CN113683739A

CN113683739A - Formula and preparation method of early-strength polycarboxylate superplasticizer for prefabricated part

Info

Publication number: CN113683739A
Application number: CN202110988596.0A
Authority: CN
Inventors: 邵渭祥; 叶雪飞; 王小兵
Original assignee: Zhejiang Jiulong New Material Co ltd
Current assignee: Zhejiang Jiulong New Material Co ltd
Priority date: 2021-08-26
Filing date: 2021-08-26
Publication date: 2021-11-23

Abstract

The invention discloses a formula of an early strength polycarboxylate water reducer for a prefabricated part, which comprises 2400 parts to 70 parts of methallyl polyoxyethylene ether, 1 part to 2 parts of mercaptopropionic acid, 5 parts to 7 parts of an oxidant, 8 parts to 12 parts of polyethylene polyamine, 10 parts to 140 parts of sodium thiosulfate, 0.5 part to 1.5 parts of a co-reducing agent, 200 parts to 300 parts of soft water, 60 parts to 80 parts of 30% sodium hydroxide, 10 parts to 20 parts of an organic early strength catalytic component, 10 parts to 20 parts of an inorganic early strength catalytic component, 8 parts to 12 parts of a quaternary ammonium salt cationic monomer, 3 parts to 5 parts of N- [4- (sulfonamide) phenyl ] acrylamide, 3 parts to 9 parts of 2-acrylamido-2-methacrylic sulfonic acid, 100 parts to 200 parts of deionized water, 2 parts to 4 parts of a neutralizer and 1 part to 3 parts of a chain transfer agent. The invention has the technical effects of short solidification time, high compressive strength and good early strength effect.

Description

Formula and preparation method of early-strength polycarboxylate superplasticizer for prefabricated part

Technical Field

The invention relates to the technical field of water reducing agent formulas and processes, in particular to a formula and a preparation method of an early-strength polycarboxylate water reducing agent for prefabricated parts.

Background

The production and application of prefabricated parts in China have a history of nearly 70 years, but only in the 21 st century, people gradually find that a cast-in-place structural system does not completely meet the requirements of the development of times any more. For the increasingly developed building market in China, the defects of the cast-in-place structure system become more and more obvious. In the face of these problems, combined with the successful experience of foreign housing industrialization, the construction industry in China again raises the wave of "building industrialization" and "housing industrialization", and the development of concrete prefabricated members enters a new era. In recent years, under the guidance of relevant policies of government departments, the development of building industrialization is better. The concrete prefabricated member is also researched by enterprise units, schools, scientific research institutions and the like, and certain results are obtained. The concrete prefabricated member has the concrete characteristics that (1) the forms and the applications of the concrete prefabricated member are increasingly increased; (2) the anti-seismic performance is ensured; (3) versatility and standardization are implemented; (4) the relevant standard and standard are continuously exported; (5) production equipment and production technology are continuously improved.

The rising of preforms has also placed increasing demands on the materials used, in particular on the core material. The water reducing agent, one of the core materials used by the prefabricated member, plays an important role in four to two thousand of gold. Compared with the third-generation high-performance water reducing agent represented by polycarboxylate at present, the first-generation common water reducing agent represented by calcium lignosulfonate and the second-generation high-efficiency water reducing agent represented by melamine, naphthalene and aliphatic have the following problems: (1) the adaptability with cement is poor, and the development trend of a multi-element gelling system is not met; (2) the water reducing rate is low, and the efficiency of saving cement is low; (3) a large amount of formaldehyde is used in the production process, the formaldehyde is a substance with higher toxicity, and the formaldehyde is high on the priority control list of toxic chemicals in China. The performance and the quality of the third-generation polycarboxylic acid high-performance water reducing agent are qualitatively improved, the synthesis of the polycarboxylic acid water reducing agent adopts aqueous solution free radical polymerization, the whole process has no formaldehyde and other harmful release substances, no waste water and waste gas are discharged, and the polycarboxylic acid water reducing agent conforms to the development direction of green building materials.

