A polyether compound and its preparation method and application in collapse-preventing agent

Abstract

The present invention provides a polyether compound and a preparation method thereof and an application in a slump-preventing agent, so as to overcome the limitations of the prior art 6C polyether macromonomer having high reaction activity and the need to polymerize under a low temperature environment. The polyether compound has a structure shown in Formula I: wherein R1 is selected from: H or CH3, R2 is selected from: C2H4 or C3H6, and R3 is selected from: a polyether chain obtained by ring-opening polymerization of ethylene oxide and / or propylene oxide. The polyether compound is used to design and synthesize a water-retaining and slurry-raising concrete slump-preventing agent, which can achieve long-term slump-preserving without loss for 4 hours, and the process does not have the phenomenon of water seepage and delayed return, has the function of water-retaining and slurry-raising, and has good workability.

Description

Technical Field

[0001] The invention relates to the technical field of concrete additives, and in particular to a polyether compound and a preparation method thereof and application thereof in a collapse-preventing agent. Background Art

[0002] Polycarboxylic acid high-performance water reducer has the characteristics of high water reduction, low dosage, high slump retention, etc. It can make concrete have good fluidity, thixotropy and long-term slump retention. However, when encountering complex and changeable materials such as cement, sand, stone, etc., polycarboxylic acid water reducers often lose their high-performance advantages. For example, there are problems such as rapid loss of concrete slump, poor concrete workability, and delayed water bleeding of concrete. In addition, the increase in ambient temperature has a greater impact on the maintenance of concrete slump. When the temperature is low, concrete bleeds water laggingly; when the temperature is high, the cement hydration reaction is accelerated, the consumption of admixtures in the cement hydration process is accelerated, and the slump loss of concrete is greater. In the ready-mixed concrete industry, concrete often loses slump too quickly when it is transported for a long time at high temperature, affecting the construction and quality of the project.

[0003] At present, due to the low quality of concrete materials, the collapse-preserving agent generally has a good collapse-preserving effect within 1 to 2 hours. After more than 2 hours, the collapse-preserving effect of concrete is poor. As the scale of cities continues to expand and traffic congestion worsens, the transportation time required for concrete from mixing to on-site pouring continues to increase. 3 hours is a common phenomenon, and even 4 hours is required under special circumstances. In addition, the workability of concrete is also a big problem. If the slurry is collected too quickly, the concrete will often be very loose and the water retention effect will be poor.

[0004] Chinese patent CN102390950A discloses a slow-release polycarboxylic acid-based slump-retaining agent and its preparation method, which is specifically prepared by copolymerizing and mixing unsaturated carboxylic acid polyethylene glycol monoester, unsaturated polyoxyalkylene ether monoester, unsaturated monocarboxylic acid and its derivative monomers, and unsaturated olefin sulfonic acid and its sodium salt. It can effectively solve the compatibility problem between sand and gravel materials with high mud content and water reducer, but it is greatly affected by temperature and pH.

[0005] Chinese patent CN1167739A discloses a method for preparing a polycarboxylic acid superplasticizer, wherein alkoxy polyalkylene glycol and (meth) acrylate are first subjected to an ester exchange reaction under the action of an alkaline catalyst to prepare alkoxy polyalkylene glycol mono(meth) acrylate, which is then mixed with (meth) acrylic acid and copolymerized under the action of ammonium persulfate to obtain a polycarboxylic acid superplasticizer. However, a large amount of excess (meth) acrylate is required when preparing the alkoxy polyalkylene glycol mono(meth) acrylate monomer, and the polycarboxylic acid superplasticizer prepared by this process has a large slump loss over time.

[0006] At present, the main raw material of the collapse-preventing agent is a polyether macromonomer prepared by using methyl allyl alcohol and isopentanol as initiators. The macromonomer is the main raw material for preparing the collapse-preventing agent, followed by the unsaturated small monomer. Therefore, in order to greatly improve the performance of the collapse-preventing agent, the material can be modified from both the main chain and the side chain of the molecule. In recent years, the popular polyether macromonomers using ethylene glycol monovinyl ether and 4-hydroxybutyl vinyl ether as initiators have been widely favored due to their high water reduction rate and good collapse-preserving performance. However, due to the high reaction activity of this type of macromonomer, it is necessary to prepare it under low temperature conditions to obtain better performance, which limits its promotion and use to a certain extent. Therefore, it is particularly important to develop a collapse-preserving agent that is insensitive to reaction temperature, has a water-retaining and slurry-raising effect, and has a collapse-preserving time of more than 4 hours. Summary of the invention

[0007] In view of this, the present invention aims to provide a polyether compound and a preparation method thereof and application in a slump retaining agent, so as to overcome the limitations of the prior art 6C polyether macromonomer having high reactivity and requiring polymerization under low temperature conditions, and to design and synthesize a water-retaining slurry-raising type concrete slump retaining agent using the polyether compound, so as to solve the problems of low-temperature hysteresis and high-temperature loss of concrete. The technical solution of the present invention is:

[0008] In a first aspect, the present invention provides a polyether compound having a structure shown in Formula I:

[0009] In formula I, R1 is selected from: H or CH3, R2 is selected from: C2H4 or C3H6, and R3 is selected from: a polyether chain obtained by ring-opening polymerization of ethylene oxide and / or propylene oxide.

[0010] Furthermore, the weight average molecular weight of the polyether compound is 600-6000.

[0011] In a second aspect, the present invention provides a method for preparing the above-mentioned polyether compound, comprising: using monomethyl allyl glycol ether or propylene glycol monoallyl ether as a starting material, introducing ethylene oxide and / or propylene oxide under anaerobic conditions and heating to carry out a polymerization reaction in the presence of a catalyst, and further introducing propylene oxide after the reaction is completed to carry out polymerization reaction capping.

