CN107298541B - A kind of viscosity-reducing composite polycarboxylate water reducer and preparation method thereof - Google Patents

Abstract

The present invention provides a viscosity-reducing composite polycarboxylate water reducer, which includes polycarboxylate water reducer A, polycarboxylate water reducer B, polycarboxylate water reducer C, β-cyclodextrin derivatives, Methyl beta cyclodextrin, deionized water; wherein, the preparation raw materials of the polycarboxylate water reducer A include isopentenyl polyoxyethylene ether, acrylic acid, initiator 1, chain transfer agent 1 and deionized water The raw materials for the preparation of the polycarboxylate water reducer B include methallyl polyglycol ether, acrylic acid, sodium methacryl sulfonate, initiator 2, chain transfer agent 2 and deionized water; the poly The raw materials for the preparation of carboxylic acid water reducer C include diallyl terminated polyether, acrylic acid, methallyl polyglycol ether, initiator 3, chain transfer agent 3 and deionized water, the diallyl The β-cyclodextrin derivatives are sodium dodecylsulfonate and carbon nanotubes. Modified β-cyclodextrin.

Description

A kind of viscosity-reducing composite polycarboxylate water reducer and preparation method thereof

technical field

The invention relates to the field of concrete admixtures, in particular to a viscosity-reducing composite polycarboxylate water reducer and a preparation method thereof.

Background technique

At present, concrete is still the main and largest building material in the construction industry. In recent years, with the development of my country's construction industry, high-grade concrete is gradually entering the construction market because of its high strength, good integrity and low weight, especially in bridge engineering. However, due to the use of a lower water-binder ratio and a larger amount of cementitious material, high-grade concrete has the problems of high viscosity and slow flow speed in application.

Polycarboxylate superplasticizer has the advantages of low dosage, high water reducing rate, strong plasticity, small slump loss, low shrinkage, green environmental protection and environmental friendliness, and has become an essential component of high performance concrete one. Its molecular structure is highly designable, and the adaptability of polycarboxylate superplasticizers to different concretes can be realized by controlling the degree of polymerization of the main chain, the density of side chains, and the types of functional groups.

The excessive decrease of concrete slump over time has always been a problem that plagues normal construction. The amount of polycarboxylate superplasticizer itself is very low, and a large amount of superplasticizer will be consumed in the early stage of concrete mixing, resulting in the lack of actual effective ingredients in the later concrete, resulting in a decline in its application performance, especially the serious loss of slump in the later stage , cannot meet the requirements of normal construction.

In addition, polycarboxylic acid has a structure with polyether as the main chain and polyether as the side chain. The molecular thermal stability of this structure is poor, and the molecular structure is easily destroyed under the condition of high temperature for a long time, so that the performance is greatly reduced.

Therefore, in view of the above problems, the present invention provides a viscosity-reducing composite polycarboxylate water-reducer, which solves the problems of high viscosity and slow flow rate in concrete, and also has low dosage, high water-reducing rate, strong plasticity, and slump. It has the advantages of small sag loss, low shrinkage, good thermal stability, green environmental protection and environmental friendliness.

Contents of the invention

In order to solve the above problems, the first aspect of the present invention provides a viscosity-reducing composite polycarboxylate water reducer, which includes polycarboxylate water reducer A, polycarboxylate water reducer B, polycarboxylate water reducer C, β-cyclodextrin derivatives, methyl beta cyclodextrin, deionized water;

Wherein, the preparation raw materials of the polycarboxylate water reducer A include isopentenyl polyoxyethylene ether, acrylic acid, initiator 1, chain transfer agent 1 and deionized water; the preparation of the polycarboxylate water reducer B The raw materials include methallyl polyglycol ether, acrylic acid, sodium methacrylic sulfonate, initiator 2, chain transfer agent 2 and deionized water; the raw materials for the preparation of the polycarboxylate water reducer C include diene Propyl-terminated polyether, acrylic acid, methallyl polyglycol ether, initiator 3, chain transfer agent 3 and deionized water, the bisallyl-terminated polyether is prepared by allyl bromide The methoxypolyethylene glycol is prepared by allylation and capping; the beta-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified beta-cyclodextrin.

In one embodiment, the weight ratio of the polycarboxylate water reducer A to the polycarboxylate water reducer B and the polycarboxylate water reducer C is 1:(0.5-1):(0.8 -2).

In one embodiment, the weight ratio of the polycarboxylate water reducer A to the polycarboxylate water reducer B and the polycarboxylate water reducer C is 1:(0.6-0.8):(1 -1.6).

In one embodiment, the weight ratio of the β-cyclodextrin derivative to the methylbeta-cyclodextrin is 1:(1-3).

In one embodiment, the weight ratio of the β-cyclodextrin derivative to the methylbeta-cyclodextrin is 1:(1.2-2).

In one embodiment, the weight ratio of the polycarboxylate superplasticizer A to the methyl beta cyclodextrin is 1:(0.002-0.02).

In one embodiment, in parts by weight, the raw materials for the preparation of the polycarboxylate water reducer A include 35-40 parts of isopentenyl polyoxyethylene ether, 3-5 parts of acrylic acid, and 0.1-0.5 parts of initiator 1. 0.1-0.4 parts of chain transfer agent 1 and 50-70 parts of deionized water; the weight average molecular weight of the isopentenyl polyoxyethylene ether is 1000-3000.

In one embodiment, in parts by weight, the raw materials for the preparation of the polycarboxylate water reducer B include 20-35 parts of methallyl polyglycol ether, 3-7 parts of acrylic acid, 0.5-3 parts Sodium methacryl sulfonate, 0.1-0.5 parts of initiator 2, 0.1-0.5 parts of chain transfer agent 2 and 50-70 parts of deionized water; the weight average molecular weight of the methallyl polyglycol ether is 1000- 2400.

In one embodiment, in parts by weight, the raw materials for the preparation of the polycarboxylate water reducer C include 20-30 parts of diallyl-terminated polyether, 2-5 parts of acrylic acid, 1-4 parts of methyl Allyl polyethylene glycol ether, 0.1-0.5 parts of initiator 3, 0.1-0.5 parts of chain transfer agent 3 and 50-70 parts of deionized water; the weight average molecular weight of the bisallyl-terminated polyether is 2000- 4000, the weight average molecular weight of methallyl polyglycol ether is 1000-2400.

