CN114409857A - Graphene oxide monomer, high-workability polycarboxylate superplasticizer and preparation method thereof - Google Patents
Graphene oxide monomer, high-workability polycarboxylate superplasticizer and preparation method thereof Download PDFInfo
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- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
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- 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
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Abstract
The invention relates to the field of concrete admixtures, and provides a graphene oxide monomer, a high workability polycarboxylic acid water reducing agent and a preparation method thereof. The graphene oxide monomer is polymerized from glycolic acid, graphene oxide and vinyl trimethoxy silane, wherein the ratio of glycolic acid: and (3) graphene oxide: the mass ratio of the vinyl trimethoxy silane is 15-25: 3-5: 36-61. The polycarboxylic acid water reducing agent is generated by the reaction of reactants including a polyether monomer, a functional monomer, unsaturated acid and a graphene oxide monomer, wherein the polyether monomer: functional monomer: unsaturated acid: the mass ratio of the graphene oxide monomer is 150-200: 1-5: 10-30: 1-5. The polycarboxylate superplasticizer prepared by the invention adopts the copolymerization function monomer mode to introduce the ester group, so that the carboxyl content can not be reduced due to esterification, and the polycarboxylate superplasticizer has the advantages of simple preparation process, excellent water reducing and defoaming effects, low biotoxicity and good environmental protection.
Description
Technical Field
The invention relates to the field of concrete admixtures, in particular to a graphene oxide monomer, a high workability polycarboxylic acid water reducing agent and a preparation method thereof.
Background
The polycarboxylate superplasticizer has the advantages of low mixing amount, high water reducing rate, good compatibility with various building materials such as cement and the like, environmental friendliness and the like, receives more attention of experts and scholars, and has more applications in the building industries such as municipal administration, bridges, roads and the like. However, with the continuous development of the engineering and building industry, higher and higher requirements are provided for the quality and the technology of concrete, and further new requirements are provided for the quality of the polycarboxylic acid water reducing agent. However, the polycarboxylate superplasticizer has problems in the application process, such as sensitivity to the mud content of sand, need to improve the compatibility with building materials such as cement, poor workability of concrete bleeding, bottom raking and the like, and the like.
Chinese patent with publication number CN109369860A published in 2, month and 22 of 2019 discloses a sustained-release controllable polycarboxylate superplasticizer mother liquor and a preparation method thereof, wherein a macromonomer TPEG, a monoester small monomer, a diester small monomer and a functional monomer are used as polymerization monomers, and the pH value of a polycarboxylate superplasticizer polymer is adjusted to be strong alkaline for partial hydrolysis, so that the sustained release controllability of the polycarboxylate superplasticizer mother liquor is realized. However, the adopted diester small monomers contain fewer functional groups with easy effect, and the adopted monoester small monomers have insufficient active density, so that the mother liquor of the polycarboxylic acid water reducing agent has limited workability.
Disclosure of Invention
In order to solve the problem of poor workability of a polycarboxylate water reducer in the prior art, the invention provides a graphene oxide monomer, wherein the graphene oxide monomer is prepared by polymerizing glycolic acid, graphene oxide and vinyl trimethoxy silane, and the ratio of glycolic acid: the graphene oxide: the mass ratio of the vinyl trimethoxy silane is 15-25: 3-5: 36-61, wherein the graphene oxide monomer contains double bonds.
In one embodiment, the glycolic acid is 15-25 parts, the graphene oxide is 3-5 parts, and the vinyltrimethoxysilane is 36-61 parts.
In one embodiment, the ratio of glycolic acid: and (3) graphene oxide: the mass ratio of the vinyl trimethoxy silane is 15-25: 3-5: 36.4-60.6.
In one embodiment, the glycolic acid is 15-25 parts, the graphene oxide is 3-5 parts, and the vinyltrimethoxysilane is 36.4-60.6 parts.