[0012] Furthermore, the preparation method specifically comprises the following steps:

[0013] Step 1, adding monomethyl allyl glycol ether or propylene glycol monoallyl ether to a catalyst, mixing evenly, and heating to 80-120° C. under an oxygen-free condition;

[0014] Step 2, introducing a certain amount of ethylene oxide and / or propylene oxide, during which the system pressure is controlled to be 0.2-3.0 MPa, and then the temperature is controlled to be 80-120° C. to react until the system pressure no longer decreases;

[0015] Step 3, further introducing a certain amount of propylene oxide under anaerobic conditions, during which the system pressure is controlled to be 0.05-2.0 MPa, and then controlling the temperature to be 80-120° C. to react until the system pressure no longer decreases, thereby obtaining the polyether compound.

[0016] Furthermore, the catalyst one is at least one of sodium methoxide, sodium tert-butoxide, sodium ethoxide, lithium aluminum hydroxide, sodium hydroxide, potassium hydroxide, and metallic sodium, and the amount of the catalyst one is 0.1 to 0.3% of the mass of ethylene oxide and / or propylene oxide.

[0017] Furthermore, the amount of ethylene oxide and / or propylene oxide used is determined according to the molecular weight of the polyether compound.

[0018] Furthermore, the molar ratio of the glycidol to monomethyl allyl glycol ether or propylene glycol monoallyl ether is 1.0-1.1:1.

[0019] In a third aspect, the present invention provides use of the above-mentioned polyether compound in preparing a concrete collapse-preventing agent.

[0020] In a fourth aspect, the present invention provides a method for preparing a concrete collapse-preventing agent, comprising the following steps:

[0021] (1) Sucrose monoallyl ether, unsaturated acid anhydride 1 and inhibitor are mixed uniformly, heated to 60-120° C. in a protective atmosphere, and then catalyst 2 is added and mixed uniformly, and the mixture is kept warm for 2-6 hours, during which water generated by the reaction is continuously removed, and the temperature is cooled to room temperature after the reaction is completed to obtain a cross-linked slow-release functional monomer;

[0022] (2) mixing the cross-linked sustained-release functional monomer obtained in step (1), the unsaturated carboxylic acid and / or the unsaturated acid anhydride II, and the above-mentioned polyether compound, and dissolving them in water to obtain a comonomer mixture solution A; mixing the unsaturated carboxylic acid ester and the workable small monomer, and dissolving them in water to obtain a comonomer mixture solution B;

[0023] (3) The comonomer mixture solution A, the comonomer mixture solution B, an initiator and a molecular weight regulator are mixed, and copolymerization reaction is carried out at 5 to 50° C. After the reaction is completed, the pH value of the system is adjusted to 5 to 7 to obtain a concrete collapse retaining agent.

[0024] Furthermore, in the step (1), the molar ratio of sucrose monoallyl ether to unsaturated acid anhydride is 1:(0.5-5).

[0025] Furthermore, the unsaturated acid anhydride 1 is at least one of citraconic anhydride, dimethylmaleic anhydride and itaconic anhydride.

[0026] Furthermore, the inhibitor is at least one of 2,2-diphenyl-1-picrylhydrazine, 1,1-diphenyl-2-picrylhydrazine, and N-nitrosodiphenylamine, and the amount of the inhibitor is 0.5% to 2.0% of the total mass of sucrose monoallyl ether and unsaturated anhydride.

[0027] Furthermore, the catalyst 2 is at least one of concentrated sulfuric acid, benzenesulfonic acid, p-toluenesulfonic acid, and ethylsulfonic acid, and the amount of the catalyst 2 is 0.2% to 3.0% of the total mass of sucrose monoallyl ether and unsaturated anhydride 1.

[0028] Furthermore, in the step (2), the mass ratio of the cross-linked sustained-release functional monomer, the unsaturated carboxylic acid and / or unsaturated acid anhydride, and the polyether compound is 3-8:5-10:200.

[0029] Furthermore, the unsaturated carboxylic acid is at least one of acrylic acid, methacrylic acid, fumaric acid and itaconic acid.

[0030] Furthermore, the unsaturated acid anhydride 2 is maleic anhydride and / or itaconic anhydride.

[0031] Furthermore, in the step (2), the mass ratio of the unsaturated carboxylic acid ester to the workable small monomer is 6-35:0.2-4.

[0032] Furthermore, the unsaturated carboxylic acid ester is at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, isooctyl acrylate, isooctyl methacrylate, and methyl methacrylate.

[0033] Furthermore, the workable small monomer is at least one of methyl methacrylate tartrate, acrylamide, and 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate.

[0034] Furthermore, in the step (3), the comonomer mixture solution A, the comonomer mixture solution B, the initiator and the molecular weight regulator are mixed, and a copolymerization reaction is carried out at 5 to 50° C.: the comonomer mixture solution A, the comonomer mixture solution B, the initiator aqueous solution and the molecular weight regulator aqueous solution are simultaneously dripped into a reaction kettle filled with water, the stirrer is turned on, and the temperature is controlled to be 5 to 50° C., and the reaction is carried out while mixing. The dripping time is 0.5 to 1.5 hours. After all the solutions are dripped, the reaction is continued by keeping the temperature warm for 1.0 to 3.0 hours.

