CN113354782A - Shrinkage-reducing polycarboxylate superplasticizer and preparation method thereof - Google Patents
Shrinkage-reducing polycarboxylate superplasticizer and preparation method thereof Download PDFInfo
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- 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
- C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
- C08F290/02—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated end groups
- C08F290/06—Polymers provided for in subclass C08G
- C08F290/062—Polyethers
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- 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
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- 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
- C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
- C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
- C08F220/04—Acids; Metal salts or ammonium salts thereof
- C08F220/06—Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
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- 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
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- 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
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- Polymers & Plastics (AREA)
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Abstract
The invention discloses a shrinkage-reducing polycarboxylate water reducer and a preparation method thereof, wherein the polycarboxylate water reducer is prepared by polymerizing maleic anhydride acylated polyether amine, unsaturated polyoxyethylene ether macromonomer and ethylenic unsaturated carboxylic acid free radical, wherein the maleic anhydride acylated polyether amine is prepared by reacting polyether amine generated by ammoniation of hydroxyl-terminated polyoxyethylene polyoxypropylene ether with maleic anhydride. According to the invention, the maleic anhydride acylation polyether amine side chain with hydrophobicity is introduced into the comb-shaped structure of the polycarboxylate superplasticizer, so that the surface tension of a concrete pore solution can be reduced, the shrinkage reduction and air introduction are enhanced, the shrinkage cracking of concrete is avoided, and the compressive strength of the concrete is enhanced; meanwhile, the polyoxyethylene polyoxypropylene long chain in the maleic anhydride acylated polyether amine can improve the adsorption conformation of the polycarboxylic acid in a cement pore solution, so that the polycarboxylic acid is more stretched in the solution, and the dispersing capacity of the polycarboxylic acid water reducing agent to cement is improved.
Description
Technical Field
The invention belongs to the field of concrete admixtures, and particularly relates to a shrinkage-reducing polycarboxylic acid water reducing agent and a preparation method thereof.
Background
The concrete may be contracted at an initial stage of setting or during hardening, and cracks generated by the contraction of the concrete may not only affect the appearance of a building, but also reduce the life span of the concrete, and even affect the stability of a concrete structure, thereby causing safety accidents. Concrete shrinkage is mainly five, and the concrete shrinkage is as follows: plastic shrinkage, temperature shrinkage, carbonization shrinkage, autogenous shrinkage and drying shrinkage, and the concrete shrinkage common in engineering at present is generally drying shrinkage and plastic shrinkage. In order to solve the problems of drying shrinkage and plastic shrinkage, the expansion agent, the fiber, the shrinkage reducing agent and the like are generally blended in the concrete stirring process, but the expansion agent, the fiber and the shrinkage reducing agent have the problem of incompatibility with the concrete admixture, namely the polycarboxylic acid water reducing agent. Therefore, the development of a polycarboxylate superplasticizer capable of reducing concrete shrinkage becomes a hot spot in the industry.
Chinese patent CN106365534B discloses the use of a water-retaining shrinkage-reducing polycarboxylate water reducer in the preparation of high-performance concrete, the water-retaining shrinkage-reducing polycarboxylate water reducer provided by the invention has the advantages that polyhydroxy groups are introduced into side chains in molecules, and hydrogen bonds are formed among the hydroxyl groups and water molecules to form micro-crosslinking structures, so that the viscosity of a solution in capillary pores of cement slurry in the concrete is increased, the evaporation rate of the water molecules is delayed, the water retention is remarkably improved, and the shrinkage of the high-performance concrete is reduced. However, the polyhydroxy structure compound has a retarding effect and can affect the setting time of concrete, so that the use of the polycarboxylate water reducer is limited, and the stability of the polycarboxylate water reducer in an aqueous solution can be affected by a micro-crosslinking structure formed by hydrogen bonds between hydroxyl and water molecules.