The prefabricated member reduces the plastering time and the pre-curing time in the production process, shortens the steam curing time, accelerates the production speed, requires the polycarboxylate superplasticizer to have the properties of early strength and early setting, particularly does not contain air-entraining and delayed coagulation components in an additive, because the steam curing technology is adopted in the production of the prefabricated member, if the delayed coagulation phenomenon occurs, the phenomena of bulging, looseness and bubbles occur on the surface of the duct piece, and the quality and the appearance of the duct piece are seriously influenced. In order to improve the production efficiency of the prefabricated member and meet the quality requirement of the prefabricated member, scientific and technological workers continuously research and develop the performance of the polycarboxylate superplasticizer.

CN 106749983A is a super early strength type polycarboxylate water reducer and a preparation method thereof, water, unsaturated polyoxyethylene ether, an early strength group monomer (acrylamide, N, N-dimethylacrylamide or 2-acrylamide-2-methylpropanesulfonic acid) and an oxidative initiator are put into a reaction kettle, stirred until dissolved, heated to 30-80 degrees, added with the prepared solution A and solution B at the same time, insulated for 1-2 hours, added with alkali to neutralize until the pH value is 6-7, and supplemented with water until the solid content is 40-50%, thus obtaining the early strength type polycarboxylate water reducer. Patent CN 106632892A is an early strength type polycarboxylate superplasticizer and a preparation method thereof, which introduces methacrylic acid-2- (dimethylamino) ethyl ester, methacrylic acid (diethylamino) ethyl ester, methacrylic acid-2- (diisopropylamino) ethyl ester or methacrylic acid-2-morpholinyl ethyl ester. Both of these patents introduce a functional monomer which contains N atom in its molecule and can be copolymerized with unsaturated polyether and acrylic acid. These functional monomers containing N atom have one lone pair of electrons, and are easy to complex with metal ions to form stable complex. These complexes form many soluble domains in solution, thereby increasing the diffusion rate of the hydration product, accelerating the hydration of C3S, and thus increasing early strength.

In addition, another way for synthesizing the early strength type polycarboxylate superplasticizer in the literature is found that unsaturated polyether with higher molecular weight of 3000-5000 is adopted to synthesize a polycarboxylate molecule with a long side chain and a relatively short main chain, the shape of the polycarboxylate molecule is changed from a traditional comb shape into an inverted T shape, and the distance between side chains is larger. The long polyether side chain can allow moisture to enter cement particles while having a strong steric hindrance effect, so that normal hydration of cement is ensured; meanwhile, the side chain of the early-strength polycarboxylic acid molecule is longer, and the adsorption state of the copolymer molecule on the surface of cement particles is improved, so that the generation of fine ettringite crystals is promoted, and the development of the early strength of concrete is accelerated.

Therefore, the formula and the preparation method of the early-strength polycarboxylate superplasticizer for the prefabricated member are very necessary, wherein the early-strength polycarboxylate superplasticizer has short solidification time, high compressive strength and good early-strength effect.

Disclosure of Invention

The invention aims to provide a formula and a preparation method of an early-strength polycarboxylate superplasticizer for a prefabricated part, so as to realize the technical effects provided in the background technology.

In order to realize the purpose, the invention provides the following technical scheme: the formula of the early strength polycarboxylate water reducer for the prefabricated part comprises 2400 parts of methallyl polyoxyethylene ether, 50-70 parts of acrylic acid, 1-2 parts of mercaptopropionic acid, 5-7 parts of an oxidant, 8-12 parts of polyethylene polyamine, 10-140 parts of sodium thiosulfate, 0.5-1.5 parts of a co-reducing agent, 200-300 parts of soft water, 60-80 parts of 30% sodium hydroxide, 10-20 parts of an organic early strength catalytic component, 10-20 parts of an inorganic early strength catalytic component, 8-12 parts of a quaternary ammonium salt cationic monomer, 3-5 parts of N- [4- (sulfonamide) phenyl ] acrylamide, 3-9 parts of 2-acrylamido-2-methylpropanesulfonic acid, 100-200 parts of deionized water, 2-4 parts of a neutralizer and 1-3 parts of a chain transfer agent.