The invention also provides a preparation method of the graphene oxide monomer in any one of the technical schemes, which comprises the following specific steps: mixing 15-25 parts of glycolic acid, 3-5 parts of graphene oxide, 400-500 parts of toluene and 0.2-0.3 part of phosphomolybdic acid, placing the mixture in a first container, heating, condensing, refluxing, distilling under reduced pressure to remove toluene, cooling to room temperature, washing and filtering with a saturated sodium bicarbonate aqueous solution and a saturated sodium chloride aqueous solution, and drying at 50-60 ℃ to obtain a first product; mixing 400 parts of deionized water and 400 parts of absolute ethyl alcohol, adjusting the pH value of the solution to 4-5, then adding 0.4 part of vinyl trimethoxy silane, carrying out prehydrolysis in a water bath at 30-40 ℃ for 30-60 min, adding 0.2 part of the first product, heating to 70-80 ℃, stirring for 3-5 h, cooling to room temperature after the reaction is finished, filtering, washing and drying at 50-60 ℃ to obtain the graphene oxide monomer.
In one embodiment of the method of preparation, glacial acetic acid is used to adjust the pH of the solution.
In one embodiment of the preparation method, the mixture is filtered and washed with 50% by weight of ethanol aqueous solution.
In one embodiment of the preparation method, the heating and condensing reflux temperature is 100 ℃ and the time is 4 hours.
In one embodiment of the preparation method, the number of washing times is 3-5.
In one embodiment of the method of preparation, the room temperature is between 25 ℃ and 28 ℃.
In a preferred embodiment of the preparation process, the room temperature is 25 ℃.
The invention also provides a high workability polycarboxylate water reducer, which is prepared by polymerizing a polyether monomer, a functional monomer, unsaturated acid and the free radical of the graphene oxide monomer in any one technical scheme, wherein the polyether monomer: the functional monomer: the unsaturated acid: the mass ratio of the graphene oxide monomer is 150-200: 1-5: 10-30: 1-5;
the structural formula of the functional monomer is as follows:
wherein R is1is-H or-CH3M is 8-12, n is 10-20, and m and n are positive integers.
In one embodiment, the polyether monomer is one of methallyl polyoxyethylene ether (HPEG), prenol polyoxyethylene ether (TPEG), or ethylene glycol monovinyl polyethylene glycol ether (EPEG).
In a preferred embodiment, the molecular weight of the polyether monomer is 1200 to 5000.
In one embodiment, the unsaturated acid is methacrylic acid or acrylic acid.
In one embodiment, the polyether monomer is 150 to 200 parts, the functional monomer is 1 to 5 parts, the unsaturated acid is 10 to 30 parts, and the graphene oxide monomer is 1 to 5 parts.
In one embodiment, the composition further comprises 1-5 parts of an initiator, 1-5 parts of a reducing agent, 0.5-1 part of a chain transfer agent, and 300-350 parts of deionized water.
The invention also provides a preparation method of the high workability polycarboxylate superplasticizer according to any one of the technical schemes, which comprises the following specific steps: dissolving a reducing agent in deionized water to obtain a solution A; dissolving the unsaturated acid and the graphene oxide monomer in deionized water to obtain BA solution; dissolving a chain transfer agent in deionized water to obtain a solution C; mixing the polyether monomer, the functional monomer, the initiator and deionized water at room temperature, uniformly stirring, and then simultaneously dropwise adding A, B and C solution for t1And keeping the temperature t after the dropwise addition2And finally, adjusting the pH value of the reaction product to n to obtain the high workability polycarboxylic acid water reducing agent.
In one embodiment of the method of preparation, the room temperature is between 25 ℃ and 28 ℃.
In a preferred embodiment of the preparation process, the room temperature is 25 ℃.
In an embodiment of the preparation process, t1Is 2 to 4 hours, t21 to 2 hours, and n is 4.0 to 6.0.
In a preferred embodiment of the preparation method, the polyether monomer is 150 to 200 parts, the functional monomer is 1 to 5 parts, the unsaturated acid is 10 to 30 parts, the graphene oxide monomer is 1 to 5 parts, the initiator is 1 to 5 parts, the reducing agent is 1 to 5 parts, the chain transfer agent is 0.5 to 1 part, and the deionized water is 300 to 350 parts.
In a more preferred embodiment of the preparation method, 30 to 50 parts of deionized water for dissolving the reducing agent, 10 to 20 parts of deionized water for dissolving the unsaturated acid and the graphene oxide monomer, 30 to 50 parts of deionized water for dissolving the chain transfer agent, and the rest of deionized water is mixed with the polyether monomer, the graphene oxide monomer and the initiator.
In one embodiment of the preparation method, the reducing agent is one of L-ascorbic acid, sodium hypophosphite, and sodium formaldehyde sulfoxylate.
