in the examples and the comparative examples were subjected to a net slurry fluidity test and a concrete test, and the net slurry fluidity of the cement was tested according to GB/T8077-2000 "Experimental method for homogeneity of concrete Admixture". The cement is Emei cement with a water cement ratio of 0.29.
The concrete performance test is carried out according to GB 8076 + 2008 concrete admixture, the slump constant, the expansion degree and the like of the concrete are measured, the modulus of the machine-made sand fineness in the concrete is 2.8, the broken stone is continuous graded broken stone with the grain diameter of 5-25mm, and the mixing amount of the polycarboxylic acid water reducing agent is 1.6-2.2 wt%.
TABLE 1 neat paste fluidity data
| Sample (I) | Cement | Mixing amount/% | Initial/mm | 1h/mm | 2h/mm | 3h/mm |
| Example 1 | Emei cement | 0.11 | 210 | 240 | 260 | 250 |
| Example 2 | Emei cement | 0.11 | 215 | 235 | 255 | 260 |
| Example 3 | Emei cement | 0.11 | 210 | 230 | 255 | 240 |
| Example 4 | Emei cement | 0.11 | 215 | 240 | 260 | 250 |
| Comparative example 1 | Emei cement | 0.15 | 190 | 210 | 220 | 180 |
| Comparative example 2 | Emei cement | 0.13 | 180 | 200 | 215 | 160 |
| Comparative example 3 | Emei cement | 0.13 | 200 | 210 | 210 | 160 |
| Comparative example 3 | Emei cement | 0.11 | 210 | 240 | 260 | 250 |
TABLE 2 concrete Performance data C30
As can be seen from the results of the neat paste performance test in Table 1 and the concrete test in Table 2, the water reducing agents in examples 1-4 are superior to the water reducing agents in comparative examples 1-3 in performance, and the water reducing and slump retaining type polycarboxylate water reducing agent provided by the invention has the advantages of high initial water reducing rate, good slump retaining performance and good workability.
Comparing the water reducing agent in the comparative example 1 with the water reducing agent in the example 3, the effects of thickening and slurry extracting, which are shown by the hydroxyethyl acrylate used in the comparative example 1, are far worse than those of the functional ester in the application, and the functional ester monomer in the application is proved to have great influence on the performance of the water reducing agent.
Comparing the water reducing agent in the comparative example 2 with the water reducing agent in the embodiment 3, after the proportional relation among the unsaturated polyether macromonomer, the unsaturated carboxylic acid and the functional ester monomer is adjusted, the fluidity of the cement paste and the working performance of the concrete are far inferior to those in the embodiment, and the proportional relation among the three is proved to influence the use effect to a great extent.
Comparing the water reducing agent of comparative example 3 with the water reducing agent of example 3, the flow properties of the cement paste and the working properties of the concrete are far inferior to those of example 3.
Taking the example 3 and the comparative example 3 as examples, the mixing amount of the water reducing agent is changed, and the performance results show that the concrete with the reduced mixing amount in the example 3 has better state and less loss with time; the mixing amount is increased, the concrete is not separated, and the slurry is rich; compared with the comparative example 3, the mixing amount is reduced, the initial state is general, and the loss with time is fast; the addition amount is increased, the ground is isolated, and the fact that the addition amount of the water reducing agent in the example 3 is insensitive to the performance influence of the concrete is shown, while the fact that the water reducing agent in the comparative example 3 is sensitive to the performance influence of the concrete shows that the sensitivity to the addition amount of the example 3 is better than that of the comparative example 3.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. The water-reducing slump-retaining comprehensive polycarboxylic acid water reducing agent is characterized by comprising an unsaturated polyether macromonomer, an unsaturated carboxylic acid monomer and a functional ester monomer, wherein the molar ratio of the unsaturated polyether macromonomer to the unsaturated carboxylic acid monomer to the functional ester monomer is 1:0.5-3.5: 0.1-2;
the functional ester monomer comprises at least one of maleic anhydride-2, 2-dimethylcyclohexanol diester, maleic anhydride-2, 2-dimethylbutyl glycol, maleic anhydride-dimethyl-1-octanol diester, maleic anhydride-2-decanol diester, acrylic acid-2-butyl-2-ethyl-1, 3-propanediol diester, methacrylic acid-ethylene glycol diester and methacrylic acid-propylene glycol diester.