Disclosure of Invention
Aiming at the problems in the prior art, the invention aims to obtain the shrinkage-reducing polycarboxylate water reducer by introducing a novel hydrophobic side chain into a comb-shaped structure of the polycarboxylate water reducer and utilizing the propoxy in the side chain structure and the hydrophobic capacity of the alkyl phenyl of the terminal group and derivative groups thereof, and the water reducer does not influence the coagulation setting time and has better stability in an aqueous solution.
In order to achieve the purpose, the invention adopts the technical scheme that:
the shrinkage-reducing polycarboxylate superplasticizer is prepared by polymerizing maleic anhydride acylated polyether amine, unsaturated polyoxyethylene ether macromonomer and ethylenic bond unsaturated carboxylic acid free radical; wherein the maleic anhydride acylated polyether amine is prepared by reacting polyether amine prepared by ammoniating hydroxyl-terminated polyoxyethylene polyoxypropylene ether with maleic anhydride, and the structural formula of the hydroxyl-terminated polyoxyethylene polyoxypropylene ether is as follows:
wherein m is any integer of 10-20, n is any integer of 2-5, and R is selected from alkylbenzene and derivative groups thereof with total carbon atoms of 8-20.
The preparation raw materials comprise maleic anhydride acylated polyether amine generated by the reaction of polyether amine and maleic anhydride, and the polyether amine is generated by ammoniation of hydroxyl-terminated polyoxyethylene polyoxypropylene ether, so that compared with a traditional polycarboxylic acid water reducing agent, the polycarboxylic acid water reducing agent finally prepared by the invention contains a maleic anhydride acylated polyether amine side chain in the structure. As is apparent from the structural formula of the hydroxyl-terminated polyoxyethylene polyoxypropylene ether, the side chain has a structure containing an oxypropylene group, and the terminal group is an alkylphenyl group and a derivative thereof, wherein the alkylphenyl group and the derivative thereof are linked to the hydroxyl-terminated polyoxyethylene polyoxypropylene ether through an alkyl group or a phenyl group, and the derivative of the alkylphenyl group is a compound obtained by substituting an alkyl group or a hydrogen atom on the phenyl group with a halogen atom, a hydroxyl group, an oxygen atom or the like. Because the propoxy groups, the alkyl phenyl groups and the derivative groups thereof have hydrophobic property, the surface tension of a concrete pore solution can be reduced, so that the shrinkage reducing property of the polycarboxylic acid water reducing agent is enhanced, and the shrinkage reducing polycarboxylic acid water reducing agent is obtained. The water reducing agent can effectively avoid the shrinkage of concrete, also reduces the air entrainment of the concrete, and avoids the influence of air bubbles mixed in the concrete on the strength of the concrete. Meanwhile, the hydrophobic property of the side chain does not influence the setting time of concrete and the stability of the water reducing agent in the water solution.
Preferably, the R group is any one of phenethylphenol, nonyl phenol, isomeric propyl benzene, octyl phenol, dodecyl benzene and tridecyl benzene. The alkyl phenyl and the derivative group thereof have stronger hydrophobicity, and the hydrophobic property of the polycarboxylic acid water reducing agent can be effectively enhanced by introducing the alkyl phenyl and the derivative group thereof into the structure of the polycarboxylic acid water reducing agent, so that the shrinkage reducing property of the polycarboxylic acid water reducing agent is enhanced.
Preferably, the unsaturated polyoxyethylene ether macromonomer is one or two of methyl allyl polyoxyethylene ether or prenol polyoxyethylene ether;
preferably, the ethylenically unsaturated carboxylic acid is one or more of acrylic acid, methacrylic acid, sodium allylsulfonate, or 2-acrylamido-2-methacrylic acid.