In an embodiment of the method of preparation, the initiator is one of hydrogen peroxide, sodium persulfate, or ammonium persulfate.
In an embodiment of the preparation method, the chain transfer agent is one of thioglycolic acid, mercaptopropionic acid, or mercaptoethanol.
In one embodiment of the preparation process, the reaction product pH is adjusted using a liquid base.
In an embodiment of the preparation method, the liquid caustic soda is 30-32% by mass.
Based on the above, compared with the prior art, the functional monomer used in the invention contains the ethoxy group and the isobutoxy group which have defoaming effect and water reducing effect in the structure, so that the synthesized polycarboxylate superplasticizer has better defoaming property and water reducing property, and better workability, and is a product obtained by activating hydroxyl groups at two ends of polyalcohol by ester groups, so that the polycarboxylate superplasticizer has higher reaction activity, can provide more active sites in the synthesis process of the polycarboxylate superplasticizer, and has better dispersing property and working property. The surface tension of the contained isobutoxy group is small, the rigidity of a liquid film can be increased, the stability of bubbles is reduced, more alkoxy structural units of the polycarboxylic acid water reducing agent participating in synthesis are provided, the gas content is obviously reduced, and the defoaming effect is achieved.
The graphene oxide monomer used in the invention contains a large amount of hydroxyl and carboxyl in the structure, so that the graphene oxide monomer can provide higher charge density when participating in oxidation reaction and carboxylation reaction, and the synthesized polycarboxylic acid water reducing agent has higher steric hindrance effect and stronger dispersing ability. In the invention, the environment for synthesizing the polycarboxylate superplasticizer is an acidic environment, more carboxyl groups are hydrolyzed by the graphene oxide monomer in comparison with the reaction in an alkaline environment, and the workability of the polycarboxylate superplasticizer is improved through an anchoring effect.
The polycarboxylate superplasticizer prepared by the invention adopts the copolymerization function monomer mode to introduce the ester group, so that the carboxyl content can not be reduced due to esterification, and the polycarboxylate superplasticizer has the advantages of simple preparation process, excellent water reducing and defoaming effects, low biotoxicity and good environmental protection.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments; the technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other; 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.
In the description of the present invention, it is to be noted that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs, and are not to be construed as limiting the present invention; it will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The invention provides the following examples and comparative examples:
example 1
Weighing the following raw material components in parts: HPEG-2400150 parts, 1 part of functional monomer, 15 parts of acrylic acid, 1 part of graphene oxide monomer, 2 parts of hydrogen peroxide, 1 part of L-ascorbic acid, 0.6 part of thioglycolic acid, 300 parts of water and 20 parts of 30-32% liquid alkali.
The functional monomer R1Is H, m is 9 and n is 10.
Dissolving L-ascorbic acid in 35 parts of deionized water to obtain a solution A; dissolving acrylic acid and graphene oxide monomers in 10 parts of deionized water to obtain a solution B; dissolving thioglycolic acid in 30 parts of deionized water to obtain a solution C; mixing HPEG-2400, a functional monomer, hydrogen peroxide and the rest water, stirring uniformly, simultaneously dripping A, B and the solution C for 2.5 hours, and preserving heat for 1 hour after dripping. And after the reaction is finished, adjusting the pH value of the reaction product to 4.0-6.0 by using liquid alkali with the mass concentration of 30-32% to obtain the polycarboxylic acid water reducing agent.
The graphene oxide monomer is prepared by the following method: mixing 15 parts of glycolic acid, 5 parts of graphene oxide, 400 parts of toluene and 0.3 part of phosphomolybdic acid, placing the mixture in a first container, heating, condensing and refluxing for 4 hours at 100 ℃, distilling under reduced pressure to remove the toluene, cooling, washing and filtering by using a saturated sodium bicarbonate aqueous solution and a saturated sodium chloride aqueous solution, and drying at 50 ℃ to obtain a first product; mixing 400 parts of deionized water and 400 parts of absolute ethyl alcohol, adjusting the pH value of the solution to 4-5 by using glacial acetic acid, then adding 0.4 part of vinyl trimethoxy silane, carrying out prehydrolysis in a water bath at 30 ℃ for 30min, adding 0.2 part of the first product, heating to 70 ℃, stirring for 5h, cooling to room temperature after the reaction is finished, filtering, washing for 3 times by using a 50% ethanol aqueous solution, and drying at 60 ℃ to obtain the graphene oxide monomer.
