A superplasticizer and its preparation method

Abstract

The present invention discloses a superplasticizer and a preparation method thereof. The superplasticizer of the present invention comprises a main chain and grafted side chains. The main chain contains a branched structure generated by the addition of an active H site to an unsaturated ester or unsaturated amide, and a polyether side chain is grafted through the functional group at the end of the main chain. An adsorption group is connected to the main chain structure through an acidifying reagent; the main chain of the superplasticizer is formed by the reaction of a hydroxyl group and an amino group with an acidifying reagent, and the grafted side chain is connected to the main chain of the superplasticizer through an epoxy ring-opening reaction, a hydroxyl transesterification reaction, a carboxyl esterification reaction or an amidation reaction. Compared with the commercially available ordinary superplasticizer, the superplasticizer of the present invention has substantially equivalent or slightly improved water-reducing / fluidity retention ability in ordinary cement-based materials. In high-fluidity ordinary commercial concrete, manufactured sand concrete and self-compacting concrete, it can significantly improve the uniformity of concrete, effectively reduce the bleeding and segregation of concrete, and significantly improve the workability.

Description

Technical Field

[0001] The present invention relates to the field of concrete superplasticizers, and particularly relates to a superplasticizer having the ability to improve the stability of concrete, a preparation method thereof, and an application thereof. Background Art

[0002] Since the invention of high-performance water-reducing agents (especially polycarboxylate water-reducing agents or polycarboxylate superplasticizers), they have been widely used and have achieved great development. They have become an essential component in concrete. Generally, polycarboxylate water-reducing agents have a comb-like structure and are generally prepared by free radical polymerization of vinyl-containing monomers. Their main chain (generally a -CH 2 -CH 2 - structure or a -CH substituted by a functional group 1 -CH 2 - structure) is connected with charged functional groups (such as carboxyl groups, sulfonic acid groups, etc.), and the corresponding side chains are mostly water-soluble polyethylene glycol chains. In concrete, they are adsorbed on the surface of cement particles through the electrostatic interaction between the charged functional groups and the surface of the cement particles, and the corresponding long side chains prevent the cement particles from approaching and aggregating with each other through steric hindrance (repulsion), release the entrapped water, improve the workability of the concrete, and reduce the water-cement ratio.

[0003] High water reduction is a key index pursued by commercially available water-reducing agents. However, polycarboxylate water-reducing agents have a high water reduction rate, are sensitive to the dosage, have a strong ability to destroy the flocculation structure of the slurry, and the viscosity of the slurry is relatively low. When the fluidity of the concrete is large, bleeding and segregation often occur, commonly known as "poor state" or "poor workability", causing a series of problems such as aggregate sedimentation and pumping blockage. The key lies in the stability of the concrete slurry and the aggregate. In addition, manufactured sand has become the main sand and gravel aggregate used in concrete, and its quality problems make it more difficult to improve the workability of the concrete. Compared with natural sand with strong and round particles and excellent gradation, the particle morphology of manufactured sand formed by artificial crushing is poor, the particle edges and corners are sharp, the surface is rough, porous, and has many microcracks; the particle gradation of manufactured sand is poor, showing a morphology of "more at both ends and less in the middle", the void ratio of manufactured sand is high, the surface area is large, the fluidity of the concrete mixture is not good, and the water retention property is poor; the lithology of manufactured sand is diverse, the powder content fluctuates greatly during production by different processes, and the batch differences of manufactured sand are significant, making the matching problem with water-reducing agents prominent.

[0004] At present, the main commercially available superplasticizers can be roughly divided into two categories according to the main chain structure: one is prepared by free radical polymerization of monomers containing vinyl crown functional groups, and its main chain is a long carbon chain or a long carbon chain substituted with methyl groups; the other is a polymer prepared by condensation polymerization (similar to phenolic condensation / aldehyde-ketone condensation), and its main chain is generally a repeating unit structure of methylene-substituted benzene rings, with stronger hydrophobicity. According to the research of the inventors, to improve the workability of concrete, it is necessary to improve its uniformity in the static and construction scenarios, and its paste network must be able to bind free water and support aggregates. The main chain structure of existing water reducers has a relatively strong hydrophobicity of the main chain skeleton, which is not conducive to binding free water, and its adhesion force to multiple particles is limited by the structure and needs to be improved.