Another aspect of the present invention provides a method for preparing a viscosity-reducing composite polycarboxylate water reducer, comprising the following steps:

(1) Add polycarboxylate superplasticizer A, polycarboxylate superplasticizer B, polycarboxylate superplasticizer C, β-cyclodextrin derivatives, methyl beta cyclodextrin and deionized water, and stirred for 2-3 hours to obtain the mother liquor of the viscosity-reducing composite polycarboxylate superplasticizer;

(2) Place the mother liquor of the viscosity-reducing composite polycarboxylate superplasticizer in a vacuum ultrasonic microwave drying oven, the depth of the mother liquor is 6cm, turn on the vacuum pump and adjust the vacuum degree in the drying oven to -0.09--0.08MPa; set the ultrasonic frequency to 30kHz, the power of the ultrasonic generator is 100W, turn on the microwave generator, the microwave frequency is 2450MHz, set the drying temperature to 55°C, and adjust the microwave power range to 200kW, and dry for 2-4h to obtain a solid viscosity-reducing composite polycarboxylate acid water reducer;

(3) The solid viscosity-reducing composite polycarboxylate water-reducer obtained by drying in step (2) is pulverized to obtain a viscosity-reducing composite polycarboxylate water-reducer powder.

These and other features, aspects and advantages of the present application will be better understood with reference to the following detailed description.

Detailed ways

The invention can be more readily understood by reference to the following detailed description of the preferred practice of the invention and the included examples. 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 definitions in this specification shall prevail.

As used herein, the term "prepared from" is synonymous with "comprising". As used herein, the terms "comprises," "including," "has," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, step, method, article, or device comprising listed elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to such composition, step, method, article, or device. elements.

The conjunction "consisting of" excludes any unspecified elements, steps or components. If used in a claim, this phrase will make the claim closed so that it does not contain material other than those described except for the customary impurities associated therewith. When the phrase "consisting of" appears in a clause of the subject of a claim rather than immediately following the subject matter, it only defines the elements described in that clause; other elements are not excluded from the claim as a whole. Outside of requirements.

When amounts, concentrations, or other values or parameters are expressed in terms of ranges, preferred ranges, or ranges bounded by a series of upper preferred values and lower preferred values, it is to be understood that any range upper or preferred value combined with any lower range limit is specifically disclosed. All ranges formed by any pairing of values or preferred values, whether or not such ranges are individually disclosed. For example, when the range "1 to 5" is disclosed, the recited range should be construed to include the ranges "1 to 4," "1 to 3," "1 to 2," "1 to 2, and 4 to 5" , "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, that range is intended to include its endpoints and all integers and fractions within the range.

Singular forms include plural referents unless the context clearly dictates otherwise. "Optional" or "either" means that the item or event described thereafter may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximate terms in the specification and claims are used to modify the quantity, which means that the present invention is not limited to the specific quantity, but also includes acceptable modifications that are close to the quantity and will not cause changes in the relevant basic functions. Accordingly, a numerical value modified by "about", "about", etc., means that the present invention is not limited to the precise numerical value. In some instances, approximate terms may correspond to the precision of the instrument for measuring the value. Throughout the specification and claims of this application, range limitations may be combined and/or interchanged, unless otherwise stated such ranges include all subranges contained therebetween.

In addition, the indefinite articles "a" and "an" preceding an element or component of the present invention have no limitation on the quantity requirement (ie, the number of occurrences) of the element or component. Thus "a" or "an" should be read to include one or at least one, and elements or components in the singular also include the plural unless the number is clearly intended to be in the singular.

"Polymer" means a polymeric compound prepared by polymerizing monomers of the same or different type. The generic term "polymer" encompasses the terms "homopolymer", "copolymer", "terpolymer" and "interpolymer".

"Interpolymer" means a polymer prepared by polymerizing at least two different monomers. The general term "interpolymer" includes the term "copolymer" (which is generally used to refer to a polymer prepared from two different monomers) and the term "terpolymer" (which is generally used to refer to a polymer prepared from three different monomers). of polymers). It also includes polymers made by polymerizing further monomers. "Blend" means a polymer formed by mixing two or more polymers together by physical or chemical means.

The first aspect of the present invention provides a viscosity-reducing composite polycarboxylate water-reducer, which includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, and β-cyclodextrin Derivatives, methyl beta cyclodextrin (CAS No.: 128446-36-6), water;

Wherein, the preparation raw materials of the polycarboxylate water reducer A include isopentenyl polyoxyethylene ether, acrylic acid, initiator 1, chain transfer agent 1 and deionized water; the preparation of the polycarboxylate water reducer B The raw materials include methallyl polyglycol ether, acrylic acid, sodium methacrylic sulfonate, initiator 2, chain transfer agent 2 and deionized water; the raw materials for the preparation of the polycarboxylate water reducer C include diene Propyl-terminated polyether, acrylic acid, methallyl polyglycol ether, initiator 3, chain transfer agent 3 and deionized water, the bisallyl-terminated polyether is prepared by allyl bromide The methoxypolyethylene glycol is prepared by allylation and capping; the beta-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified beta-cyclodextrin.

In one embodiment, the weight ratio of the polycarboxylate water reducer A to the polycarboxylate water reducer B and the polycarboxylate water reducer C is 1:(0.5-1):(0.8 -2).

In one embodiment, the weight ratio of the polycarboxylate water reducer A to the polycarboxylate water reducer B and the polycarboxylate water reducer C is 1:(0.6-0.8):(1 -1.6); Preferably, the weight ratio of the polycarboxylate water reducer A to the polycarboxylate water reducer B and the polycarboxylate water reducer C is 1:0.7:1.1.

In one embodiment, the weight ratio of the β-cyclodextrin derivative to the methylbeta-cyclodextrin is 1:(1-3).

In one embodiment, the weight ratio of the β-cyclodextrin derivative to the methylbeta-cyclodextrin is 1: (1.2-2); preferably, the β-cyclodextrin derivative The weight ratio to the methyl beta cyclodextrin is 1:1.3.