Preferably, the polyethylene polyamine is one or more of triethylene tetramine, tetraethylene pentamine and pentaethylene hexamine.

Preferably, the polyethylene polyamine and the sodium thiosulfate are combined to form a reducing agent with an early strength effect.

Preferably, the oxidant is hydrogen peroxide and ammonium persulfate.

Preferably, the reductant aid is a sodium formaldehyde sulfoxylate.

Preferably, the organic early-strength catalytic component is alkyl organic amine, and comprises one or more than two mixtures of diethanolamine, triethanolamine and triisopropanolamine or one or more than two mixtures of sodium formate, calcium formate and sodium acetate.

Preferably, the inorganic early-strength catalytic component is one or a mixture of more than two of sodium sulfate, sodium thiosulfate, sodium thiocyanate, sodium nitrate and calcium nitrate.

Preferably, the neutralizing agent is one or a mixture of more of ethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, dihydroxyethyl ethylenediamine, dihydroxypropyl ethylenediamine, tetrahydroxyethyl ethylenediamine and tetrahydroxypropyl ethylenediamine.

Preferably, the chain transfer agent is one or a mixture of more of thioglycolic acid, thioglycerol, 3-mercaptopropionic acid isooctyl dodecyl mercaptan, 3-mercaptopropionic acid and thiomalic acid.

A preparation method of a formula of an early strength polycarboxylate superplasticizer for a prefabricated part specifically comprises the following steps:

the method comprises the following steps: placing acrylic acid and mercaptopropionic acid in a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser tube and a dropping device, starting stirring and keeping the rotating speed at 120r/min, adding soft water, mixing and stirring for 30-50 min, and preparing a material A;

step two: putting polyethylene polyamine into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser tube and a dropping device, starting stirring, keeping the rotating speed at 120r/min, adding water, mixing and stirring for 30-50 min, and preparing a material B;

step three: adding soft water, methylallyl polyoxyethylene ether 2400, hydrogen peroxide, ammonium persulfate and sodium formaldehyde sulfoxylate into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, and then stirring and heating to 20-30 ℃;

step four: dripping the material A and the material B into the four-neck flask in the third step at the same time, wherein the material A is uniformly dripped after 2-4 hours, and the material B is uniformly dripped after 3-4 hours;

step five: after the material B in the fourth step is dripped, curing is carried out for 1-2 hours, and then 30% sodium hydroxide aqueous solution and water are added;

step six: adding deionized water in the fifth step, mixing and dissolving at normal temperature, adding an oxidant, heating to 40-60 ℃, and uniformly mixing;

step seven: dropwise adding a solution mixed by quaternary ammonium salt cationic monomers, N- [4- (sulfamide) phenyl ] acrylamide, 2-acrylamide-2-methacrylic sulfonic acid and deionized water;

step eight: and then dropwise adding a solution prepared by mixing a reducing agent, a chain transfer agent and deionized water to perform aqueous polymerization reaction, after dropwise adding, adding an organic early-strength catalytic component and an inorganic early-strength catalytic component to stir, heating to react, cooling to room temperature, adding a neutralizer to adjust the pH to 6-8, and thus obtaining the polycarboxylic acid water reducer.

Compared with the prior art, the invention has the beneficial effects that:

1. the early strength polycarboxylate superplasticizer for the prefabricated member has the formula and the preparation method, and when in use: the workability of the fresh concrete is good, the setting time of the concrete is short, and the early strength is high; more particularly, the invention relates to shortening the quiescent time of the prefabricated member, namely improving the early strength of the concrete, accelerating the turnover of the prefabricated member mould and improving the production capacity.

2. The formula and the preparation method of the early-strength polycarboxylate superplasticizer for the prefabricated member adopt a method different from the method for preparing the early-strength polycarboxylate superplasticizer for the prefabricated member at present, namely, a functional monomer which contains N atoms and can be copolymerized with unsaturated polyether and acrylic acid is not adopted, higher unsaturated polyether with the molecular weight of 3000-5000 is not adopted, and the molecular weight of unsaturated polyether commonly used in the market is 2400, so that the production cost is reduced.