2. The water reducing and slump retaining comprehensive polycarboxylate superplasticizer according to claim 1, wherein the unsaturated polyether macromonomer is at least one of prenyl alcohol polyoxyethylene ether, isobutenyl alcohol polyoxyethylene ether and methallyl alcohol polyoxyethylene ether.
3. The water reducing and slump retaining comprehensive polycarboxylic acid water reducing agent according to claim 1, wherein the unsaturated carboxylic acid monomer is at least one of acrylic acid, methacrylic acid and maleic anhydride.
4. The water reducing and slump retaining comprehensive polycarboxylate superplasticizer according to claim 1, wherein the functional ester monomer is prepared by the following method: adding an alcohol monomer into an unsaturated carboxylic acid monomer, then sequentially adding a catalyst and a polymerization inhibitor into the unsaturated carboxylic acid monomer, and reacting for 3-15h at the temperature of 40-110 ℃ to obtain the unsaturated carboxylic acid monomer, wherein the molar ratio of the unsaturated carboxylic acid monomer to the alcohol monomer is 1: 0.3-3.
5. The water reducing and slump retaining comprehensive polycarboxylic acid water reducing agent of claim 4, wherein the alcohol monomer comprises at least one of 2, 2-dimethylcyclohexanol, 2-dimethylbutanol, dimethyl-1-octanol, 2-decanol, 2-butyl-2-ethyl-1, 3-propanediol, ethylene glycol and propylene glycol.
6. The water reducing and slump retaining comprehensive polycarboxylate superplasticizer according to claim 4, wherein the catalyst is used in an amount of 0.1-5% by weight based on the weight of the functional ester monomer, and the catalyst is at least one of p-toluenesulfonic acid and sodium acetate.
7. The water reducing and slump retaining comprehensive polycarboxylate superplasticizer according to claim 4, wherein the amount of the polymerization inhibitor is 0.1-3% of the weight of the functional ester monomer, and the polymerization inhibitor is at least one of hydroquinone and phenothiazine.
8. The preparation method of the water reducing and slump retaining comprehensive polycarboxylate superplasticizer according to any one of claims 1 to 7, characterized by comprising the following steps:
(1) dissolving unsaturated polyether macromonomer in water, and then adding an oxidant to obtain a reactant solution;
(2) respectively dropwise adding a mixed solution of an unsaturated carboxylic acid monomer and a functional ester monomer, a mixed solution of a reducing agent and a chain transfer agent into the obtained reactant solution under the condition of stirring at 10-60 ℃, preserving heat for reaction after dropwise adding is finished, and then adding alkali to adjust the pH value to 5-7 to obtain the water-reducing comprehensive polycarboxylic acid water reducer.
9. The method for preparing the water reducing and slump retaining comprehensive polycarboxylate superplasticizer according to claim 8, wherein the dropping time of the mixed solution of the unsaturated carboxylate monomer and the functional ester monomer is 30-180min, and the dropping time of the mixed solution of the reducing agent and the chain transfer agent is 30-180 min.