A preparation method of a shrinkage-reducing polycarboxylate superplasticizer comprises the following steps:
s1, adding the hydroxyl-terminated polyoxyethylene polyoxypropylene ether and liquid ammonia into a closed container filled with a catalyst, and carrying out an ammoniation reaction at 200-250 ℃ under the pressure of 1-20 Mpa to obtain the polyether amine, wherein the reaction formula is as follows:
s2, performing amidation reaction on the polyether amine and the maleic anhydride at the temperature of 60-80 ℃ to obtain maleic anhydride acylated polyether amine, wherein the reaction formula is as follows:
s3, stirring the maleic anhydride acylated polyether amine, the unsaturated polyoxyethylene ether macromonomer and water at 15-50 ℃ until the maleic anhydride acylated polyether amine, the unsaturated polyoxyethylene ether macromonomer and the water are completely dissolved, then sequentially dropwise adding an oxidant, the ethylenically unsaturated carboxylic acid, a reducing agent and a molecular weight regulator, and preserving heat for 1h after dropwise adding;
s4, adding a NaOH solution into the mixed solution obtained in the step S3 to adjust the pH value to 5-7, and then adding water to adjust the solid content of the mixed solution to 40% to obtain the shrinkage-reducing polycarboxylic acid water reducer.
Preferably, the mass ratio of the unsaturated polyoxyethylene ether macromonomer, the maleic anhydride acylated polyether amine, the ethylenically unsaturated carboxylic acid, the oxidant, the reducing agent and the molecular weight regulator is 100: 3-5: 8-12: 0.3-1: 0.1-0.5: 0.3 to 0.7.
Preferably, in step S1, the catalyst is a nickel and magnesium oxide composite catalyst, and the mass ratio of nickel to magnesium oxide is 1-5: 1; the mass ratio of the hydroxyl-terminated polyoxyethylene polyoxypropylene ether to the liquid ammonia is 1: 0.02-0.08.
Preferably, the mass ratio of the polycarboxylic acid to the maleic anhydride in step S2 is 1: 0.02-0.08.
Preferably, in step S3, the oxidizing agent is one or more of hydrogen peroxide, ammonium persulfate, or benzoyl peroxide;
preferably, the reducing agent is one or more of ascorbic acid, ferrous sulfate, ferrous pyrophosphate or sodium formaldehyde sulfoxylate;
preferably, the molecular weight regulator is one or more of thioglycolic acid, mercaptopropionic acid, mercaptoethanol, and sodium methallylsulfonate.
Compared with the prior art, the invention has the beneficial effects that:
(1) the maleic anhydride acylated polyether amine branched chain is grafted on the main chain of the polycarboxylic acid molecule through free radical polymerization, in the molecular structure of the maleic anhydride acylated polyether amine, a propoxy group with hydrophobicity, an alkyl phenyl group at the tail end and a derivative group of the alkyl phenyl group can reduce the surface tension of a concrete pore solution, so that the shrinkage reduction is enhanced, the cracking of the concrete caused by shrinkage is avoided, the air introducing property is also reduced, the influence of excessive air bubbles in the concrete on the strength of the concrete is avoided, and the strength of the concrete is enhanced.
(2) The carboxylic acid in the structures of the maleic anhydride acylated polyether amine and the ethylenic bond unsaturated carboxylic acid can be used as an anchoring group to be adsorbed on the surface of cement particles to provide a fulcrum for the dispersion action of the polycarboxylic acid, and meanwhile, the polyoxyethylene polyoxypropylene long chain in the maleic anhydride acylated polyether amine can improve the adsorption conformation of the polycarboxylic acid in a cement pore solution, so that the side chain of the maleic anhydride acylated polyether amine is more stretched in the solution, thereby further improving the dispersing capacity of the polycarboxylic acid water reducing agent on cement, reducing the water consumption in concrete mixing and neutralizing and increasing the fluidity of concrete mixtures.