In one embodiment, the weight ratio of the polycarboxylate water reducer A to the methyl beta cyclodextrin is 1: (0.002-0.02); preferably, the polycarboxylate water reducer A The weight ratio to the methyl beta cyclodextrin is 1:0.016.

The preparation method of the β-cyclodextrin derivative comprises the following steps:

(1) Add concentrated sulfuric acid and sodium nitrate to the reactor, cool in an ice-water bath, stir and add carbon nanotubes at 0-5°C, mix well and slowly add potassium permanganate, and control the reaction temperature at 10-15°C , react for 2h, continue to stir and react for 2h at 35°C, add deionized water, control the temperature of the reaction solution at 98°C, continue to stir for 0.5h, then add hydrogen peroxide with a mass concentration of 30%, filter while it is hot, and dilute hydrochloric acid (1mol /L) washing the product to neutrality, and drying under reduced pressure at 60° C. for 24 hours to obtain acidified carbon nanotubes; the weight ratio of the acidified carbon nanotubes to the sodium nitrate and the potassium permanganate is 1 : 0.6:4; the mass volume ratio of the carbon nanotubes to the concentrated sulfuric acid with a mass concentration of 98%, the hydrogen peroxide with a mass concentration of 30%, and the deionized water is 1:20:3:20;

(2) Add acidified carbon nanotubes, hexamethylenediamine, and N,N-dimethylformamide into the reactor, blow in nitrogen, stir for 1 hour, add dicyclohexylcarbodiimide (CAS No.: 538-75- 0) mixed solution with tetrahydrofuran (the weight ratio of the dicyclohexylcarbodiimide to the tetrahydrofuran is 1:5), react at room temperature for 72h, after the reaction, filter with a cellulose acetate filter membrane with a pore size of 0.45 μm, The filter cake was dried under reduced pressure at 80°C for 24 hours to obtain aminated carbon nanotubes; The weight ratio of diimine is 1:20:20:15;

(3) Add aminated carbon nanotubes and dichloromethane into the reactor, stir for 10 h at 30°C, add dropwise the silane coupling agent KH-560, continue stirring for 3 h, and then adjust the pH to 4 with 1 mol/L hydrochloric acid , add β-cyclodextrin, keep warm for 3 hours, add acetone and stir for 0.5 hours, filter, and dry the filter cake under reduced pressure at 50°C for 24 hours to obtain carbon nanotube modified β-cyclodextrin; the aminated carbon nano The weight ratio of the tube to the dichloromethane, the KH-560, and the β-cyclodextrin is 1:12:2:2;

(4) Add carbon nanotube modified β-cyclodextrin, sodium dodecylsulfonate, and polyphosphoric acid to the reactor, heat up to 180°C, keep the temperature for 6 hours, cool down to room temperature after the reaction, add acetone, and filter , and washed 3 times with acetone, and dried under reduced pressure at 60° C. for 12 hours to obtain sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the carbon nanotube modified β-cyclodextrin and The weight ratio of the sodium dodecylsulfonate to the polyphosphoric acid is 1:0.1:20.

In one embodiment, in parts by weight, the raw materials for the preparation of the polycarboxylate water reducer A include 35-40 parts of isopentenyl polyoxyethylene ether, 3-5 parts of acrylic acid, and 0.1-0.5 parts of initiator 1. 0.1-0.4 parts of chain transfer agent 1 and 50-70 parts of deionized water; the weight average molecular weight of the isopentenyl polyoxyethylene ether is 1000-3000; preferably, the polycarboxylate water reducer A The preparation raw materials include 37 parts of isopentenyl polyoxyethylene ether, 4 parts of acrylic acid, 0.3 part of initiator 1, 0.2 part of chain transfer agent 1 and 60 parts of deionized water; the weight average molecular weight of the isopentenyl polyoxyethylene ether for 2400.

In one embodiment, the initiator 1 includes one or more of ammonium persulfate, benzoyl peroxide, and azobisisobutyronitrile; preferably, the initiator 1 is ammonium persulfate.

In one embodiment, the chain transfer agent 1 includes one or more of sodium bisulfite, ammonium ferrous sulfate, glucose, and oxalic acid; preferably, the chain transfer agent 1 is sodium bisulfite.

The preparation method of described polycarboxylate water reducer A comprises the following steps:

Add 37 parts of isopentenyl polyoxyethylene ether and 52 parts of deionized water to the reactor in parts by weight, stir, heat up to 80°C, add 0.2 parts of sodium bisulfite, dropwise add acrylic acid/deionized water (4 parts of acrylic acid , 6 parts of deionized water) and ammonium persulfate/deionized water (0.3 parts of ammonium persulfate, 2 parts of deionized water), after the dropwise addition, continue the reaction for 2 hours, cool down to 40 ° C, adjust the pH value to 7-8, Obtain the polycarboxylate water reducer A solution; place the polycarboxylate water reducer A solution in a vacuum ultrasonic microwave drying oven, the solution depth is 6cm, turn on the vacuum pump and adjust the vacuum degree in the drying oven to -0.09--0.08MPa; Set the ultrasonic frequency to 30kHz, the power of the ultrasonic generator to 100W, turn on the microwave generator, set the microwave frequency to 2450MHz, set the drying temperature to 55°C, adjust the microwave power range to 200kW, and dry for 3 hours to obtain polycarboxylic acid water-reducing Agent A.

In one embodiment, in parts by weight, the raw materials for the preparation of the polycarboxylate water reducer B include 20-35 parts of methallyl polyglycol ether, 3-7 parts of acrylic acid, 0.5-3 parts Sodium methacryl sulfonate, 0.1-0.5 parts of initiator 2, 0.1-0.5 parts of chain transfer agent 2 and 50-70 parts of deionized water; the weight average molecular weight of the methallyl polyglycol ether is 1000- 2400; Preferably, the raw materials for the preparation of the polycarboxylate water reducer B include 25 parts of methallyl polyglycol ether, 5 parts of acrylic acid, 1.5 parts of sodium methacryl sulfonate, 0.4 parts of initiator 2, 0.3 parts of chain transfer agent 2 and 65 parts of deionized water; the weight average molecular weight of the methallyl polyglycol ether is 1200.

In one embodiment, the initiator 2 includes one or more of ammonium persulfate, benzoyl peroxide, and azobisisobutyronitrile; preferably, the initiator 2 is ammonium persulfate.

