CN107602782B - Preparation method of polycarboxylic acid water reducing agent containing polyurea structure - Google Patents
Preparation method of polycarboxylic acid water reducing agent containing polyurea structure Download PDFInfo
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- CN107602782B CN107602782B CN201710723232.3A CN201710723232A CN107602782B CN 107602782 B CN107602782 B CN 107602782B CN 201710723232 A CN201710723232 A CN 201710723232A CN 107602782 B CN107602782 B CN 107602782B
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Abstract
The invention provides a preparation method of a polycarboxylic acid water reducing agent containing a polyurea structure, which comprises the following steps: and reacting acrylic acid, a polyoxyethylene ether macromonomer with one end being an alkenyl group and a water-based polyurea macromonomer with one end being an alkenyl group in the presence of an initiator and a chain transfer agent to obtain the polycarboxylic acid water reducing agent containing the polyurea structure. According to the technical scheme of the invention, the prepared polycarboxylic acid water reducing agent containing the polyurea structure not only has improved concrete dispersibility, but also has improved concrete slump retaining property.
Description
Technical Field
The invention relates to the field of water reducing agents for concrete, in particular to a preparation method of a polycarboxylic acid water reducing agent containing a polyurea structure.
Background
Since the 21 st century, the polycarboxylic acid high-performance water reducing agent is favored by people in heavy projects such as nuclear power and water conservancy gradually due to the advantages of low mixing amount, high water reducing rate, good slump retaining property, good compatibility with cement, strong molecular design, environmental protection and the like, and becomes a development hotspot and direction of the water reducing agent technology. However, many engineering problems are encountered in the application process of the polycarboxylic acid water reducing agent, and the most prominent problem is the loss of concrete slump. Because of the great difference of concrete raw materials, the phenomenon of too fast concrete slump loss can often occur in the concrete transportation and construction process, and the difficulty is increased for concrete construction and quality control. During construction, water is added for remodeling, so that the concrete has good fluidity and is easy to pump and pour, but water addition and remodeling can change the water-cement ratio and the air content of the concrete, reduce the impermeability of the concrete and seriously influence the strength of the concrete. In addition, the concrete can recover better working performance by increasing the using amount of the water reducing agent or adding or reducing the water reducing agent before construction to remold the concrete, but the phenomena of segregation, bleeding and the like of the concrete can occur when the using amount of the water reducing agent is increased in the initial stirring stage, the uniformity of the concrete is damaged, the strength of each part of the concrete has larger difference, and the breaking and compression strength of the concrete is reduced. None of these methods effectively solves the problem of excessive concrete slump. In order to solve this problem, people at home and abroad have already studied slow-release polycarboxylic acid water reducing agents. The polycarboxylic slump retaining agent is an additive for slowly releasing the components of the water reducing agent, and can effectively solve the problem of too fast slump loss of concrete, thereby ensuring that commercial concrete has good construction performance for a long time in engineering construction.
The molecular structure of the polycarboxylic acid high-efficiency water reducing agent is variable, the performances of different molecular structures are different, the great difference in the performances such as water reducing rate, net slurry fluidity, initial slump and slump loss of concrete, gas content and the like is shown, and numerous scholars discuss the structural relationship of the polycarboxylic acid high-efficiency water reducing agent in the aspects of the content of an adsorption group of a main chain, the size of molecular weight, the length and the content of a branched chain and the like. The influence of the length of the main side chain of the molecular structure on the performance of the polycarboxylic acid water reducer is researched, and from the angle of the surface performance and the dispersing performance of the polycarboxylic acid water reducer, the influence of the polycarboxylic acid water reducers with different molecular structures on the fluidity and the fluidity loss of cement paste is explained, so that the stability and the fluidity of the cement paste dispersing system are effectively controlled.
Chinese patent publication No. CN 105712652A provides a slump retaining agent for concrete with medium and low slump and a preparation method thereof, and the invention relates to a polycarboxylic acid slump retaining agent synthesized by macromonomer acrylate. Chinese patent publication No. CN 105254825A discloses a method for preparing ester-type delayed-setting polycarboxylic acid slump retaining agent, which takes unsaturated carboxylic acid or anhydride, alkoxy polyalkylene glycol, hydroxy ethylidene diphosphonic acid or 2-hydroxy phosphono acetic acid and polymerization inhibitor as raw materials, and ester monomer mixture is synthesized at high temperature to synthesize the delayed-setting polycarboxylic acid slump retaining agent. Chinese patent publication No. CN 105566572A discloses a maleic anhydride grafted polycarboxylic acid plastic-retaining agent and a preparation method thereof. The method utilizes maleic anhydride, cellulose hydroxypropyl methyl ether and phosphorous acid as raw materials to synthesize intermediate polyester, and then obtains the polycarboxylic acid water reducing agent through polymerization, and the polycarboxylic acid water reducing agent has comprehensive effects of good dispersibility, plasticity retention and thickening property.