3. The formula and the preparation method of the early-strength polycarboxylate superplasticizer for the prefabricated member simultaneously use N- [4- (sulfamide) phenyl ] acrylamide and 2-acrylamide-2-methyl propylene sulfonic acid, and utilize the synergistic effect of the N- [4- (sulfamide) phenyl ] acrylamide and the 2-acrylamide-2-methyl propylene sulfonic acid and quaternary ammonium salt cationic monomers, wherein the quaternary ammonium salt cationic monomers are cationic quaternary ammonium salt organic molecules containing two unsaturated double bonds, and can prepare a cationic polymer through free radical ring-forming polymerization, and the polymer has high positive charge density, good water solubility and stable structural units, thereby achieving the optimal early-strength effect.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The formula of the early strength polycarboxylate water reducer for the prefabricated part comprises 2400 parts of methallyl polyoxyethylene ether, 50-70 parts of acrylic acid, 1-2 parts of mercaptopropionic acid, 5-7 parts of an oxidant, 8-12 parts of polyethylene polyamine, 10-140 parts of sodium thiosulfate, 0.5-1.5 parts of a co-reducing agent, 200-300 parts of soft water, 60-80 parts of 30% sodium hydroxide, 10-20 parts of an organic early strength catalytic component, 10-20 parts of an inorganic early strength catalytic component, 8-12 parts of a quaternary ammonium salt cationic monomer, 3-5 parts of N- [4- (sulfonamide) phenyl ] acrylamide, 3-9 parts of 2-acrylamido-2-methylpropanesulfonic acid, 100-200 parts of deionized water, 2-4 parts of a neutralizer and 1-3 parts of a chain transfer agent.

Preferably, the polyethylene polyamine is combined with the sodium thiosulfate to form a reducing agent with an early strength effect.

Preferably, the oxidant is hydrogen peroxide and ammonium persulfate.

Preferably, the reductant aid is a rongalite.

Preferably, the organic early-strength catalytic component is alkyl organic amine, including one or more than two mixtures of diethanolamine, triethanolamine and triisopropanolamine, or one or more than two mixtures of sodium formate, calcium formate and sodium acetate.

Preferably, the neutralizing agent is one or more of ethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, dihydroxyethyl ethylenediamine, dihydroxypropyl ethylenediamine, tetrahydroxyethyl ethylenediamine and tetrahydroxypropyl ethylenediamine.

Preferably, the chain transfer agent is one or more of thioglycolic acid, thioglycerol, 3-mercaptopropionic acid isooctyl dodecyl mercaptan, 3-mercaptopropionic acid and thiomalic acid.

The preparation is implemented according to the formula and the preparation method, and the preparation is implemented according to the formula and the preparation method:

having the following embodiments

200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 2 g of ammonium persulfate and 0.5 g of rongalite are added into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, then the mixture is stirred and heated to 25 ℃, then a material A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water) and a material B (8 g of tetraethylenepentamine and 100 g of water) are simultaneously dropped, the material A is uniformly dropped for 3 hours, the material B is uniformly dropped for 3.5 hours, after the material B is dropped, the mixture is cured for 1.5 hours, and then 60 g of 30% sodium hydroxide aqueous solution and 60 g of water are added to obtain the polycarboxylic acid water reducer.

Example two

200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 2 g of ammonium persulfate and 0.5 g of rongalite are added into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, then the mixture is stirred and heated to 25 ℃, then a material A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water) and a material B (2 g of tetraethylenepentamine and 100 g of water) are simultaneously dropped, the material A is uniformly dropped for 3 hours, the material B is uniformly dropped for 3.5 hours, after the material B is dropped, the mixture is cured for 1.5 hours, and then 60 g of 30% sodium hydroxide aqueous solution and 66 g of water are added to obtain the polycarboxylic acid water reducer.

