1. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide is characterized by comprising the following steps of:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 2.2-5.2: 1, the chain transfer agent accounts for 0.1-0.8% of the total mass of the monomers, the reducing agent accounts for 0.051-0.25% of the total mass of the monomers, the oxidizing agent accounts for 0.15-2.6% of the total mass of the monomers, and the catalyst accounts for 0.009-0.08% of the total mass of the monomers;

mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use;

mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

the macromonomer is diethylene glycol monovinyl ether;

the small monomer is acrylic acid;

the chain transfer agent is one or a mixture of two of thioglycolic acid, thioglycolic acid and mercaptopropionic acid;

the catalyst is any one of magnesium oxide, aluminum oxide and copper oxide;

the reducing agent is one or a mixture of more than two of sodium hypophosphite, sodium bisulfite, sodium sulfite and ascorbic acid;

the oxidant is one or a mixture of more than two of hydrogen peroxide, potassium persulfate and ammonium persulfate;

b. and (3) synthesis reaction:

adding a macromonomer and water into a reactor with a thermometer, cooling and stirring, adding a catalyst and water, mixing and stirring for 10-30 min when the temperature is controlled to be 2-28 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water, mixing and stirring for 5-10 min, simultaneously dropwise adding the solution A and the solution B, keeping the temperature at the temperature of 2-28 ℃ for reaction for 1-2 h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

2. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing the magnesium oxide, the aluminum oxide or the copper oxide according to claim 1 is characterized in that: step a, the ingredients are as follows: the mol ratio of the small monomer to the large monomer is 3.4:1, the chain transfer agent accounts for 0.22-0.68 percent of the total mass of the monomers, the reducing agent accounts for 0.09-0.22 percent of the total mass of the monomers, the oxidizing agent accounts for 0.35-0.95 percent of the total mass of the monomers, and the catalyst accounts for 0.01-0.062 percent of the total mass of the monomers.

3. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing the magnesium oxide, the aluminum oxide or the copper oxide according to the claim 1 or 2, which is characterized in that: in the step a, the small monomer is mixed with water to prepare a solution A, which comprises the following steps: and mixing the small monomer and water according to the mass ratio of 1: 3.9-8.6 of the small monomer to the water to prepare the solution A.

4. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing the magnesium oxide, the aluminum oxide or the copper oxide according to the claim 1 or 2, which is characterized in that: in the step a, the reducing agent, the chain transfer agent and water are mixed to prepare a solution B, which comprises the following steps: and mixing the reducing agent and the chain transfer agent with water according to the mass ratio of the total mass of the reducing agent and the chain transfer agent to the mass of water of 1: 48-90 to prepare liquid B.

5. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing the magnesium oxide, the aluminum oxide or the copper oxide according to the claim 1 or 2, which is characterized in that: the water in step a is distilled water, ultrapure water or deionized water.

6. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing the magnesium oxide, the aluminum oxide or the copper oxide according to the claim 1 or 2, which is characterized in that: and b, adding the macromonomer and the water into a reactor with a thermometer in the step b, wherein the macromonomer and the water are added into the reactor with the thermometer according to the mass ratio of the macromonomer to the water of 1: 0.38-0.86.

7. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing the magnesium oxide, the aluminum oxide or the copper oxide according to the claim 1 or 2, which is characterized in that: and c, adding the catalyst and water, mixing and stirring, namely adding the catalyst and the water according to the mass ratio of 1: 120-500 of the catalyst and the water, and mixing and stirring.

8. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing the magnesium oxide, the aluminum oxide or the copper oxide according to the claim 1 or 2, which is characterized in that: and b, adding an oxidant and water, mixing and stirring, namely adding the oxidant and the water according to the mass ratio of the oxidant to the water of 1: 1-5, and mixing and stirring.

9. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing the magnesium oxide, the aluminum oxide or the copper oxide according to the claim 1 or 2, which is characterized in that: and (c) performing heat preservation reaction at the temperature of 2-28 ℃ in the step b, wherein the heat preservation reaction is performed at the temperature of 2-20 ℃.

10. The method for synthesizing the polycarboxylic acid water reducing agent by catalyzing the magnesium oxide, the aluminum oxide or the copper oxide according to the claim 1 or 2, which is characterized in that: and c, simultaneously dropwise adding the solution A and the solution B in the step B, wherein the total time of dropwise adding and heat preservation reaction at the temperature of 2-28 ℃ is 1-2 h, and the steps are as follows: and simultaneously dripping the solution A and the solution B, wherein the solution A is dripped after 0.7 hour, the solution B is dripped after 1.2 hours, and after the solution B is dripped, the temperature is maintained for 0.5 hour at the temperature of 2-28 ℃.

Background

The development of the modern concrete admixture technology is the key of the development of the modern concrete technology and plays a decisive role. The concrete admixture is an essential important component for removing cement, sand, stone, water and admixture in modern concrete, particularly a third-generation polycarboxylic acid series high-performance admixture which accounts for about 80 percent of the using amount of the concrete admixture and is one of important technical approaches for reducing the using amount of the cement, improving the utilization rate of industrial waste residue and realizing the durability and high performance of the concrete. The polycarboxylic acid high-efficiency water reducing agent (PCE for short) is widely applied to the fields of high-speed rails, sea-crossing bridges, super high-rise buildings and the like. The PCE is developed very rapidly mainly because of the low doping amount of the ether polycarboxylic acid admixture, the cheap and easily available raw materials, the simple synthesis process, the low cost and the water reduction rate of 30-40%, so that the performances of cement and gelled materials can reach the optimal state, the setting retardation is hardly generated, and the slump of concrete is maintained (less than 1cm within 1 h). Therefore, the research on the synthesis technology of the polycarboxylic acid water reducing agent has important practical significance.