In one embodiment, the chain transfer agent 2 includes one or more of sodium bisulfite, ammonium ferrous sulfate, glucose, and oxalic acid; preferably, the chain transfer agent 2 is sodium bisulfite.

The preparation method of described polycarboxylate water reducer B comprises the following steps:

Add 25 parts of methallyl polyglycol ether and 51 parts of deionized water to the reactor in parts by weight, stir, heat up to 70°C, add 0.3 parts of sodium bisulfite, add dropwise acrylic acid/deionized water ( 5 parts acrylic acid, 7 parts deionized water) and sodium methacrylate/deionized water (1.5 parts sodium methacrylate, 4 parts deionized water), ammonium persulfate/deionized water (0.4 parts persulfate Ammonium, 3 parts of deionized water), after the dropwise addition, continue to react for 1h, cool down to 40°C, adjust the pH value to 7-8, and obtain the polycarboxylate superplasticizer B solution; put the polycarboxylate superplasticizer B solution in In the vacuum ultrasonic microwave drying oven, the solution depth is 6cm, turn on the vacuum pump to adjust the vacuum degree in the drying oven to -0.09--0.08MPa; set the ultrasonic frequency to 30kHz, the power of the ultrasonic generator is 100W, turn on the microwave generator , the microwave frequency is 2450MHz, the drying temperature is set at 55°C, and the microwave power range is adjusted to 200kW, and dried for 3 hours to obtain polycarboxylate superplasticizer B.

In one embodiment, in parts by weight, the raw materials for the preparation of the polycarboxylate water reducer C include 20-30 parts of diallyl-terminated polyether, 2-5 parts of acrylic acid, 1-4 parts of methyl Allyl polyethylene glycol ether, 0.1-0.5 parts of initiator 3, 0.1-0.5 parts of chain transfer agent 3 and 50-70 parts of deionized water; the weight average molecular weight of the bisallyl-terminated polyether is 2000- 4000, the weight-average molecular weight of methallyl polyethylene glycol ether is 1000-2400; preferably, the preparation raw materials of the polycarboxylate water reducer C include 22 parts of diallyl-terminated polyether, 3 parts of acrylic acid , 2 parts of methallyl polyglycol ether, 0.4 part of initiator 3, 0.3 part of chain transfer agent 3 and 60 parts of deionized water; The weight average molecular weight of allyl polyglycol ether is 1600.

In one embodiment, the initiator 3 includes one or more of ammonium persulfate, benzoyl peroxide, and azobisisobutyronitrile; preferably, the initiator 3 is ammonium persulfate.

In one embodiment, the chain transfer agent 3 includes one or more of sodium bisulfite, ammonium ferrous sulfate, glucose, and oxalic acid; preferably, the chain transfer agent 3 is sodium bisulfite.

The preparation method of described polycarboxylate water reducer C comprises the following steps:

(1) Preparation of bisallyl-terminated polyether: add methoxypolyethylene glycol into the reactor, feed nitrogen, raise the temperature to 60°C, add potassium methoxide in four times, and stir for 0.5h after feeding is completed , and then add allyl bromide dropwise. After the dropwise addition, keep warm at 60°C for 3 hours. After the reaction, cool down to room temperature, add phosphoric acid to adjust the pH value to neutral, and perform refining treatment to obtain diallyl-terminated polyether ;

(2) Preparation of polycarboxylate water reducer C: add 25 parts of 22 parts of diallyl-terminated polyether and 51 parts of deionized water to the reactor in parts by weight, stir, heat up to 80°C, and add 0.3 parts Sodium bisulfite, dropwise add acrylic acid/deionized water (3 parts acrylic acid, 5 parts deionized water) and 2 parts methallyl polyglycol ether, ammonium persulfate/deionized water (0.4 parts , 3 parts of deionized water), after the dropwise addition, continue to react for 1h, lower the temperature to 35°C, adjust the pH value to 7-8, and obtain the polycarboxylate superplasticizer C solution; place the polycarboxylate superplasticizer C solution in In the vacuum ultrasonic microwave drying oven, the solution depth is 6cm, turn on the vacuum pump to adjust the vacuum in the drying oven to -0.09--0.08MPa; set the ultrasonic frequency to 30kHz, the power of the ultrasonic generator is 100W, turn on the microwave generator, The microwave frequency is 2450MHz, the drying temperature is set at 55°C, and the microwave power range is adjusted to 200kW, and dried for 3 hours to obtain polycarboxylate superplasticizer C.

Another aspect of the present invention provides a method for preparing a viscosity-reducing composite polycarboxylate water reducer, comprising the following steps:

(1) Add polycarboxylate superplasticizer A, polycarboxylate superplasticizer B, polycarboxylate superplasticizer C, β-cyclodextrin derivatives, methyl beta cyclodextrin and deionized water, and stirred for 2-3 hours to obtain the mother liquor of the viscosity-reducing composite polycarboxylate superplasticizer;

(2) Place the mother liquor of the viscosity-reducing composite polycarboxylate superplasticizer in a vacuum ultrasonic microwave drying oven, the depth of the mother liquor is 6cm, turn on the vacuum pump and adjust the vacuum degree in the drying oven to -0.09--0.08MPa; set the ultrasonic frequency to 30kHz, the power of the ultrasonic generator is 100W, turn on the microwave generator, the microwave frequency is 2450MHz, set the drying temperature to 55°C, and adjust the microwave power range to 200kW, and dry for 2-4h to obtain a solid viscosity-reducing composite polycarboxylate acid water reducer;

(3) The solid viscosity-reducing composite polycarboxylate water-reducer obtained by drying in step (2) is pulverized to obtain a viscosity-reducing composite polycarboxylate water-reducer powder.

In the present invention, the polycarboxylate water reducer is compounded, and the polycarboxylate water reducer is coated on β-cyclodextrin derivatives and methyl beta cyclodextrin, and the β-cyclodextrin derivatives, methyl The beta-cyclodextrin-coated polycarboxylate water reducer can increase the thermal decomposition temperature of the polycarboxylate water reducer, while increasing the water content of the composite polycarboxylate water reducer and improving the powdery composite polycarboxylate water reducer. The performance of the water agent, and the composite polycarboxylate water reducer has good workability, high strength and good adaptability.

