阅读说明：本技术 一种六碳单体合成缓释型聚羧酸减水剂及制备方法 (Six-carbon monomer synthesized slow-release polycarboxylate superplasticizer and preparation method thereof ) 是由 刘斌 于 2020-08-25 设计创作，主要内容包括：本发明涉及混凝土外加剂技术领域,具体涉及一种六碳单体合成缓释型聚羧酸减水剂及制备方法,按重量份计,制备原料至少包括：六碳单体5-15份、功能单体20-40份、酯类化合物12-23份、链转移剂1-3份、还原剂0.5-2份、氧化剂2-8份、pH调节剂2-8份、水65-85份。(The invention relates to the technical field of concrete admixtures, in particular to a six-carbon monomer synthesized slow-release type polycarboxylate superplasticizer and a preparation method thereof, wherein the preparation raw materials at least comprise the following components in parts by weight: 5-15 parts of six-carbon monomer, 20-40 parts of functional monomer, 12-23 parts of ester compound, 1-3 parts of chain transfer agent, 0.5-2 parts of reducing agent, 2-8 parts of oxidizing agent, 2-8 parts of pH regulator and 65-85 parts of water.)

1. The slow-release polycarboxylate superplasticizer synthesized by six carbon monomers is characterized by comprising the following raw materials in parts by weight: 5-15 parts of six-carbon monomer, 20-40 parts of functional monomer, 12-23 parts of ester compound, 1-3 parts of chain transfer agent, 0.5-2 parts of reducing agent, 2-8 parts of oxidizing agent, 2-8 parts of pH regulator and 65-85 parts of water.

2. The six-carbon monomer synthetic slow-release polycarboxylate water reducer according to claim 1, wherein the six-carbon monomer is selected from one or more of hydroxyethyl-3-butenyl ether, hydroxypropyl allyl ether, diethylene glycol monovinyl ether and prenyl polyoxyethylene ether.

3. The slow-release polycarboxylate superplasticizer synthesized by six carbon monomers as claimed in claim 1 or 2, wherein the six carbon monomers are prenyl polyoxyethylene ether.

4. The six-carbon monomer synthesized slow-release polycarboxylate water reducer as claimed in claim 3, wherein the molecular weight of the prenyl alcohol polyoxyethylene ether is 2800-6000.

5. The six-carbon monomer synthetic slow-release polycarboxylate water reducer according to claim 1, wherein the functional monomer is selected from one or more of acrylic acid, methacrylic acid, acrylate, methacrylate, hydroxybutyl methacrylate, hydroxyethyl methacrylate, acrylamide, hydroxymethyl acrylamide, diacetone acrylamide, acetoacetic ester methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, hydroxypropyl acrylate and hydroxyethyl acrylate.

6. The six-carbon monomer synthesis slow-release polycarboxylate water reducer according to claim 1, wherein the ester compound is selected from one or more of vinyl acetate, allyl acetate, hydroxypropyl acrylate, diethylhexyl maleate, diethyl maleate, polyethylene glycol mono-maleate, dilauryl maleate and diethylene glycol maleate.

7. The six-carbon monomer synthesis slow-release type polycarboxylate superplasticizer according to claim 1 or 6, wherein the ester compound is a combination of vinyl acetate and hydroxypropyl acrylate, wherein the mass ratio of the vinyl acetate to the hydroxypropyl acrylate is (2-8): 1.

8. the six-carbon monomer synthesized slow-release polycarboxylate water reducer according to claim 1, wherein the reducing agent is one or more selected from ascorbic acid, sodium formaldehyde sulfoxylate, sodium bisulfite and ferrous sulfate.

9. The six-carbon monomer synthesized slow-release polycarboxylate water reducer according to claim 1, wherein the oxidant is one or more selected from hydrogen peroxide, potassium persulfate, ammonium persulfate and sodium bisulfite.