However, there is still an urgent need in the art to develop a new method for preparing a polycarboxylic acid water reducing agent containing a polyurea structure to improve the concrete dispersibility and the concrete slump retention of the polycarboxylic acid water reducing agent.
Disclosure of Invention
Based on the technical problems stated above and based on the mechanisms and process technologies of the traditional concrete water reducing agent and slump retaining agent, the invention aims to introduce a novel water-based polyurea monomer into the structure of the traditional polycarboxylic acid water reducing agent, so that the dispersibility of concrete is improved, the slump retaining property of concrete is improved, and the preparation method of the novel polycarboxylic acid water reducing agent containing the polyurea structure is provided.
The present inventors have made intensive studies and completed the present invention.
According to one aspect of the invention, a preparation method of a polycarboxylic acid water reducing agent containing a polyurea structure is provided, and the preparation method comprises the following steps: and reacting acrylic acid, a polyoxyethylene ether macromonomer with one end being an alkenyl group and a water-based polyurea macromonomer with one end being an alkenyl group in the presence of an initiator and a chain transfer agent to obtain the polycarboxylic acid water reducing agent containing the polyurea structure.
According to some embodiments of the invention, the polyoxyethylene ether macromonomer having one terminal alkenyl group has a number average molecular weight of 1000-3400.
According to certain embodiments of the invention, the polyoxyethylene ether macromonomer having one terminal alkenyl group is selected from one or more of allyl polyglycol ether, methallyl polyglycol ether, prenol polyoxyethylene ether, and isobutenol polyoxyethylene ether.
According to certain embodiments of the present invention, the aqueous alkenyl-terminated polyurea macromonomer has a structure represented by the following formula:
wherein X is a divalent residue resulting from the removal of two amine groups from a polyetheramine; y is a divalent residue obtained after removal of two isocyanate groups from a diisocyanate; z is a residue obtained by removing a hydrogen atom from a hydroxyl group of an unsaturated carboxylic acid hydroxy ester or an enol, the number of carbon atoms of which is 4 to 7.
According to certain embodiments of the present invention, the polyetheramine is selected from one or more of polyetheramines having an amine functionality of 2 and a number average molecular weight of 230 to 5000.
According to certain embodiments of the present invention, the diisocyanate is selected from one or more of p-xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate.
According to certain embodiments of the present invention, the unsaturated carboxylic acid hydroxy ester is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.
According to certain embodiments of the invention, the enol is selected from methallyl alcohol, isopentenol, isobutenol and methallyl alcohol polyethylene glycol having a number average molecular weight of 600-1200.
According to certain embodiments of the present invention, the number average molecular weight of the aqueous alkenyl terminated polyurea macromonomer is 1000-.
According to certain embodiments of the invention, the alkenyl-terminated aqueous polyurea macromonomer is a polyetheramine; a diisocyanate; unsaturated carboxylic acid hydroxy esters or alkenols; and glycolic acid as a reactant.
According to certain embodiments of the invention, the initiator is a hydrogen peroxide-ascorbic acid initiator.
According to certain embodiments of the invention, the molar ratio of the acrylic acid to the alkenyl terminated polyoxyethylene ether macromonomer is from 3:1 to 4.2: 1; and the weight of the polyoxyethylene ether macromonomer with one end as alkenyl group is 100 wt%, and the weight of the aqueous polyurea macromonomer with one end as alkenyl group is 3 to 10 wt%.
According to certain embodiments of the present invention, the chain transfer agent is selected from one or more of mercaptoethanol, thioglycolic acid, sodium methallyl sulfonate, mercaptopropionic acid.
According to certain embodiments of the present invention, the weight of the polyoxyethylene ether macromonomer having one terminal alkenyl group is 100 wt%, the weight of the hydrogen peroxide solution in the initiator is 0.6 to 1 wt%, the weight of the ascorbic acid is 0.2 to 0.5 wt%, and the weight of the chain transfer agent is 0.2 to 0.6 wt%.
According to certain embodiments of the present invention, in the preparation of the alkenyl-terminated aqueous polyurea macromonomer, the polyetheramine; a diisocyanate; unsaturated carboxylic acid hydroxy esters or alkenols; and glycolic acid in a molar ratio of 1:2 to 3:1 to 2.
Compared with the prior art, the unsaturated aqueous polyurea monomer is prepared by taking polyether amine, diisocyanate, unsaturated carboxylic acid hydroxy ester or enol and glycollic acid as raw materials, and a polyurea structure and an ester structure are introduced while the double bond polymerization activity of unsaturated carboxylic acid and enol is kept. At present, all polycarboxylic acid slump retaining agents are prepared by introducing micromolecular unsaturated carboxylic acid ester, and performing hydrolysis reaction on later esters in an alkaline environment of cement hydration to release carboxylic acid groups and continuously exert an alkaline water dispersion effect, so that concrete can keep good slump retaining performance within a certain time. However, this inevitably sacrifices the initial dispersing effect of the water-reducing agent, so that the initial dispersing property of the concrete is deteriorated. The water-based polyurea monomer is used as a branched chain in the grafted polycarboxylate superplasticizer and can provide sufficient steric hindrance, so that the initial dispersibility of the water-based polyurea monomer is not reduced but is improved compared with the conventional polycarboxylate superplasticizer. Meanwhile, the structure of the concrete slump retaining agent contains a special polyurea structure which has excellent chemical properties and physical properties and can delay hydration and agglomeration of cement particles, so that the slump retaining property is improved. But also can improve the tensile strength, the breaking strength, the impermeability, the ion resistance and other properties of the concrete.
Detailed Description
The present invention will be described in further detail with reference to specific embodiments. It will be appreciated that other embodiments are contemplated and may be made without departing from the scope or spirit of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense.
Unless otherwise indicated, all numbers expressing feature sizes, quantities, and physical and chemical properties used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can be suitably varied by those skilled in the art in seeking to obtain the desired properties utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range and any range within that range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, and the like.
The invention provides a preparation method of a polycarboxylic acid water reducing agent containing a polyurea structure, which comprises the following steps: and reacting acrylic acid, a polyoxyethylene ether macromonomer with one end being an alkenyl group and a water-based polyurea macromonomer with one end being an alkenyl group in the presence of an initiator and a chain transfer agent to obtain the polycarboxylic acid water reducing agent containing the polyurea structure.
According to some embodiments of the present invention, the number average molecular weight of the polyoxyethylene ether macromonomer having one terminal alkenyl group is 1000-3400, preferably 2200-2600.
According to certain embodiments of the invention, the polyoxyethylene ether macromonomer having one terminal alkenyl group is selected from one or more of allyl polyglycol ether, methallyl polyglycol ether, prenol polyoxyethylene ether, and isobutenol polyoxyethylene ether.
According to certain embodiments of the present invention, the aqueous alkenyl-terminated polyurea macromonomer has a structure represented by the following formula:
wherein X is a divalent residue resulting from the removal of two amine groups from a polyetheramine; y is a divalent residue obtained after removal of two isocyanate groups from a diisocyanate; z is a residue obtained by removing a hydrogen atom from a hydroxyl group of an unsaturated carboxylic acid hydroxy ester or an enol, which has 4 to 7, preferably 5 to 6 carbon atoms.
The polyetheramines according to the present invention have the meaning generally known in the art, i.e., polyetheramines are a class of polymers having a polyether structure in the main chain and amine groups as terminal reactive functional groups. According to certain embodiments of the present invention, the polyetheramine is selected from one or more of polyetheramines having an amine functionality of 2 and a number average molecular weight of 230 to 5000. Specific examples of polyetheramines that can be used in the present invention include Jeffamine D-230, Jeffamine D-400, Jeffamine D-2000, Jeffamine D-4000, Jeffamine T-3000, and Jeffamine T-5000, which are manufactured by Huntsman Chemical Company. Most preferably, a specific example of a polyetheramine that can be used in the present invention is Jeffamine D-2000, manufactured by Huntsman Chemical Company.
Preferably, the polyisocyanate used in the present invention is an aliphatic polyisocyanate. Preferably, the polyisocyanate is a diisocyanate. According to certain embodiments of the present invention, the diisocyanate is selected from one or more of para-Xylylene Diisocyanate (XDI), Hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI) and dicyclohexylmethane diisocyanate (HMDI).
According to certain embodiments of the present invention, the unsaturated carboxylic acid hydroxy ester is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.
According to certain embodiments of the invention, the enol is selected from methallyl alcohol, isopentenol, isobutenol and methallyl alcohol polyethylene glycol having a number average molecular weight of 600-1200. Preferably, the methallyl alcohol polyethylene glycol with the number average molecular weight of 600-1200 is methallyl alcohol polyethylene glycol-400 produced by north river kaimei building materials ltd.
According to certain embodiments of the present invention, the number average molecular weight of the aqueous polyurea macromonomer having one terminal alkenyl group is 1000-.
According to certain embodiments of the invention, the alkenyl-terminated aqueous polyurea macromonomer is a polyetheramine; a diisocyanate; unsaturated carboxylic acid hydroxy esters or alkenols; and glycolic acid as a reactant. The polyether amine; the diisocyanates, unsaturated carboxylic acid hydroxy esters and enols have the definitions stated above.
According to certain embodiments of the invention, the initiator is a hydrogen peroxide-ascorbic acid initiator.
According to certain embodiments of the present invention, in the above-described method for producing a polycarboxylic acid water reducing agent containing a polyurea structure, the molar ratio of the acrylic acid to the polyoxyethylene ether macromonomer having an alkenyl group at one end is 3:1 to 4.2:1, preferably 3.5: 1 to 3.8: 1; and the weight of the alkenyl group-terminated polyoxyethylene ether macromonomer is from 3 to 10% by weight, preferably from 3 to 6% by weight, based on 100% by weight of the alkenyl group-terminated aqueous polyurea macromonomer.
According to certain embodiments of the present invention, the chain transfer agent is selected from one or more of mercaptoethanol, thioglycolic acid, sodium methallyl sulfonate, mercaptopropionic acid.
According to certain embodiments of the present invention, in the above-described method for preparing a polycarboxylic acid water reducing agent containing a polyurea structure, the weight of the polyoxyethylene ether macromonomer having an alkenyl group at one end is 100% by weight, the weight of the hydrogen peroxide solution in the initiator is 0.6 to 1% by weight, the weight of the ascorbic acid is 0.2 to 0.5% by weight, and the weight of the chain transfer agent is 0.2 to 0.6% by weight.
According to certain embodiments of the present invention, in the preparation of the alkenyl-terminated aqueous polyurea macromonomer, the polyetheramine; a diisocyanate; unsaturated carboxylic acid hydroxy esters or alkenols; and glycolic acid in a molar ratio of 1:2 to 3:1 to 2, preferably 1: 3: 2:2.
The preparation method of the polycarboxylic acid water reducing agent containing the polyurea structure is mainly characterized in that an unsaturated aqueous polyurea polymeric monomer (i.e., an aqueous polyurea macromonomer having one terminal alkenyl group) is introduced into the conventional water reducing agent structure, and the aqueous polyurea macromonomer having one terminal alkenyl group has a structure represented by the following formula:
wherein X is a divalent residue resulting from the removal of two amine groups from a polyetheramine; y is a divalent residue obtained after removal of two isocyanate groups from a diisocyanate; z is a residue obtained by removing a hydrogen atom from a hydroxyl group of an unsaturated carboxylic acid hydroxy ester or an enol, the number of carbon atoms of which is 4 to 7.
According to the technical scheme of the invention, polyether amine; a diisocyanate; unsaturated carboxylic acid hydroxy esters or alkenols; and the synthetic route for preparing the aqueous polyurea macromonomer with one end being an alkenyl group by using glycolic acid as a reactant is shown as follows:
wherein NH 2 -X-NH 2 Is polyether amine; o ═ C ═ N-Y-N ═ C ═ O is diisocyanate; ZH is unsaturated carboxylic acid hydroxy ester or enol. The polyetheramine is selected from one or more of polyetheramines having an amine functionality of 2 and a number average molecular weight of 230 to 5000. The diisocyanate is selected from one or more of p-xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and dicyclohexylmethane diisocyanate.
More specifically, the following shows a route for preparing aqueous polyurea monomers starting from polyetheramine Jeffamine D-2000, isophorone diisocyanate (IPDI), hydroxyethyl acrylate and glycolic acid:
where x is 56.
Specifically, the aqueous polyurea macromonomer having one terminal alkenyl group is prepared by the following method:
1) heating the polyether amine to 110-120 ℃ for dehydration;
2) dropwise adding the dehydrated polyether amine to a mixture of diisocyanate and a solvent at a temperature of 0-10 ℃, and reacting the resulting mixture at a temperature of 40-50 ℃ for 1-2 hours, wherein the solvent is one or more selected from acetone, ethyl acetate, butyl acetate and ethylene glycol dimethyl ether;
3) adding an unsaturated carboxylic acid hydroxy ester or an enol to the mixture obtained in step 2), and reacting the resulting mixture at a temperature of 60 to 70 ℃ for 2 to 3 hours; and
4) adding glycolic acid to the mixture obtained in step 3), and reacting the resulting mixture at a temperature of 60-70 ℃ for 2-3 hours,
wherein the polyetheramine; a diisocyanate; unsaturated carboxylic acid hydroxy esters or alkenols; and glycolic acid in a molar ratio of 1:2 to 3:1 to 2.
Specifically, the polycarboxylic acid water reducing agent containing the polyurea structure is prepared by the following method:
1) preparing an acrylic acid aqueous solution A;
2) preparing an aqueous solution B of ascorbic acid and a chain transfer agent;
3) preparing a mixture containing a polyoxyethylene ether macromonomer with one end being alkenyl, a water-based polyurea macromonomer with one end being alkenyl and hydrogen peroxide, wherein the molar ratio of the acrylic acid to the polyoxyethylene ether macromonomer with one end being alkenyl is 3:1 to 4.2: 1; and the weight of the polyoxyethylene ether macromonomer with one end as an alkenyl group is 100 wt%, the weight of the aqueous polyurea macromonomer with one end as an alkenyl group is 3 to 10 wt%, the weight of the hydrogen peroxide is 0.6 to 1 wt%, the weight of the ascorbic acid is 0.2 to 0.5 wt%, and the weight of the chain transfer agent is 0.2 to 0.6 wt%;
4) respectively dripping the aqueous solution A and the aqueous solution B into the mixture obtained in the step 3) at the same time under the condition of normal temperature, and reacting for 2-3 hours after dripping;
5) adjusting the pH value of the mixture obtained in the step 4) to 6-7 to obtain the polycarboxylic acid water reducing agent containing the polyurea structure.
Compared with the prior art, the unsaturated aqueous polyurea monomer is prepared by taking polyether amine, diisocyanate, unsaturated carboxylic acid hydroxy ester or enol and glycollic acid as raw materials, and a polyurea structure and an ester structure are introduced while the double bond polymerization activity of unsaturated carboxylic acid and enol is kept. At present, all polycarboxylic acid slump retaining agents are prepared by introducing micromolecular unsaturated carboxylic acid ester, and performing hydrolysis reaction on later esters in an alkaline environment of cement hydration to release carboxylic acid groups and continuously exert an alkaline water dispersion effect, so that concrete can keep good slump retaining performance within a certain time. However, this inevitably sacrifices the initial dispersing effect of the water-reducing agent, so that the initial dispersing property of the concrete is deteriorated. The water-based polyurea monomer is used as a branched chain in the grafted polycarboxylate superplasticizer and can provide sufficient steric hindrance, so that the initial dispersibility of the water-based polyurea monomer is not reduced but is improved compared with the conventional polycarboxylate superplasticizer. Meanwhile, the structure of the concrete slump retaining agent contains a special polyurea structure which has excellent chemical properties and physical properties and can delay hydration and agglomeration of cement particles, so that the slump retaining property is improved. But also can improve the tensile strength, the breaking strength, the impermeability, the ion resistance and other properties of the concrete.
The present invention will be described in more detail with reference to examples. It should be noted that the description and examples are intended to facilitate the understanding of the invention, and are not intended to limit the invention. The scope of the invention is to be determined by the claims appended hereto.
Examples
In the present invention, unless otherwise indicated, all reagents used were commercially available and were used without further purification treatment. Further, "%" mentioned is "% by weight", and "parts" mentioned is "parts by weight".
Test method
Measurement of net pulp fluidity
The net slurry fluidity of each of the polycarboxylic acid water-reducing agents obtained in examples 1 to 4 and comparative example 1 below was measured according to the measurement method specified in GB/T8077-2000.
Example 1
Preparation of unsaturated aqueous polyurea monomers：
200g of polyether amine Jeffamine D-2000 is heated to 110 ℃ for dehydration for 1 hour, and then cooled to room temperature for standby after dehydration. 46.62g of isophorone diisocyanate (IPDI) and 30g of acetone solvent are added into a four-neck flask provided with a stirrer and a thermometer, dehydrated polyether amine D-2000 is slowly added dropwise in a cold water bath and stirred for reaction for 3 hours, and then the temperature is raised to 30-40 ℃ for reaction for 1 hour. After the reaction was completed, 11.60g of hydroxyethyl acrylate and 30g of acetone solvent were added to react at 70 ℃ for 2 hours, followed by addition of 4.6g of glycolic acid and reaction at 70 ℃ for 2 hours, and the remaining NCO was blocked. Then 614g of deionized water, 2g of Sodium Dodecyl Sulfate (SDS) and 4g of OP-10 emulsifier are added, and the mixture is emulsified for 30 minutes at 3000r/min in a high-shear disperser, and finally the solvent is removed in vacuum, so that the aqueous polyurea macromonomer with 30 percent of mass fraction and one alkenyl end is obtained.
Preparation of polycarboxylate superplasticizer mother liquor：
An aqueous solution A of acrylic acid having a concentration of 8 mol/l was prepared. In addition, an aqueous solution B of ascorbic acid and mercaptopropionic acid was prepared, in which the concentration of ascorbic acid was 0.57 mol/liter and the concentration of chain transfer agent was 1 mol/liter. Preparing a mixture containing an isoamyl alcohol polyoxyethylene ether macromonomer (with the molecular weight of 2600), the prepared aqueous polyurea macromonomer and hydrogen peroxide, wherein the molar ratio of acrylic acid to the isoamyl alcohol polyoxyethylene ether macromonomer is 1: 3.8; and the weight of the prenyl polyoxyethylene ether macromonomer is 100 wt%, the weight of the aqueous polyurea macromonomer with one end being an alkenyl group is 3 wt%, the weight of the hydrogen peroxide is 0.7 wt%, the weight of the ascorbic acid is 0.3 wt%, and the weight of the chain transfer agent is 0.3 wt%. And (2) respectively dripping the aqueous solution A and the aqueous solution B into a mixture containing an isopentenol polyoxyethylene ether macromonomer (with the molecular weight of 2600), the prepared aqueous polyurea macromonomer and hydrogen peroxide at the same time under the condition of normal temperature, wherein the solution A is uniformly dripped for 3-4 hours, then the solution B is dripped for 0.5 hour in a prolonged manner, reacting for 2-3 hours after the dripping is finished, and finally, neutralizing with a sodium hydroxide solution until the pH value is 6-7 to obtain the polycarboxylic acid water reducer mother liquor marked as PC 1. The polycarboxylate superplasticizer mother liquor is subjected to a cement paste fluidity test according to the test method, and the data are shown in an experimental data table 1.
Example 2
A polycarboxylate water reducing agent mother liquor PC2 was prepared in a similar manner to example 1 except that the weight of the alkenyl group-terminated aqueous polyurea macromonomer calculated as 100% by weight of the prenyl alcohol polyoxyethylene ether macromonomer was adjusted to 5% by weight. The polycarboxylate superplasticizer mother liquor is subjected to a cement paste fluidity test according to the test method, and the data are shown in an experimental data table 1.
Example 3
A polycarboxylate water reducing agent mother liquor PC3 was prepared in a similar manner to example 1 except that the weight of the alkenyl group-terminated aqueous polyurea macromonomer calculated as 100% by weight of the prenyl alcohol polyoxyethylene ether macromonomer was adjusted to 7% by weight. The polycarboxylate superplasticizer mother liquor is subjected to a cement paste fluidity test according to the test method, and the data are shown in an experimental data table 1.
Example 4
A polycarboxylate water reducing agent mother liquor PC4 was prepared in a similar manner to example 1 except that the weight of the alkenyl group-terminated aqueous polyurea macromonomer calculated as 100% by weight of the prenyl alcohol polyoxyethylene ether macromonomer was adjusted to 9% by weight. The polycarboxylate superplasticizer mother liquor is subjected to a cement paste fluidity test according to the test method, and the data are shown in an experimental data table 1.
Comparative example 1
An aqueous solution A of acrylic acid having a concentration of 8 mol/l was prepared. In addition, an aqueous solution B of ascorbic acid and mercaptopropionic acid was prepared, in which the concentration of ascorbic acid was 0.57 mol/liter and the concentration of chain transfer agent was 1 mol/liter. Preparing a mixture containing an isoamyl alcohol polyoxyethylene ether macromonomer (with the molecular weight of 2600) and hydrogen peroxide, wherein the molar ratio of acrylic acid to the isoamyl alcohol polyoxyethylene ether macromonomer is 1: 3.8; and the weight of the prenyl polyoxyethylene ether macromonomer is 100 wt%, the weight of the hydrogen peroxide is 0.7 wt%, the weight of the ascorbic acid is 0.3 wt%, and the weight of the chain transfer agent is 0.3 wt%. And (2) respectively dripping the aqueous solution A and the aqueous solution B into a mixture containing an isopentenol polyoxyethylene ether macromonomer (with the molecular weight of 2600) and hydrogen peroxide at the same time under the condition of normal temperature, wherein the solution A is uniformly dripped for 3-4 hours, then the solution B is dripped for 0.5 hour in a prolonged manner, reacting for 2-3 hours after the dripping is finished, and finally neutralizing with a sodium hydroxide solution until the pH value is 6-7 to obtain the polycarboxylic acid water reducer mother liquor, which is marked as PC 0. The polycarboxylate superplasticizer mother liquor is subjected to a cement paste fluidity test according to the test method, and the data are shown in an experimental data table 1.
In comparative example 1, no aqueous polyurea macromonomer was used for the preparation of the water-reducing agent mother liquor.
TABLE 1 test results on neat paste fluidity of the water-reducing agent mother liquors prepared in examples 1 to 4 and comparative example 1
As can be seen from the comparison between examples 1 to 4 and comparative example 1, the polycarboxylic acid water reducing agent containing the polyurea structure of the present invention has good initial dispersibility, almost no loss of fluidity for 30min and 1h, and slump retention is superior to that of the conventional polycarboxylic acid water reducing agent. By adopting the water-based polyurea monomer, the polymerization activity of unsaturated carboxylic acid and enol double bonds is kept, and a polyurea structure and an ester structure are introduced. The water-based polyurea monomer is used as a branched chain in the grafted polycarboxylate superplasticizer and can provide sufficient steric hindrance, so that the initial dispersibility of the water-based polyurea monomer is not reduced but is improved compared with the conventional polycarboxylate superplasticizer. Meanwhile, the structure of the concrete slump retaining agent contains a special polyurea structure which has excellent chemical properties and physical properties and can delay hydration and agglomeration of cement particles, so that the slump retaining property is improved.
The embodiments of the present invention are described only for the preferred embodiments of the present invention, and not for the purpose of limiting the spirit and scope of the present invention, and various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention shall fall within the protection scope of the present invention, and the technical contents of the present invention as claimed are all described in the claims.
Claims (13)
1. A preparation method of a polycarboxylic acid water reducing agent containing a polyurea structure comprises the following steps: reacting acrylic acid, a polyoxyethylene ether macromonomer having an alkenyl group at one end, and an aqueous polyurea macromonomer having an alkenyl group at one end in the presence of an initiator and a chain transfer agent to obtain the polycarboxylic acid water reducing agent containing a polyurea structure, wherein the aqueous polyurea macromonomer having an alkenyl group at one end has a structure represented by the following formula:
wherein X is a divalent residue resulting from the removal of two amine groups from a polyetheramine; y is a divalent residue obtained after removal of two isocyanate groups from a diisocyanate; z is a residue obtained after removing a hydrogen atom from a hydroxyl group of an unsaturated carboxylic acid hydroxy ester or an enol, the number of carbon atoms of the unsaturated carboxylic acid hydroxy ester or the enol being 4 to 7, and the diisocyanate being isophorone diisocyanate.
2. The method for preparing a polycarboxylic acid water reducing agent containing a polyurea structure as claimed in claim 1, wherein the number average molecular weight of the polyoxyethylene ether macromonomer having an alkenyl group at one end is 1000-3400.
3. The method for preparing a polycarboxylic acid water reducing agent containing a polyurea structure according to claim 1, wherein the polyoxyethylene ether macromonomer having an alkenyl group at one end is one or more selected from allyl polyglycol ether, methallyl polyglycol ether, prenol polyoxyethylene ether, and isobutenol polyoxyethylene ether.
4. The method for producing a polycarboxylic acid water reducing agent containing a polyurea structure according to claim 1, wherein the polyether amine is one or more selected from polyether amines having an amine group functionality of 2 and a number average molecular weight of 230 to 5000.
5. The method for preparing a polycarboxylic acid water reducing agent containing a polyurea structure according to claim 1, wherein the unsaturated carboxylic acid hydroxy ester is selected from one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.
6. The method for preparing a polycarboxylic acid water reducing agent containing a polyurea structure as claimed in claim 1, wherein the enol is selected from the group consisting of methallyl alcohol, isopentenol, isobutenol and methallyl alcohol polyethylene glycol with a number average molecular weight of 600-1200.
7. The method for preparing a polycarboxylic acid water reducing agent containing a polyurea structure as claimed in claim 1, wherein the number average molecular weight of the aqueous polyurea macromonomer having an alkenyl group at one end is 1000-6000.
8. The method for preparing a polycarboxylic acid water reducing agent containing a polyurea structure according to claim 1, wherein the aqueous polyurea macromonomer having an alkenyl group at one end is polyetheramine; a diisocyanate; unsaturated carboxylic acid hydroxy esters or alkenols; and glycolic acid as a reactant.
9. The preparation method of the polycarboxylic acid water reducer containing the polyurea structure according to claim 1, wherein the initiator is a hydrogen peroxide-ascorbic acid initiator.
10. The preparation method of the polycarboxylic acid water reducer containing the polyurea structure according to claim 1, wherein the molar ratio of the acrylic acid to the polyoxyethylene ether macromonomer having an alkenyl group at one end is 3:1 to 4.2: 1; and the weight of the polyoxyethylene ether macromonomer with one end as alkenyl group is 100 wt%, and the weight of the aqueous polyurea macromonomer with one end as alkenyl group is 3 to 10 wt%.
11. The method for preparing a polycarboxylate water reducer containing a polyurea structure as claimed in claim 1, wherein the chain transfer agent is selected from one or more of mercaptoethanol, mercaptoacetic acid, sodium methallyl sulfonate and mercaptopropionic acid.
12. The method for preparing a polycarboxylic acid water reducing agent containing a polyurea structure according to claim 1, wherein the weight of the polyoxyethylene ether macromonomer having an alkenyl group at one end is 100 wt%, the weight of hydrogen peroxide in the initiator is 0.6 to 1 wt%, the weight of ascorbic acid is 0.2 to 0.5 wt%, and the weight of the chain transfer agent is 0.2 to 0.6 wt%.
13. The method for producing a polycarboxylic acid water reducing agent containing a polyurea structure according to claim 8, wherein in the production of the aqueous polyurea macromonomer having an alkenyl group at one end, the polyether amine; a diisocyanate; unsaturated carboxylic acid hydroxy esters or alkenols; and glycolic acid in a molar ratio of 1:2 to 3:1 to 2.
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| CN112592091B (en) * | 2020-11-27 | 2022-07-29 | 南京博科新材料产业研究院有限公司 | Coagulation accelerating early strength agent for 3D printing cement-based material |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0682049A1 (en) * | 1994-05-09 | 1995-11-15 | Hoechst Aktiengesellschaft | Hydrophilic polyurethane-polyureas and their use as a dispersant for synthetic resins |
| JP2007076972A (en) * | 2005-09-15 | 2007-03-29 | Hokkaido Univ | Self shrinkage-reducing agent |
| CN103011674A (en) * | 2012-12-20 | 2013-04-03 | 南京瑞迪高新技术有限公司 | Polyether amine modified polycarboxylate-type concrete slump retaining agent and preparation method thereof |
| CN106832147A (en) * | 2017-03-02 | 2017-06-13 | 太原理工大学 | A kind of preparation method containing phosphonyl group polycarboxylate water-reducer |
-
2017
- 2017-08-22 CN CN201710723232.3A patent/CN107602782B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0682049A1 (en) * | 1994-05-09 | 1995-11-15 | Hoechst Aktiengesellschaft | Hydrophilic polyurethane-polyureas and their use as a dispersant for synthetic resins |
| JP2007076972A (en) * | 2005-09-15 | 2007-03-29 | Hokkaido Univ | Self shrinkage-reducing agent |
| CN103011674A (en) * | 2012-12-20 | 2013-04-03 | 南京瑞迪高新技术有限公司 | Polyether amine modified polycarboxylate-type concrete slump retaining agent and preparation method thereof |
| CN106832147A (en) * | 2017-03-02 | 2017-06-13 | 太原理工大学 | A kind of preparation method containing phosphonyl group polycarboxylate water-reducer |
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