In addition, the adsorption of carboxyl groups in the molecular structure of polycarboxylate superplasticizer A and the steric hindrance of polyoxyalkylene side chains make cement have a high initial dispersion in concrete; polycarboxylate superplasticizer B and polycarboxylate Carboxylic acid superplasticizer C, in the alkaline environment provided by cement hydration, opens the gel-like structure of superplasticizer molecules through hydrolysis, expands the molecular chain, and releases the carboxyl and polyoxyalkylene sides wrapped in the gel structure. Chain, timely replenish the lost active ingredients in the system, so that it has better concrete slump retention. After compounding various polycarboxylate water reducers, it has good concrete slump retention for a long time, avoids bleeding and segregation caused by excessive slump of early-strength concrete, and makes the concrete have an ideal The slump retention time solves the problem of excessive slump loss in engineering; through the modification of β-cyclodextrin and the introduction of carbon nanotubes, the polycarboxylate superplasticizer has a better performance in a longer period of time. Excellent concrete slump retention, further reducing the viscosity of polycarboxylate superplasticizer.

The viscosity-reducing composite polycarboxylate superplasticizer provided by the invention has excellent performance, strong product adaptability, and is suitable for various specifications and types of cement. Crystallization; the product is non-toxic and pollution-free.

The present invention is specifically described below by way of examples. It is necessary to point out that the following examples are only used to further illustrate the present invention, and can not be interpreted as limiting the protection scope of the present invention, some non-essential improvements made by those skilled in the art according to the content of the present invention above And adjustments still belong to the protection scope of the present invention.

In addition, unless otherwise stated, all raw materials used were commercially available from Sinopharm Chemical Reagents.

Example 1

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, β-cyclodextrin derivatives, methyl double other cyclodextrin, deionized water; wherein, the β-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the polycarboxylate water reducer A and The weight ratio of the polycarboxylate water reducer B to the polycarboxylate water reducer C is 1:0.7:1.1; the weight of the β-cyclodextrin derivative and the methyl beta cyclodextrin The ratio is 1:1.3; the weight ratio of the polycarboxylate superplasticizer A to the methyl beta cyclodextrin is 1:0.016;

The preparation method of the described viscosity-reducing composite polycarboxylate water reducer comprises the following steps:

(1) Add polycarboxylate superplasticizer A, polycarboxylate superplasticizer B, polycarboxylate superplasticizer C, β-cyclodextrin derivatives, methyl beta cyclodextrin and deionized water, and stirred for 2 hours to obtain the mother liquor of the viscosity-reducing composite polycarboxylate superplasticizer; the weight ratio of the polycarboxylate superplasticizer A to the deionized water was 1:8;

(2) Place the mother liquor of the viscosity-reducing composite polycarboxylate superplasticizer in a vacuum ultrasonic microwave drying oven, the depth of the mother liquor is 6cm, turn on the vacuum pump and adjust the vacuum degree in the drying oven to -0.09--0.08MPa; set the ultrasonic frequency to 30kHz, the power of the ultrasonic generator is 100W, turn on the microwave generator, the microwave frequency is 2450MHz, set the drying temperature to 55°C, and adjust the microwave power range to 200kW, and dry for 2-4h to obtain a solid viscosity-reducing composite polycarboxylate Acid water reducer;

(3) The solid viscosity-reducing composite polycarboxylate water-reducer obtained by drying in step (2) is pulverized to obtain a viscosity-reducing composite polycarboxylate water-reducer powder.

Calculated in parts by weight, the raw materials for the preparation of the polycarboxylate water reducer A include 37 parts of isopentenyl polyoxyethylene ether, 4 parts of acrylic acid, 0.3 parts of initiator 1, 0.2 parts of chain transfer agent 1 and 60 parts of deionized Water; The weight-average molecular weight of the isopentenyl polyoxyethylene ether is 2400;

The preparation method of described polycarboxylate water reducer A comprises the following steps:

Add 37 parts of isopentenyl polyoxyethylene ether and 52 parts of deionized water to the reactor in parts by weight, stir, heat up to 80°C, add 0.2 parts of sodium bisulfite, dropwise add acrylic acid/deionized water (4 parts of acrylic acid , 6 parts of deionized water) and ammonium persulfate/deionized water (0.3 parts of ammonium persulfate, 2 parts of deionized water), after the dropwise addition, continue the reaction for 2 hours, cool down to 40 ° C, adjust the pH value to 7-8, Obtain the polycarboxylate water reducer A solution; place the polycarboxylate water reducer A solution in a vacuum ultrasonic microwave drying oven, the solution depth is 6cm, turn on the vacuum pump and adjust the vacuum degree in the drying oven to -0.09--0.08MPa; Set the ultrasonic frequency to 30kHz, the power of the ultrasonic generator to 100W, turn on the microwave generator, set the microwave frequency to 2450MHz, set the drying temperature to 55°C, adjust the microwave power range to 200kW, and dry for 3 hours to obtain polycarboxylic acid water-reducing Agent A.

Calculated in parts by weight, the raw materials for the preparation of the polycarboxylate water reducer B include 25 parts of methallyl polyglycol ether, 5 parts of acrylic acid, 1.5 parts of sodium methacryl sulfonate, 0.4 parts of initiator 2, 0.3 parts of chain transfer agent 2 and 65 parts of deionized water; the weight average molecular weight of the methallyl polyglycol ether is 1200; the initiator 2 is ammonium persulfate; the chain transfer agent 2 is sulfurous acid sodium hydrogen;

The preparation method of described polycarboxylate water reducer B comprises the following steps:

Add 25 parts of methallyl polyglycol ether and 51 parts of deionized water to the reactor in parts by weight, stir, heat up to 70°C, add 0.3 parts of sodium bisulfite, add dropwise acrylic acid/deionized water ( 5 parts acrylic acid, 7 parts deionized water) and sodium methacrylate/deionized water (1.5 parts sodium methacrylate, 4 parts deionized water), ammonium persulfate/deionized water (0.4 parts persulfate Ammonium, 3 parts of deionized water), after the dropwise addition, continue to react for 1h, cool down to 40°C, adjust the pH value to 7-8, and obtain the polycarboxylate superplasticizer B solution; put the polycarboxylate superplasticizer B solution in In the vacuum ultrasonic microwave drying oven, the solution depth is 6cm, turn on the vacuum pump to adjust the vacuum degree in the drying oven to -0.09--0.08MPa; set the ultrasonic frequency to 30kHz, the power of the ultrasonic generator is 100W, turn on the microwave generator , the microwave frequency is 2450MHz, the drying temperature is set at 55°C, and the microwave power range is adjusted to 200kW, and dried for 3 hours to obtain polycarboxylate superplasticizer B.