10. The preparation method of the six-carbon monomer synthesized slow-release type polycarboxylate water reducer according to any one of claims 1 to 9, characterized by at least comprising the following steps:

(1) mixing the functional monomer and the ester compound to obtain a component A; mixing a chain transfer agent, a reducing agent and an oxidizing agent to obtain a component B;

(2) mixing water and a six-carbon monomer and putting into a reaction kettle; simultaneously, dropwise adding the component A and the component B into the reaction kettle, and controlling the dripping completion time of the component A to be 40-60 min; controlling the dripping-off time of the component B to be 50-80 min; keeping the temperature for 1h after the two solutions are dripped, adding a pH regulator, and stirring to obtain the final product.

Technical Field

The invention relates to the technical field of concrete admixtures, in particular to a six-carbon monomer synthesized slow-release polycarboxylic acid water reducer and a preparation method thereof.

Background

The polycarboxylic acid water reducing agent has the advantages of low mixing amount, high water reducing rate, strong designability, environmental friendliness and the like, and becomes a concrete admixture which is most widely applied. In addition, the low-temperature control process is selected for the novel six-carbon monomer synthesis process in the early market, so that the equipment investment cost is greatly increased, and a large amount of electric energy is greatly consumed; unsaturated polyether is used as a main raw material of the polycarboxylic acid water reducing agent, and allyl alcohol, isopentenol and methallyl alcohol are commonly used as raw materials to directly carry out anionic polymerization with ethylene oxide to obtain a polyether product with a certain molecular weight. However, with the improvement of the concrete engineering requirement, the contradiction between the requirement of higher durability index of high-performance concrete and the deterioration of sand and stone mixing materials is increasingly sharp, and the existing polycarboxylic acid water reducing agent has the performance defects of low water reducing rate and weak slump retention.

In addition, many users at present need to meet certain pumping requirements for long-distance transportation of concrete, pumping construction of high-rise building concrete also has high requirements for workability of the concrete, and in order to achieve a high transportation distance, a novel six-carbon normal-temperature synthesized ultra-slow release type polycarboxylate water reducer capable of effectively solving the problem that concrete is not collapsed in three hours after long-distance transportation of the concrete is developed, and the ultra-slow release type polycarboxylate water reducer has important significance for development of concrete admixtures and the concrete industry.

Disclosure of Invention

In order to solve the technical problems, the first aspect of the invention provides a six-carbon monomer synthesized slow-release polycarboxylate superplasticizer which at least comprises the following raw materials in parts by weight: 5-15 parts of six-carbon monomer, 20-40 parts of functional monomer, 12-23 parts of ester compound, 1-3 parts of chain transfer agent, 0.5-2 parts of reducing agent, 2-8 parts of oxidizing agent, 2-8 parts of pH regulator and 65-85 parts of water.

As a preferable technical scheme of the invention, the six-carbon monomer is selected from one or more of hydroxyethyl-3-butenyl ether, hydroxypropyl allyl ether, diethylene glycol monovinyl ether and prenol polyoxyethylene ether.

As a preferable technical scheme of the invention, the six-carbon monomer is isopentenol polyoxyethylene ether.

As a preferable technical scheme of the invention, the molecular weight of the isopentenol polyoxyethylene ether is 2800-6000.

In a preferred embodiment of the present invention, the functional monomer is selected from one or more of acrylic acid, methacrylic acid, acrylate, methacrylate, hydroxybutyl methacrylate, hydroxyethyl methacrylate, acrylamide, methylolacrylamide, diacetone acrylamide, ethyl acetoacetate methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, hydroxypropyl acrylate, and hydroxyethyl acrylate.

As a preferred embodiment of the present invention, the ester compound is selected from one or more of vinyl acetate, allyl acetate, hydroxypropyl acrylate, diethylhexyl maleate, diethyl maleate, polyethylene glycol mono-maleate, dilauryl maleate, and diethylene glycol maleate.