(3) The preparation method of the shrinkage-reducing polycarboxylate superplasticizer is simple, and the polycarboxylate superplasticizer cannot influence the setting time of concrete and the stability of the water reducer in an aqueous solution.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The embodiment provides a shrinkage-reducing polycarboxylate superplasticizer and a preparation method thereof, and the preparation method specifically comprises the following steps:
s1, filling nickel and magnesium oxide as a catalyst in a mass ratio of 2:1 in a closed container, adding a hydroxyl-terminated polyoxyethylene polyoxypropylene ether (where m is 10, n is 4) in which R is phenethylphenol and liquid nitrogen to the closed container, and the mass ratio of the hydroxyl-terminated polyoxyethylene polyoxypropylene ether to the liquid nitrogen is 1: 0.04, controlling the reaction temperature to be 200-250 ℃, controlling the reaction pressure to be 1-20 Mpa, and carrying out ammoniation reaction for 2 h; and (3) after gas-liquid separation of the reaction product, dehydrating and deaminating the liquid material, continuously putting the liquid material into a closed container for ammoniation to ensure that the hydroxyl-terminated polyoxyethylene polyoxypropylene ether is completely ammoniated, cooling the reaction product, then performing gas-liquid separation, and dehydrating and deaminating to obtain the polyether amine PEA1.
S2, stirring maleic anhydride at 60-80 ℃ until the maleic anhydride is completely melted, and adding the polyether amine PEA1 obtained in the step S1 for 1-3 h in five times, wherein the mass ratio of the polyether amine to the maleic anhydride is 1: 0.06, and cooling to normal temperature after the reaction is finished to obtain the maleic anhydride acylated polyether amine MAPEA1.
S3, stirring methyl allyl polyoxyethylene ether HPEG, maleic acid acylated polyether amine MAPEA1 and a proper amount of water at the temperature of 20 ℃ until the methyl allyl polyoxyethylene ether HPEG, the maleic acid acylated polyether amine MAPEA1 and the proper amount of water are completely dissolved, then adding an oxidant solution of hydrogen peroxide, and then simultaneously dropwise adding an ethylenically unsaturated carboxylic acid solution of acrylic acid, an ascorbic acid reducing agent solution and a molecular weight regulator solution of thioglycolic acid, wherein the dropwise adding time of the three solutions is 2.5 hours, 3 hours and 3 hours respectively, and after dropwise adding, keeping the temperature for 1 hour; wherein the mass ratio of the methyl allyl polyoxyethylene ether, the maleic acid acylated polyether amine, the acrylic acid ethylenic unsaturated carboxylic acid, the hydrogen peroxide oxidant, the ascorbic acid reducing agent and the thioglycolic acid molecular weight regulator is 100: 3: 8: 0.5: 0.3: 0.5.
s4, adding a NaOH solution into the mixed solution obtained in the step S3 to adjust the pH value to 5-7, and then adding water to adjust the solid content of the mixed solution to 40% to obtain the shrinkage-reducing polycarboxylic acid water reducer.
Example 2
The present embodiment is different from embodiment 1 in that: wherein the mass ratio of the methyl allyl polyoxyethylene ether, the maleic acid acylated polyether amine, the acrylic acid ethylenic unsaturated carboxylic acid, the hydrogen peroxide oxidant, the ascorbic acid reducing agent and the thioglycolic acid molecular weight regulator is 100: 3: 10: 0.5: 0.3: 0.5.
example 3
Wherein the mass ratio of the methyl allyl polyoxyethylene ether, the maleic acid acylated polyether amine, the acrylic acid ethylenic unsaturated carboxylic acid, the hydrogen peroxide oxidant, the ascorbic acid reducing agent and the thioglycolic acid molecular weight regulator is 100: 3: 12: 0.5: 0.3: 0.5.
example 4
The present embodiment is different from embodiment 1 in that: (1) in step S1, the group R is hydroxy-terminated polyoxyethylene polyoxypropylene ether of dodecylbenzene (where m is 20 and n is 5) and liquid ammonia in a mass ratio of 1:0.08, and ammoniation reaction is performed; (2) in the step S2, the mass ratio of the polyether amine to the maleic anhydride is 1: 0.08; (3) in step S3, the oxidant is ammonium persulfate, the reducing agent is ferrous sulfate, the molecular weight regulator is mercaptopropionic acid, and the mass ratio of the methallyl polyoxyethylene ether, the maleic acid acylated polyether amine, the ethylenically unsaturated carboxylic acid of acrylic acid, the ammonium persulfate oxidant, the ferrous sulfate reducing agent, and the molecular weight regulator of mercaptopropionic acid is 100: 4: 9: 0.5: 0.3: 0.5.