[0005] In addition, another commonly used method to improve the workability of concrete is to add thickeners, but thickeners will inevitably weaken the dispersing ability of water reducers. To achieve the same concrete fluidity, the dosage of water reducers needs to be increased to varying degrees, and as the dosage of thickeners increases, the dosage of water reducers needs to be significantly increased. In addition, increasing the dosage of thickeners also has the risk of affecting strength.

[0006] When using existing polycarboxylate water reducers, ready-mixed concrete with lax control of raw material quality is prone to problems with poor state, especially it is often difficult to reconcile the fluidity and workability of concrete. According to the research of the inventors, existing polycarboxylate water reducers overly strengthen the ability to release free water, resulting in too much free water in the paste. Under the condition of the same paste fluidity, free water is prone to free migration, which is likely to cause bleeding. Once bleeding occurs, its viscosity will decrease significantly (aqueous phase), which will exacerbate the problem of concrete aggregate settlement (segregation), and the enrichment of particles in the bottom paste of concrete is likely to cause hardening, which is very unfavorable for construction.

[0007] The term "concrete" used herein generally refers indiscriminately to concrete, mortar, grout, etc., which also applies elsewhere in this article. Summary of the Invention

[0008] To solve the problems of poor workability, easy bleeding and segregation of high-fluidity concrete prepared with the original water reducer, the present invention provides a superplasticizer with a strong rigid polar main chain and its preparation method.

[0009] The present invention provides a superplasticizer, which comprises a main chain and grafted side chains. Its main chain contains a branched structure generated by the addition of active H sites to unsaturated esters or unsaturated amides, and grafts polyether side chains through the end functional groups of the main chain, and connects adsorption groups to the main chain structure through an acidifying reagent.

[0010] The main chain of the superplasticizer of the present invention is a branched structure containing the functional groups and branched structures shown in the following general formulas (0-1), (0-2) and (0-3),

[0011]

[0012]

[0013] wherein R 51 、R 52 、R 53 and R 54 each independently represents H or -CH 3 , X 21 、X 22 、X 23 and X 24 each independently represents an -O- or -NH- functional group; represents covalently connecting to other structures;

[0014] The superplasticizer main chain is connected with carboxyl groups and phosphate groups, and is formed by reacting with a hydroxyl group, an amino group and an acidifying reagent;

[0015] The graft side chain of the superplasticizer is a poly(ethylene glycol - isopropoxy) ether structure substituted with a terminal saturated alkyl group or a phenyl group, and is connected to the superplasticizer main chain through ring - opening of an epoxy group, trans - esterification of a hydroxyl group, esterification of a carboxyl group or amidation reaction.

[0016] The weight - average molecular weight range of the superplasticizer described in the present invention is 10,000 - 100,000. When the weight - average molecular weight is less than 10,000, although the superplasticizer sample still has good water - reducing performance, its ability to solvate and restrict the movement of free water will be significantly reduced, thus being disadvantageous to improving the workability of concrete; although a too high molecular weight has good workability, its water - reducing ability will be significantly decreased. In addition, when applied, it is easily consumed due to interaction with particles such as cement and hydration products, so the ability of concrete to maintain fluidity is significantly decreased.

[0017] The superplasticizer described in the present invention can be prepared through three steps, including Michael addition, side - chain grafting and adsorption group modification. The preparation method is as follows:

[0018] (1) Michael addition: A small molecule A containing active functional groups reacts with an unsaturated monomer B under the action of a catalyst to carry out a Michael addition reaction, forming an intermediate polymer Ⅰ with multiple branched chains containing multiple hydrogen - bond - forming functional groups;

[0019] The intermediate polymer Ⅰ contains hydroxyl groups and a small amount of unreacted amino active H sites;

[0020] The small molecule A containing active functional groups is an amine containing two or more active H sites, a polyhydroxyamine, a polyhydroxythiol or an amino acid ester with an esterified carboxyl group; the active H site refers to an -NH- or -SH functional group structure, and a primary amine functional group is regarded as containing two active H sites;

[0021] The unsaturated monomer B contains at least two unsaturated ester or unsaturated amide bond functional groups. The unsaturated ester bond is derived from an acrylate or methacrylate monomer, and the unsaturated amide bond is derived from an acrylamide or methacrylamide monomer;