As a preferable technical scheme of the invention, the ester compound is a combination of vinyl acetate and hydroxypropyl acrylate, wherein the mass ratio of the vinyl acetate to the hydroxypropyl acrylate is (2-8): 1.

as a preferable technical scheme of the invention, the reducing agent is selected from one or more of ascorbic acid, sodium formaldehyde sulfoxylate, sodium bisulfite and ferrous sulfate.

As a preferable technical scheme of the invention, the oxidant is selected from one or more of hydrogen peroxide, potassium persulfate, ammonium persulfate and sodium bisulfite.

The second aspect of the invention provides a preparation method for synthesizing a slow-release polycarboxylate superplasticizer by using six-carbon monomers, which at least comprises the following steps:

(1) mixing the functional monomer and the ester compound to obtain a component A; mixing a chain transfer agent, a reducing agent and an oxidizing agent to obtain a component B;

(2) mixing water and a six-carbon monomer and putting into a reaction kettle; simultaneously, dropwise adding the component A and the component B into the reaction kettle, and controlling the dripping completion time of the component A to be 40-60 min; controlling the dripping-off time of the component B to be 50-80 min; keeping the temperature for 1h after the two solutions are dripped, adding a pH regulator, and stirring to obtain the final product.

Has the advantages that:

the invention provides a six-carbon monomer synthesized slow-release polycarboxylate water reducer and a preparation method thereof.

Compared with the common slow-release polycarboxylic acid water reducing agent on the market, the six-carbon monomer synthesized slow-release polycarboxylic acid water reducing agent obtained by the invention has obvious long-distance transportation advantages, shows excellent concrete flow property and pumping property and can obviously improve the transportation property of long-distance concrete in high-strength and low-water-cement ratio concrete.

The preparation method is simple and safe, and compared with the prior art, the preparation method can be synthesized at normal temperature, thereby reducing the cost to a certain extent and optimizing the synthesis conditions.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The term "prepared from …" as used herein is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received for modification without substantial change in the basic function to which the invention is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

In order to solve the technical problems, the first invention of the invention provides a six-carbon monomer synthesized slow-release type polycarboxylate superplasticizer which at least comprises the following preparation raw materials in parts by weight: 5-15 parts of six-carbon monomer, 20-40 parts of functional monomer, 12-23 parts of ester compound, 1-3 parts of chain transfer agent, 0.5-2 parts of reducing agent, 2-8 parts of oxidizing agent, 2-8 parts of pH regulator and 65-85 parts of water.

In a more preferred embodiment, the six-carbon monomer synthesized slow-release polycarboxylate superplasticizer provided by the invention is prepared from at least the following raw materials in parts by weight: 6-10 parts of six-carbon monomer, 25-36 parts of functional monomer, 12-23 parts of ester compound, 1.5-2.5 parts of chain transfer agent, 0.6-1 part of reducing agent, 2.5-5 parts of oxidant, 3-7 parts of pH regulator and 70-80 parts of water.

In a most preferred embodiment, the six-carbon monomer synthesized slow-release polycarboxylate superplasticizer provided by the invention at least comprises the following preparation raw materials in parts by weight: 8 parts of six-carbon monomer, 35.2 parts of functional monomer, 15 parts of ester compound, 1.8 parts of chain transfer agent, 0.7 part of reducing agent, 3 parts of oxidizing agent, 5 parts of pH regulator and 75 parts of water.

Six carbon monomer

In a preferred embodiment, the six-carbon monomer of the present invention is selected from one or more of hydroxyethyl-3-butenyl ether, hydroxypropyl allyl ether, diethylene glycol monovinyl ether, and prenyl polyoxyethylene ether.

In a preferred embodiment, the six-carbon monomer of the present invention is prenyl polyoxyethylene ether.

In a more preferred embodiment, the prenyl polyoxyethylene ethers of the present invention have a molecular weight of 2800-.

In a most preferred embodiment, the prenyl polyoxyethylene ethers of the present invention have a molecular weight of 3000.