EXAMPLE III

200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 2 g of ammonium persulfate and 0.5 g of rongalite are added into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, then the mixture is stirred and heated to 25 ℃, then a material A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water), a material B (4 g of triethylene tetramine and 100 g of water) are simultaneously dropped, the material A is uniformly dropped for 3 hours, the material B is uniformly dropped for 3.5 hours, after the material B is dropped, the mixture is cured for 1.5 hours, then 60 g of 30 percent sodium hydroxide aqueous solution and 64 g of water are added to obtain the comparative polycarboxylic acid water reducer of the invention

Example four

200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 1.5 g of ammonium persulfate and 0.5 g of rongalite are added into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, then the mixture is stirred and heated to 25 ℃, then materials A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water) and materials B (12 g of triethylene tetramine and 100 g of water) are simultaneously dropped, the materials A are uniformly dropped for 3 hours, the materials B are uniformly dropped for 3.5 hours, after the materials B are dropped, the materials A are cured for 1.5 hours, then 60 g of 30% sodium hydroxide aqueous solution and 56 g of water are added, and the comparative polycarboxylate superplasticizer of the invention is obtained

EXAMPLE five

200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 2 g of ammonium persulfate and 0.5 g of rongalite are added into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, then the mixture is stirred and heated to 25 ℃, then a material A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water), a material B (2 g of pentaethylenehexamine and 100 g of water) are simultaneously dropped, the material A is uniformly dropped for 3 hours, the material B is uniformly dropped for 3.5 hours, after the material B is dropped, the mixture is cured for 1.5 hours, then 60 g of 30% sodium hydroxide aqueous solution and 66 g of water are added, and the comparative polycarboxylic acid water reducing agent is obtained

EXAMPLE six

200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 2 g of ammonium persulfate and 0.5 g of rongalite are added into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, then the mixture is stirred and heated to 25 ℃, then a material A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water), a material B (8 g of pentaethylenehexamine and 100 g of water) are simultaneously dropped, the material A is uniformly dropped for 3 hours, the material B is uniformly dropped for 3.5 hours, after the material B is dropped, the mixture is cured for 1.5 hours, then 60 g of 30% sodium hydroxide aqueous solution and 60 g of water are added, and the comparative polycarboxylic acid water reducing agent is obtained

EXAMPLE seven

Adding 200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 2 g of ammonium persulfate and 0.5 g of rongalite into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, stirring and heating to 25 ℃, then simultaneously dropping materials A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water), materials B (5 g of sodium thiosulfate and 100 g of water), uniformly dropping the materials A for 3 hours, uniformly dropping the materials B for 3.5 hours, curing for 1.5 hours after dropping the materials B, then adding 60 g of 30% sodium hydroxide aqueous solution and 63 g of water to obtain the comparative polycarboxylic acid water reducer of the invention

Example eight

Adding 200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 2 g of ammonium persulfate and 0.5 g of rongalite into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, stirring and heating to 25 ℃, then simultaneously dropping materials A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water), materials B (10 g of sodium thiosulfate and 100 g of water), uniformly dropping the materials A for 3 hours, uniformly dropping the materials B for 3.5 hours, curing for 1.5 hours after dropping the materials B, then adding 60 g of 30% sodium hydroxide aqueous solution and 58 g of water to obtain the comparative polycarboxylic acid water reducer disclosed by the invention

Comparative example 1

200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 2 g of ammonium persulfate and 0.5 g of rongalite are added into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, then the mixture is stirred and heated to 25 ℃, then a material A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water) and a material B (1 g of vitamin C and 100 g of water) are simultaneously dropped, the material A is uniformly dropped for 3 hours, the material B is uniformly dropped for 3.5 hours, after the material B is dropped, the mixture is cured for 1.5 hours, then 60 g of 30% sodium hydroxide aqueous solution and 67.45 g of water are added, and the comparative polycarboxylic acid water reducing agent is obtained.