At present, the production and application of the polycarboxylic acid water reducer are wide, and in the prior art, the polycarboxylic acid water reducer is mainly produced by taking a 5C polyether (isopentenol polyoxyethylene ether) macromonomer, a 4C polyether (isobutenol polyoxyethylene ether) macromonomer and various small monomers as main raw materials and adopting an oxidation-reduction initiation system to prepare the polycarboxylic acid water reducer. Redox initiation systems initiate polymerization of monomers by generating free radicals through redox reactions. In the process of preparing the polycarboxylate superplasticizer by free radical polymerization, the activity of the polyether macromonomer is far lower than that of the micromolecular unsaturated carboxylic acid monomer; in order to ensure the uniform copolymerization of the terminal alkenyl polyoxyethylene ether and the small molecular monomer, only the dripping time of the small molecular monomer can be prolonged, so that the preparation time of the polycarboxylic acid water reducing agent is generally more than 3 hours; the heating method is used for synthesizing the polycarboxylic acid water reducing agent, the polymerization reaction temperature is usually 40-60 ℃, the higher temperature increases the energy consumption and increases the production cost, thereby reducing the market competitiveness of the product, and the product has the defects of dispersion performance, slump retaining performance and the like.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a method for synthesizing a polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide. The invention adopts a heterogeneous catalysis binary copolymerization synthesis method of metal oxide of 6C polyether macromonomer (namely diethylene glycol monovinyl ether), thereby providing a method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide with simple production process and good product performance.

The content of the invention is as follows: the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide is characterized by comprising the following steps of:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 2.2-5.2: 1, the chain transfer agent accounts for 0.1-0.8% of the total mass of the monomers (the sum of the small monomer and the large monomer is the total mass of the monomers, and the mass is the same as the total mass of the monomers), the reducing agent accounts for 0.051-0.25% of the total mass of the monomers, the oxidizing agent accounts for 0.15-2.6% of the total mass of the monomers, and the catalyst accounts for 0.009-0.08% of the total mass of the monomers;

mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use;

mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

the macromonomer is diethylene glycol monovinyl ether (EPEG and 6C polyether macromonomer for short, and the product production providing enterprises are Sichuan Hongcong new material company, Liaoke chemical company, Bailingwei science and technology company, Saen chemical technology (Shanghai) company); the molecular weight of the macromonomer is 1500-4000;

the small monomer is acrylic acid;

the chain transfer agent is one or a mixture of two of thioglycolic acid, thioglycolic acid and mercaptopropionic acid, and mercaptopropionic acid is preferred;

the catalyst is any one of magnesium oxide, aluminum oxide and copper oxide;

the reducing agent is one or a mixture of more than two of sodium hypophosphite, sodium bisulfite, sodium sulfite and ascorbic acid, and ascorbic acid is preferred;

the oxidant is one or a mixture of more than two of hydrogen peroxide, potassium persulfate, ammonium persulfate and the like, preferably hydrogen peroxide;

b. and (3) synthesis reaction:

adding the macromonomer and water into a reactor (such as a three-neck flask) with a thermometer, (gradually) cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 10-30 min when the temperature is controlled to be 2-28 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 5-10 min, then (using a constant-pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, keeping the temperature at 2-28 ℃ for reaction for a total time of 1-2 h, and standing the reacted material to room temperature to obtain the polycarboxylic acid water reducer (namely the polycarboxylic acid water reducer synthesized by catalyzing magnesium oxide, aluminum oxide or copper oxide).

The invention comprises the following steps: step a, the ingredients are as follows: the molar ratio of the small monomer to the large monomer is preferably 3.4:1, the chain transfer agent is preferably 0.22 to 0.68% of the total mass of the monomers, the reducing agent is preferably 0.09 to 0.22% of the total mass of the monomers, the oxidizing agent is preferably 0.35 to 0.95% of the total mass of the monomers, and the catalyst is preferably 0.01 to 0.062% of the total mass of the monomers.

The invention comprises the following steps: in the step a, the small monomer is mixed with water to prepare a solution A, preferably: and mixing the small monomer and water according to the mass ratio of 1: 3.9-8.6 of the small monomer to the water to prepare the solution A.

The invention comprises the following steps: in the step a, the reducing agent, the chain transfer agent and water are mixed to prepare a solution B, preferably: and mixing the reducing agent and the chain transfer agent with water according to the mass ratio of the total mass of the reducing agent and the chain transfer agent to the mass of water of 1: 48-90 to prepare liquid B.

The invention comprises the following steps: the water in step a is preferably distilled water, ultrapure water or deionized water.

The invention comprises the following steps: in the step b, the macromonomer and the water are added into a reactor with a thermometer, preferably, the macromonomer and the water are added into the reactor with the thermometer according to the mass ratio of 1: 0.38-0.86 of the macromonomer and the water.

The invention comprises the following steps: and c, adding the catalyst and water, mixing and stirring, namely adding the catalyst and the water according to the mass ratio of 1: 120-500 of the catalyst and the water, and mixing and stirring.

The invention comprises the following steps: and b, adding an oxidant and water, mixing and stirring, namely adding the oxidant and the water according to the mass ratio of the oxidant to the water of 1: 1-5, and mixing and stirring.

The invention comprises the following steps: and (c) performing heat preservation reaction at the temperature of 2-28 ℃ in the step b, preferably at the temperature of 2-20 ℃.

The invention comprises the following steps: in the step B, the liquid A and the liquid B are dropwise added simultaneously (at a constant speed) by using a constant-pressure dropping funnel, and the total time of dropwise addition and heat preservation reaction at the temperature of 2-28 ℃ is 1-2 h, preferably: and (4) dripping the liquid A and the liquid B (by using a constant-pressure dropping funnel) at the same time (at a constant speed), wherein the liquid A is dripped off after 0.7h, the liquid B is dripped off after 1.2h, and after the liquid B is dripped off, the temperature is maintained for 0.5h at the temperature of 2-28 ℃. When the solution B is dripped, a reducing substance and an oxide react to generate active free radicals to initiate polymerization between monomers, a reducing component in the solution B must be separated from an oxidizing component in a base material, and the dripping time of the solution B is prolonged by half an hour compared with that of the solution A, so that the catalytic effect is best, the polymerization is more sufficient, and the performance of the obtained product is best.

The chemical reaction formula of the polymerization reaction is as follows [ an initiating system consisting of an initiating agent (an oxidant, hydrogen peroxide, a reducing agent, ascorbic acid and the like) and a catalyst ]:

the invention comprises the following steps: the prepared polycarboxylate superplasticizer is subjected to performance evaluation by adopting infrared spectroscopy (FT-IR) and a cement paste test and a concrete test.

The invention comprises the following steps: by infrared spectrum characterization (FT-IR analysis data, see figure description), the characteristic functional group of the polycarboxylate superplasticizer appears in the synthesized product.