In a preferred embodiment, the prenyl polyoxyethylene ethers of the present invention are commercially available from a manufacturer including, but not limited to, Shanghai fine chemical Co., Ltd., under the designation PCB 7230.

The six-carbon monomer is preferably isopentenol polyoxyethylene ether, has the characteristics of early strength, high strength and high durability, participates in the preparation of the polycarboxylic acid water reducing agent by reasonably controlling the molecular weight and the mass ratio of the six-carbon monomer to other monomers, can increase the adaptability of the product to cement, has low slump loss and initial growth trend, does not influence the strength, and has a slow release effect; on the other hand, the water-cement ratio of the concrete can be effectively reduced, and the cost is reduced.

Functional monomer

The functional monomer of the present invention refers to a monomer providing a specific functional group.

In a preferred embodiment, the functional monomer of the present invention is selected from one or more of acrylic acid, methacrylic acid, acrylate, methacrylate, hydroxybutyl methacrylate, hydroxyethyl methacrylate, acrylamide, methylolacrylamide, diacetone acrylamide, acetoacetic acid ethyl methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, hydroxypropyl acrylate, hydroxyethyl acrylate.

In a preferred embodiment, the functional monomer of the present invention is acrylic acid.

The acrylic acid of the invention has the molecular formula C₃H₄O₂Molecular weight 72.06; the liquid is colorless, has pungent smell and strong acidity and is corrosive; dissolving in water, ethanol and diethyl ether, and dissolving in benzene, acetone, chloroform, etc.; melting point 13.5 deg.C, boiling point 140.9 deg.C, density (20/4 deg.C) 1.0611g/cm³(ii) a The chemical property is active; the catalyst is easy to polymerize in the air and can be reduced into propionic acid by hydrogenation; adding hydrogen chloride to generate 2-chloropropionic acid; used for preparing acrylic resin and other organic synthesis. Prepared by oxidation of acrolein or by hydrolysis of acrylonitrile, or by the action of a nickel catalyst of carbon monoxide, acetylene and water.

Acrylic acid is unsaturated organic acid, and the molecule contains a carbon-carbon double bond and a carboxyl structure, and the invention adopts the acrylic acid, particularly controls the mass ratio of the acrylic acid to a six-carbon monomer to be 4: 1, the reaction temperature can reach about 50 ℃, and the molecular weight of the six-carbon monomer is controlled within a certain range, so that the polycarboxylic acid water reducing agent with good dispersibility and slump retention can be obtained.

Ester compounds

The ester compound of the present invention refers to a compound containing an ester group.

In a preferred embodiment, the ester compound of the present invention is selected from one or more of vinyl acetate, allyl acetate, hydroxypropyl acrylate, diethylhexyl maleate, diethyl maleate, polyethylene glycol mono maleate, dilauryl maleate, and diethylene glycol maleate.

In a preferred embodiment, the ester compound of the present invention is a combination of vinyl acetate and hydroxypropyl acrylate, wherein the mass ratio of vinyl acetate to hydroxypropyl acrylate is (2-8): 1.

in a most preferred embodiment, the ester compound of the present invention is a combination of vinyl acetate and hydroxypropyl acrylate, wherein the mass ratio of vinyl acetate to hydroxypropyl acrylate is 4: 1.

according to the invention, the ester compound and the functional monomer are selected for compounding, and particularly, when the ester compound is vinyl acetate and hydroxypropyl acrylate and the functional monomer is acrylic acid, the polycarboxylic acid type water reducing agent with shorter molecular side chains can be formed, the thickness of hydration films of the polycarboxylic acid type water reducing agent on the surfaces of cement particles is further reduced, and more free water is released.

Chain transfer agent

The chain transfer agent of the present invention is a substance that is effective in radical transfer of a chain propagating radical. Used for adjusting the relative molecular mass of the polymer, so the polymer is also called a relative molecular mass regulator.

In a preferred embodiment, the chain transfer agent of the present invention is selected from one of sodium methallyl sulfonate, dithiobenzoate transfer agent, trithiocarbonate transfer, mercaptopropionic acid.