Example 2
Weighing the following raw material components in parts: TPEG-2400200 parts, 3 parts of functional monomer, 20 parts of methacrylic acid, 5 parts of graphene oxide monomer, 3 parts of sodium persulfate, 2 parts of sodium hypophosphite, 0.8 part of mercaptopropionic acid, 320 parts of water and 25 parts of 30-32% mass concentration liquid alkali.
Said functional monomer R1Is CH3M is 9 and n is 12.
Dissolving sodium hypophosphite into 40 parts of deionized water to obtain a solution A; dissolving methacrylic acid and graphene oxide monomers in 15 parts of deionized water to obtain a solution B; dissolving mercaptopropionic acid in 40 parts of deionized water to obtain a solution C; mixing TPEG-2400, a functional monomer, sodium persulfate and the rest water, uniformly stirring, simultaneously dropwise adding A, B and the solution C for 3 hours, and preserving heat for 1.5 hours after dropwise adding. And after the reaction is finished, adjusting the pH value of the reaction product to 4.0-6.0 by using liquid alkali with the mass concentration of 30-32% to obtain the polycarboxylic acid water reducing agent.
The double-bond-containing modified graphene oxide is prepared by the following method: mixing 25 parts of glycolic acid, 3 parts of graphene oxide, 500 parts of toluene and 0.2 part of phosphomolybdic acid, placing the mixture in a first container, heating, condensing and refluxing for 4 hours at 100 ℃, distilling under reduced pressure to remove the toluene, cooling, washing and filtering by using a saturated sodium bicarbonate aqueous solution and a saturated sodium chloride aqueous solution, and drying at 60 ℃ to obtain a first product; mixing 400 parts of deionized water and 400 parts of absolute ethyl alcohol, adjusting the pH value of the solution to 4-5 by using glacial acetic acid, then adding 0.4 part of vinyl trimethoxy silane, carrying out prehydrolysis in a water bath at 40 ℃ for 60min, adding 0.2 part of the first product, heating to 80 ℃, stirring for 3h, cooling to room temperature after the reaction is finished, filtering, washing for 3 times by using a 50% ethanol aqueous solution, and drying at 60 ℃ to obtain the graphene oxide monomer.
Example 3
Weighing the following raw material components in parts: the coating comprises, by mass, 5 parts of EPEG-3600170, 5 parts of a functional monomer, 30 parts of methacrylic acid, 2 parts of a graphene oxide monomer, 2 parts of ammonium persulfate, 3 parts of sodium formaldehyde sulfoxylate, 1 part of mercaptoethanol, 350 parts of water and 15 parts of liquid alkali with the mass concentration of 30-32%.
The functional monomer R1Is CH3M is 12 and n is 18.
Dissolving sodium formaldehyde sulfoxylate in 30 parts of deionized water to obtain a solution A; dissolving methacrylic acid and graphene oxide monomers in 15 parts of deionized water to obtain a solution B; dissolving mercaptoethanol in 50 parts of deionized water to obtain a solution C; mixing the EPEG-3600, the functional monomer, the ammonium persulfate and the rest water, stirring uniformly, simultaneously dripping A, B and the solution C for 3.5h, and preserving heat for 2h after dripping is finished. And after the reaction is finished, adjusting the pH value of the reaction product to 4.0-6.0 by using liquid alkali with the mass concentration of 30-32% to obtain the polycarboxylic acid water reducing agent.
The graphene oxide monomer is prepared by the following method: mixing 20 parts of glycolic acid, 4 parts of graphene oxide, 450 parts of toluene and 0.25 part of phosphomolybdic acid, placing the mixture in a first container, heating, condensing and refluxing for 4 hours at 100 ℃, distilling under reduced pressure to remove the toluene, cooling, washing and filtering by using a saturated sodium bicarbonate aqueous solution and a saturated sodium chloride aqueous solution, and drying at 55 ℃ to obtain a first product; mixing 400 parts of deionized water and 400 parts of absolute ethyl alcohol, adjusting the pH value of the solution to 4-5 by using glacial acetic acid, then adding 0.4 part of vinyl trimethoxy silane, carrying out prehydrolysis in a 35 ℃ water bath for 40min, adding 0.2 part of the first product, heating to 75 ℃, stirring for 4h, cooling to room temperature after the reaction is finished, filtering, washing for 3 times by using a 50% ethanol aqueous solution, and drying at 55 ℃ to obtain the graphene oxide monomer.