Calculated in parts by weight, the raw materials for the preparation of the polycarboxylate water reducer C include 22 parts of diallyl-terminated polyether, 3 parts of acrylic acid, 2 parts of methallyl polyethylene glycol ether, 0.4 parts of initiator 3. 0.3 parts of chain transfer agent 3 and 60 parts of deionized water; the weight-average molecular weight of the bisallyl-terminated polyether is 3000, and the weight-average molecular weight of methallyl polyethylene glycol ether is 1600; the initiation The agent 3 is ammonium persulfate, and the chain transfer agent 3 is sodium bisulfite;

The preparation method of described polycarboxylate water reducer C comprises the following steps:

(1) Preparation of bisallyl-terminated polyether: add methoxypolyethylene glycol into the reactor, feed nitrogen, raise the temperature to 60°C, add potassium methoxide in four times, and stir for 0.5h after feeding is completed , and then add allyl bromide dropwise. After the dropwise addition, keep warm at 60°C for 3 hours. After the reaction, cool down to room temperature, add phosphoric acid to adjust the pH value to neutral, and perform refining treatment to obtain diallyl-terminated polyether ;

(2) Preparation of polycarboxylate water reducer C: add 25 parts of 22 parts of diallyl-terminated polyether and 51 parts of deionized water to the reactor in parts by weight, stir, heat up to 80°C, and add 0.3 parts Sodium bisulfite, dropwise add acrylic acid/deionized water (3 parts acrylic acid, 5 parts deionized water) and 2 parts methallyl polyglycol ether, ammonium persulfate/deionized water (0.4 parts , 3 parts of deionized water), after the dropwise addition, continue to react for 1h, lower the temperature to 35°C, adjust the pH value to 7-8, and obtain the polycarboxylate superplasticizer C solution; place the polycarboxylate superplasticizer C solution in In the vacuum ultrasonic microwave drying oven, the solution depth is 6cm, turn on the vacuum pump to adjust the vacuum in the drying oven to -0.09--0.08MPa; set the ultrasonic frequency to 30kHz, the power of the ultrasonic generator is 100W, turn on the microwave generator, The microwave frequency is 2450MHz, the drying temperature is set at 55°C, and the microwave power range is adjusted to 200kW, and dried for 3 hours to obtain polycarboxylate superplasticizer C.

The preparation method of the β-cyclodextrin derivative comprises the following steps:

(1) Add concentrated sulfuric acid and sodium nitrate to the reactor, cool in an ice-water bath, stir and add carbon nanotubes at 0-5°C, mix well and slowly add potassium permanganate, and control the reaction temperature at 10-15°C , react for 2h, continue to stir and react for 2h at 35°C, add deionized water, control the temperature of the reaction solution at 98°C, continue to stir for 0.5h, then add hydrogen peroxide with a mass concentration of 30%, filter while it is hot, and dilute hydrochloric acid (1mol /L) washing the product to neutrality, and drying under reduced pressure at 60° C. for 24 hours to obtain acidified carbon nanotubes; the weight ratio of the acidified carbon nanotubes to the sodium nitrate and the potassium permanganate is 1 : 0.6:4; the mass volume ratio of the carbon nanotubes to the concentrated sulfuric acid with a mass concentration of 98%, the hydrogen peroxide with a mass concentration of 30%, and the deionized water is 1:20:3:20;

(2) Add acidified carbon nanotubes, hexamethylenediamine, and N,N-dimethylformamide into the reactor, blow in nitrogen, stir for 1 hour, add dicyclohexylcarbodiimide (CAS No.: 538-75- 0) mixed solution with tetrahydrofuran (the weight ratio of the dicyclohexylcarbodiimide to the tetrahydrofuran is 1:5), react at room temperature for 72h, after the reaction, filter with a cellulose acetate filter membrane with a pore size of 0.45 μm, The filter cake was dried under reduced pressure at 80°C for 24 hours to obtain aminated carbon nanotubes; The weight ratio of diimine is 1:20:20:15;

(3) Add aminated carbon nanotubes and dichloromethane into the reactor, stir for 10 h at 30°C, add dropwise the silane coupling agent KH-560, continue stirring for 3 h, and then adjust the pH to 4 with 1 mol/L hydrochloric acid , add β-cyclodextrin, keep warm for 3 hours, add acetone and stir for 0.5 hours, filter, and dry the filter cake under reduced pressure at 50°C for 24 hours to obtain carbon nanotube modified β-cyclodextrin; the aminated carbon nano The weight ratio of the tube to the dichloromethane, the KH-560, and the β-cyclodextrin is 1:12:2:2;

(4) Add carbon nanotube modified β-cyclodextrin, sodium dodecylsulfonate, and polyphosphoric acid to the reactor, heat up to 180°C, keep the temperature for 6 hours, cool down to room temperature after the reaction, add acetone, and filter , and washed 3 times with acetone, and dried under reduced pressure at 60° C. for 12 hours to obtain sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the carbon nanotube modified β-cyclodextrin and The weight ratio of the sodium dodecylsulfonate to the polyphosphoric acid is 1:0.1:20.

Example 2

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, β-cyclodextrin derivatives, methyl double other cyclodextrin, deionized water; wherein, the β-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the polycarboxylate water reducer A and The weight ratio of the polycarboxylate water reducer B to the polycarboxylate water reducer C is 1:0.5:0.8; the weight of the β-cyclodextrin derivative and the methyl beta cyclodextrin The ratio is 1:1.3; the weight ratio of the polycarboxylate water reducer A to the methyl beta cyclodextrin is 1:0.016; the preparation method of the viscosity-reducing composite polycarboxylate water reducer, the The preparation method of the polycarboxylate water reducer A, the preparation method of the polycarboxylate water reducer B, the preparation method of the polycarboxylate water reducer C, the preparation method of the β-cyclodextrin derivative With embodiment 1.