10. The preparation method of the water reducing and slump retaining comprehensive polycarboxylate superplasticizer according to claim 8, wherein the reaction temperature is 20-50 ℃ and the reaction time is 0.5-1.5 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111486110.XA CN114057956A (en) | 2021-12-07 | 2021-12-07 | Water-reducing slump-retaining comprehensive polycarboxylic acid water reducer and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111486110.XA CN114057956A (en) | 2021-12-07 | 2021-12-07 | Water-reducing slump-retaining comprehensive polycarboxylic acid water reducer and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114057956A true CN114057956A (en) | 2022-02-18 |
Family
ID=80228841
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111486110.XA Pending CN114057956A (en) | 2021-12-07 | 2021-12-07 | Water-reducing slump-retaining comprehensive polycarboxylic acid water reducer and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114057956A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105461866A (en) * | 2014-09-05 | 2016-04-06 | 深圳市迈地砼外加剂有限公司 | Viscosity-reducing type polycarboxylic-acid water-reducing agent and preparation method thereof |
| CN110028632A (en) * | 2019-04-25 | 2019-07-19 | 江苏尼高科技有限公司 | Anti- chamotte mould polycarboxylate water-reducer of high water reduction and preparation method thereof |
| CN110790872A (en) * | 2019-11-27 | 2020-02-14 | 中建西部建设股份有限公司 | Viscosity-reducing polycarboxylate superplasticizer with micro-crosslinking structure and preparation method thereof |
-
2021
- 2021-12-07 CN CN202111486110.XA patent/CN114057956A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105461866A (en) * | 2014-09-05 | 2016-04-06 | 深圳市迈地砼外加剂有限公司 | Viscosity-reducing type polycarboxylic-acid water-reducing agent and preparation method thereof |
| CN110028632A (en) * | 2019-04-25 | 2019-07-19 | 江苏尼高科技有限公司 | Anti- chamotte mould polycarboxylate water-reducer of high water reduction and preparation method thereof |
| CN110790872A (en) * | 2019-11-27 | 2020-02-14 | 中建西部建设股份有限公司 | Viscosity-reducing polycarboxylate superplasticizer with micro-crosslinking structure and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| XIA LV, ET AL.: "Preparation and Cement Fluidity of Slow-release Polycarboxylate-type Superplasticizer", ADVANCED MATERIALS RESEARCH, pages 1307 - 1311 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105110687B (en) | A kind of anti-mud collapse protective poly-carboxylic acid water reducing agent and preparation method thereof | |
| CN112694574B (en) | Polycarboxylate superplasticizer with high mud resistance and high slump loss resistance and preparation method thereof | |
| CN108794700B (en) | Carboxylic acid-based polymer, preparation method thereof and slow-release polycarboxylic acid water reducing agent | |
| CN109053974B (en) | Preparation method of viscosity-reducing polycarboxylate superplasticizer | |
| CN107474196B (en) | Polycarboxylate superplasticizer for low-slump concrete and preparation method thereof | |
| CN109776742A (en) | A kind of anti-chamotte mould polycarboxylate water-reducer of phosphate ester-containing and preparation method thereof | |
| CN109880020B (en) | Concrete workability regulator and preparation method thereof | |
| CN110642994A (en) | Preparation method of stone powder adaptive polycarboxylate superplasticizer | |
| CN111100253A (en) | Concrete anti-sensitive polycarboxylate superplasticizer and preparation method thereof | |
| CN111333787A (en) | Gradient release type long-acting slump loss resistant polycarboxylic acid water reducing agent and preparation and application thereof | |
| CN112608420A (en) | Preparation method of air-entraining type ester polycarboxylate superplasticizer | |
| CN108192010B (en) | Viscosity-reducing polycarboxylic acid water reducer and preparation method thereof | |
| CN107759742A (en) | A kind of polycarboxylate water-reducer and preparation method thereof and application method | |
| CN112608424B (en) | Ester ether copolymerization low-bleeding type polycarboxylate superplasticizer and preparation method thereof | |
| CN112608421B (en) | Preparation method of air-entraining ether polycarboxylate superplasticizer | |
| CN109320668B (en) | Viscosity-reducing polycarboxylate superplasticizer and preparation method thereof | |
| CN114057956A (en) | Water-reducing slump-retaining comprehensive polycarboxylic acid water reducer and preparation method thereof | |
| CN115894910A (en) | Doped monomer and preparation method and application thereof | |
| CN116265500A (en) | Viscosity-reducing polycarboxylate superplasticizer and preparation method thereof | |
| CN113896845A (en) | Low-sensitivity slow-release polycarboxylic slump retaining agent and preparation method thereof | |
| CN109721722B (en) | Viscosity-reducing type polycarboxylate superplasticizer containing double viscosity-reducing functional groups, and preparation method and application thereof | |
| CN112920341A (en) | Low-molecular-weight polymer for viscosity-reducing concrete and preparation method thereof | |
| CN112759725A (en) | Novel mud-resistant slump-retaining nano polycarboxylic acid water reducer and preparation method thereof | |
| CN115466362A (en) | High-water-reduction high-slump-retaining type polycarboxylate superplasticizer and preparation method thereof | |
| CN112390918B (en) | Polycarboxylic acid superplasticizer and preparation method thereof |
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 |