The invention comprises the following steps: in the performance test of the prepared polycarboxylic acid water reducing agent, a cement paste fluidity test is carried out according to the national standard GB/T8077-2000 'concrete admixture homogeneity test method'; the concrete test is carried out according to the national standard GB/T50080-2002 'test standard for the performance of common concrete mixture'; GB/T50081-2002 Standard test method for mechanical properties of common concrete carries out related tests.

Compared with the prior art, the invention has the following characteristics and beneficial effects:

(1) by adopting the method, the metal oxide (magnesium oxide, aluminum oxide or copper oxide) is used as the catalyst for the first time, the water reducing agent is synthesized by heterogeneous catalysis, and the catalyst can be recycled, so that the cost is reduced; meanwhile, the reaction temperature is reduced to room temperature or below, the redox efficiency is higher, the total reaction time is about 2 hours, the initial dispersibility (the water reducing rate is improved by 4-8% under the same doping amount) and the slump retaining performance (the slump loss is reduced within 1 hour) are good, the raw materials for synthesis are cheap and easy to obtain, the synthesis process is simple and efficient, the prepared polycarboxylic acid water reducer can be directly used without adjusting the pH value, and the industrial production is easy to realize;

(2) by adopting the invention, diethylene glycol monovinyl ether (EPEG for short) macro-monomer and small monomer are copolymerized, the reactivity ratio of the ethylene glycol monovinyl ether and the small monomer determines that the reaction of the ethylene glycol monovinyl ether and the small monomer is closer to ideal constant ratio copolymerization, and the reaction process is easy to control;

(3) by adopting the invention, the action mechanism of the metal oxide catalyst on the free radical polymerization mainly has the following two aspects:

on one hand: gold (Au)Metal oxides MO (magnesium oxide, aluminum oxide or copper oxide) can be used as catalysts for redox initiation systems to make H₂O₂The decomposition rate is increased, so that the rate of generating free radicals is increased, the monomer is initiated to form monomer free radicals, and the synthesis temperature of the polycarboxylate superplasticizer is reduced, wherein the chemical reaction equation is as follows:

more monomer free radicals are generated in unit time, so that the chain initiation rate is increased, the chain free radicals are further generated, the chain growth is promoted, the molecular weight of the synthesized polycarboxylic acid water reducing agent is finally reduced, and the dispersibility of the water reducing agent with the same mixing amount is enhanced;

on the other hand: the carboxyl can not only be matched with the metal oxide in a plurality of coordination modes, but also can be combined with the metal oxide to form a polynuclear metal secondary structure unit, so that various coordination polymer network structures are constructed; the metal oxide being capable of reacting with-COO^-A coordination reaction is carried out, electron deviation is caused through steric hindrance and an electronic effect, so that the double bond activity is increased, the polymerization reaction is promoted, and the molecular weight of the synthesized polycarboxylic acid water reducing agent is increased; the reaction mechanism is shown as follows:

(4) by adopting the method, catalysts such as metal oxide and the like are added to improve the free radical polymerization for catalysis, the monomer conversion rate can be improved, the polycarboxylic acid water reducing agent with an optimized molecular structure (shown as the following formula) is obtained, and the prepared polycarboxylic acid water reducing agent has good dispersing performance and slump retaining performance and excellent adaptability to different cement materials, and is particularly suitable for concrete preparation;

(5) according to the invention, in a novel polyether macromonomer represented by an EPEG macromonomer, in macromonomer diethylene glycol monovinyl ether (EPEG for short), unsaturated double bonds in a molecular structure are directly connected with an oxygen atom to form a group of molecular structures with C-0 bonds, so that the electron cloud distribution of the double bonds shifts, the charge environment of the unsaturated double bonds in the macromonomer is improved, the reaction activity of the double bonds in the macromonomer is much higher than that of a common macromonomer, and the polymerization reaction is easier to carry out. The double bonds in the molecules are of a substituted structure, so that the space resistance of swinging of the polyether side chains is further reduced, the swinging of the polyether side chains is more free, and the moving range is larger; the swinging freedom degree of the polyether side chain is increased, the wrapping property and the winding property of the polyether side chain are improved, namely the space free rotation degree of a synthesized product is high, and the wrapping effect on a concrete raw material is good, so that the synthesized polycarboxylate superplasticizer has higher adaptability, and particularly has obvious effect on the conditions of poor quality of sand and stone materials and high mud content; the production process of the initiator is pollution-free, the initiator can adapt to low-temperature synthesis of the polycarboxylate superplasticizer, and the initiator has the characteristics of high double bond activity, simple and convenient synthesis process and excellent performance of the polycarboxylate superplasticizer;

(6) compared with the cement dispersing performance without the catalyst water reducing agent, the fluidity of the net slurry is increased by 30-60 mm, and the loss of the fluidity over time is small; reference is made to national standard GB/T50080-2002 Standard for testing the performance of common concrete mixture, GB-T50081-2002 Standard for testing the mechanical properties of common concrete and GBT 50082-; the slump loss is small, which shows that the slump loss prevention effect is good; the compressive strength of the C30 concrete reaches more than 34.5MPa, the concrete is qualified, and the compressive strength of the product prepared by the invention is 40.7-54.4 MPa in 7d, which is higher than that of a blank group (25.3MPa) and a commercial group (38.7 MPa); the concrete freeze-thaw test has the quality loss rate below 5 percent, and the product prepared by the invention passes through the freeze-thaw resistance test for 300 times, has the quality loss rate below 0.5 percent and good durability;

(7) the preparation method has the advantages of simple preparation process, easy operation, low reaction temperature, high production efficiency, low production cost, industrial production and strong practicability.