Example 4
Weighing the following raw material components in parts: the coating comprises, by mass, 4 parts of EPEG-5000180, 4 parts of functional monomer, 30 parts of acrylic acid, 2 parts of graphene oxide monomer, 5 parts of hydrogen peroxide, 5 parts of sodium formaldehyde sulfoxylate, 1 part of mercaptoethanol, 350 parts of water and 15 parts of 30-32% liquid alkali.
The functional monomer R1Is H, m is 10, n is 20.
Dissolving sodium formaldehyde sulfoxylate in 45 parts of deionized water to obtain a solution A; dissolving methacrylic acid and graphene oxide monomers in 15 parts of deionized water to obtain a solution B; dissolving mercaptoethanol in 30 parts of deionized water to obtain a solution C; mixing the EPEG-5000, the functional monomer, the hydrogen peroxide and the rest water, stirring uniformly, simultaneously dripping A, B and the solution C for 3 hours, and preserving heat for 2 hours after dripping is finished. And after the reaction is finished, adjusting the pH value of the reaction product to 4.0-6.0 by using liquid alkali with the mass concentration of 30-32% to obtain the polycarboxylic acid water reducing agent.
The graphene oxide monomer is prepared by the following method: mixing 20 parts of glycolic acid, 4 parts of graphene oxide, 450 parts of toluene and 0.25 part of phosphomolybdic acid, placing the mixture in a first container, heating, condensing and refluxing for 4 hours at 100 ℃, distilling under reduced pressure to remove the toluene, cooling, washing and filtering by using a saturated sodium bicarbonate aqueous solution and a saturated sodium chloride aqueous solution, and drying at 55 ℃ to obtain a first product; mixing 400 parts of deionized water and 400 parts of absolute ethyl alcohol, adjusting the pH value of the solution to 4-5 by using glacial acetic acid, then adding 0.4 part of vinyl trimethoxy silane, carrying out prehydrolysis in a 35 ℃ water bath for 40min, adding 0.2 part of the first product, heating to 75 ℃, stirring for 4h, cooling to room temperature after the reaction is finished, filtering, washing for 3 times by using a 50% ethanol aqueous solution, and drying at 55 ℃ to obtain the graphene oxide monomer.
Comparative example 1
Comparative example 1 differs from example 1 in that polyethylene glycol diacrylate was used instead of the functional monomer in example 1.
Comparative example 2
Comparative example 2 differs from example 1 in that hydroxyethyl acrylate was used instead of the graphene oxide monomer in example 1.
Comparative example 3
The difference between the comparative example 3 and the example 1 is that 0.5 part of graphene oxide monomer and 300.5 parts of water are adopted.
Comparative example 4
Comparative example 4 is different from example 1 in that 6 parts of graphene oxide monomer and 295 parts of water are used.
Comparative example 5
Comparative example 5 differs from example 1 in that 0.5 parts of functional monomer and 300.5 parts of water are used.
Comparative example 6
Comparative example 6 differs from example 1 in that 6 parts of functional monomer and 295 parts of water are used.
The grade and other technical indexes of the raw materials adopted in the preparation method, the examples and the comparative examples can be selected according to the prior art, and if the technical indexes are specified in the invention, the technical indexes are selected within the range specified in the invention, so that the technical effect of the invention is not influenced.
Measuring the surface tension value of the polycarboxylate superplasticizers synthesized in the examples and the comparative examples by using an automatic interface/surface tension meter; the slump constant, the slump loss over time and the air content of the concrete are measured by adopting standard cement with the mixing amount of 0.20 percent (folded into solid) of the mass of the cement according to GB 8076 plus 2008 concrete admixture. The concrete mixing proportion is as follows: cement 360kg/m3790kg/m of sand3Stone 1060kg/m3The results obtained are shown in Table 1.