Example 3

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, β-cyclodextrin derivatives, methyl double other cyclodextrin, deionized water; wherein, the β-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the polycarboxylate water reducer A and The weight ratio of the polycarboxylate water reducer B to the polycarboxylate water reducer C is 1:1:2; the weight ratio of the β-cyclodextrin derivative to the methylbeta cyclodextrin The ratio is 1:1.3; the weight ratio of the polycarboxylate superplasticizer A to the methyl beta cyclodextrin is 1:0.016;

The preparation method of the viscosity-reducing composite polycarboxylate water reducer, the preparation method of the polycarboxylate water reducer A, the preparation method of the polycarboxylate water reducer B, the polycarboxylate water reducer The preparation method of C and the preparation method of the β-cyclodextrin derivative are the same as in Example 1.

Example 4

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, β-cyclodextrin derivatives, methyl double other cyclodextrin, deionized water; wherein, the β-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the polycarboxylate water reducer A and The weight ratio of the polycarboxylate water reducer B to the polycarboxylate water reducer C is 1:0.7:1.1; the weight of the β-cyclodextrin derivative and the methyl beta cyclodextrin The ratio is 1:1; the weight ratio of the polycarboxylate superplasticizer A to the methyl beta cyclodextrin is 1:0.016;

The preparation method of the viscosity-reducing composite polycarboxylate water reducer, the preparation method of the polycarboxylate water reducer A, the preparation method of the polycarboxylate water reducer B, the polycarboxylate water reducer The preparation method of C and the preparation method of the β-cyclodextrin derivative are the same as in Example 1.

Example 5

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, β-cyclodextrin derivatives, methyl double other cyclodextrin, deionized water; wherein, the β-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the polycarboxylate water reducer A and The weight ratio of the polycarboxylate water reducer B to the polycarboxylate water reducer C is 1:0.7:1.1; the weight of the β-cyclodextrin derivative and the methyl beta cyclodextrin The ratio is 1:3; the weight ratio of the polycarboxylate superplasticizer A to the methyl beta cyclodextrin is 1:0.016;

The preparation method of the viscosity-reducing composite polycarboxylate water reducer, the preparation method of the polycarboxylate water reducer A, the preparation method of the polycarboxylate water reducer B, the polycarboxylate water reducer The preparation method of C and the preparation method of the β-cyclodextrin derivative are the same as in Example 1.

Example 6

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, β-cyclodextrin derivatives, methyl double other cyclodextrin, deionized water; wherein, the β-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the polycarboxylate water reducer A and The weight ratio of the polycarboxylate water reducer B to the polycarboxylate water reducer C is 1:0.7:1.1; the weight of the β-cyclodextrin derivative and the methyl beta cyclodextrin The ratio is 1:1.3; the weight ratio of the polycarboxylate superplasticizer A to the methyl beta cyclodextrin is 1:0.002;

The preparation method of the viscosity-reducing composite polycarboxylate water reducer, the preparation method of the polycarboxylate water reducer A, the preparation method of the polycarboxylate water reducer B, the polycarboxylate water reducer The preparation method of C and the preparation method of the β-cyclodextrin derivative are the same as in Example 1.

Example 7

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, β-cyclodextrin derivatives, methyl double other cyclodextrin, deionized water; wherein, the β-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the polycarboxylate water reducer A and The weight ratio of the polycarboxylate water reducer B to the polycarboxylate water reducer C is 1:0.7:1.1; the weight of the β-cyclodextrin derivative and the methyl beta cyclodextrin The ratio is 1:1.3; the weight ratio of the polycarboxylate superplasticizer A to the methyl beta cyclodextrin is 1:0.02;

The preparation method of the viscosity-reducing composite polycarboxylate water reducer, the preparation method of the polycarboxylate water reducer A, the preparation method of the polycarboxylate water reducer B, the polycarboxylate water reducer The preparation method of C and the preparation method of the β-cyclodextrin derivative are the same as in Example 1.

Comparative example 1

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, methylbeta-cyclodextrin, deionized water The weight ratio of the polycarboxylate water reducer A to the polycarboxylate water reducer B and the polycarboxylate water reducer C is 1:0.7:1.1; the polycarboxylate water reducer A and The weight ratio of the methyl beta cyclodextrin is 1:0.016;

The preparation method of the viscosity-reducing composite polycarboxylate water reducer, the preparation method of the polycarboxylate water reducer A, the preparation method of the polycarboxylate water reducer B, the polycarboxylate water reducer The preparation method of C is the same as that of Example 1, except that there is no β-cyclodextrin derivative in the formula.

Comparative example 2

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, β-cyclodextrin derivatives, and water; wherein , the β-cyclodextrin derivative is sodium dodecylsulfonate and carbon nanotube modified β-cyclodextrin; the polycarboxylate water reducer A and the polycarboxylate water reducer B, The weight ratio of the polycarboxylate water reducer C is 1:0.7:1.1; the weight ratio of the polycarboxylate water reducer A to the β-cyclodextrin derivative is 1:0.016;

The preparation method of the viscosity-reducing composite polycarboxylate water reducer, the preparation method of the polycarboxylate water reducer A, the preparation method of the polycarboxylate water reducer B, the polycarboxylate water reducer The preparation method of C and the preparation method of the β-cyclodextrin derivative are the same as those in Example 1, except that there is no methyl beta-cyclodextrin in the formula.

Comparative example 3

The viscosity-reducing composite polycarboxylate water-reducer includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, and deionized water; the polycarboxylate water-reducer The weight ratio of agent A to the polycarboxylate superplasticizer B and the polycarboxylate superplasticizer C is 1:0.7:1.1;

The preparation method of the viscosity-reducing composite polycarboxylate water reducer, the preparation method of the polycarboxylate water reducer A, the preparation method of the polycarboxylate water reducer B, the polycarboxylate water reducer The preparation method of C is the same as that in Example 1, except that the formulation of the viscosity-reducing composite polycarboxylate superplasticizer does not contain β-cyclodextrin derivatives or methylbeta-cyclodextrin.