Drawings

FIG. 1 is an infrared spectrum of a polycarboxylic acid water-reducing agent prepared in example 9 of the present invention, the abscissa thereof being the wave number (cm)^-1) And the ordinate represents the transmittance (%); in the infrared spectrum, 3436.42cm^-1The position is the stretching vibration peak of the terminal hydroxyl of the water reducing agent, 2883.79cm^-1The vibration peak of the expansion and contraction is the saturated C-H bond of the hydrocarbon, and the bending vibration peak is 1467.51cm^-1And 1346.03cm^-1；1280.59cm^-1,1241.91cm^-1The position is a carboxyl COOH stretching vibration peak; 1726.89cm^-1A stretching vibration peak of carboxylic acid C ═ O bond; 1113.84cm^-1、954.36cm^-1And 843.39cm^-1The absorption peak at (A) is a characteristic absorption peak of a long side chain polyoxyethylene group, wherein 1113.84cm^-1Is the stretching vibration peak of the ether bond C-O-C, 954.36cm^-1And 843.39cm^-1Respectively C-O and C-C stretching vibration peaks; the characteristic peaks can show that the small monomer and the polyether macromonomer are copolymerized in the solution to generate the polycarboxylic acid water reducing agent;

FIG. 2 is an infrared spectrum of a polycarboxylic acid water-reducing agent prepared in example 3 of the present invention, the abscissa thereof being the wave number (cm)^-1) And the ordinate represents the transmittance (%); in the infrared spectrum, 3440.13cm^-1The position is the stretching vibration peak of the terminal hydroxyl of the water reducing agent, 2875.70cm^-1The vibration peak of the expansion and contraction is the saturated C-H bond of the hydrocarbon, and the bending vibration peak is 1455.27cm^-1And 1352.02cm^-1；1251.21cm^-1The position is a carboxyl COOH stretching vibration peak; 1725.99cm^-1A stretching vibration peak of carboxylic acid C ═ O bond; 1100.65cm^-1、952.02cm^-1And 845.18cm^-1The absorption peak at (A) is a characteristic absorption peak of a long side chain polyoxyethylene group, wherein 1100.65cm^-1Is the stretching vibration peak of the ether bond C-O-C, 952.02cm^-1And 845.18cm^-1Respectively C-O and C-C stretching vibration peaks; the characteristic peaks can show that the small monomer and the polyether macromonomer are copolymerized in the solution to generate the polycarboxylic acid water reducing agent;

FIG. 3 is an infrared spectrum of a polycarboxylic acid water-reducing agent prepared in example 8 of the present invention, the abscissa thereof being the wave number (cm)^-1) And the ordinate represents the transmittance (%); in the infrared spectrum, 3433.28cm^-1The position is the stretching vibration peak of the terminal hydroxyl of the water reducing agent, 2874.37cm^-1The vibration peak of the expansion and contraction is the saturated C-H bond of the hydrocarbon, and the bending vibration peak is 1455.34cm^-1And 1351.84cm^-1；1251.29cm^-1The position is a carboxyl COOH stretching vibration peak; 1724.76cm^-1A stretching vibration peak of carboxylic acid C ═ O bond; 1105.65cm^-1、952.17cm^-1And 845.16cm^-1The absorption peak at (A) is a characteristic absorption peak of a long side chain polyoxyethylene group, wherein 1105.65cm^-1Is the stretching vibration peak of the ether bond C-O-C, 952.17cm^-1And 845.16cm^-1Respectively C-O and C-C stretching vibration peaks; the characteristic peaks can show that the small monomer and the polyether macromonomer are copolymerized in the solution to generate the polycarboxylic acid water reducing agent.

Detailed Description

The following examples are intended to further illustrate the present invention and should not be construed as limiting the scope of the invention, which is intended to be covered by the claims appended hereto.

Example 1:

a method for synthesizing a polycarboxylate superplasticizer by magnesium oxide catalysis comprises the following steps: respectively preparing solution A (3.6064 g of small monomer acrylic acid and 14.3838g of distilled water) and solution B (0.0345 g of ascorbic acid, 0.3066g of thioglycolic acid and 20.8792g of distilled water) for later use, adding 36.0242g of macromonomer diethylene glycol monovinyl ether (EPEG for short) and 15.0135g of distilled water into a three-neck flask with a thermometer, gradually cooling and stirring for dissolving at room temperature, adding 0.01g of magnesium oxide and 5g of water when the temperature is controlled to be 2 ℃ and the large monomer is completely dissolved, mixing and stirring for 10min, adding 0.25g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (after 45 min) and solution B (after 70 min), keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

Example 2:

a method for synthesizing a polycarboxylate superplasticizer by magnesium oxide catalysis comprises the following steps: respectively preparing solution A (3.4064 g of small monomer acrylic acid and 15.3838g of distilled water) and solution B (0.0335 g of ascorbic acid, 0.3566g of thioglycolic acid and 18.8792g of distilled water) for later use, adding 35.9986g of macromonomer (EPEG) and 16.0135g of distilled water into a three-neck flask with a thermometer, gradually cooling and stirring for dissolving at room temperature, adding 0.015g of magnesium oxide and 5g of water when the temperature is controlled to be 2 ℃ and the macromonomer is completely dissolved, mixing and stirring for 15min, adding 0.23g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (48min is finished) and solution B (72min is finished) at constant speed by using a constant-pressure dropping funnel, keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

Example 3:

a method for synthesizing a polycarboxylate superplasticizer by magnesium oxide catalysis comprises the following steps: respectively preparing solution A (3.5066 g of small monomer acrylic acid and 16.3278g of distilled water) and solution B (0.0338 g of ascorbic acid, 0.3316g of thioglycolic acid and 21.7772g of distilled water) for later use, adding 36.1248g of macromonomer (EPEG) and 16.0135g of distilled water into a three-neck flask with a thermometer, gradually cooling and stirring for dissolving at room temperature, adding 0.017g of magnesium oxide and 5g of water when the temperature is controlled to be 2 ℃ and the macromonomer is completely dissolved, mixing and stirring for 10min, adding 0.245g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (after 45min of dripping) and solution B (after 75min of dripping) by using a constant-pressure dropping funnel, keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

Example 4:

a method for synthesizing a polycarboxylate superplasticizer by using alumina as a catalyst comprises the following steps: respectively preparing solution A (3.5084 g of small monomer acrylic acid and 16.7838g of distilled water) and solution B (0.0395 g of ascorbic acid, 0.2866g of thioglycolic acid and 21.1772g of distilled water) for later use, adding 36.3241g of macromonomer (EPEG) and 16.3135g of distilled water into a three-neck flask with a thermometer, gradually cooling and stirring for dissolving at room temperature, adding 0.021g of aluminum oxide and 5g of water when the temperature is controlled to be 2 ℃ and the macromonomer is completely dissolved, mixing and stirring for 18min, adding 0.15g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (48min is finished) and solution B (78min is finished) by using a constant-pressure dropping funnel, keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