[0022] The small molecule A containing active functional groups undergoes an addition reaction with the unsaturated ester or unsaturated amide bond of the unsaturated monomer B through the active H site. Therefore, when there are 3 or more active H sites in a single molecule of A or 3 or more unsaturated ester or unsaturated amide bond functional groups in a single molecule of monomer B, a branched structure is generated in the polymer I structure;

[0023] (2) Side chain grafting: The polyether C with functional groups reacts with the intermediate polymer I prepared in step (1) and connects the polyether side chain to the intermediate polymer I to obtain polymer II;

[0024] The connection method varies according to the type of terminal functional group of the polyether C. When the terminal functional group of the polyether C is an epoxy group, the polyether C undergoes a ring-opening addition reaction with the surplus hydroxyl or amino groups in the intermediate polymer I through the terminal epoxy group; when the terminal functional group of the polyether C is a carboxyl group, the polyether C undergoes a dehydration condensation reaction with the surplus hydroxyl or amino groups in the intermediate polymer I through the terminal carboxyl group; when the terminal functional group of the polyether C is a hydroxyl or amino group, the polyether C is connected to the ester functional group of the intermediate polymer I through an ester exchange reaction using the terminal hydroxyl or amino group.

[0025] The polymer II generated in this step contains a multi-branched main chain and grafted side chains, and there are still surplus hydroxyl or amino groups on the multi-branched main chain;

[0026] (3) Adsorption group modification: The surplus hydroxyl or amino groups remaining in the polymer II prepared in step (2) react with the acidifying reagent D to connect the adsorption group to the polymer II, obtaining the superplasticizer of the present invention.

[0027] The specific preparation method of the superplasticizer of the present invention is as follows:

[0028] (1) Add a certain amount of solvent S1, small molecule A containing active functional groups, unsaturated monomer B, regulator G, and catalyst M1 to the reactor, stir and react for a certain period of time under certain conditions, and then stop to obtain a mixture of intermediate polymer I;

[0029] (2) Add the polyether C with functional groups and catalyst M2 to the mixture of intermediate polymer I generated in step (1), vacuum-remove the volatile components, and then stir and react for a certain period of time under certain conditions and stop to obtain a mixture of polymer II;

[0030] (3) In the presence or absence of solvent S2, a certain amount of acidifying reagent D is added to the reactor, and all of the product of step (2), i.e., the mixture of polymer II, is added. The reaction is stirred for a period of time under certain conditions, and volatile organic small molecules are removed under vacuum to obtain a superplasticizer sample (solid); or after removing small molecules, it is dissolved in water and neutralized to obtain a superplasticizer solution.

[0031] The small molecule A containing active functional groups in step (1) is a composition in which E and F are mixed in any proportion, and the sum of the average molar number of hydroxyl groups per single molecule of A and the molar number of ester functional groups is not less than 1; and the amount of component E cannot be 0, and the average molar number of hydroxyl groups per single molecule of component E is not less than 1. The hydroxyl groups and ester functional groups in A are the sites for subsequent polyether grafting and adsorption group modification, so it is necessary to ensure their density in the main chain. If the density is too low, although the superplasticizer product can still be prepared, the problem is that the density of the side chains or adsorption groups of the final superplasticizer product is too low, which is not conducive to performance.

[0032] Wherein component E is an organic small molecule containing 2 - 8 carbon atoms, without unsaturated bonds, containing two or more active H sites, and without any other elements except carbon, hydrogen, oxygen, nitrogen, and sulfur, or an amino polyether molecule conforming to the structure shown in the following general formula (1), or any mixture of more than one of the above organic small molecules and amino polyethers:

[0033]

[0034] Where a and b respectively represent the repeating units of ethoxy and isopropoxy groups, which can be integers or not, the value range of (a + b) is 8 - 114, and b / (a + b) is not greater than 1 / 3. The connection order of the repeating units of ethoxy and isopropoxy groups shown in the general formula (1) is not limited, and it can be block or random.