example 5
The present embodiment is different from embodiment 1 in that: (1) in step S1, the hydroxyl-terminated polyoxyethylene polyoxypropylene ether (where m is 13 and n is 2) in which the R group is nonylphenol is aminated with liquid ammonia in a mass ratio of 1: 0.02; (2) in the step S2, the mass ratio of the polyether amine to the maleic anhydride is 1: 0.04; (3) in the step S3, the unsaturated polyoxyethylene ether macromonomer is prenyl polyoxyethylene ether TPEG, the ethylenically unsaturated carboxylic acid is methacrylic acid, and the mass ratio of the prenyl polyoxyethylene ether TPEG, the maleic acid acylated polyether amine, the ethylenically unsaturated carboxylic acid of methacrylic acid, the oxidant of hydrogen peroxide, the ascorbic acid reducing agent and the molecular weight regulator of thioglycolic acid is 100: 5: 12: 0.5: 0.3: 0.5.
comparative example 1
This comparative example differs from example 1 in that: step S1 is omitted, and the commercial polyether amine PN-220 is directly reacted with maleic anhydride to obtain maleic anhydride acylated polyether amine. Wherein the commercially available polyetheramine PN-220 differs from the polyetheramines obtained herein in that the R group is different and the R group of the polyetheramine PN-220 is a methyl group.
Comparative example 2
This comparative example differs from example 1 in that: the preparation method of the traditional polycarboxylic acid water reducing agent is adopted, namely step S1 and step S2 are omitted, methyl allyl polyoxyethylene ether HPEG is directly dissolved in water, then oxidant solution of hydrogen peroxide is added, then acrylic acid ethylenic unsaturated carboxylic acid solution, ascorbic acid reducing agent solution and mercaptoacetic acid molecular weight regulator solution are simultaneously dripped, and the mass ratio of the prenyl polyoxyethylene ether TPEG, methacrylic acid ethylenic unsaturated carboxylic acid, the hydrogen peroxide oxidant, the ascorbic acid reducing agent and the mercaptoacetic acid molecular weight regulator is 100: 8: 0.5: 0.3: 0.3. application example
The polycarboxylic acid water reducing agents obtained in examples 1 to 5 and comparative examples 1 to 2 were added to concrete in an amount of 0.2%, and the concrete was tested for properties such as 28d shrinkage, slump, expansion, air content and 28d compressive strength according to GB-8076 "concrete Admixture", and the results are shown in the following table:
the 28d shrinkage ratio refers to the volume ratio of the concrete doped with the water reducing agent to the concrete not doped with the water reducing agent in the 28d, so that the higher the data is, the better the shrinkage reduction effect of the water reducing agent is; the air content is the content of air bubbles in the concrete, and the higher the air content in the concrete is, the compressive strength of the concrete can be correspondingly reduced.
From the above measurement results, when the maleic anhydride acylated polyether amine disclosed in the present application is added to the raw materials for preparing the polycarboxylic acid water reducer, the maleic anhydride acylated polyether amine has hydrophobic propoxy groups, alkyl phenyl groups and derivative groups thereof, so that the surface tension of a concrete pore solution can be reduced, the shrinkage reducing property of concrete is remarkably enhanced, the gas content in the concrete is reduced, and the compressive strength of the concrete is enhanced. From the results of the measurements of examples 1 to 3, it is found that the compatibility of the polycarboxylic acid water reducing agent with concrete can be increased by appropriately increasing the content of the ethylenically unsaturated carboxylic acid, thereby enhancing the dispersing ability of the water reducing agent to cement and improving the compressive strength of the cement, however, the hydrophilicity of the polycarboxylic acid water reducing agent is increased when the ethylenically unsaturated carboxylic acid is further increased, further reducing the shrinkage reducing performance of the water reducing agent, but at the moment, the hydrophobicity of the water reducing agent can be enhanced by properly increasing the content of the maleic anhydride acylated polyether amine (examples 4-5) so as to compensate the negative influence of the increase of the content of the ethylenically unsaturated carboxylic acid on the shrinkage reducing performance, that is, the contents of the maleic anhydride-acylated polyetheramine, the unsaturated polyoxyethylene ether macromonomer and the ethylenically unsaturated carboxylic acid are maintained within the ranges as described in examples 4 to 5, the shrinkage reducing property of the water-reducing agent can be enhanced while the dispersing property of the water-reducing agent is enhanced. Compared with the existing water reducing agent, the polycarboxylic acid water reducing agent prepared by the invention has little influence on the slump and the expansion degree of concrete.
When the R group of the maleic anhydride acylated polyether amine is changed to be methyl (comparative example 1), the hydrophobic property of the methyl is lower than that of alkyl phenyl and derivative groups thereof, so that the reduction effect of the water reducer obtained in the comparative example 1 is obviously lower than that of the polycarboxylic acid water reducer prepared in the application, and the air-entraining property of the water reducer in the comparative example 1 is higher, so that the air content and compressive strength of concrete are obviously reduced. The polycarboxylate superplasticizer prepared by the invention has excellent shrinkage reducing performance and reduced air entraining property, can effectively avoid concrete shrinkage cracking by adding the polycarboxylate superplasticizer into concrete, and simultaneously enhances the compressive strength of the concrete.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (10)
1. The shrinkage-reducing polycarboxylate water reducer is characterized by being prepared by polymerizing maleic anhydride acylated polyether amine, unsaturated polyoxyethylene ether macromonomer and ethylenic unsaturated carboxylic acid free radical;
wherein the maleic anhydride acylated polyether amine is prepared by reacting polyether amine prepared by ammoniating hydroxyl-terminated polyoxyethylene polyoxypropylene ether with maleic anhydride, and the structural formula of the hydroxyl-terminated polyoxyethylene polyoxypropylene ether is as follows:
wherein m is any integer of 10-20, n is any integer of 2-5, and R is selected from alkylbenzene and derivative groups thereof with total carbon atoms of 8-20.
2. The water reducing agent according to claim 1, wherein R is any one of phenethylphenol, nonylphenol, iso-propylbenzene, octylphenol, dodecylbenzene and tridecylbenzene.
3. The reduction type polycarboxylate superplasticizer according to claim 1, wherein the unsaturated polyoxyethylene ether macromonomer is one or two of methyl allyl polyoxyethylene ether or prenyl polyoxyethylene ether;
the ethylenically unsaturated carboxylic acid is one or more of acrylic acid, methacrylic acid, sodium allylsulfonate or 2-acrylamido-2-methacrylic acid.
4. The preparation method of the reduction type polycarboxylate superplasticizer of claim 1 is characterized by comprising the following steps:
s1, adding the hydroxyl-terminated polyoxyethylene polyoxypropylene ether and liquid ammonia in the presence of a catalyst, and carrying out an ammoniation reaction at 200-250 ℃ under the pressure of 1-20 Mpa to obtain the polyether amine;
s2, carrying out amidation reaction on the polyether amine and the maleic anhydride at the temperature of 60-80 ℃ to obtain maleic anhydride acylated polyether amine;
s3, adding the maleic anhydride acylated polyether amine and the unsaturated polyoxyethylene ether macromonomer into water, stirring at 15-50 ℃ until the maleic anhydride acylated polyether amine and the unsaturated polyoxyethylene ether macromonomer are completely dissolved, then sequentially dropwise adding an oxidant, the ethylenically unsaturated carboxylic acid, a reducing agent and a molecular weight regulator, and preserving heat for 1h after dropwise adding;
s4, adjusting the pH value of the mixed solution obtained in the step S3 to 5-7, and then adjusting the solid content of the mixed solution to 40% to obtain the shrinkage-reducing polycarboxylic acid water reducer.
5. The preparation method of the reduction type polycarboxylate superplasticizer according to claim 4, wherein the mass ratio of the unsaturated polyoxyethylene ether macromonomer, the maleic anhydride acylated polyether amine, the ethylenically unsaturated carboxylic acid, the oxidant, the reducing agent and the molecular weight regulator is 100: 3-5: 8-12: 0.3-1: 0.1-0.5: 0.3 to 0.7.
6. The preparation method of the reduction type polycarboxylate superplasticizer according to claim 4, wherein in step S1, the catalyst is a nickel and magnesium oxide composite catalyst, and the mass ratio of nickel to magnesium oxide is 1-5: 1; the mass ratio of the hydroxyl-terminated polyoxyethylene polyoxypropylene ether to the liquid ammonia is 1: 0.02-0.08.
7. The preparation method of the reduction type polycarboxylate superplasticizer according to claim 4, wherein the mass ratio of the polycarboxylic acid to the maleic anhydride in step S2 is 1: 0.02-0.08.
8. The method for preparing a shrinkage-reducing polycarboxylic acid water reducing agent according to claim 4, characterized in that in step S3, the oxidizing agent is one or more of hydrogen peroxide, ammonium persulfate or benzoyl peroxide.
9. The preparation method of the reduction type polycarboxylate water reducer according to claim 4, wherein in step S3, the reducing agent is one or more of ascorbic acid, ferrous sulfate, ferrous pyrophosphate and sodium formaldehyde sulfoxylate.
10. The method for preparing a reduction type polycarboxylate water reducer according to claim 4, wherein in step S3, the molecular weight regulator is one or more of thioglycolic acid, mercaptopropionic acid, mercaptoethanol and sodium methallyl sulfonate.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102532558A (en) * | 2011-12-29 | 2012-07-04 | 上海三瑞高分子材料有限公司 | Preparation method of amido polycarboxylic water-reducing agent |
| CN104031216A (en) * | 2014-05-26 | 2014-09-10 | 中科院广州化学有限公司 | Polyether-amide type polycarboxylic high-efficiency water reducer and preparation method thereof |
| US20170113969A1 (en) * | 2015-10-22 | 2017-04-27 | United States Gypsum Company | Freeze-thaw durable geopolymer compositions and methods for making same |
| CN107286298A (en) * | 2017-07-07 | 2017-10-24 | 江苏中铁奥莱特新材料股份有限公司 | A kind of sustained-release polycarboxylic water reducer and preparation method thereof |
| CN108192040A (en) * | 2017-12-28 | 2018-06-22 | 科之杰新材料集团有限公司 | A kind of preparation method of low entraining type solid polycarboxylic acid water reducing agent |
-
2020
- 2020-04-27 CN CN202010344368.5A patent/CN113354782B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102532558A (en) * | 2011-12-29 | 2012-07-04 | 上海三瑞高分子材料有限公司 | Preparation method of amido polycarboxylic water-reducing agent |
| CN104031216A (en) * | 2014-05-26 | 2014-09-10 | 中科院广州化学有限公司 | Polyether-amide type polycarboxylic high-efficiency water reducer and preparation method thereof |
| US20170113969A1 (en) * | 2015-10-22 | 2017-04-27 | United States Gypsum Company | Freeze-thaw durable geopolymer compositions and methods for making same |
| CN107286298A (en) * | 2017-07-07 | 2017-10-24 | 江苏中铁奥莱特新材料股份有限公司 | A kind of sustained-release polycarboxylic water reducer and preparation method thereof |
| CN108192040A (en) * | 2017-12-28 | 2018-06-22 | 科之杰新材料集团有限公司 | A kind of preparation method of low entraining type solid polycarboxylic acid water reducing agent |
Non-Patent Citations (1)
| Title |
|---|
| 杨晓晨等: "马来酸酐制备酰趣型聚羧酸減水剂及其性能研究", 《新型建筑材料》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113816649A (en) * | 2021-09-24 | 2021-12-21 | 贵州石博士科技股份有限公司 | Shrinkage-reducing polycarboxylate superplasticizer and preparation method and application thereof |
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