Example 5:

a method for synthesizing a polycarboxylate superplasticizer by using alumina as a catalyst comprises the following steps: respectively preparing solution A (3.5484 g of small monomer acrylic acid and 15.78g of distilled water) and solution B (0.033 g of ascorbic acid, 0.28g of thioglycolic acid and 17.5772g of distilled water) for later use, adding 36g of macromonomer (EPEG) and 16g of distilled water into a three-neck flask with a thermometer, gradually cooling and stirring for dissolving at room temperature, adding 0.02g of alumina and 5g of water when the temperature is controlled to be 2 ℃ and the macromonomer is completely dissolved, mixing and stirring for 15min, adding 0.19g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (after 45min is finished) and solution B (after 74min is finished) at constant speed by using a constant-pressure dropping funnel, keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

Example 6:

a method for synthesizing a polycarboxylate superplasticizer by using alumina as a catalyst comprises the following steps: respectively preparing solution A (3.7 g of small monomer acrylic acid and 15g of distilled water) and solution B (0.034 g of ascorbic acid, 0.25g of thioglycolic acid and 16.77g of distilled water) for later use, adding 36g of large monomer (EPEG) and 16g of distilled water into a three-necked flask with a thermometer, gradually cooling and stirring for dissolving at room temperature, adding 0.03g of aluminum oxide and 5g of water when the temperature is controlled to be 2 ℃ and the large monomer is completely dissolved, mixing and stirring for 15min, adding 0.2g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (46min is finished) and solution B (72min is finished) at constant speed by using a constant-pressure dropping funnel, keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

Example 7:

a method for synthesizing a polycarboxylate superplasticizer by copper oxide catalysis comprises the following steps: respectively preparing solution A (3.684 g of small monomer acrylic acid and 15.38g of distilled water are weighed) and solution B (0.0337 g of ascorbic acid, 0.285g of thioglycolic acid and 17.576g of distilled water) for later use, adding 36.11g of macromonomer (EPEG) and 15g of distilled water into a three-neck flask with a thermometer, gradually cooling and stirring for dissolving at room temperature, adding 0.033g of copper oxide and 5g of water when the temperature is controlled to be 2 ℃ and the macromonomer is completely dissolved, mixing and stirring for 13min, adding 0.12g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (after 45min is finished) and solution B (after 78min is finished) at constant speed by using a constant-pressure dropping funnel, keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

Example 8:

a method for synthesizing a polycarboxylate superplasticizer by copper oxide catalysis comprises the following steps: respectively preparing solution A (3.7124 g of small monomer acrylic acid and 15.178g of distilled water) and solution B (0.0343 g of ascorbic acid, 0.248g of thioglycolic acid and 17.721g of distilled water) for later use, adding 36g of macromonomer (EPEG) and 15.55g of distilled water into a three-neck flask with a thermometer, gradually cooling and stirring for dissolving at room temperature, adding 0.0112g of copper oxide and 5g of water when the temperature is controlled to be 2 ℃ and the macromonomer is completely dissolved, mixing and stirring for 25min, adding 0.29g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (after 45min of dripping) and solution B (after 79min of dripping) at constant speed by using a constant-pressure dropping funnel, keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

Example 9:

a method for synthesizing a polycarboxylate superplasticizer by copper oxide catalysis comprises the following steps: respectively preparing solution A (3.1484 g of small monomer acrylic acid and 15.378g of distilled water) and solution B (0.0353 g of ascorbic acid, 0.25g of thioglycolic acid and 18.275g of distilled water) for later use, adding 36.134g of macromonomer (EPEG) and 16g of distilled water into a three-neck flask with a thermometer, gradually cooling and stirring for dissolving at room temperature, adding 0.04g of magnesium oxide and 5g of water when the temperature is controlled to be 2 ℃ and the macromonomer is completely dissolved, mixing and stirring for 15min, adding 0.159g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (after 42min is finished) and solution B (after 70min is finished) at constant speed by using a constant-pressure dropping funnel, keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

Example 10:

a method for synthesizing a polycarboxylate superplasticizer by copper oxide catalysis comprises the following steps: respectively preparing solution A (3.7 g of small monomer acrylic acid and 15.18g of distilled water) and solution B (0.035 g of ascorbic acid, 0.26g of thioglycolic acid and 17.51g of distilled water) for later use, adding 35g of large monomer (EPEG) and 16g of distilled water into a three-neck flask with a thermometer, gradually cooling and stirring to dissolve at room temperature, adding 0.021g of copper oxide and 5g of water when the temperature is controlled to be 2 ℃ and the large monomer is completely dissolved, mixing and stirring for 15min, adding 0.24g of hydrogen peroxide and 0.5g of water, uniformly mixing, simultaneously dropwise adding solution A (after 44 min) and solution B (after 71 min) at constant speed by using a constant-pressure dropping funnel, keeping the temperature for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

The application example is as follows:

and carrying out a cement paste test and a concrete test on the synthesized polycarboxylate superplasticizer. The performance index of the polycarboxylate superplasticizer is according to the industry standard JG/T223-2007 polycarboxylic acid high-performance water reducing agent; the cement paste fluidity test is carried out according to the national standard GB/T8077-2000 'concrete admixture homogeneity test method', the water reducing agent folded solid mixing amount is 0.11%, and the test results are shown in Table 1; according to the national standard GB/T50080-2002 performance test standards of common concrete mixture, the concrete test has the water reducing agent bending solid content of 0.17 percent; GB-T50081-2002 Standard test method for mechanical properties of common concrete carries out related tests.

Table 1: application performance test results:

description of the drawings: the breaking and mixing amount of the polycarboxylate superplasticizer is 0.11 percent, and the Czochralski method is P.O 42.5.5R cement. W/C is water/cement (mass ratio).

Table 2: c₃₀Concrete test results:

description of the drawings: the bending and consolidation blending amount of the polycarboxylic acid water reducer is tested to be 0.17%, the cement with the tensile modulus of P.O 42.5.5R, medium sand (machine-made sand) and 5-25 continuous granular-grade macadam are adopted, the consumption of each side of the cement is 360 kg, and the sand rate is 45%.

Table 3: test result of concrete freezing and thawing test quality loss rate

Description of the drawings: the water-gel ratio of the polycarboxylic acid water reducer is tested to be 0.4, the bending and fixing parameters of the water reducer are 0.2%, cement of a drawing base P.O 42.5.5R, medium sand (machine-made sand) and 5-25 continuous granular rubbles are adopted, the consumption of each side of the cement is 360 kilograms, and the sand rate is 45%. (-representing no loss).

Example 11:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 2.2:1, the chain transfer agent accounts for 0.1 percent of the total mass of the monomers (the sum of the masses of the small monomer and the large monomer is the total mass of the monomers, and the chain transfer agent is 0.051 percent of the total mass of the monomers, the reducing agent accounts for 0.15 percent of the total mass of the monomers, and the catalyst accounts for 0.009 percent of the total mass of the monomers; mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding the macromonomer and water into a reactor (such as a three-neck flask, and then the same) with a thermometer, (gradually) cooling and stirring (dissolving), when the temperature is controlled to 2 ℃ and the macromonomer is completely dissolved, adding a catalyst and water, mixing and stirring for 10min, then adding an oxidant and water, mixing and stirring for 5min, then (using a constant-pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, keeping the temperature at the temperature of 2 ℃ for reaction for 1h, and standing the reacted material to room temperature to obtain the polycarboxylic acid water reducer (namely, the polycarboxylic acid water reducer synthesized by catalyzing magnesium oxide, aluminum oxide or copper oxide, and then the same).

With reference to national standard GB/T50080-2002 Standard for testing the performance of common concrete mixture, GB-T50081-2002 Standard for testing the mechanical properties of common concrete and GBT 50082 Standard for testing the Long-term Performance and durability of common concrete 2009 Standard for testing the Long-term Performance and durability of common concrete, the slump loss is small with time, and the compressive strength of C30 concrete reaches more than 34.5MPa and is calculated to be qualified; the concrete freeze-thaw test is qualified when the mass loss rate is below 5 percent; the product prepared by the embodiment is qualified.

Example 12:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 3.0:1, the chain transfer agent accounts for 0.18 percent of the total mass of the monomers, the reducing agent accounts for 0.088 percent of the total mass of the monomers, the oxidizing agent accounts for 0.19 percent of the total mass of the monomers, and the catalyst accounts for 0.019 percent of the total mass of the monomers; mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding a macromonomer and water into a reactor with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 12min when the temperature is controlled to be 5 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 7min, then (using a constant-pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, keeping the temperature at 5 ℃ for reaction for a total time of 1.6h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer;

otherwise, the same as example 1; the product prepared by the embodiment is qualified.

Example 13:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 2.8:1, the chain transfer agent accounts for 0.31 percent of the total mass of the monomers, the reducing agent accounts for 0.151 percent of the total mass of the monomers, the oxidizing agent accounts for 0.85 percent of the total mass of the monomers, and the catalyst accounts for 0.079 percent of the total mass of the monomers; mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding a macromonomer and water into a reactor with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 20min when the temperature is controlled to 12 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 8min, then (using a constant-pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, keeping the temperature at 12 ℃ for reaction for a total time of 1.9h, and standing the reacted material to room temperature to obtain the polycarboxylic acid water reducer;

otherwise, the same as example 1; the product prepared by the embodiment is qualified.

Example 14:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 3.5:1, the chain transfer agent accounts for 0.55 percent of the total mass of the monomers, the reducing agent accounts for 0.058 percent of the total mass of the monomers, the oxidizing agent accounts for 1.5 percent of the total mass of the monomers, and the catalyst accounts for 0.069 percent of the total mass of the monomers; mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding a macromonomer and water into a reactor with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 30min when the temperature is controlled to 18 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 6min, then (using a constant-pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, keeping the temperature at 18 ℃ for reaction for 2h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer;

otherwise, the same as example 1; the product prepared by the embodiment is qualified.

Example 15:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 4.2:1, the chain transfer agent accounts for 0.66 percent of the total mass of the monomers, the reducing agent accounts for 0.081 percent of the total mass of the monomers, the oxidizing agent accounts for 1.8 percent of the total mass of the monomers, and the catalyst accounts for 0.066 percent of the total mass of the monomers; mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding a macromonomer and water into a reactor with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 15min when the temperature is controlled to 20 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 10min, then (using a constant-pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, keeping the temperature at 20 ℃ for reaction for 2h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer;

otherwise, the same as example 1; the product prepared by the embodiment is qualified.

Example 16:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 5.2:1, the chain transfer agent accounts for 0.8 percent of the total mass of the monomers, the reducing agent accounts for 0.25 percent of the total mass of the monomers, the oxidizing agent accounts for 2.6 percent of the total mass of the monomers, and the catalyst accounts for 0.08 percent of the total mass of the monomers; mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding a macromonomer and water into a reactor with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 30min when the temperature is controlled to 28 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 10min, then (using a constant-pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, keeping the temperature at 28 ℃ for reaction for 2h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer;

otherwise, the same as example 1; the product prepared by the embodiment is qualified.

Example 17:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 3.7:1, the chain transfer agent accounts for 0.45 percent of the total mass of the monomers, the reducing agent accounts for 0.15 percent of the total mass of the monomers, the oxidizing agent accounts for 1.37 percent of the total mass of the monomers, and the catalyst accounts for 0.05 percent of the total mass of the monomers; mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding the macromonomer and water into a reactor with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 20min when the temperature is controlled to 15 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 8min, then (using a constant pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, wherein the total time of dropwise adding and heat preservation reaction at the temperature of 15 ℃ is 1.5h, and standing the reacted material to room temperature to obtain the polycarboxylic acid water reducer.

With reference to national standard GB/T50080-2002 Standard for testing the performance of common concrete mixture, GB-T50081-2002 Standard for testing the mechanical properties of common concrete and GBT 50082 Standard for testing the Long-term Performance and durability of common concrete 2009 Standard for testing the Long-term Performance and durability of common concrete, the slump loss is small with time, and the compressive strength of C30 concrete reaches more than 34.5MPa and is calculated to be qualified; the concrete freeze-thaw test is qualified when the mass loss rate is below 5 percent; the product prepared by the embodiment is qualified.

Example 18:

a method for synthesizing a polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps: the molar ratio of the large monomer to the small monomer is 5:1, the chain transfer agent accounts for 0.45 percent of the total mass of the monomers, the reducing agent accounts for 0.08 percent of the total mass of the monomers, the oxidizing agent accounts for 2 percent of the total mass of the monomers, and the catalyst accounts for 0.059 percent of the total mass of the monomers; the same as any of embodiments 11 to 17, except that the above-mentioned embodiment is omitted.

Example 19:

a method for synthesizing a polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps: the molar ratio of the large monomer to the small monomer is 4:1, the chain transfer agent accounts for 0.51 percent of the total mass of the monomers, the reducing agent accounts for 0.25 percent of the total mass of the monomers, the oxidizing agent accounts for 0.197 percent of the total mass of the monomers, and the catalyst accounts for 0.025 percent of the total mass of the monomers; the same as any of embodiments 11 to 17, except that the above-mentioned embodiment is omitted.

Example 20:

a method for synthesizing a polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps: the molar ratio of the large monomer to the small monomer is 4:1, the chain transfer agent accounts for 0.58 percent of the total mass of the monomers, the reducing agent accounts for 0.095 percent of the total mass of the monomers, the oxidizing agent accounts for 0.191 percent of the total mass of the monomers, and the catalyst accounts for 0.045 percent of the total mass of the monomers; the same as any of embodiments 11 to 17, except that the above-mentioned embodiment is omitted.

Example 21:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is 3.4:1, the chain transfer agent accounts for 0.68 percent of the total mass of the monomers, the reducing agent accounts for 0.22 percent of the total mass of the monomers, the oxidizing agent accounts for 0.95 percent of the total mass of the monomers, and the catalyst accounts for 0.062 percent of the total mass of the monomers; mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding the macromonomer and water into a reactor with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 30min when the temperature is controlled to 28 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 10min, then (using a constant pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, wherein the total time of dropwise adding and heat preservation reaction at the temperature of 28 ℃ is 2h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer.

With reference to national standard GB/T50080-2002 Standard for testing the performance of common concrete mixture, GB-T50081-2002 Standard for testing the mechanical properties of common concrete and GBT 50082 Standard for testing the Long-term Performance and durability of common concrete 2009 Standard for testing the Long-term Performance and durability of common concrete, the slump loss is small with time, and the compressive strength of C30 concrete reaches more than 34.5MPa and is calculated to be qualified; the concrete freeze-thaw test is qualified when the mass loss rate is below 5 percent; the product prepared by the embodiment is qualified.

Example 22:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is preferably 3.4:1, the chain transfer agent is 0.22% by mass of the total mass of the monomers, the reducing agent is 0.09% by mass of the total mass of the monomers, the oxidizing agent is 0.35% by mass of the total mass of the monomers, and the catalyst is 0.01% by mass of the total mass of the monomers. Mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding a macromonomer and water into a reactor with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 10min when the temperature is controlled to be 2 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 5min, then (using a constant-pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, wherein the total time of dropwise adding and heat-preservation reaction at the temperature of 2 ℃ is 1h, and standing the reacted material to room temperature to obtain the polycarboxylic acid water reducer;

otherwise, the same as example 21; the product prepared by the embodiment is qualified.

Example 23:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is preferably 3.4:1, the chain transfer agent is preferably 0.45% by mass, the reducing agent is preferably 0.12% by mass, the oxidizing agent is preferably 0.65% by mass, and the catalyst is preferably 0.036% by mass, based on the total mass of the monomers. Mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding a macromonomer and water into a reactor with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 20min when the temperature is controlled to 15 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 8min, then (using a constant-pressure dropping funnel) simultaneously (at a constant speed) dropwise adding the solution A and the solution B, keeping the temperature at 15 ℃ for reaction for a total time of 1.5h, and standing the reacted material to room temperature to obtain the polycarboxylic acid water reducer;

otherwise, the same as example 21; the product prepared by the embodiment is qualified.

Example 24:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

in the step a, the small monomer is mixed with water to prepare a solution A, which comprises the following steps: mixing the small monomer and water according to the mass ratio of 1:3.9 of the small monomer to the water to prepare solution A;

in the step a, the reducing agent, the chain transfer agent and water are mixed to prepare a solution B, which comprises the following steps: mixing the reducing agent and the chain transfer agent with water according to the mass ratio of the total mass of the reducing agent and the chain transfer agent to the mass of water being 1:48 to prepare a solution B;

adding the macromonomer and the water into a reactor with a thermometer in the step b, wherein the macromonomer and the water are added into the reactor with the thermometer according to the mass ratio of 1:0.38 of the macromonomer to the water;

the same as any of embodiments 11 to 23, except that the above-mentioned embodiment is omitted.

Example 25:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

in the step a, the small monomer is mixed with water to prepare a solution A, which comprises the following steps: mixing the small monomer and water according to the mass ratio of 1:8.6 of the small monomer to the water to prepare solution A;

in the step a, the reducing agent, the chain transfer agent and water are mixed to prepare a solution B, which comprises the following steps: mixing the reducing agent and the chain transfer agent with water according to the mass ratio of the total mass of the reducing agent and the chain transfer agent to the mass of water being 1:90 to prepare a solution B;

adding the macromonomer and the water into a reactor with a thermometer in the step b, wherein the macromonomer and the water are added into the reactor with the thermometer according to the mass ratio of 1:0.86 of the macromonomer to the water;

the same as any of embodiments 11 to 23, except that the above-mentioned embodiment is omitted.

Example 26:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

in the step a, the small monomer is mixed with water to prepare a solution A, which comprises the following steps: mixing the small monomer and water according to the mass ratio of 1:6.6 of the small monomer to the water to prepare solution A;

in the step a, the reducing agent, the chain transfer agent and water are mixed to prepare a solution B, which comprises the following steps: mixing the reducing agent and the chain transfer agent with water according to the mass ratio of the total mass of the reducing agent and the chain transfer agent to the mass of water being 1:69 to prepare a solution B;

adding the macromonomer and the water into a reactor with a thermometer in the step b, wherein the macromonomer and the water are added into the reactor with the thermometer according to the mass ratio of 1:0.62 of the macromonomer to the water;

the same as any of embodiments 11 to 23, except that the above-mentioned embodiment is omitted.