[0035] Furthermore, the initiator is a water-soluble inorganic peroxide initiator, a water-soluble redox initiator or a water-soluble azo initiator, wherein the water-soluble inorganic peroxide initiator is at least one of ammonium persulfate and potassium persulfate; the water-soluble redox initiator is at least one of a combination of hydrogen peroxide and bleaching powder, a combination of hydrogen peroxide and ascorbic acid, and a combination of persulfate and sodium bisulfite; the water-soluble azo initiator is at least one of azobisisobutylamidine and its hydrochloride, azobisisopropylimidazoline and its hydrochloride, azobiscyanovaleric acid, and azobisisopropylimidazoline; the amount of the initiator used is 0.5 to 3.0% of the total mass of the solute in the comonomer mixture solution A and the comonomer mixture solution B.

[0036] Furthermore, the molecular weight regulator is at least one of thioglycolic acid, mercaptopropionic acid, mercaptoethanol, isopropanol, sodium hypophosphite, trisodium phosphate, sodium formate, sodium acetate, and dodecanethiol; the amount of the molecular weight regulator is 0.2 to 2.0% of the total mass of the solute in the comonomer mixture solution A and the comonomer mixture solution B.

[0037] In a fifth aspect, the present invention provides a concrete collapse-preventing agent obtained by the above-mentioned preparation method.

[0038] The beneficial effects of the present invention are:

[0039] 1. The present invention uses monomethyl allyl glycol ether and propylene glycol monoallyl ether as initiators to prepare polyether compounds, and uses propylene oxide to end-cap the polyether monomers. The obtained new polyether macromonomers with dihydroxyl groups at the end groups are less sensitive to reaction temperature than conventional polyether macromonomers, and can achieve polymerization at different ambient temperatures. The prepared concrete collapse-preventing agent has more excellent collapse-preventing performance.

[0040] 2. The polyether compound prepared by the present invention using propylene oxide blocking has two hydroxyl groups at the molecular end and participates in the copolymerization reaction. The prepared polycarboxylic acid collapse inhibitor molecules are adsorbed on the surface of cement particles, which can increase the thickness of the water film layer between particles, adjust the viscosity of concrete, improve the water retention of concrete, have a significant slurry lifting effect, and slow down the slurry collection rate of concrete.

[0041] 3. In the present invention, the hydroxyl group of sucrose monoallyl ether (as shown in the following structural formula) is esterified with unsaturated acid anhydride to prepare a cross-linked sustained-release functional monomer having multiple ester groups. The collapse-preventing agent molecules prepared by graft copolymerization are lightly cross-linked in local space to form a three-dimensional structure, which increases the local spatial steric hindrance of the molecule. At the same time, the functional monomer introduces multiple ester functional groups, which will gradually hydrolyze in the alkaline environment of cement to release multiple hydroxyl and carboxyl groups, which are helpful to adjust the dispersion performance of concrete and achieve long-term collapse prevention of concrete for 4 hours. The concrete has good workability and does not bleed or return.

[0042] The structural formula of sucrose monoallyl ether: DETAILED DESCRIPTION

[0043] In the description of the present invention, it should be noted that, if the specific conditions are not specified in the examples, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0044] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0045] Example 1

[0046] This embodiment provides a method for preparing a polyether compound, and using the polyether compound to prepare a water-retaining slurry-raising type concrete collapse-preventing agent, as follows:

[0047] (1) Preparation of dihydroxy-terminated polyether macromonomers:

[0048] Add 58.0g propylene glycol monoallyl ether and 1.7g lithium aluminum tetrahydride into the reactor, stir evenly, evacuate to -0.1MPa, replace with N2 directly 3 times, heat the reaction to 80°C, introduce 942.0g ethylene oxide into the reactor, maintain the reactor temperature between 80°C and 100°C and the pressure between 0.5MPa and 2Mpa during the addition process, and keep the temperature at 80°C for about 2h after the addition of ethylene oxide. Stop the reaction when the pressure of the reactor no longer decreases, continue to evacuate to -0.1Mpa, and then introduce 37.0g propylene oxide into the reactor, maintain the reactor temperature between 80°C and 100°C and the pressure between 0.5MPa and 2Mpa during the addition process, and when the pressure of the reactor no longer decreases, the reaction ends, and a polyether macromonomer P1 containing dihydroxyl end-capping having a weight average molecular weight of 2000 is obtained.

[0049] (2) Preparation of water-retaining and slurry-raising concrete collapse-preventing agent:

[0050] a. Esterification reaction: 382.0g sucrose monoallyl ether, 60.0g dimethyl maleic anhydride, 200.0g citraconic anhydride and 3.5g 2,2-diphenyl-1-picrylhydrazine were placed in a reactor equipped with a condensing device. Under nitrogen protection, the temperature was raised to 70°C, and then 2.0g concentrated sulfuric acid was added. The reaction was kept warm for 5.0h. During the reaction, water was removed by passing nitrogen gas with water. After the reaction, the temperature was cooled to room temperature to obtain a cross-linked sustained-release functional monomer GD1.

[0051] b 6.0gGD1, 6.0g acrylic acid, 200.0g of P1 and 100.0g of water were mixed and stirred to dissolve to obtain a comonomer mixture solution A; 27.0g of hydroxyethyl acrylate and 2.0g of methacrylic tartrate and 10.0g of water were mixed and stirred to obtain a comonomer mixture solution B;

[0052] c. Monomer blending: 20.0 g of water was added to the reactor, 2.0 g of hydrogen peroxide was added at one time, 312.0 g of the comonomer mixture solution A, 39.0 g of the comonomer mixed solution B, an ascorbic acid aqueous solution (0.4 g of ascorbic acid, 20.0 g of water) and a thioglycolic acid aqueous solution (0.9 g of thioglycolic acid, 20.0 g of water) were dripped into the reactor, the stirrer was turned on, and the reaction was carried out at a reaction temperature of 5 ° C. The dropping time was 1.0 h. After the dropwise addition was completed, the reaction was continued for 1.0 h to obtain a copolymer product;

[0053] d. Neutralization reaction: The copolymerization product obtained in step c is adjusted to pH 6.0 with alkali to obtain the water-retaining slurry-raising concrete collapse-preventing agent KZJ-1.

[0054] Example 2

[0055] This embodiment provides a method for preparing a polyether compound, and using the polyether compound to prepare a water-retaining slurry-raising type concrete collapse-preventing agent, as follows:

[0056] (1) Preparation of dihydroxy-terminated polyether macromonomers: 39.0 g of propylene glycol monoallyl ether and 1.9 g of sodium hydroxide (4.9%) were added to a reaction kettle, stirred evenly, evacuated to -0.1 MPa, replaced with N2 three times, and the reaction temperature was raised to 80°C. 961.0 g of ethylene oxide was introduced into the reaction kettle. During the addition process, the reaction kettle temperature was maintained between 80°C and 100°C and the pressure was maintained between 1.0 MPa and 2.0 MPa. After the addition of ethylene oxide was completed, the temperature was kept at 90°C for about 1.5 h. When the pressure in the reactor no longer decreases, stop the reaction, continue to evacuate to -0.1 MPa, and then introduce 24.7 g of propylene oxide (0.33 mol) into the reactor. During the addition process, maintain the temperature of the reactor between 80°C and 100°C and the pressure between 1.0 MPa and 2 MPa. When the pressure in the reactor no longer decreases, the reaction is terminated, and a dihydroxy-terminated polyether macromonomer P2 with a weight average molecular weight of 3000 is obtained.

[0057] (2) Preparation of water-retaining and slurry-raising concrete collapse-preventing agent:

[0058] a. Esterification reaction: 382.0g sucrose monoallyl ether, 50.0g citraconic anhydride, 310.0g itaconic anhydride, and 4.2g 2,2-diphenyl-1-picrylhydrazine were charged into a reactor equipped with a condensing device. Under nitrogen protection, the temperature was raised to 80°C, and then 1.5g concentrated sulfuric acid and 1.0g p-toluenesulfonic acid were added. The reaction was kept warm for 4.0h. During the reaction, water was removed by nitrogen gas. After the reaction, the temperature was cooled to room temperature to obtain a cross-linked sustained-release functional monomer GD2.

[0059] b. Monomer blending: 5.0 g GD2, 8.0 g methacrylic acid, 200.0 g P2 and 100.0 g water were mixed and stirred to dissolve to obtain a comonomer mixture solution A; 30.0 g hydroxyethyl methacrylate and 3.0 g acrylamide and 10.0 g water were mixed and stirred to obtain a comonomer mixture solution B;

[0060] c. Copolymerization: 20.0 g of water was added to the reactor, 1.8 g of hydrogen peroxide was added at one time, 313.0 g of the comonomer mixture solution A, 43.0 g of the comonomer mixed solution B, an aqueous solution of bleaching block (0.5 g of bleaching block, 20.0 g of water) and an aqueous solution of mercaptopropionic acid (1.2 g of mercaptopropionic acid, 20.0 g of water) were dripped into the reactor, the stirrer was turned on, and the reaction was carried out at a reaction temperature of 15 ° C. The dropping time was 1.2 h, and the reaction was continued for 1.0 h after the dropwise addition was completed to obtain a copolymer product;

[0061] d. Neutralization reaction: The copolymerization product obtained in step c is adjusted to pH 6.0 with alkali to obtain the water-retaining slurry-type concrete collapse-preventing agent KZJ-2.

[0062] Example 3

[0063] This embodiment provides a method for preparing a polyether compound, and using the polyether compound to prepare a water-retaining slurry-raising type concrete collapse-preventing agent, as follows:

[0064] (1) Preparation of polyether macromonomer containing dihydroxyl end capping: 29.0g monomethylallyl glycol ether and 1.5g sodium metal were added to a reactor, stirred evenly, evacuated to -0.1MPa, replaced with N2 for 3 times, the reaction temperature was raised to 80°C, 971.0g propylene oxide was introduced into the reactor, and the reactor temperature was maintained between 90°C and 110°C and the pressure was maintained between 0.5MPa and 2.0MPa during the addition process. After the addition of propylene oxide was completed, the reactor was kept at 100°C for about 1h. When the pressure of the reactor no longer decreased, the reaction was stopped, and the evacuation to -0.1MPa was continued. 18.5g propylene oxide was introduced into the reactor, and the reactor temperature was maintained between 90°C and 110°C and the pressure was maintained between 0.5MPa and 2MPa during the addition process. When the pressure of the reactor no longer decreased, the reaction was completed, and a polyether macromonomer P3 containing dihydroxyl end capping with a weight average molecular weight of 4000 was obtained.

[0065] (2) Preparation of water-retaining and slurry-raising concrete collapse-preventing agent:

[0066] a. Esterification reaction: 382.0g sucrose monoallyl ether, 46.0g dimethyl maleic anhydride, 220.0g itaconic anhydride, 1.8g 2,2-diphenyl-1-picrylhydrazine and 3.2g 1,1-diphenyl-2-picrylhydrazine were placed in a reactor equipped with a condenser. Under nitrogen protection, the temperature was raised to 90°C, and 2.2g p-toluenesulfonic acid was added. The reaction was kept warm for 3.5h. During the reaction, water was removed by passing nitrogen gas with water. After the reaction, the temperature was cooled to room temperature to obtain a cross-linked sustained-release functional monomer GD3.

[0067] b. Monomer blending: 3.0 g of GD3, 10.0 g of fumaric acid, 200.0 g of P3 and 100.0 g of water were mixed and stirred to dissolve to obtain a comonomer mixture solution A; 24.0 g of hydroxypropyl acrylate and 1.0 g of 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate were mixed and stirred to obtain a comonomer mixture solution B;

[0068] c. Copolymerization reaction: 40.0 g of water was added to the reactor, and 313.0 g of the comonomer mixture solution A, 35.0 g of the comonomer mixed solution B, an aqueous solution of ammonium persulfate (including 1.5 g of ammonium persulfate and 20.0 g of water) and an aqueous solution of mercaptoethanol (including 0.6 g of mercaptoethanol and 20.0 g of water) were dripped into the reactor, and the stirrer was turned on to react. The reaction temperature was 45 ° C. The dropping time was 1.0 h. After the dropwise addition was completed, the reaction was continued for 2.0 h to obtain a copolymer product;

[0069] d. Neutralization reaction: The copolymerization product obtained in step c is adjusted to pH 6.0 with alkali to obtain the water-retaining slurry-type concrete collapse-preventing agent KZJ-3.

[0070] Example 4

[0071] This embodiment provides a method for preparing a polyether compound, and using the polyether compound to prepare a water-retaining slurry-raising type concrete collapse-preventing agent, as follows:

[0072] (1) Preparation of dihydroxy-terminated polyether macromonomer: Add 23.0 g of monomethyl allyl glycol ether and 1.6 g of potassium hydroxide into a reaction kettle, stir evenly, evacuate to -0.1 MPa, replace with N2 three times, heat the reaction to 80°C, introduce 477.0 g of ethylene oxide and 500.0 g of propylene oxide into the reaction kettle, maintain the temperature of the reaction kettle between 100°C and 120°C and the pressure between 0.5 MPa and 1.0 MPa during the addition process, and keep the temperature at 110°C for about 1 hour after the addition of ethylene oxide and propylene oxide. When the pressure in the reactor stops decreasing, stop the reaction, continue to evacuate to -0.1 MPa, and then introduce 14.8 g of propylene oxide into the reactor. During the addition process, maintain the temperature of the reactor between 100°C and 120°C and the pressure between 0.5 MPa and 1 MPa. When the pressure in the reactor stops decreasing, the reaction is terminated, and a dihydroxy-terminated polyether macromonomer P4 with a weight average molecular weight of 5000 is obtained.

[0073] (2) Preparation of water-retaining and slurry-raising concrete collapse-preventing agent:

[0074] a. Esterification reaction: 382.0g sucrose monoallyl ether, 360.0g dimethyl maleic anhydride, and 3.8g 2,2-diphenyl-1-picrylhydrazine were placed in a reactor equipped with a condensing device. Under nitrogen protection, the temperature was raised to 110°C, and 2.5g ethyl sulfonic acid was added. The reaction was kept warm for 2.0h. During the reaction, water was removed by passing nitrogen gas with water. After the reaction, the temperature was cooled to room temperature to obtain a cross-linked sustained-release functional monomer GD4.

[0075] b. Monomer blending: 3.0 g of GD4, 6.0 g of itaconic acid, 200.0 g of P4 and 100.0 g of water were mixed and stirred to dissolve to obtain a comonomer mixture solution A; 32.0 g of hydroxypropyl methacrylate and 1.2 g of 2-methyl-2-acrylic acid-2-hydroxyethyl phosphate were mixed and stirred to obtain a comonomer mixture solution B;

[0076] c. Copolymerization reaction: 60.0 g of water was added to the reactor, 2.5 g of hydrogen peroxide was added at one time, 309.0 g of the comonomer mixture solution A, 43.2 g of the comonomer mixed solution B, an aqueous ascorbic acid solution (0.25 g of ascorbic acid, 20.0 g of water) and an aqueous sodium hypophosphite solution (2.5 g of sodium hypophosphite, 20.0 g of water) were dripped into the reactor, the stirrer was turned on, and the reaction was carried out at a reaction temperature of 35 ° C. The dropping time was 0.5 h, and the reaction was continued for 2.0 h after the dropwise addition was completed to obtain a copolymer product;

[0077] d. Neutralization reaction: The copolymerization product obtained in step c is adjusted to pH 6.0 with alkali to obtain the water-retaining slurry-type concrete collapse-preventing agent KZJ-4.

[0078] Example 5

[0079] This embodiment provides a method for preparing a polyether compound, and using the polyether compound to prepare a water-retaining slurry-raising type concrete collapse-preventing agent, as follows:

[0080] (1) Preparation of dihydroxy-terminated polyether macromonomer: 19.0 g of monomethyl allyl glycol ether and 1.6 g of sodium ethoxide were added to a reaction kettle, stirred evenly, evacuated to -0.1 MPa, replaced with N2 three times, the reaction temperature was raised to 80°C, and 981.0 g of ethylene oxide was introduced into the reaction kettle. During the addition process, the temperature of the reaction kettle was maintained between 90°C and 100°C and the pressure was maintained between 0.5 MPa and 2.0 MPa. After the addition of ethylene oxide was completed, the temperature was kept at 100°C for about 2.0 h. When the pressure in the reactor stops decreasing, the reaction is stopped and the vacuum is continued to be drawn to -0.1 MPa. Then 12.3 g of propylene oxide is introduced into the reactor. During the addition process, the temperature of the reactor is maintained between 90°C and 100°C and the pressure is maintained between 0.5 MPa and 1 MPa. When the pressure in the reactor stops decreasing, the reaction is terminated, and a polyether macromonomer P5 containing dihydroxyl groups and having a weight average molecular weight of 6000 is obtained.

[0081] (2) Preparation of water-retaining and slurry-raising concrete collapse-preventing agent:

[0082] a. Esterification reaction: 382.0 g sucrose monoallyl ether, 300.0 g itaconic anhydride and 6.2 g N-nitrosodiphenylamine were placed in a reactor equipped with a condensing device. Under nitrogen protection, the temperature was raised to 120°C, and 2.6 g concentrated sulfuric acid was added. The reaction was kept warm for 2.0 h. During the reaction, water was removed by passing nitrogen with water. After the reaction, the temperature was cooled to room temperature to obtain a cross-linked sustained-release functional monomer GD5.

[0083] b. Monomer blending: 7.0 g of GD5, 6.0 g of maleic anhydride, 200.0 g of P5 and 100.0 g of water were mixed and stirred to dissolve to obtain a comonomer mixture solution A; 32.0 g of hydroxyethyl acrylate and 2.5 g of acrylamide and 10.0 g of water were mixed and stirred to obtain a comonomer mixture solution B;

[0084] c. Copolymerization reaction: 20.0 g of water was added to the reactor, 1.2 g of hydrogen peroxide was added at one time, 313.0 g of the comonomer mixture solution A, 42.5 g of the comonomer mixed solution B, an aqueous ascorbic acid solution (0.35 g of ascorbic acid, 20.0 g of water) and an aqueous solution of trisodium phosphate (2.0 g of trisodium phosphate, 20.0 g of water) were dripped into the reactor, the stirrer was turned on, and the reaction was carried out at a reaction temperature of 25 ° C. The dropping time was 0.8 h, and the reaction was continued for 1.0 h after the dropwise addition was completed to obtain a copolymer product;

[0085] d. Neutralization reaction: The copolymerization product obtained in step c is adjusted to pH 6.0 with alkali to obtain the water-retaining slurry-type concrete collapse-preventing agent KZJ-5.

[0086] Example 6

[0087] This embodiment provides a method for preparing a polyether compound, and using the polyether compound to prepare a water-retaining slurry-raising type concrete collapse-preventing agent, as follows:

[0088] (1) Preparation of dihydroxy-terminated polyether macromonomer: 33.0 g of propylene glycol monoallyl ether and 1.8 g of sodium methoxide were added to a reaction kettle, stirred evenly, evacuated to -0.1 MPa, replaced with N2 three times, the reaction temperature was raised to 80°C, and 967.0 g of ethylene oxide was introduced into the reaction kettle. During the addition process, the reaction kettle temperature was maintained between 100°C and 110°C and the pressure was maintained between 1.0 MPa and 2.0 MPa. After the addition of ethylene oxide was completed, the temperature was maintained at 105°C for about 1.0 h. When the pressure in the reactor stops decreasing, stop the reaction, continue to evacuate to -0.1 MPa, and then introduce 21.1 g of propylene oxide into the reactor. During the addition process, maintain the reactor temperature between 100°C and 110°C and the pressure between 0.05 MPa and 2.0 MPa. When the pressure in the reactor stops decreasing, the reaction is terminated, and a dihydroxy-terminated polyether macromonomer P6 with a weight average molecular weight of 3500 is obtained.

[0089] (2) Preparation of water-retaining and slurry-raising concrete collapse-preventing agent:

[0090] a. Esterification reaction: 382.0 g sucrose monoallyl ether, 320.0 g citraconic anhydride and 7.0 g N-nitrosodiphenylamine were charged into a reactor equipped with a condensing device. Under nitrogen protection, the temperature was raised to 100 ° C. Then 3.0 g concentrated sulfuric acid was added and the reaction was kept warm for 3.0 h. During the reaction, water was removed by nitrogen gas with water. After the reaction, the temperature was lowered to room temperature to obtain a cross-linked sustained-release functional monomer GD6.

[0091] b. Monomer blending: 4.0 g GD6, 9.0 g acrylic acid, 200.0 g P6 and 100.0 g water were mixed and stirred to dissolve to obtain a comonomer mixture solution A; 22.0 g hydroxypropyl acrylate and 1.5 g methacrylic tartrate and 10.0 g water were mixed and stirred to obtain a comonomer mixture solution B;

[0092] c. Copolymerization reaction: 80.0 g of water was added to the reactor, 313.0 g of the comonomer mixture solution A, 39.0 g of the comonomer mixed solution B, an aqueous solution of azodiisopropylimidazoline (wherein 1.5 g of ascorbic acid, 20.0 g of water) and an aqueous solution of mercaptoethanol (wherein 0.8 g of mercaptoethanol, 20.0 g of water) were dripped into the reactor, the stirrer was turned on, and the reaction was carried out at a reaction temperature of 40 ° C. The dropping time was 1.5 h, and the reaction was continued for 3.0 h after the dropwise addition was completed to obtain a copolymer product;

[0093] d. Neutralization reaction: The copolymerization product obtained in step c is adjusted to pH 6.0 with alkali to obtain the water-retaining slurry-type concrete collapse-preventing agent KZJ-6.

[0094] Comparative Example 1

[0095] The model sold by Kezhijie is PT sustained-release polycarboxylic acid collapse-preventing agent PCE-1.

[0096] Comparative Example 2

[0097] The process for preparing the collapse retaining agent in Example 2 is used as the basic process, with the following differences: the dihydroxy-terminated polyether compound P2 prepared in the present invention is replaced by Point-XD22 polyether macromonomer of Kezhijie, and the other parts remain unchanged to obtain PCE-2.

[0098] Comparative Example 3

[0099] The overall process of Example 2 was used as the basic process, with the following differences: there was no preparation process of the cross-linked sustained-release functional monomer GD2, and the cross-linked sustained-release functional monomer GD2 prepared by the present invention was replaced by the commercially available sustained-release functional monomer K2 of Kezhijie, and the other processes remained unchanged to obtain PCE-3.

[0100] Comparative Example 4

[0101] The process of Example 2 was used as the basic process, with the following differences: no cross-linked sustained-release functional monomer GD2 was used in the preparation process, and no cross-linked sustained-release functional monomer GD2 was added during the monomer blending process. Other factors remained unchanged, and PCE-4 was obtained.

[0102] Comparative Example 5

[0103] The process of Example 2 was used as the basic process, with the following differences: no cross-linking sustained-release functional monomer GD2 was used for preparation, and an equal amount of hydroxyethyl methacrylate was used to replace the cross-linking sustained-release functional monomer GD2, while other factors remained unchanged, to obtain PCE-5.

[0104] Comparative Example 6

[0105] The process of Example 2 was used as the basic process, except that acrylamide was not added to the copolymerization reaction, and other factors remained unchanged, to obtain PCE-6.

[0106] Comparative Example 7

[0107] The process of Example 2 is used as the basic process, with the following differences: the methyl allyl polyethylene glycol in CN102390950A mentioned in the background technology is used instead of the dihydroxy-terminated polyether compound P2 prepared in the present invention, and the other parts remain unchanged to obtain PCE-7.

[0108] Comparative Example 8

[0109] The process of Example 2 is used as the basic process, with the following differences: there is no preparation process of the cross-linked sustained-release functional monomer GD2, the methoxypolyethylene glycol monomethacrylate in CN1167739A mentioned in the background technology replaces the cross-linked sustained-release functional monomer GD2 prepared in the present invention, and the other parts remain unchanged to obtain PCE-8.

[0110] Performance Test:

[0111] 1) Molecular weight detection

[0112] The molecular weight of the collapse-preventing agents of Examples 1 to 6 was measured by gel chromatography. The results are shown in Table 1.

[0113] Table 1 Molecular weight test results

[0114] Case Weight average molecular weight Example 1 94706 Example 2 95054 Example 3 86586 Example 4 92115 Example 5 106189 Example 6 123108

[0115] It can be seen that the polymerization reactions of Examples 1 to 6 yielded high-polymer products.

[0116] 2) The slump retaining agents prepared in Examples 1 to 6 and Comparative Examples 1 to 8 were compounded with the Kezhijie water reducing agent PointTS08 at a solid content of 7:3 to form a sample with a solid content of 12%. The relevant performance was measured according to GB 8076-2008 "Concrete Admixtures". When the dosage was 1.0% (relative to the amount of cementitious material), the water reduction rate of the products prepared by the present invention was higher than 32%, the 1d compressive strength ratio was greater than 200%, the 28d compressive strength ratio was greater than 170%, and the 28d shrinkage ratio was less than 60%. The results are shown in Table 2.

[0117] Table 2 Concrete performance test indicators

[0118] sample Water reduction rate / % 1d compressive strength ratio / % 28d compressive strength ratio / % 28d shrinkage ratio / % KZJ-1 34.5 205 176 46 KZJ-2 34.8 210 180 32 KZJ-3 34.0 210 172 50 KZJ-4 35.0 207 177 49 KZJ-5 34.2 206 178 38 KZJ-6 33.9 208 180 32 PCE-1 34.6 192 160 80 PCE-2 33.9 190 166 89 PCE-3 30.5 180 162 92 PCE-4 31.2 188 166 88 PCE-5 30.9 172 158 86 PCE-6 30.4 190 171 77 PCE-7 28.3 190 168 80 PCE-8 29.6 191 167 77

[0119] 3) Use Runfeng P.O42.5 ordinary Portland cement, the concrete mix ratio is: cement 170kg / m3, fly ash 80kg / m 3 、Mineral powder 90kg / m 3 、Mechanical sand 740kg / m 3 、Stone 1020kg / m 3 , water 155kg / m 3 The slump retaining agent prepared in Examples 1 to 6 and Comparative Examples 1 to 8 was compounded with the KZJ water reducing agent PointTS08 at a solid content ratio of 7:3 to form a sample with a solid content of 12%. The performance was compared with the same dosage. The dosage was 1.5%. The concrete initial, 2.5h and 4h concrete flow, water bleeding rate strength and 4h concrete paste residual rate were tested. The results are shown in Table 3:

[0120] Table 3 Concrete test results

[0121]

[0122]

[0123] Note: In the table, “+” indicates that the concrete has good workability, “-” indicates that the concrete has slightly poor workability and poor cohesion, and “--” indicates that the concrete has poor workability and poor encapsulation.

[0124] From the test results in the above table, we can get:

[0125] 1) The concrete collapse retaining agent prepared by the present invention can achieve long-term collapse retaining without loss for 4 hours, and there is no bleeding and delayed return during the process. The concrete slurry residue rate is high, the slurry collection rate is slow, it has the effect of water retention and slurry extraction, and has good workability;

[0126] 2) The commercially available collapse-preventing agent PCE-1 has a slight loss in 2.5 hours and cannot achieve collapse-preventing performance of 4 hours. Its collapse-preventing performance is inferior to that of the patented product of the present invention, and its water seepage rate is high, and its strength is lower than that of the product of the present invention;

[0127] 3) The comparative products PCE-2 to PCE-5 cannot achieve 4h collapse protection, and their collapse protection performance is inferior to that of the patented product of the present invention. They have high water seepage rate and lower strength than the product of the present invention.

[0128] 4) The comparative product PCE-6 has the best collapse resistance performance compared with other comparative products, but is not as good as the patented product of the present invention, and has a high water seepage rate of up to 12.0%, poor concrete workability and low strength.

[0129] 5) The comparative product PCE-7 has comparable water-reducing performance to the patented product of the present invention, but its slump retention is inferior to that of the patented product of the present invention, and its water seepage rate is relatively high, as high as 10.0%, and its concrete workability is poor.

[0130] 6) The comparative product PCE-8 has poor slump retention performance compared to the patented product of the present invention, with a large loss in 2.5 hours, and the slump retention cannot meet the 4-hour requirement. After 4 hours, the concrete has no fluidity.

[0131] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a concrete collapse-preventing agent, characterized in that: The steps include: (1) Sucrose monoallyl ether, unsaturated acid anhydride 1 and inhibitor are mixed uniformly, heated to 60-120° C. in a protective atmosphere, and then catalyst 2 is added and mixed uniformly, and the mixture is kept warm for 2-6 hours, during which water generated by the reaction is continuously removed, and the temperature is cooled to room temperature after the reaction is completed to obtain a cross-linked slow-release functional monomer; (2) mixing the cross-linked sustained-release functional monomer, unsaturated carboxylic acid and / or unsaturated acid anhydride, and polyether compound prepared in step (1) and dissolving them in water to obtain a comonomer mixture solution A; mixing unsaturated carboxylic acid ester and workable small monomer and dissolving them in water to obtain a comonomer mixture solution B; (3) mixing the comonomer mixture solution A, the comonomer mixture solution B, an initiator and a molecular weight regulator, and performing a copolymerization reaction at 5 to 50° C., and adjusting the pH of the system to 5 to 7 after the reaction to obtain a concrete collapse retaining agent; The polyether compound has a structure shown in Formula I: In formula I, R1 is selected from: H or CH3, R2 is selected from: C2H4 or C3H6, and R3 is selected from: a polyether chain obtained by ring-opening polymerization of ethylene oxide and / or propylene oxide; The workable small monomer is one of methyl methacrylate tartrate, acrylamide, and 2-methyl-2-acrylic acid-2-hydroxyethyl ester phosphate; In the step (1), the molar ratio of sucrose monoallyl ether to unsaturated acid anhydride is 1:(0.5-5); The unsaturated anhydride 1 is at least one of citraconic anhydride, dimethyl maleic anhydride and itaconic anhydride; The unsaturated carboxylic acid ester is at least one of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, isooctyl acrylate, isooctyl methacrylate, and methyl methacrylate.

2. The method for preparing a concrete collapse-preventing agent according to claim 1, characterized in that: The inhibitor is at least one of p-2,2-diphenyl-1-picrylhydrazyl, 1,1-diphenyl-2-picrylhydrazyl, and N-nitrosodiphenylamine; the catalyst is at least one of concentrated sulfuric acid, benzenesulfonic acid, p-toluenesulfonic acid, and ethylsulfonic acid; the unsaturated carboxylic acid is at least one of acrylic acid, methacrylic acid, fumaric acid, and itaconic acid; the initiator is a water-soluble inorganic peroxide initiator, a water-soluble redox initiator, or a water-soluble azo initiator, wherein the water-soluble inorganic peroxide initiator is ammonium persulfate, potassium persulfate, or the like. at least one of; the water-soluble redox initiator is at least one of a combination of hydrogen peroxide and bleaching powder, a combination of hydrogen peroxide and ascorbic acid, and a combination of persulfate and sodium bisulfite; the water-soluble azo initiator is at least one of azobisisobutylamidine hydrochloride, azobisisopropylimidazoline hydrochloride, azobiscyanovaleric acid, and azobisisopropylimidazoline; the molecular weight regulator is at least one of thioglycolic acid, mercaptopropionic acid, mercaptoethanol, isopropyl alcohol, sodium hypophosphite, trisodium phosphate, sodium formate, sodium acetate, and dodecanethiol.

3. The preparation method according to claim 1, characterized in that: The weight average molecular weight of the polyether compound is 600-6000.

4. The preparation method according to claim 1, characterized in that: The preparation method of the polyether compound comprises the following steps: using monomethyl allyl glycol ether or propylene glycol monoallyl ether as a starting material, introducing ethylene oxide and / or propylene oxide under anaerobic conditions and heating to carry out polymerization reaction under the action of a catalyst, and further introducing propylene oxide to carry out polymerization reaction end-capping after the reaction is completed.

5. The preparation method according to claim 4, characterized in that: The preparation method of the polyether compound specifically comprises the following steps: Step 1, adding monomethyl allyl glycol ether or propylene glycol monoallyl ether to a catalyst, mixing evenly, and heating to 80-120° C. under an oxygen-free condition; Step 2, introducing a certain amount of ethylene oxide and / or propylene oxide, during which the system pressure is controlled to be 0.2-3.0 MPa, and then the temperature is controlled to be 80-120° C. to react until the system pressure no longer decreases; Step 3, further introducing a certain amount of propylene oxide under anaerobic conditions, during which the system pressure is controlled to be 0.05-2.0 MPa, and then controlling the temperature to be 80-120° C. to react until the system pressure no longer decreases, thereby obtaining the polyether compound.

6. The preparation method according to claim 4, characterized in that: The catalyst one is at least one of sodium methoxide, sodium tert-butoxide, sodium ethoxide, lithium aluminum hydroxide, sodium hydroxide, potassium hydroxide, and metallic sodium. The amount of the catalyst one is 0.1-0.3% of the mass of ethylene oxide and / or propylene oxide.

7. The preparation method according to claim 4, characterized in that: The molar ratio of the glycidol to monomethyl allyl glycol ether or propylene glycol monoallyl ether is 1.0-1.1:

1.

8. A concrete collapse-preventing agent, characterized in that: The method is obtained by the preparation method of claim 1 or 2.

Images