[0035] The organic small molecule in component E is preferably saturated thiol or polythiol, saturated amine or polyamine, mercapto - substituted saturated amine, saturated amine containing ether functional group, thiol containing ether functional group, or hydroxyl - substituted saturated thiol or polythiol, saturated amine or polyamine, mercapto - substituted saturated amine, saturated amine containing ether functional group, thiol containing ether functional group.

[0036] The amino polyether in component E is connected to the main chain of the polymer superplasticizer through an amino reaction. In the structure of the final superplasticizer product, it is similar to the grafted polyether chain. If its length is too short or the content of isopropoxy repeating units is too high, it is not conducive to improving water reduction, while if it is too long, it is not conducive to the reaction in step (1).

[0037] Component F is a small molecule conforming to the following general formula (2) or one or more of its hydrochloride or sulfate salts in any mixture:

[0038]

[0039] Among them, R 1 represents a saturated alkyl group containing 1 to 4 carbon atoms, R 2 The functional group structure of methyl ester, ethyl ester or propyl ester formed by H, the R group of natural amino acid I or the R group of natural amino acid II, wherein the R group is the group remaining after removing the -CH- group connected to both the amino group and the carboxyl group and the amino group and the carboxyl group directly connected thereto in the natural amino acid. When the R group contains a carboxyl group, the carboxyl group contained in the R group of the natural amino acid can be esterified to form a functional group structure of methyl ester, ethyl ester or propyl ester; the natural amino acid I is a natural amino acid whose R group does not contain a carboxyl group, and the natural amino acid II is a natural amino acid whose R group contains a carboxyl group; the chirality of any carbon atom in the small molecule represented by the general formula (2) is not limited.

[0040] The unsaturated monomer B is one or more than one small molecule having the structure shown in the following general formula (3):

[0041]

[0042] Where m is a positive integer ranging from 2 to 6, R 3 Indicates H or -CH 3 ; R 4 The functional group represented does not contain any elements other than carbon, hydrogen, oxygen, and nitrogen, contains 2-10 carbon atoms, does not contain unsaturated bonds, does not contain active H sites, and the functional group directly connected to each carbonyl group in the brackets of the general formula (3) is -O- or -NH- or a tertiary amine functional group. At the same time, in each small molecule represented by the general formula (3), the functional group directly connected to R 4 The functional groups in the brackets may be the same or different. 4 The purpose of increasing the number of carbon atoms is to increase the grafting density, adsorption group density, main chain rigidity and hydrogen bond functional group density of the polyether chain in the product superplasticizer as much as possible. Otherwise, although the polymer can be prepared, it is completely detrimental to the performance of the final product superplasticizer in reducing water and improving concrete workability.

[0043] The organic small molecule represented by the general formula (3) can be a commercially available product or can be prepared by dehydration condensation of acrylic acid, methacrylic acid with an organic small molecule containing 2 - 10 carbon atoms, no unsaturated bonds, and the total number of hydroxyl groups, primary amine groups and secondary amine groups being between 2 and 6 (including 2 and 6) and containing no other elements except carbon, hydrogen, oxygen and nitrogen. The reactions involved are esterification or amidation, which are technical methods well-known to those skilled in the art and are reported in many literatures (such as Polymer-Plastics Technology and Engineering, 2011, 50, 59). A condensing agent is used for the dehydration condensation reaction. For example, the condensing agent N,N-dicyclohexylcarbodiimide (DCC) catalyzes the condensation in the presence of 4-dimethylaminopyridine (DMAP), or a strong acid is used as a catalyst and an azeotropic dehydrating agent such as toluene, xylene, cyclohexane, etc. is used for dehydration (J.Colloid.Interf.Sci., 2017, 504, 12). They are not listed here one by one.

[0044] The regulator G is a mixture of component G-A and G-B in any proportion. Among them, component G-A is an organic small molecule containing only 2 - 6 carbon atoms, no unsaturated bonds, and only one active H site. Component G-B is any one small molecule or a mixture of more than one conforming to the following general formula (4):

[0045]

[0046] Among them, R 10 represents H or -CH 3 , R 11 represents a functional group containing no more than 6 carbon atoms, no unsaturated bonds, no active H sites, no other elements except carbon, hydrogen, oxygen and nitrogen, and the end is connected to the carbonyl group in the structure shown by the general formula (4) through -O- or -NH- or a tertiary amine functional group. The limitation on the number of carbon atoms in the R 11 functional group is not because more carbon atoms cannot react, but only to control the hydrophobicity of the functional group so that it is not too strong, otherwise it will affect the overall conformation of the polymer, thereby weakening the adsorption and water-reducing ability of the product superplasticizer.