Performance Testing

With reference to the relevant provisions of JC/T985-2005 "Cement-based self-leveling mortar for ground", the mortar mix ratio test shown in Table 1 was used to detect the various properties of the examples and comparative examples in the present invention, including air content, moisture content, Expansion, void time, compressive strength and flexural strength performance parameters and concrete state.

Concrete state evaluation criteria:

Good: good workability, easy to flip;

Poor: Poor workability, sticky concrete, difficult turning.

Table 1 Mortar mix ratio

water cement river sand small stone Zhongshi Superplasticizer 200 350 730 410 600 1

Table 2 performance test results

As can be seen from the above data, compared with polycarboxylate water reducer A, polycarboxylate water reducer B, polycarboxylate water reducer C and modified β-cyclodextrin in different proportions, the present invention The viscosity-reducing composite polycarboxylate superplasticizer provided has excellent performance, strong product adaptability, and is suitable for various specifications and types of cement. The product performance is stable, and there is no stratification, no precipitation, and no crystallization in winter during long-term storage; The product is non-toxic and pollution-free.

The foregoing examples are illustrative only, used to explain some of the features of the present disclosure. The appended claims are intended to claim the broadest scope conceivable and the embodiments presented herein are merely illustrations of selected implementations according to all possible combinations of embodiments. Accordingly, it is the applicant's intention that the appended claims not be limited by the selection of examples which characterize the invention. Moreover, advances in science and technology will create possible equivalents or sub-replacements not presently considered due to inaccuracies of language, and these changes should also be construed to be covered by the appended claims where possible .

Claims (8)

1. a kind of viscosity reduction type composite polycarboxylic acid water reducing agent, which is characterized in that it includes polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, beta-cyclodextrin derivative, methyl betadex, deionized water；

Wherein, the raw material for preparing of the polycarboxylate water-reducer A includes isopentene group polyoxyethylene ether, acrylic acid, initiator 1, chain Transfer agent 1 and deionized water；The polycarboxylate water-reducer B prepare raw material include methacrylic polyglycol ether, acrylic acid, Methylpropene sodium sulfonate, initiator 2, chain-transferring agent 2 and deionized water；The raw material for preparing of the polycarboxylate water-reducer C includes double Allyl capped polyethers, acrylic acid, methacrylic polyglycol ether, initiator 3, chain-transferring agent 3 and deionized water, it is described double Allyl capped polyethers is to carry out allylation sealing end to methoxy poly (ethylene glycol) with allyl bromide, bromoallylene to be prepared；The β-ring paste Smart derivative is dodecyl sodium sulfate and carbon nano-tube modification beta-cyclodextrin；

The polycarboxylate water-reducer A and the polycarboxylate water-reducer B, the polycarboxylate water-reducer C weight ratio be 1:(0.6- 0.8): (1-1.6).

2. viscosity reduction type composite polycarboxylic acid water reducing agent according to claim 1, which is characterized in that the beta-cyclodextrin derivative with The weight ratio of the methyl betadex is 1:(1-3).

3. viscosity reduction type composite polycarboxylic acid water reducing agent according to claim 2, which is characterized in that the beta-cyclodextrin derivative with The weight ratio of the methyl betadex is 1:(1.2-2).

4. viscosity reduction type composite polycarboxylic acid water reducing agent according to claim 1, which is characterized in that the polycarboxylate water-reducer A with The weight ratio of the methyl betadex is 1:(0.002-0.02).

5. viscosity reduction type composite polycarboxylic acid water reducing agent according to claim 1, which is characterized in that it calculates by weight, it is described poly- The raw material for preparing of carboxylic acid water reducer A includes 35-40 parts of isopentene group polyoxyethylene ether, 3-5 parts of acrylic acid, 0.1-0.5 parts of initiations Agent 1,0.1-0.4 parts of chain-transferring agents 1 and 50-70 parts of deionized waters；The isopentene group polyoxyethylene ether weight average molecular weight is 1000-3000。

6. viscosity reduction type composite polycarboxylic acid water reducing agent according to claim 1, which is characterized in that it calculates by weight, it is described poly- The raw material for preparing of carboxylic acid water reducer B includes 20-35 parts of methacrylic polyglycol ethers, 3-7 parts of acrylic acid, 0.5-3 parts of methyl Sodium allylsulfonate, 0.1-0.5 part initiator 2,0.1-0.5 parts of chain-transferring agents 2 and 50-70 parts of deionized waters；The methallyl Base polyglycol ether weight average molecular weight is 1000-2400.

7. viscosity reduction type composite polycarboxylic acid water reducing agent according to claim 1, which is characterized in that it calculates by weight, it is described poly- The raw material for preparing of carboxylic acid water reducer C includes 20-30 parts of diallyl end capped polyethers, 2-5 parts of acrylic acid, 1-4 parts of methacrylics Polyglycol ether, 0.1-0.5 part initiator 3,0.1-0.5 parts of chain-transferring agents 3 and 50-70 parts of deionized waters；The diallyl End capped polyether weight average molecular weight is 2000-4000, and methacrylic polyglycol ether weight average molecular weight is 1000-2400.

8. the preparation method of -7 viscosity reduction type composite polycarboxylic acid water reducing agents according to claim 1, which is characterized in that including following Step:

(1) it is derivative that polycarboxylate water-reducer A, polycarboxylate water-reducer B, polycarboxylate water-reducer C, beta-cyclodextrin are added into reactor Object, methyl betadex and deionized water stir 2-3h, obtain viscosity reduction type composite polycarboxylic acid water reducing agent mother liquor；

(2) viscosity reduction type composite polycarboxylic acid water reducing agent mother liquor is placed in vacuum ultrasonic microwave drying oven, mother liquor depth is 6cm, is beaten It opens vacuum pump and adjusts vacuum degree in drying box to -0.09--0.08MPa；Setting ultrasonic frequency is 30kHz, the ultrasonic wave The power of generator is 100W, opens microwave generator, microwave frequency 2450MHz, setting drying temperature is 55 DEG C, and is adjusted Range of microwave power dries 2-4h, obtains solid viscosity reduction type composite polycarboxylic acid water reducing agent to 200kW；

(3) the solid viscosity reduction type composite polycarboxylic acid water reducing agent for being dried to obtain step (2) crushes, and obtains the compound polycarboxylic acids of viscosity reduction type Water-reducing agent pulvis.