Comparative example 2

200 g of soft water, 365 g of methylallyl polyoxyethylene ether 2400, 3 g of hydrogen peroxide, 2 g of ammonium persulfate and 0.5 g of rongalite are added into a four-neck flask provided with a thermometer, a speed-regulating stirrer, a reflux condenser and a dropping device, then the mixture is stirred and heated to 25 ℃, then materials A (50 g of acrylic acid, 1.5 g of mercaptopropionic acid and 150 g of soft water), materials B (1 g of vitamin C, 10 g of sodium thiosulfate and 100 g of water) are simultaneously dropped into the mixture after the materials A are uniform for 3 hours, the materials B are uniformly dropped into the mixture after the materials B are uniformly dropped for 3.5 hours, the mixture is aged for 1.5 hours after the materials B are dropped, then 60 g of 30% sodium hydroxide aqueous solution and 67.45 g of water are added, and the comparative polycarboxylic acid water reducing agent of the invention is obtained.

Experiment one: the water reducing agents prepared in the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, the sixth embodiment, the seventh embodiment, the eighth embodiment, the first comparative embodiment and the second comparative embodiment are subjected to a test of a curing process of a preform to obtain data of setting time and compressive strength, wherein the curing process comprises the following steps: standing for 4h, heating to 55 deg.C for 3h, holding the temperature for 6h, cooling for 3h, and cooling to 25 deg.C. Demoulding immediately after the steam curing is finished, measuring the compressive strength of the mould, and testing the 28d compressive strength to be that the mould is removed and the mould is standard cured to the corresponding age after the steam curing is finished; the specific parameters are shown in the following table:

and (3) analyzing an experimental result: from the above preform experimental data, the setting times for the cement paste are shorter for examples one to eight than for comparative example, and also shorter than for (comparative example + sodium thiosulfate). The reducing agent with early strength function is used for synthesis, so that the cement paste cleaning time can be shortened, and the cement paste cleaning time is also shorter than that of a physical mixing method by adding an early strength agent of thiosulfuric acid. As can be seen from the 16-hour steam-curing strength, the compressive strength of the precast concrete in the static stop stage of the comparative example is increased more slowly than that of the examples one to eight synthesized by the reducing agent with the early strength function, resulting in a 16-hour steam-curing compressive strength which is smaller by more than one grade (more than 5 MPa). Meanwhile, the compressive strength of the comparative example + sodium thiosulfate is higher than that of the comparative example, but is smaller than that of the examples one to eight. The law of the compressive strength of the standard sample after being steamed for 16 hours and converted to 28 days is consistent with the compressive strength of the standard sample after being steamed for 16 hours. Therefore, the reducing agent with the early strength function is grafted on the polycarboxylate superplasticizer molecules through free radicals, and the early strength effect of the reducing agent is obviously better than that of the water reducing agent synthesized by the reducing agent without the early strength function. And also has better early strength effect than that of adding the early strength agent after polymerization.

Experiment two: the water-reducing agents prepared in example one, example two, example three, example four, example five, example six, example seven, example eight, comparative example one and comparative example two were tested for setting time: according to GB8076-2008 concrete admixture, the slump and the strength of concrete at each age are measured.

The experimental results are as follows: the water reducing agents prepared in the first embodiment, the second embodiment, the third embodiment, the fourth embodiment, the fifth embodiment, the sixth embodiment, the seventh embodiment, the eighth embodiment, the first comparative embodiment and the second comparative embodiment have equivalent setting times and are obviously higher than those of the water reducing agents in the prior art.