[0047] The polyether C is any mixture of one or more than one conforming to the general formula (5-1) or (5-2) or (5-3),

[0048]

[0049] Among them, R 6 , R 7 and R 8 respectively and independently represent a saturated alkyl group or a phenyl group containing 1 - 6 carbon atoms, and R 9 represents -OH or -NH 2 , and X represents -(CH2 ) n -CO-, where n is an integer from 2 to 4 (including 2 and 4), and Y represents -O- or -NH-; in the shown structure, c, e, g and d, f, h respectively and independently represent the number of repeating units of ethoxy and isopropoxy in their respective general formulas, which can be an integer or not. In the above general formulas (i.e., general formulas 5-1, 5-2 and 5-3), the sum of the number of repeating units of ethoxy and isopropoxy ranges from 8 to 114, and the proportion of the number of repeating units of isopropoxy in the sum of the number of repeating units of ethoxy and isopropoxy is not greater than 1 / 3. The structure shown in general formula (5-1) or (5-2) or (5-3) does not limit the connection order of the repeating units of ethoxy and isopropoxy, which can be block or random. The sum of the number of repeating units of ethoxy and isopropoxy reflects the side chain length. If the value is too small, the side chain is short. This does not mean that the dispersant with this structure cannot be prepared, but because the short side chain will lead to poor dispersion performance. If the value is too high, it will increase the preparation difficulty of this plasticizer itself, the reaction efficiency is difficult to improve, and the conversion rate is low. In addition, too long side chain will also cause the adsorption group to be shielded by the side chain, which is not conducive to improving the adhesion ability on the surface of solid particles to a certain extent.

[0050] The polyether structure shown in general formula (5-1) can be derived from commercially available products or can be prepared by reacting the corresponding poly(ethylene glycol-propylene glycol) or polyethylene glycol polyether with epichlorohydrin, which belongs to the technical methods well-known to relevant technical personnel and has been reported in many literatures (refer to Imaging Science and Photochemistry, 29, 2011, 456; Synthesis, 1983, 117; J. Org. Chem. 1943, 08, 2, 189 and the cited literatures), and will not be listed here.

[0051] The polyether structure shown in general formula (5-2) can be prepared by reacting the corresponding poly(ethylene glycol-propylene glycol) or polyethylene glycol polyether with the corresponding dianhydride, which belongs to the technical methods well-known to relevant technical personnel and will not be listed here.

[0052] The polyether structure shown in general formula (5-3) can be prepared by ring-opening polymerization of ethylene oxide-propylene oxide initiated by the corresponding initiator, which belongs to a mature industrial process. Reference can be made to Chem. Rev. 2016, 116, 2170 and its citations, and will not be listed here.

[0053] The acidifying reagent D is any one or more than one of dianhydrides or phosphorylating reagents, which can react with hydroxyl or amino groups to connect carboxyl or phosphonic acid groups to the polymer. The dianhydrides are selected from one or more than one of succinic anhydride, glutaric anhydride, adipic anhydride and maleic anhydride, and the phosphorylating reagent is a mixture of one or more than one of phosphoric acid, polyphosphoric acid, pyrophosphoric acid, phosphorus pentoxide and water, which is a mixture prepared by the reaction of the acid anhydride of phosphoric acid with water, cannot be purified and separated, and has reaction activity; the ratio of the total molar amount of H to the total molar amount of P in the phosphorylating reagent is between 1 and 1.5.