TABLE 1
In summary, compared with the comparative example, the performance of the example is better than that of the comparative example, and in the comparative example 1, the surface tension value of the comparative example 1 is larger than that of the example 1; the air content, slump and spread at 0h and 1h are both less than those of example 1, because the polyethylene glycol diacrylate of comparative example 1 does not contain a polyhydroxy structure, the water-reducing property and the defoaming property are reduced; the hydroxyethyl acrylate of comparative example 2, which has less hydroxyl groups and double bonds than the graphene oxide monomer, cannot release as many hydroxyl groups and ester groups as the graphene oxide monomer, and has decreased water-reducing and defoaming properties; in comparative example 3, too little graphene oxide monomer releases insufficient ester groups and hydroxyl groups, and in comparative example 4, too much graphene oxide monomer releases too much ester groups and hydroxyl groups, so that the water reducing performance and the defoaming performance are reduced due to too much cement viscosity. In comparative example 5, too little functional monomer, too little ethoxy group and isobutoxy group for defoaming and water reducing, resulted in a decrease in water reducing performance, defoaming performance and workability, and in comparative example 6, too much functional monomer, also suppressed the release of ethoxy group and isobutoxy group, thus resulted in a decrease in water reducing performance and defoaming performance.
In conclusion, compared with the prior art, the functional monomer used in the invention contains an ethoxy group and an isobutoxy group which have defoaming effect and water reducing effect in the structure, so that the synthesized polycarboxylate superplasticizer has better defoaming property and water reducing property and better workability, and is a product obtained by activating hydroxyl groups at two ends of polyalcohol by ester groups, the reaction activity is higher, more active sites can be provided in the synthesis process of the polycarboxylate superplasticizer, and the synthesized polycarboxylate superplasticizer has better dispersing property and working property. The surface tension of the alkoxy group contained in the polycarboxylic acid water reducer is small, the rigidity of a liquid film can be increased, the stability of bubbles is reduced, the concrete gas content of the synthesized polycarboxylic acid water reducer is obviously reduced, and the defoaming effect is achieved.
The graphene oxide monomer used in the invention contains a large amount of hydroxyl and carboxyl in the structure, so that the graphene oxide monomer can provide higher charge density when participating in oxidation reaction and carboxylation reaction, and the synthesized polycarboxylic acid water reducing agent has higher steric hindrance effect and stronger dispersing ability. In the invention, the environment for synthesizing the polycarboxylate superplasticizer is an acidic environment, more carboxyl groups are hydrolyzed by the graphene oxide monomer in comparison with the reaction in an alkaline environment, and the workability of the polycarboxylate superplasticizer is improved through an anchoring effect.
The polycarboxylate superplasticizer prepared by the invention adopts the copolymerization function monomer mode to introduce the ester group, so that the carboxyl content can not be reduced due to esterification, and the polycarboxylate superplasticizer has the advantages of simple preparation process, excellent water reducing and defoaming effects, low biotoxicity and good environmental protection.
In addition, it will be appreciated by those skilled in the art that, although there may be many problems with the prior art, each embodiment or aspect of the present invention may be improved only in one or several respects, without necessarily simultaneously solving all the technical problems listed in the prior art or in the background. It will be understood by those skilled in the art that nothing in a claim should be taken as a limitation on that claim.
Although terms such as unsaturated acids, polyether monomers, graphene oxide monomers, functional monomers, etc. are used more often herein, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention; the terms "first," "second," and the like in the description and in the claims, if any, of the embodiments of the invention are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A graphene oxide monomer is characterized in that: the graphene oxide film is prepared by polymerizing glycolic acid, graphene oxide and vinyl trimethoxy silane, wherein the ratio of glycolic acid: the graphene oxide: the mass ratio of the vinyl trimethoxy silane is 15-25: 3-5: 36-61.
2. The graphene oxide monomer of claim 1, wherein: 15-25 parts of glycolic acid, 3-5 parts of graphene oxide and 36-61 parts of vinyl trimethoxy silane.
3. A method for preparing the graphene oxide monomer according to claim 1 or 2, wherein: mixing 15-25 parts of glycolic acid, 3-5 parts of graphene oxide, 400-500 parts of toluene and 0.2-0.3 part of phosphomolybdic acid, heating, condensing, refluxing, then distilling under reduced pressure to remove toluene, cooling to room temperature, washing with a saturated sodium bicarbonate aqueous solution and a saturated sodium chloride aqueous solution, filtering, and drying at 50-60 ℃ to obtain a first product; mixing 400 parts of deionized water and 400 parts of absolute ethyl alcohol, adjusting the pH value of the solution to 4-5, then adding 0.4 part of vinyl trimethoxy silane, carrying out prehydrolysis in a water bath at 30-40 ℃ for 30-60 min, adding 0.2 part of the first product, heating to 70-80 ℃, stirring for 3-5 h, cooling to room temperature after the reaction is finished, filtering, washing and drying at 50-60 ℃ to obtain the graphene oxide monomer.