Example 27:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

in the step a, the small monomer is mixed with water to prepare a solution A, which comprises the following steps: mixing the small monomer and water according to the mass ratio of 1:4.6 of the small monomer to the water to prepare solution A;

in the step a, the reducing agent, the chain transfer agent and water are mixed to prepare a solution B, which comprises the following steps: mixing the reducing agent, the chain transfer agent and water according to the mass ratio of the total mass of the reducing agent and the chain transfer agent to the mass of water of 1:58 to prepare a solution B;

adding the macromonomer and the water into a reactor with a thermometer in the step b, wherein the macromonomer and the water are added into the reactor with the thermometer according to the mass ratio of 1:0.58 of the macromonomer to the water;

the same as any of embodiments 11 to 23, except that the above-mentioned embodiment is omitted.

Example 28:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

adding the catalyst and water in the step b, mixing and stirring, namely adding the catalyst and the water according to the mass ratio of 1:120 of the catalyst to the water, and mixing and stirring;

adding an oxidant and water in a mass ratio of 1:1, mixing and stirring;

the same as any of embodiments 11 to 27, except that the above-mentioned embodiment is omitted.

Example 29:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

adding the catalyst and water in the step b, mixing and stirring, namely adding the catalyst and the water according to the mass ratio of 1:500 of the catalyst to the water, and mixing and stirring;

adding an oxidant and water in a mass ratio of 1:5, mixing and stirring;

the same as any of embodiments 11 to 27, except that the above-mentioned embodiment is omitted.

Example 30:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

adding the catalyst and water in the step b, mixing and stirring, namely adding the catalyst and the water according to the mass ratio of 1:310 of the catalyst to the water, and mixing and stirring;

adding an oxidant and water in a mass ratio of 1:2, and mixing and stirring;

the same as any of embodiments 11 to 27, except that the above-mentioned embodiment is omitted.

Example 31:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

adding the catalyst and water in the step b, mixing and stirring, namely adding the catalyst and the water according to the mass ratio of 1:220 of the catalyst to the water, and mixing and stirring;

adding an oxidant and water in a mass ratio of 1:2, and mixing and stirring;

the same as any of embodiments 11 to 27, except that the above-mentioned embodiment is omitted.

Example 32:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

adding the catalyst and water in the step b, mixing and stirring, namely adding the catalyst and the water according to the mass ratio of 1:400 of the catalyst to the water, and mixing and stirring;

adding an oxidant and water in a mass ratio of 1:4, mixing and stirring;

the same as any of embodiments 11 to 27, except that the above-mentioned embodiment is omitted.

Example 33:

the method for synthesizing the polycarboxylic acid water reducing agent by catalyzing magnesium oxide, aluminum oxide or copper oxide comprises the following steps:

a. preparing materials:

taking raw materials including a macromonomer, a small monomer, a chain transfer agent, a reducing agent, an oxidizing agent, a catalyst and water, wherein: the molar ratio of the small monomer to the large monomer is preferably 3.4:1, the chain transfer agent accounts for 0.44 percent of the total mass of the monomers, the reducing agent accounts for 0.11 percent of the total mass of the monomers, the oxidizing agent accounts for 0.65 percent of the total mass of the monomers, and the catalyst accounts for 0.03 percent of the total mass of the monomers; mixing the small monomer with water, and stirring uniformly to prepare a solution A for later use; mixing a reducing agent, a chain transfer agent and water, and uniformly stirring to prepare a solution B for later use;

b. and (3) synthesis reaction:

adding the macromonomer and water into a reactor (such as a three-neck flask) with a thermometer, gradually cooling and stirring (dissolving), adding a catalyst and water to mix and stir for 20min when the temperature is controlled to be 20 ℃ and the macromonomer is completely dissolved, then adding an oxidant and water to mix and stir for 7min, then (using a constant pressure dropping funnel) dropwise adding the solution A and the solution B simultaneously (at a constant speed), finishing dropping the solution A for 0.7h, finishing dropping the solution B for 1.2h, after finishing dropping the solution B, keeping the temperature at 20 ℃ for 0.5h, and standing the reacted materials to room temperature to obtain the polycarboxylic acid water reducer (namely the polycarboxylic acid water reducer synthesized by catalyzing magnesium oxide, aluminum oxide or copper oxide).

In the above embodiments 11 to 33:

the macromonomer is diethylene glycol monovinyl ether (EPEG and 6C polyether macromonomer for short, and the product production providing enterprises are Sichuan Hongcong new material company, Liaoke chemical company, Bailingwei science and technology company, Saen chemical technology (Shanghai) company); the molecular weight of the macromonomer is 1500-4000;

the small monomer is acrylic acid;

the chain transfer agent is one or a mixture of two of thioglycolic acid, thioglycolic acid and mercaptopropionic acid, and mercaptopropionic acid is preferred;

the catalyst is any one of magnesium oxide, aluminum oxide and copper oxide;

the reducing agent is one or a mixture of more than two of sodium hypophosphite, sodium bisulfite, sodium sulfite and ascorbic acid, and ascorbic acid is preferred;

the oxidant is one or a mixture of more than two of hydrogen peroxide, potassium persulfate, ammonium persulfate and the like, preferably hydrogen peroxide;

the water is distilled water, ultrapure water or deionized water.

The polycarboxylate superplasticizer prepared in the embodiment is subjected to performance evaluation by adopting infrared spectroscopy (FT-IR) and a cement paste test and a concrete test; by infrared spectrum characterization (FT-IR analysis data, see figure description), the characteristic functional group of the polycarboxylate superplasticizer appears in the synthesized product.

The content and embodiment of the invention are as follows: in the performance test of the prepared polycarboxylic acid water reducing agent, a cement paste fluidity test is carried out according to the national standard GB/T8077-2000 'concrete admixture homogeneity test method'; the concrete test is carried out according to the national standard GB/T50080-2002 'test standard for the performance of common concrete mixture'; GB/T50081-2002 Standard test method for mechanical properties of common concrete carries out related tests.

In the above embodiment: all the raw materials are commercially available products.

In the above embodiment: the percentages used, not specifically indicated, are percentages by weight or known to those skilled in the art; the parts by mass (by weight) may all be grams or kilograms.

In the above embodiment: the process parameters (temperature, time, etc.) and the numerical values of the components in each step are in the range, and any point can be applicable.

The present invention and the technical contents not specifically described in the above embodiments are the same as the prior art.

The present invention is not limited to the above-described embodiments, and the present invention can be implemented with the above-described advantageous effects.