The invention has the beneficial effects that: the early strength polycarboxylate superplasticizer for the prefabricated member has the formula and the preparation method, and when in use: the workability of the fresh concrete is good, the setting time of the concrete is short, and the early strength is high; more particularly, the invention relates to shortening the quiescent time of the prefabricated member, namely improving the early strength of the concrete, accelerating the turnover of the prefabricated member mould and improving the production capacity. The formula and the preparation method of the early-strength polycarboxylate superplasticizer for the prefabricated member adopt a method different from the method for preparing the early-strength polycarboxylate superplasticizer for the prefabricated member at present, namely, a functional monomer which contains N atoms and can be copolymerized with unsaturated polyether and acrylic acid is not adopted, higher unsaturated polyether with the molecular weight of 3000-5000 is not adopted, and the molecular weight of unsaturated polyether commonly used in the market is 2400, so that the production cost is reduced. The formula and the preparation method of the early-strength polycarboxylate superplasticizer for the prefabricated member simultaneously use N- [4- (sulfamide) phenyl ] acrylamide and 2-acrylamide-2-methyl propylene sulfonic acid, and utilize the synergistic effect of the N- [4- (sulfamide) phenyl ] acrylamide and the 2-acrylamide-2-methyl propylene sulfonic acid and quaternary ammonium salt cationic monomers, wherein the quaternary ammonium salt cationic monomers are cationic quaternary ammonium salt organic molecules containing two unsaturated double bonds, and can prepare a cationic polymer through free radical ring-forming polymerization, and the polymer has high positive charge density, good water solubility and stable structural units, thereby achieving the optimal early-strength effect.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The formula of the early strength polycarboxylate superplasticizer for the prefabricated member is characterized in that: the catalyst comprises, by weight, 2400 parts of methallyl polyoxyethylene ether, 50-70 parts of acrylic acid, 1-2 parts of mercaptopropionic acid, 5-7 parts of an oxidant, 8-12 parts of polyethylene polyamine, 10-140 parts of sodium thiosulfate, 0.5-1.5 parts of a reducing assistant agent, 200-300 parts of soft water, 60-80 parts of 30% sodium hydroxide, 10-20 parts of an organic early strength catalytic component, 10-20 parts of an inorganic early strength catalytic component, 8-12 parts of a quaternary ammonium salt cationic monomer, 3-5 parts of N- [4- (sulfonamide) phenyl ] acrylamide, 3-9 parts of 2-acrylamido-2-methacrylic sulfonic acid, 100-200 parts of deionized water, 2-4 parts of a neutralizer and 1-3 parts of a chain transfer agent.

2. The formulation of an early strength polycarboxylate superplasticizer for a preform as claimed in claim 1, wherein: the polyethylene polyamine is one or more of triethylene tetramine, tetraethylene pentamine and pentaethylene hexamine.

3. The formulation of an early strength polycarboxylate superplasticizer for a preform as claimed in claim 1, wherein: the polyethylene polyamine and the sodium thiosulfate are combined to form the reducing agent with an early strength effect.

4. The formulation of an early strength polycarboxylate superplasticizer for a preform as claimed in claim 1, wherein: the oxidant is hydrogen peroxide and ammonium persulfate.

5. The formulation of an early strength polycarboxylate superplasticizer for a preform as claimed in claim 1, wherein: the reducing aid is a rongalite.

6. The formulation of an early strength polycarboxylate superplasticizer for a preform as claimed in claim 1, wherein: the organic early-strength catalytic component is alkyl organic amine, and comprises one or more than two mixtures of diethanolamine, triethanolamine and triisopropanolamine or one or more than two mixtures of sodium formate, calcium formate and sodium acetate.

7. The formulation of an early strength polycarboxylate superplasticizer for a preform as claimed in claim 1, wherein: the inorganic early-strength catalytic component is one or a mixture of more than two of sodium sulfate, sodium thiosulfate, sodium thiocyanate, sodium nitrate and calcium nitrate.

8. The formulation of an early strength polycarboxylate superplasticizer for a preform as claimed in claim 1, wherein: the neutralizer is one or more of ethanolamine, diethanolamine, triethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, dihydroxyethyl ethylenediamine, dihydroxypropyl ethylenediamine, tetrahydroxyethyl ethylenediamine and tetrahydroxypropyl ethylenediamine.

9. The formulation of an early strength polycarboxylate superplasticizer for a preform as claimed in claim 1, wherein: the chain transfer agent is one or a mixture of more of thioglycolic acid, thioglycerol, 3-isooctyl mercaptopropionate dodecyl mercaptan, 3-mercaptopropionic acid and thiomalic acid.

10. A preparation method of a formula of an early strength polycarboxylate superplasticizer for a prefabricated part is characterized by comprising the following steps: the method specifically comprises the following steps: