Polycarboxylate superplasticizer powder, preparation method and application thereof, and preparation method of polyether

Abstract

The invention provides polycarboxylate superplasticizer powder, a preparation method and application thereof and a preparation method of polyether, and the preparation method of the polycarboxylate superplasticizer powder comprises the following steps: (1) adding dihydric alcohol, arylamine and a first solvent into a reaction system, adding a catalyst to carry out first reaction, and then introducing first alkylene oxide to carry out second reaction to obtain a double-tailed polyether macromonomer; and (2) melting the double-tailed polyether macromonomer into liquid, adding an initiator, then adding a mixture of unsaturated carboxylic acid and a chain transfer agent, curing and crushing to obtain polycarboxylic acid water reducer powder. The polycarboxylate superplasticizer powder is prepared on the basis of the double-tailed polyether macromonomer, the special structure of double-tailed polyether endows the polycarboxylate superplasticizer with better dispersing performance, and the prepared polycarboxylate superplasticizer powder has higher early mechanical property, is beneficial to forming a tighter structure in the early stage, and enables the gypsum block to have higher compressive strength.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and specifically relates to a polycarboxylate water reducing agent powder, its preparation method, application, and the preparation method of polyether. Background Art

[0002] In the field of building materials, gypsum blocks, as an important wall material, are widely used due to their good environmental protection performance, fire resistance performance, and construction convenience. However, in the production and use process of gypsum blocks, some challenges are also faced.

[0003] On the one hand, in order to ensure the strength and construction performance of gypsum blocks, a certain amount of water reducing agent is usually required. Traditional water reducing agents have some deficiencies in the use process, such as limited water reducing effect and less environmentally friendly. Therefore, the development of a new type of high - efficiency and environmentally friendly water reducing agent has become an urgent need in the gypsum block industry.

[0004] On the other hand, polycarboxylate water reducing agents, as a new type of high - performance water reducing agent, have achieved remarkable application effects in fields such as concrete. However, most of the polycarboxylate water reducing agents on the market are liquid products, which have many inconveniences in the transportation, storage, and use processes. To solve these problems, the research and development of polycarboxylate water reducing agent powder has gradually attracted attention.

[0005] Aiming at the problems of limited water reducing effect of traditional water reducing agents, environmental unfriendliness in the production of existing gypsum blocks, and inconvenience in the transportation, storage, and use of polycarboxylate water reducing agent liquid products, how to prepare a polycarboxylate water reducing agent powder with high efficiency, environmental friendliness, easy transportation, storage, and use, and excellent performance is a technical problem that needs to be solved urgently at present. Summary of the Invention

[0006] In view of the above problems, the present invention provides a polycarboxylate water reducing agent powder, its preparation method, application, and the preparation method of polyether.

[0007] On the one hand, the present invention provides a preparation method of a polycarboxylate water reducing agent powder, which includes the following steps:

[0008] (1) Add diol, aromatic amine, and a first solvent to the reaction system, add a catalyst for a first reaction, and then introduce a first alkylene oxide for a second reaction to obtain a double - tailed polyether macromonomer;

[0009] (2) Melt the double - tailed polyether macromonomer into a liquid, add an initiator, and then add a mixture of unsaturated carboxylic acid and a chain transfer agent, and carry out curing and pulverization to obtain the polycarboxylate water reducing agent powder.

[0010] Optionally, the catalyst in step (1) is synthesized as follows:

[0011] Add N(R1 R 2 R 3 R 4 ) X is mixed with a second solvent and undergoes an activation reaction with a second alkylene oxide at 150 - 180 °C for 2 - 6 h. After the reaction is completed, the second solvent is removed to obtain the catalyst;

[0012] Among them, R 1 , R 2 , R 3 , R 4 are each an alkyl group selected from C 1 to C 7 , X is selected from halogen anions, and N is a nitrogen atom.

[0013] Optionally, N(R 1 R 2 R 3 R 4 )X is one or more selected from tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrapropylammonium chloride, tetrapropylammonium bromide, tetrapropylammonium iodide, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide;

[0014] The second solvent is acetone and / or toluene;

[0015] The second alkylene oxide is one or more selected from ethylene oxide, propylene oxide, butylene oxide;

[0016] The mass ratio of N(R 1 R 2 R 3 R 4 )X to the second solvent is 1:(1 - 2), and the mass ratio of the sum of the mass of N(R 1 R 2 R 3 R 4 )X and the second solvent to the second alkylene oxide is 1:(1 - 5).

[0017] Optionally, the catalyst in step (1) is one or several selected from triethylaluminum, ferric chloride, zinc chloride, triethylboron.

[0018] Optionally, in step (1), the diol is an enol selected from C 4 to C 8 , preferably one or more of butenediol, pentenediol, hexenediol; the aromatic amine is one or more selected from p-phenylenediamine, m-phenylenediamine, o-phenylenediamine; the first solvent is one or more selected from toluene, xylene, dichloromethane, dichloroethane, chloroform, trichloroethane, cyclohexane; the first alkylene oxide is one or more selected from ethylene oxide, propylene oxide, butylene oxide.

[0019] Optionally, in step (1), the molar ratio of the diol to the aromatic amine is 1:(1 - 1.5), the dosage of the catalyst is 0.1 - 0.5% by mass of the first alkylene oxide, the mass ratio of the first solvent to the diol is 2 - 2.1:1, and the molar ratio of the aromatic amine to the first alkylene oxide is 1:(100 - 110).

[0020] Optionally, in step (1), the first reaction is carried out for 6 - 8 h;

[0021] The conditions for introducing the first alkylene oxide for the second reaction include:

[0022] The first alkylene oxide is introduced at 80 - 150 °C, the pressure of the reaction system is controlled to be 0.3 - 1 MPa, and the reaction is carried out for 4 - 12 h;

[0023] The polyether macromonomer solution is obtained through the second reaction, and then vacuum distillation is carried out to remove the solvent and the remaining first alkylene oxide to obtain the double-tailed polyether macromonomer.

[0024] Optionally, in step (2),

[0025] The double-tailed polyether macromonomer is melted into a liquid by heating to 60 - 90 °C;

[0026] The initiator is one or more selected from benzoyl peroxide, ammonium persulfate, potassium persulfate, and azobisisobutyronitrile, the unsaturated carboxylic acid is one or more selected from acrylic acid, methacrylic acid, and fumaric acid, and the chain transfer agent is one or more selected from sodium methallylsulfonate, mercaptoacetic acid, mercaptopropionic acid, mercaptoethanol, and sodium hypophosphite;

[0027] The mixture of the unsaturated carboxylic acid and the chain transfer agent is added dropwise, the dropping time is 0.5 - 2.5 h, and the aging time is 1 - 3 h;

[0028] Based on the total feeding amount of the double-tailed polyether macromonomer, the initiator, the unsaturated carboxylic acid, and the chain transfer agent, the addition amount of the double-tailed polyether macromonomer is 85 - 90%, the addition amount of the initiator is 0.4 - 2.0%, the addition amount of the unsaturated carboxylic acid is 7 - 12%, and the addition amount of the chain transfer agent is 0.2 - 1.0%.

[0029] On the other hand, the present invention also provides a polycarboxylate water reducing agent powder, which is prepared by the foregoing preparation method.

[0030] On yet another aspect, the present invention also provides an application of the polycarboxylate water reducing agent powder in gypsum blocks, and the polycarboxylate water reducing agent powder is the foregoing polycarboxylate water reducing agent powder.

[0031] Furthermore, the present invention also provides a method for preparing a polyether, comprising:

[0032] Adding a diol, an aromatic amine and a first solvent into a reaction system, adding a catalyst to carry out a first reaction, and then introducing a first alkylene oxide to carry out a second reaction to obtain a polyether;

[0033] Wherein, the catalyst is synthesized as follows:

[0034] Mixing N(R 1 R 2 R 3 R 4 )X with a second solvent, carrying out an activation reaction with a second alkylene oxide at 150 - 180 °C for 2 - 6 h, and removing the second solvent after the reaction is completed to obtain the catalyst;

[0035] Wherein, R 1 , R 2 , R 3 , R 4 are each an alkyl group selected from C 1 - C 7 , X is selected from halogen anions, and N is a nitrogen atom.

[0036] Beneficial effects:

[0037] (1) The present invention prepares a polycarboxylate superplasticizer powder based on a double - tailed polyether monomer. The special structure of the double - tailed polyether endows the polycarboxylate superplasticizer with better dispersion performance. The prepared polycarboxylate superplasticizer powder has higher early mechanical properties, which helps to form a more compact structure at an early stage, thereby increasing the early strength development rate of gypsum blocks, enabling the gypsum blocks to have higher compressive strength, improving the performance of gypsum blocks, meeting the requirements of gypsum blocks under different production processes and usage environments, having better adaptability, and promoting the progress and development of gypsum block production technology;

[0038] (2) Reducing transportation costs: The polycarboxylate superplasticizer in powder form is more convenient during transportation compared to liquid products, which can effectively reduce transportation costs. Especially for long - distance transportation and large - scale use, it can significantly reduce the production costs of construction enterprises;

[0039] (3) Facilitating storage and use: The storage conditions of powder products are relatively loose, without the need for specific temperature and environment, facilitating storage and use, not easily prone to problems such as deterioration and stratification, and being more convenient during use, which can better meet the needs of the modern construction industry for high - performance building materials;

[0040] (4) Reducing pollution risks: Reducing the possibility of microbial contamination of liquid superplasticizers during storage and use, thereby improving the performance and service life of products, and promoting the progress and development of gypsum block production technology;

[0041] (5) The present invention uses a catalyst synthesized by the activation reaction of N(R 1 R 2 R 3 R 4 )X and a second alkylene oxide to catalytically synthesize a double-tailed polyether macromonomer, which can obtain a higher double bond retention rate, and the reaction time required for synthesizing the double-tailed polyether macromonomer can be significantly shortened. Detailed Embodiments

[0042] The present application will be further described in detail below through examples. Through these descriptions, the features and advantages of the present application will become clearer and more definite.

[0043] Here, the special term "exemplary" means "serving as an example, embodiment, or illustration". Any embodiment described as "exemplary" here does not have to be construed as superior to or better than other embodiments.

[0044] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0045] On the one hand, the present invention provides a preparation method of a polycarboxylate superplasticizer powder,

[0046] (1) Add a diol, an aromatic amine, and a first solvent to the reaction system, add a catalyst for a first reaction, and then introduce a first alkylene oxide for a second reaction to obtain a double-tailed polyether macromonomer;

[0047] (2) Melt the double-tailed polyether macromonomer into a liquid, add an initiator, and then add a mixture of an unsaturated carboxylic acid and a chain transfer agent, and carry out curing and pulverization to obtain a polycarboxylate superplasticizer powder.

[0048] It should be noted that in the aforementioned preparation method of the present invention, the entire preparation process of step (1) can be carried out in an inert atmosphere such as N 2 atmosphere; in step (2), after adding the mixture of the unsaturated carboxylic acid and the chain transfer agent to obtain a mixed solution, the mixed solution is cured to obtain a polycarboxylate superplasticizer, which can be cooled to room temperature, sliced, and then pulverized to obtain a polycarboxylate superplasticizer powder.

[0049] In step (1) of the present invention, a double-tailed polyether macromonomer with a special structure is first synthesized. As a polyether macromonomer with a special structure, the synthesized double-tailed polyether has unique advantages in the preparation of polycarboxylate water reducers. In step (2), through a specific preparation method, the double-tailed polyether is combined with other raw materials to prepare a polycarboxylate water reducer powder for gypsum blocks. This powder product not only has good water-reducing performance, but also can overcome the disadvantages of liquid water reducers, is convenient for transportation and storage, improves the convenience and stability of use, and has advantages such as high efficiency and environmental protection. In the production of gypsum blocks, by adding the double-tailed polyether type polycarboxylate water reducer powder synthesized by the present invention, the water consumption can be effectively reduced, the strength and durability of the gypsum blocks can be improved, and the energy consumption and cost in the production process can be reduced at the same time. In addition, the special structure of the double-tailed polyether can endow the polycarboxylate water reducer with better dispersion performance and adaptability, so that it can better meet the requirements of gypsum blocks under different production processes and use environments.

[0050] In an embodiment of the foregoing preparation method of the present invention, the catalyst in step (1) is synthesized as follows:

[0051] Mix N(R 1 R 2 R 3 R 4 )X with a second solvent, and carry out an activation reaction with a second alkylene oxide at 150-180 °C for 2-6 h. After the reaction is completed, the second solvent is removed to obtain the catalyst;

[0052] Wherein, R 1 , R 2 , R 3 , R 4 are each an alkyl group selected from C 1 -C 7 , X is selected from halogen anions, and N is a nitrogen atom.

[0053] It should be noted that in the foregoing preparation method of the present invention, the catalyst formed by the activation reaction of N(R 1 R 2 R 3 R 4 )X and the second alkylene oxide catalyzes the reaction in step (1) to synthesize the double-tailed polyether macromonomer, and a high double bond retention rate can be obtained, and the time for introducing the first alkylene oxide for the second reaction in step (1) can be greatly shortened.

[0054] In an embodiment of the foregoing preparation method of the present invention, N(R 1 R 2 R 3 R 4)X is one or more selected from tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrapropylammonium chloride, tetrapropylammonium bromide, tetrapropylammonium iodide, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide;

[0055] The second solvent is acetone and / or toluene;

[0056] The second alkylene oxide is one or more selected from ethylene oxide, propylene oxide, butylene oxide;

[0057] N(R 1 R 2 R 3 R 4 )X and the second solvent have a mass ratio of 1:(1 - 2), and the sum of the masses of N(R 1 R 2 R 3 R 4 )X and the second solvent and the second alkylene oxide have a mass ratio of 1:(1 - 5).

[0058] Specifically, the mass ratio of N(R 1 R 2 R 3 R 4 )X to the second solvent can be 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, and the mass ratio of the sum of the masses of N(R 1 R 2 R 3 R 4 )X and the second solvent to the second alkylene oxide can be 1:2, 1:3, 1:4, etc. It should be noted that in the foregoing preparation method of the present invention, with the foregoing specific N(R 1 R 2 R 3 R 4 )X and the second alkylene oxide for the activation reaction to generate the catalyst, which catalyzes the reaction in step (1) to synthesize the double-tailed polyether macromonomer, can better improve the double bond retention rate. The synthesized polycarboxylate superplasticizer powder can form a more compact structure in the early stage, better improve the early strength development rate of the gypsum block, and make the gypsum block have higher compressive strength.

[0059] In another embodiment of the foregoing preparation method of the present invention, the catalyst in step (1) is one or several selected from triethylaluminum, ferric trichloride, zinc chloride, and triethylboron.

[0060] In still another embodiment of the foregoing preparation method of the present invention, in step (1), the diol is selected from C 4 ~C 8The enediol is preferably one or more of butenediol, pentenediol, and hexenediol; the aromatic amine is one or more selected from p-phenylenediamine, m-phenylenediamine, and o-phenylenediamine; the first solvent is one or more selected from toluene, xylene, dichloromethane, dichloroethane, chloroform, trichloroethane, and cyclohexane; the first alkylene oxide is one or more selected from ethylene oxide, propylene oxide, and butylene oxide.

[0061] It should be noted that in the aforementioned preparation method of the present invention, using the aforementioned specific diol, aromatic amine, and first alkylene oxide as raw materials to synthesize a double-tailed polyether macromonomer with a special structure, using such a double-tailed polyether macromonomer as a monomer raw material to synthesize a polycarboxylate superplasticizer powder can endow the polycarboxylate superplasticizer with better dispersion performance and higher early mechanical properties, which helps to form a more compact structure at an early stage, thereby increasing the early strength development rate of the gypsum block, enabling the gypsum block to have higher compressive strength, and improving the performance of the gypsum block.

[0062] In one embodiment of the aforementioned preparation method of the present invention, in step (1), the molar ratio of the diol to the aromatic amine is 1:(1 - 1.5), the dosage of the catalyst is 0.1 - 0.5% by mass of the first alkylene oxide, the mass ratio of the first solvent to the diol is 2 - 2.1:1, and the molar ratio of the aromatic amine to the first alkylene oxide is 1:(100 - 110).

[0063] It should be noted that in the aforementioned preparation method of the present invention, by controlling the dosage relationship between the materials in step (1) as above, it is possible to better control the structure and performance of the synthesized double-tailed polyether macromonomer, and then prepare a polycarboxylate superplasticizer powder with more excellent comprehensive performance to better improve the performance of the gypsum block.

[0064] In one embodiment of the aforementioned preparation method of the present invention, in step (1), the first reaction is carried out for 6 - 8 h;

[0065] The conditions for introducing the first alkylene oxide for the second reaction include:

[0066] The first alkylene oxide is introduced at 80 - 150 °C, the pressure of the reaction system is controlled to be 0.3 - 1 MPa, and the reaction is carried out for 4 - 12 h;

[0067] After obtaining the polyether macromonomer solution through the second reaction, then carry out vacuum distillation to remove the solvent and the remaining first alkylene oxide to obtain the double-tailed polyether macromonomer.

[0068] It should be noted that in step (1), by controlling the conditions of the first reaction and the second reaction as above, it is possible to better synthesize a double-tailed polyether macromonomer with a special structure.

[0069] In another embodiment of the foregoing preparation method of the present invention, in step (2),

[0070] The double-tailed polyether macromonomer is melted into a liquid by heating to 60-90 °C;

[0071] The initiator is one or more selected from benzoyl peroxide, ammonium persulfate, potassium persulfate, and azobisisobutyronitrile. The unsaturated carboxylic acid is one or more selected from acrylic acid, methacrylic acid, and fumaric acid. The chain transfer agent is one or more selected from sodium methallylsulfonate, mercaptoacetic acid, mercaptopropionic acid, mercaptoethanol, and sodium hypophosphite;

[0072] The mixture of the unsaturated carboxylic acid and the chain transfer agent is added dropwise, and the dropping time is 0.5-2.5 h, and the aging time is 1-3 h;

[0073] Based on the total feeding amount of the double-tailed polyether macromonomer, the initiator, the unsaturated carboxylic acid, and the chain transfer agent, the addition amount of the double-tailed polyether macromonomer is 85-90%, the addition amount of the initiator is 0.4-2.0%, the addition amount of the unsaturated carboxylic acid is 7-12%, and the addition amount of the chain transfer agent is 0.2-1.0%.

[0074] It should be noted that in step (2), the foregoing initiator, unsaturated carboxylic acid, and chain transfer agent are selected, and the amounts and conditions of various materials are controlled as described above. In this way, the double-tailed polyether macromonomer synthesized in step (1) can better synthesize a polycarboxylate superplasticizer powder with excellent performance, and further can better improve the performance of the gypsum block.

[0075] On the other hand, the present invention also provides a polycarboxylate superplasticizer powder, which is prepared by the foregoing preparation method.

[0076] The polycarboxylate superplasticizer powder prepared by the preparation method of the present invention has the advantages of high efficiency, environmental protection, convenient transportation and storage, etc., and has excellent performance, and can effectively improve the performance of the gypsum block.

[0077] On still another aspect, the present invention also provides an application of the polycarboxylate superplasticizer powder in the gypsum block, and the polycarboxylate superplasticizer powder is the foregoing polycarboxylate superplasticizer powder.

[0078] The polycarboxylate superplasticizer powder prepared by the preparation method of the present invention is prepared based on a special structure double-tailed polyether macromonomer, has higher early mechanical properties, helps to form a more compact structure at an early stage, thereby improving the early strength development rate of the gypsum block, enabling the gypsum block to have higher compressive strength, improving the performance of the gypsum block, meeting the requirements of the gypsum block under different production processes and use environments, and promoting the progress and development of the gypsum block production technology.

[0079] Furthermore, the present invention also provides a method for preparing a polyether, comprising:

[0080] Adding a diol, an aromatic amine, and a first solvent to a reaction system, adding a catalyst for a first reaction, and then introducing a first alkylene oxide for a second reaction to obtain a polyether;

[0081] Wherein, the catalyst is synthesized as follows:

[0082] Mixing N(R 1 R 2 R 3 R 4 )X with a second solvent, carrying out an activation reaction with a second alkylene oxide at 150 - 180 °C for 2 - 6 h, and removing the second solvent after the reaction is completed to obtain the catalyst;

[0083] Wherein, R 1 、R 2 、R 3 、R 4 are each an alkyl group selected from C 1 - C 7 , X is selected from halogen anions, and N is a nitrogen atom.

[0084] It should be noted that, firstly, in the method for preparing the polycarboxylate superplasticizer powder of the present invention, the limitations on the dosage relationship, reaction conditions, etc. of the diol, aromatic amine, first solvent, catalyst, and materials in step (1) thereof can all be applied to the method for preparing the polyether of the present invention; or rather, the method for preparing the polyether of the present invention is step (1) in the method for preparing the polycarboxylate superplasticizer powder of the present invention.

[0085] Secondly, in the method for preparing the polyether of the present invention, the catalyst formed by the activation reaction of N(R 1 R 2 R 3 R 4 )X with the second alkylene oxide is used to catalyze the reaction to synthesize the polyether, which can obtain a high double bond retention rate, and the time for introducing the first alkylene oxide for the second reaction can be significantly shortened.

[0086] The present invention will be further described in detail below through examples, but it does not limit the present invention. In the following examples, unless otherwise specified, the experimental instruments and raw materials involved are all commercially available products.

[0087] Example 1

[0088] (1) Preparation of polyether macromonomer

[0089] Add 50 g of butanediol, 62.5 g of p-phenylenediamine and 100 g of toluene solvent into the reaction kettle in sequence, add 12.75 g of triethylaluminum as the catalyst, stir evenly and then carry out the reaction. The whole reaction is carried out under a nitrogen atmosphere. After reacting for 6 h, slowly introduce 2550 g of ethylene oxide at 110 °C, control the pressure in the kettle at 0.3 - 1 MPa, and obtain the polyether macromonomer solution after reacting for 8 h. Then carry out vacuum distillation at 90 °C and -0.1 MPa for 1 h to remove the solvent and unreacted ethylene oxide, and obtain 2625 g of the target product, the double-tailed polyether macromonomer.

[0090] (2) Preparation of polycarboxylate superplasticizer powder

[0091] First, put 375 g of the polyether macromonomer synthesized in step (1) into the reactor, heat up to 85 °C, and after the material is completely melted into a liquid state, add 4 g of ammonium persulfate as the initiator. After stirring for 10 minutes, start to dropwise add the mixed dropping material composed of 40 g of acrylic acid and 2.5 g of mercaptoacetic acid as the chain transfer agent. Control the dropping reaction time at 1.5 h, keep the temperature constant for aging for 1 h after the reaction. After the aging is completed, pour it into the tray for discharging. After the product is cooled to room temperature, crush it with a pulverizer to obtain the polycarboxylate superplasticizer powder.

[0092] Example 2

[0093] (1) Preparation of polyether macromonomer

[0094] Add 50 g of butanediol, 65 g of p-phenylenediamine and 100 g of xylene solvent into the reaction kettle in sequence, add 5.83 g of ferric chloride as the catalyst, stir evenly and then carry out the reaction. The whole reaction is carried out under a nitrogen atmosphere. After reacting for 8 h, slowly introduce 2915 g of ethylene oxide at 120 °C, control the pressure in the kettle at 0.3 - 1 MPa, and obtain the polyether macromonomer solution after reacting for 11 h. Then carry out vacuum distillation at 90 °C and -0.1 MPa for 1 h to remove the solvent and unreacted ethylene oxide, and obtain 2957 g of the target product, the double-tailed polyether macromonomer.

[0095] (2) Preparation of polycarboxylate superplasticizer powder

[0096] First, put 380 g of the polyether macromonomer synthesized in step (1) into the reactor, heat up to 75 °C, and after the material is completely melted into a liquid state, add 3.5 g of azobisisobutyronitrile as the initiator. After stirring for 10 minutes, start to dropwise add the mixed dropping material composed of 36 g of acrylic acid and 2.2 g of mercaptopropionic acid as the chain transfer agent. Control the dropping reaction time at 1 h, keep the temperature constant for aging for 2 h after the reaction. After the aging is completed, pour it into the tray for discharging. After the product is cooled to room temperature, crush it with a pulverizer to obtain the polycarboxylate superplasticizer powder.

[0097] Example 3

[0098] (1) Preparation of polyether macromonomer

[0099] 50 g of butanediol, 67.5 g of p-phenylenediamine and 100 g of dichloroethane solvent were successively added into a reaction kettle, and 8.58 g of zinc chloride as a catalyst was added. After stirring evenly, the reaction was carried out. The whole reaction was carried out under a nitrogen atmosphere. After reacting for 7 h, 2860 g of ethylene oxide was slowly introduced at 130 °C, and the pressure in the kettle was controlled at 0.3 - 1 MPa. After reacting for 12 h, a polyether macromonomer solution was obtained. Then, under the conditions of 90 °C and -0.1 MPa, vacuum distillation was carried out for 1 h to remove the solvent and unreacted ethylene oxide, and 2910 g of the target product, double-tailed polyether macromonomer, was obtained.

[0100] (2) Preparation of polycarboxylate superplasticizer powder

[0101] First, 350 g of the polyether macromonomer synthesized in step (1) was put into a reactor, and the temperature was raised to 90 °C. After the material was completely melted into a liquid state, 3.5 g of benzoyl peroxide as an initiator was added. After stirring for 10 minutes, a mixed dropping material composed of 40 g of acrylic acid and 1.9 g of mercaptoethanol as a chain transfer agent was started to be dropped. The dropping reaction time was controlled at 2.5 h. After the reaction, it was thermally aged at a constant temperature for 3 h. After the aging was completed, it was poured into a tray for discharging. After the product was cooled to room temperature, it was pulverized with a pulverizer to obtain the polycarboxylate superplasticizer powder.

[0102] Example 4

[0103] (1) Preparation of polyether macromonomer

[0104] 50 g of butanediol, 69.5 g of p-phenylenediamine and 100 g of trichloroethane solvent were successively added into a reaction kettle, and 9.0 g of zinc chloride as a catalyst was added. After stirring evenly, the reaction was carried out. The whole reaction was carried out under a nitrogen atmosphere. After reacting for 7 h, 3021 g of ethylene oxide was slowly introduced at 130 °C, and the pressure in the kettle was controlled at 0.3 - 1 MPa. After reacting for 12 h, a polyether macromonomer solution was obtained. Then, under the conditions of 90 °C and -0.1 MPa, vacuum distillation was carried out for 1 h to remove the solvent and unreacted ethylene oxide, and 3082 g of the target product, double-tailed polyether macromonomer, was obtained.

[0105] (2) Preparation of polycarboxylate superplasticizer powder

[0106] First, 360 g of the polyether macromonomer synthesized in step (1) was put into a reactor, and the temperature was raised to 85 °C. After the material was completely melted into a liquid state, 3.5 g of ammonium persulfate as an initiator was added. After stirring for 10 minutes, a mixed dropping material composed of 38 g of acrylic acid, 1.5 g of sodium methallylsulfonate and 1.5 g of sodium hypophosphite as a chain transfer agent was started to be dropped. The dropping reaction time was controlled at 1 h. After the reaction, it was thermally aged at a constant temperature for 1 h. After the aging was completed, it was poured into a tray for discharging. After the product was cooled to room temperature, it was pulverized with a pulverizer to obtain the polycarboxylate superplasticizer powder.

[0107] Example 5

[0108] (1) Preparation of polyether macromonomer

[0109] 50 g of butylene glycol, 72.4 g of p-phenylenediamine and 100 g of cyclohexane solvent were successively added into the reaction kettle, and 6.0 g of triethylboron as the catalyst was added and stirred evenly before reaction. The reaction was carried out under a nitrogen atmosphere throughout. After 7 h of reaction, 3009 g of ethylene oxide was slowly introduced at 130 °C, and the pressure in the kettle was controlled at 0.3 - 1 MPa. After 12 h of reaction, a polyether macromonomer solution was obtained. Then, under the conditions of 90 °C and -0.1 MPa, vacuum distillation was carried out for 1 h to remove the solvent and unreacted ethylene oxide, and 3054 g of the target product, double-tailed polyether macromonomer, was obtained.

[0110] (2) Preparation of polycarboxylate superplasticizer powder

[0111] First, 390 g of the polyether macromonomer synthesized in step (1) was put into the reactor, and the temperature was raised to 85 °C. After the material was completely melted into a liquid state, 4 g of benzoyl peroxide as the initiator was added. After stirring for 10 minutes, a mixed dropping material composed of 20 g of methacrylic acid, 15 g of fumaric acid, and 2 g of mercaptoethanol as the chain transfer agent was added dropwise. The dropping reaction time was controlled at 1 h. After the reaction, it was thermally aged at a constant temperature for 2.5 h. After the aging was completed, it was poured into the tray for discharging. After the product was cooled to room temperature, it was crushed with a pulverizer to obtain the polycarboxylate superplasticizer powder.

[0112] Example 6

[0113] The polycarboxylate superplasticizer powder was prepared according to the method of Example 1, except that:

[0114] The catalyst triethylaluminum was replaced with a catalyst synthesized as follows with the same mass:

[0115] Tetrabutylammonium iodide and the solvent acetone were mixed at a mass ratio of 50 g:50 g and activated with 200 g of ethylene oxide at 150 °C for 4 h. After the reaction was completed, the acetone solvent was removed to obtain the catalyst.

[0116] In step (1), the reaction time after introducing ethylene oxide was only 4 h.

[0117] Example 7

[0118] The polycarboxylate superplasticizer powder was prepared according to the method of Example 3, except that:

[0119] The catalyst zinc chloride was replaced with a catalyst synthesized as follows with the same mass:

[0120] Tetrabutylammonium iodide and the solvent acetone were mixed at a mass ratio of 40 g:60 g and activated with 200 g of ethylene oxide at 180 °C for 4 h. After the reaction was completed, the acetone solvent was removed to obtain the catalyst.

[0121] In step (1), the reaction time is only 4 h after introducing ethylene oxide.

[0122] Example 8

[0123] The polycarboxylate superplasticizer powder was prepared according to the method of Example 4, except that:

[0124] The catalyst zinc chloride was replaced with a catalyst synthesized as follows with the same mass:

[0125] Tetrabutylammonium iodide and the solvent acetone were mixed in a mass ratio of 45 g:55 g and activated with 200 g of ethylene oxide at 170 °C for 4 h. After the reaction was completed, the acetone solvent was removed to obtain the catalyst.

[0126] In step (1), the reaction time is only 4 h after introducing ethylene oxide.

[0127] Comparative Example 1

[0128] The polycarboxylate superplasticizer powder was prepared according to the method of Example 1, except that:

[0129] The catalyst was replaced with tetrabutylammonium iodide.

[0130] Comparative Example 2

[0131] The polycarboxylate superplasticizer powder was prepared according to the method of Example 1, except that:

[0132] In step (1), butylene glycol was replaced with the same mass of methallyl alcohol.

[0133] Comparative Example 3

[0134] The polycarboxylate superplasticizer powder was prepared according to the method of Example 6, except that:

[0135] In step (1), butylene glycol was replaced with the same mass of methallyl alcohol.

[0136] Test Example 1

[0137] In order to evaluate the effect of the polycarboxylate superplasticizer powder of the present invention on the early strength of gypsum blocks, the polycarboxylate superplasticizer powders prepared in the foregoing examples and comparative examples were compared with two commercially available polycarboxylate superplasticizer powders. Referring to the standards of GB / T 9776-2022 "Building Gypsum" and GB / T 17669.3-1999 "Determination of Mechanical Properties of Building Gypsum", the compressive strengths of the gypsum blocks added with the polycarboxylate superplasticizer powder at 8 h, 16 h, and 24 h were tested, and the test results are shown in Table 1.

[0138] Table 1 Comparison of early strength of gypsum blocks

[0139]

[0140] By comparison, it can be seen that the polycarboxylate superplasticizer powder prepared by the present invention has higher early mechanical properties and higher compressive strength compared with the commercially available polycarboxylate superplasticizer powder. It can accelerate the turnover of the gypsum block mold. During the use process, the polycarboxylate superplasticizer in powder form is more convenient during transportation than the liquid product, and can effectively reduce the transportation cost. Especially for long-distance transportation and large-scale use, it can significantly reduce the production cost of construction enterprises. It reduces the possibility of microbial contamination of the liquid superplasticizer during storage and use, reduces the pollution risk, thereby improving the performance and service life of the product, and promoting the progress and development of the gypsum block production technology. Moreover, by comparison, it can be seen that the polycarboxylate superplasticizer powder prepared in Examples 6-8 has higher compressive strength compared with Examples 1, 3 and 4.

[0141] The special structure of the double-tailed polyether endows the polycarboxylate superplasticizer with better dispersion performance, enabling it to better meet the requirements of gypsum blocks under different production processes and use environments. The polycarboxylate superplasticizer powder has better dispersion performance and adaptability.

[0142] Test Example 2

[0143] The double bond retention rate of the double-tailed polyether macromonomer synthesized in step (1) of the foregoing examples and comparative examples was tested according to JC / T 2033-2018 "Polyethers and Their Derivatives for Concrete Admixtures", and the test results are as follows:

[0144] Table 2

[0145]

[0146] From the above test results, it can be seen that in Examples 6-8, the double-tailed polyether macromonomer was catalytically synthesized with the catalyst generated by the activation reaction of tetrabutylammonium iodide and ethylene oxide. Not only was the reaction time for adding the first alkylene oxide for reaction shortened to 30-50% of the time in Examples 1-5, but also the double bond retention rate of the synthesized double-tailed polyether macromonomer could reach 97%.

[0147] The above description of the present application combines preferred embodiments. However, these embodiments are only exemplary and only serve an illustrative purpose. On this basis, various substitutions and improvements can be made to the present application, and these all fall within the protection scope of the present application.

Claims

1. A method for preparing a polycarboxylate water-reducing agent powder, characterized in that: The steps include: (1) adding a diol, an aromatic amine and a first solvent to a reaction system, adding a catalyst to carry out a first reaction, and then introducing a first alkylene oxide to carry out a second reaction to obtain a double-tail polyether macromonomer; (2) Melting the double-tail polyether macromonomer into a liquid, adding an initiator, and then adding a mixture of an unsaturated carboxylic acid and a chain transfer agent, aging, and crushing to obtain a polycarboxylic acid water-reducing agent powder.

2. The preparation method according to claim 1, characterized in that: The catalyst described in step (1) is synthesized as follows: Mixing N(R1R2R3R4)X with a second solvent, performing an activation reaction with a second alkylene oxide at 150-180° C. for 2-6 hours, and removing the second solvent after the reaction is completed to obtain the catalyst; Wherein, R1, R2, R3, and R4 are each an alkyl group selected from C1 to C7, X is selected from a halogen anion, and N is a nitrogen atom.

3. The preparation method according to claim 2, characterized in that: N(R1R2R3R4)X is one or more selected from tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrapropylammonium chloride, tetrapropylammonium bromide, tetrapropylammonium iodide, tetraethylammonium chloride, tetraethylammonium bromide, and tetraethylammonium iodide; The second solvent is acetone and / or toluene; The second alkylene oxide is one or more selected from ethylene oxide, propylene oxide, and butylene oxide; The mass ratio of N(R1R2R3R4)X to the second solvent is 1:(1-2), and the mass ratio of N(R1R2R3R4)X to the second solvent and to the second alkylene oxide is 1:(1-5).

4. The preparation method according to claim 1, characterized in that: The catalyst in step (1) is one or more selected from triethylaluminum, ferric chloride, zinc chloride and triethylboron.

5. The preparation method according to claim 1, characterized in that: In step (1), the diol is selected from C4 to C8 olefinic alcohols, preferably one or more of butene glycol, pentene glycol, and hexene glycol; the aromatic amine is selected from one or more of p-phenylenediamine, m-phenylenediamine, and o-phenylenediamine; the first solvent is selected from one or more of toluene, xylene, dichloromethane, dichloroethane, chloroform, trichloroethane, and cyclohexane; and the first alkylene oxide is selected from one or more of ethylene oxide, propylene oxide, and butylene oxide.

6. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of the diol to the aromatic amine is 1:(1-1.5), the amount of the catalyst used is 0.1-0.5% by mass of the first alkylene oxide, the mass ratio of the first solvent to the diol is 2-2.1:1, and the molar ratio of the aromatic amine to the first alkylene oxide is 1:(100-110).

7. The preparation method according to claim 1, characterized in that: In step (1), the first reaction is carried out for 6 to 8 hours; The conditions for introducing the first alkylene oxide to carry out the second reaction include: The first alkylene oxide is introduced at 80-150°C, the pressure of the reaction system is controlled to be 0.3-1 MPa, and the reaction is carried out for 4-12 hours; The polyether macromonomer solution is obtained through the second reaction, and then subjected to reduced pressure distillation to remove the solvent and the remaining first alkylene oxide to obtain the double-tail polyether macromonomer.

8. The preparation method according to claim 1, characterized in that: In step (2), Heating to 60-90° C. to melt the double-tail polyether macromonomer into a liquid; The initiator is one or more selected from benzoyl peroxide, ammonium persulfate, potassium persulfate, and azobisisobutyronitrile; the unsaturated carboxylic acid is one or more selected from acrylic acid, methacrylic acid, and fumaric acid; the chain transfer agent is one or more selected from sodium methacrylic acid, thioglycolic acid, mercaptopropionic acid, mercaptoethanol, and sodium hypophosphite; The mixture of the unsaturated carboxylic acid and the chain transfer agent is added dropwise for 0.5 to 2.5 hours and the aging time is 1 to 3 hours; Based on the total amount of the double-tail polyether macromonomer, the initiator, the unsaturated carboxylic acid and the chain transfer agent, the amount of the double-tail polyether macromonomer added is 85-90%, the amount of the initiator added is 0.4-2.0%, the amount of the unsaturated carboxylic acid added is 7-12%, and the amount of the chain transfer agent added is 0.2-1.0%.

9. A polycarboxylate water-reducing agent powder, characterized in that: The invention is prepared by the preparation method described in any one of claims 1 to 8.

10. Application of polycarboxylate water-reducing agent powder in gypsum blocks, characterized in that: The polycarboxylate water-reducing agent powder is the polycarboxylate water-reducing agent powder according to claim 9.

11. A method for preparing a polyether, characterized in that: include: Adding diol, aromatic amine and a first solvent into a reaction system, adding a catalyst to carry out a first reaction, and then introducing a first alkylene oxide to carry out a second reaction to obtain a polyether; Wherein, the catalyst is synthesized as follows: Mixing N(R1R2R3R4)X with a second solvent, performing an activation reaction with a second alkylene oxide at 150-180° C. for 2-6 hours, and removing the second solvent after the reaction is completed to obtain the catalyst; Wherein, R1, R2, R3, and R4 are each an alkyl group selected from C1 to C7, X is selected from a halogen anion, and N is a nitrogen atom.

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