4. A high workability polycarboxylate superplasticizer is characterized in that: is produced by radical polymerization of a monomer comprising a polyether monomer, a functional monomer, an unsaturated acid and the graphene oxide monomer of claim 1 or 2, wherein the polyether monomer: the functional monomer: the unsaturated acid: the mass ratio of the graphene oxide monomer is 150-200: 1-5: 10-30: 1-5;
the structural formula of the functional monomer is as follows:
wherein R is1is-H or-CH3M is 8-12, n is 10-20, and m and n are positive integers.
5. The high workability polycarboxylic acid water reducing agent according to claim 4, characterized in that: the polyether monomer is one of methyl allyl polyoxyethylene ether, isopentenol polyoxyethylene ether or ethylene glycol monovinyl polyglycol ether.
6. The high workability polycarboxylic acid water reducing agent according to claim 5, characterized in that: the molecular weight of the polyether monomer is 1200-5000.
7. The high workability polycarboxylic acid water reducing agent according to claim 4, characterized in that: the unsaturated acid is methacrylic acid or acrylic acid.
8. The high workability polycarboxylic acid water reducing agent according to any of claims 4 to 7, characterized in that: the modified graphene oxide material is characterized by comprising 150-200 parts of polyether monomer, 1-5 parts of functional monomer, 10-30 parts of unsaturated acid and 1-5 parts of graphene oxide monomer.
9. A method for preparing a high workability polycarboxylic acid water reducing agent according to any one of claims 4 to 8, characterized in that: dissolving a reducing agent in deionized water to obtain a solution A; dissolving unsaturated acid and the graphene oxide monomer in deionized water to obtain a solution B; dissolving a chain transfer agent in deionized water to obtain a solution C; mixing the polyether monomer, the functional monomer, the initiator and deionized water at room temperature, uniformly stirring, and then simultaneously dropwise adding A, B and C solution for t1And keeping the temperature t after the dropwise addition2And finally, adjusting the pH value of the reaction product to n to obtain the high workability polycarboxylic acid water reducing agent.
10. The preparation method of the high workability polycarboxylic acid water reducing agent according to claim 7, characterized by comprising: t is t1Is 2 to 4 hours, t21-2 h, n is 4.0-6.0, the reducing agent is one of L-ascorbic acid, sodium hypophosphite and sodium formaldehyde sulfoxylate, the initiator is one of hydrogen peroxide, sodium persulfate or ammonium persulfate, the chain transfer agent is one of thioglycolic acid, mercaptopropionic acid or mercaptoethanol, and the chain transfer agent is prepared byAdjusting the pH value of the reaction product by liquid caustic soda, wherein the mass fraction of the liquid caustic soda is 30-32%.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US20150291716A1 (en) * | 2012-12-05 | 2015-10-15 | Sobute New Materials Co., Ltd. | Slump retaining polycarboxylic acid superplasticizer |
| CN105367720A (en) * | 2015-11-25 | 2016-03-02 | 科之杰新材料集团有限公司 | Water-reducing slump-retaining type polycarboxylic acid water reducing agent and preparing method thereof |
| CN107814886A (en) * | 2017-11-16 | 2018-03-20 | 科之杰新材料集团有限公司 | A kind of defoaming type polycarboxylate water-reducer and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20150291716A1 (en) * | 2012-12-05 | 2015-10-15 | Sobute New Materials Co., Ltd. | Slump retaining polycarboxylic acid superplasticizer |
| CN105367720A (en) * | 2015-11-25 | 2016-03-02 | 科之杰新材料集团有限公司 | Water-reducing slump-retaining type polycarboxylic acid water reducing agent and preparing method thereof |
| CN107814886A (en) * | 2017-11-16 | 2018-03-20 | 科之杰新材料集团有限公司 | A kind of defoaming type polycarboxylate water-reducer and preparation method thereof |
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