In a most preferred embodiment, the chain transfer agent of the present invention is mercaptopropionic acid.

The mercaptopropionic acid is a molecular chain regulator, plays a role in catalysis and participates in reaction in the synthesis process of the water reducing agent to form a part of the molecular structure of the water reducing agent, has obvious targeting property, comprehensively improves the performance of the polycarboxylic acid master batch, saves the cost and has better effect.

Reducing agent

The reducing agent is a substance that loses electrons or has an electron deviation in a redox reaction. The reducing agent itself has reducing properties and is oxidized, and the product is called an oxidation product. The reduction and the oxidation reaction are carried out simultaneously, that is, the reducing agent itself is oxidized to become an oxide while the reducing agent is oxidized with the reduced material. The reactant containing a certain substance with an increased valence is a reducing agent.

In a preferred embodiment, the reducing agent of the present invention is selected from one or more of ascorbic acid, sodium formaldehyde sulfoxylate, sodium bisulfite, and ferrous sulfate.

In a most preferred embodiment, the reducing agent of the present invention is ascorbic acid.

The six-carbon monomer synthesized slow-release type polycarboxylate superplasticizer obtained by the invention has good fluidity and slump retention, and the possible reason is that more free water can be released due to the fact that the molecular side chain is shorter, and the thickness of a hydration film formed on the surface of cement particles is thinner; on the other hand, a hydrophobic group is introduced into the molecular structure, so that the possibility of the combination of the polycarboxylic acid water reducing agent molecules and the water phase is reduced, and a certain amount of free water is released.

Oxidizing agent

In the redox reaction, a substance that acquires electrons is called an oxidizing agent, and a substance that loses electrons is called a reducing agent. In a narrow sense, an oxidizing agent may also refer to a substance that can make another substance available for oxygen.

In a preferred embodiment, the oxidant is selected from one or more of hydrogen peroxide, potassium persulfate, ammonium persulfate and sodium bisulfite.

In a preferred embodiment, the oxidant is hydrogen peroxide.

pH regulator

The pH regulator is also called as acidity regulator and is used for maintaining or changing the pH value in the system.

In a preferred embodiment, the pH regulator of the present invention is selected from one or more of sodium bicarbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

In a most preferred embodiment, the pH adjusting agent of the present invention is sodium hydroxide.

The sodium hydroxide is also called caustic soda, solid alkali, caustic soda and caustic soda. Sodium hydroxide has strong basicity and strong hygroscopicity. Is easy to dissolve in water, releases heat when dissolved, and the water solution is alkaline and has greasy feeling; the method is mainly used for providing alkalinity and neutralizing the water reducing agent.

The six-carbon monomer synthesized slow-release type polycarboxylate superplasticizer obtained by the invention has good fluidity and slump retention, and the possible reason is that more free water can be released due to the fact that the molecular side chain is shorter, and the thickness of a hydration film formed on the surface of cement particles is thinner; on the other hand, a hydrophobic group is introduced into the molecular structure, so that the possibility of the combination of the polycarboxylic acid water reducing agent molecules and the water phase is reduced, and a certain amount of free water is released.

The second aspect of the invention provides a preparation method for synthesizing a slow-release polycarboxylate superplasticizer by using six-carbon monomers, which at least comprises the following steps:

(1) mixing the functional monomer and the ester compound to obtain a component A; mixing a chain transfer agent, a reducing agent and an oxidizing agent to obtain a component B;

(2) mixing water and a six-carbon monomer and putting into a reaction kettle; simultaneously, dropwise adding the component A and the component B into the reaction kettle, and controlling the dripping completion time of the component A to be 40-60 min; controlling the dripping-off time of the component B to be 50-80 min; keeping the temperature for 1h after the two solutions are dripped, adding a pH regulator, and stirring to obtain the final product.

It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.

In addition, the raw materials used are commercially available from national chemical reagents, unless otherwise specified.