[0054] The certain conditions in step (1) are the common conditions for Michael addition, which are technical methods well-known to those skilled in the art. Referring to the literature (RSC Adv. 2017, 7, 56157; Polym. Chem. 2010, 1, 1196; J. Org. Chem. 2017, 82, 10219; Chem. Res. Chin. Univ. 2009, 25, 461; J. Am. Chem. Soc. 2001, 123, 8155 - 8156), the reaction temperature range mainly includes 0 - 100 °C, the reaction time is generally 1 - 24 h. In addition, an acid or base catalyst can be added or not added. Suitable catalysts M1 include but are not limited to formic acid, acetic acid, lithium hydroxide, sodium hydroxide, sodium alkoxides corresponding to organic alcohols with saturated alkyls containing 1 - 12 carbon atoms, or any one of the structures represented by the following general formula (6 - 1) or general formula (6 - 2):

[0055]

[0056] In general formula (6 - 1), R 16 , R 17 , R 18 independently represent H or saturated alkyls containing 1 - 6 carbon atoms respectively. In general formula (6 - 2), R 13 , R 14 , R 15 independently represent H, saturated alkyls containing 1 - 6 carbon atoms, phenyl, cyclohexyl, cyclopentyl, phenyl substituted by saturated alkyls with 1 - 3 carbon atoms, cyclohexyl substituted by saturated alkyls with 1 - 3 carbon atoms or cyclopentyl substituted by saturated alkyls with 1 - 3 carbon atoms respectively.

[0057] The molecular weight of the polymer prepared in step (1) is closely related to the final molecular weight of the product superplasticizer, and the reaction time and process can be adjusted as needed.

[0058] There is no restriction on the feeding order of each component in step (1), and the feeding method of each component is not limited to one - time feeding. It can be fed in batches or continuously within a certain period of time.

[0059] To ensure the simplicity of the entire superplasticizer preparation process, since the subsequent steps involve anhydrous and dehydration reactions, water is generally not used as a solvent in step (1). The solvent S1 used must be able to dissolve all reactants and product polymers. Those skilled in the art can select appropriate organic solvents according to the reaction temperature and the solubility requirements of substances, with reference to relevant reactions in the literature, including but not limited to dichloromethane, chloroform, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, 1,2-dichloroethane, dimethyl sulfoxide, acetonitrile, N-methylpyrrolidone.

[0060] The certain conditions described in step (2) are related to the reaction being carried out. When polyether C is a component with the structure shown in general formula (5-1), an epoxy ring-opening addition reaction is carried out. The reaction temperature is 60-150 °C, the reaction time is 2-24 h, and a catalyst is required. Catalyst M2 is well-known to professionals in the field, including but not limited to sodium metal, sodium hydride, sodium methoxide, sodium hydroxide, potassium hydroxide, or the sodium or potassium alkoxide corresponding to an organic alcohol with a saturated alkyl group containing 1-12 carbon atoms, with reference to Chem. Rev. 2016, 116, 2170.

[0061] The removal of volatile small molecules in step (2) can be carried out before or after the addition of the catalyst.

[0062] When polyether C is a component with the structure shown in general formula (5-2), a dehydration condensation reaction between a carboxyl group and a hydroxyl group or an amino group is carried out. The "certain conditions" are to continuously introduce N 2 or maintain a vacuum in the presence of a catalyst. The reaction temperature is 100-200 °C, and the reaction time is 3-24 h; the catalyst M2 is a Lewis acid, Bronst acid, or Lewis base. The catalyst M2 is preferably any one of p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, sodium acetate, potassium acetate, sodium hydroxide, potassium hydroxide, or the sodium or potassium alkoxide corresponding to an organic alcohol with a saturated alkyl group containing 1-12 carbon atoms. The reaction conditions are all conducive to removing the water generated in the reaction and promoting the chemical equilibrium to shift towards the product superplasticizer.

[0063] When polyether C is a component with the structure shown in general formula (5-3) (amino or hydroxyl polyether), a transesterification reaction or an aminolysis reaction of an ester is carried out. The "certain conditions" are to continuously introduce N 2Or maintain a vacuum, with the reaction temperature being 80 - 200 °C and the reaction time being 3 - 24 h; the catalyst M2 is an acid or a base, and the catalyst M2 is preferably any one of p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, sodium acetate, potassium acetate, sodium hydroxide, potassium hydroxide, or the sodium alkoxide or potassium alkoxide corresponding to an organic alcohol with a saturated alkyl group containing 1 - 12 carbon atoms. The reaction conditions are all conducive to removing the water generated by the reaction and promoting the chemical equilibrium to shift towards the direction of the product superplasticizer.

[0064] When polyether C contains both the component with the structure shown in general formula (5 - 1) and the component with the structure shown in general formula (5 - 2) or general formula (5 - 3), the catalyst M2 used in step (2) is unified as a strong base. The representative catalyst M2 is any one of sodium, sodium hydride, sodium methoxide, sodium hydroxide, potassium hydroxide, or the sodium alkoxide or potassium alkoxide corresponding to an organic alcohol with a saturated alkyl group containing 1 - 12 carbon atoms. The reaction is carried out in two stages. In the first stage, the reaction of the component with the structure shown in general formula (5 - 1) is carried out at a temperature of 60 - 150 °C and a reaction time of 2 - 24 h; then the reaction of the component with the structure shown in general formula (5 - 2) or general formula (5 - 3) is carried out. The reaction of the components with the structures shown in general formula (5 - 2) and general formula (5 - 3) can be carried out in stages or simultaneously, and sufficient temperature and time are ensured; when the reactions of the components with the structures shown in general formula (5 - 2) and general formula (5 - 3) are carried out simultaneously, the above reaction conditions need to be satisfied simultaneously.

[0065] When the catalysts used in different reaction stages of step (2) are the same, they can be added in one reaction at a certain stage.

[0066] The amount of the solvent S2 used in step (3) needs to meet the following conditions: at the reaction temperature, ensure that the acidifying reagent D and the entire reaction system are in a solution or liquid state rather than in other states such as frozen or insoluble. There is no specific limit on the amount of the solvent, and it can also not be used under the condition of meeting the above requirements. However, the larger the amount of the solvent, the slower the reaction process. A smaller amount of the solvent is preferred. Those skilled in the art can also select the solvent suitable for step (3) according to the reaction temperature and the requirements for substance dissolution, referring to the relevant reactions in the literature, including but not limited to chloroform, tetrahydrofuran, dioxane, N,N-dimethylformamide, acetonitrile, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone.

[0067] The reaction conditions in step (3) are 20 - 120 °C and the reaction time is 2 - 12 h. This reaction is carried out under anhydrous conditions.

[0068] In step (1), the total mass of the small molecule A with active functional groups, the unsaturated monomer B, and the regulator G accounts for 20-60% of the total mass of the reaction system. If the concentration is too low, both the reaction rate and efficiency will decrease. In addition, the reactant concentration needs to be adjusted according to the situation, because too high a concentration may increase the risk of over-crosslinking while improving the reaction efficiency. The dosage of the regulator G accounts for 0-50% of the total molar amount of the small molecule A with active functional groups and the unsaturated monomer B, including 0 and 50%. The regulator G is used to control the molecular weight of the polymer prepared in step (1), and thus control the molecular weight range of the product superplasticizer. Too high a dosage will result in a too small molecular weight of the polymer prepared in step (1).

[0069] In step (1), the molar ratio range of the small molecule A with active functional groups to the unsaturated monomer B is 0.25-4, including 0.25 and 4. Exceeding this range will make it very difficult to control the molecular weight of the polymer prepared in step (1), either too large or prone to gel formation.

[0070] The dosage of the catalyst M1 used in step (1) accounts for 0-20% of the total molar amount of all reactants.

[0071] In step (2), the dosage of the polyether C needs to meet the following conditions: the molar amount of the polyether conforming to the structures shown in general formulas (5-1) and (5-2) accounts for no less than 10% and no more than 60% of the total molar amount of the hydroxyl groups in the small molecule A with active functional groups, the unsaturated monomer B, and the regulator G; the polyether conforming to the structures shown in general formulas (5-1) and (5-2) reacts with the hydroxyl groups and grafts onto the polymer, and the remaining hydroxyl groups will participate in the reaction in step (3). If this ratio is too high, the ratio of the adsorption groups will be too low. If this ratio is too low, there will be too few polyether chains, both of which are not conducive to the performance of the product superplasticizer.

[0072] The molar amount of the polyether conforming to the structure shown in general formula (5-3) is not higher than 1.1 times the total molar amount of the ester bonds in the component F and the regulator G; too high a molar amount helps to improve the conversion efficiency of the ester bonds, but will result in waste of polyether and is not conducive to cost control.

[0073] The total amount of the catalyst M2 used in step (2) accounts for 0-20% of the total molar amount of the polyether C used in step (2); the amount of the catalyst used in each stage (stepwise reaction with different polyethers) accounts for 0-20% of the molar amount of the corresponding polyether.

[0074] The ratio of the total molar amount of hydrogen to the total molar amount of phosphorus in the phosphorylating agent in the acidifying reagent D is between 1 and 1.5. The molar amount of hydrogen element in the phosphorylating agent is denoted as n(H), and the molar amount of phosphorus element is denoted as n(P). Its effective phosphorylation equivalent is calculated as [1.5n(P) - 0.5n(H)]. Then, the sum of the molar amount of dianhydride and the effective phosphorylation equivalent (i.e., the dosage of the acidifying reagent) is equivalent to 0.5 - 1.5 times the difference between the total molar amount of hydroxyl groups in the active functional group small molecule A, the unsaturated monomer B, and the regulator G and the molar amount of the polyether conforming to the structure shown in the general formula (5-2). If it is less than 0.5 times, there are fewer adsorbed active functional groups in the intermediate mixture. If it is higher than 1.5 times, it is uneconomical, and at the same time, intermolecular coupling by-products may occur, making it difficult to control the molecular weight.

[0075] The superplasticizer described in the present invention has the following remarkable characteristics: (1) The main chain contains many polar groups that can form hydrogen bonds. Its solvation effect in the solution is significant, adsorbing water molecules, reducing the free movement of water molecules, and significantly reducing bleeding; (2) The main chain contains many locally conjugated amide bonds, has strong rigidity, small shrinkage, can significantly improve the adsorption ability at different solid interfaces, and enhances the adaptability to powders such as admixtures and stone powder; (3) The main chain contains a linear and branched network structure. The hydrogen bond effect is conducive to bridging between different particles, enabling the particles to form a framework network structure with a certain spacing. While ensuring the spacing, it restricts the free movement of particles (preventing sedimentation), enhances the cohesiveness of the slurry, and further reduces bleeding and segregation.

[0076] Compared with the commercially available ordinary superplasticizer, the superplasticizer described in the present invention has basically equivalent or slightly improved water reduction / fluidity retention ability in ordinary cement-based materials (paste, mortar or concrete). In high-fluidity ordinary commercial concrete, manufactured sand concrete and self-compacting concrete, it can significantly improve the uniformity of concrete, effectively reduce bleeding and segregation of concrete, and significantly improve workability. Detailed implementation mode

[0077] To better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments. However, the content of the present invention is not limited to the following embodiments. All units used below are parts by mass. All compounds used are commercial products or synthetic products reported in the literature.

[0078] The solvents, catalysts, component E, component F, part of the unsaturated monomer B, and part of the polyether C used in each step of the reaction are commercially available (J&K Scientific, TCI, Sigma-Aldrich, Huntsman, and Romil, etc.).

[0079] Table 1 Names and sources of compounds used in the examples

[0080]

[0081]

[0082] The structures of the compounds listed in Table 1 are as follows. The chiralities of some compounds are not drawn:

[0083]

[0084]

[0085] The preparation methods of some raw materials refer to the following steps:

[0086] (1) E8: Prepared by the addition reaction of triethylenetetramine and ethylene oxide. The product is the product of the addition reaction of ethylene oxide with different secondary or primary amine sites. The product is a mixture. The structure shown in the above formula is only one of the components, which on average has two active H sites and 4 hydroxyl groups. Add 146.23 g of triethylenetetramine and 300 g of N,N-dimethylformamide to a stainless steel reactor, freeze and evacuate to remove air, and fill with N 2 , repeat 3 times. Continuously and slowly introduce 176.2 g of ethylene oxide into it at room temperature. The addition time of ethylene oxide accumulates for 12 h. After adding, continue to stir for 12 h. After completion, evacuate the solvent under vacuum and cool to a light yellow solid. The yield is 99%.

[0087] (2) B5: Prepared by the dehydration condensation of pentaethylenehexamine and acrylic acid. Add 72 g of acrylic acid and 72 g of dichloromethane to a flask. Slowly dropwise add a dichloromethane solution of pentaethylenehexamine (23.2 g dissolved in 80 g of dichloromethane) into it under stirring at room temperature. After dropping, continue to dropwise add a dichloromethane solution of N,N-dicyclohexylcarbodiimide (123.8 g dissolved in 500 g of dichloromethane) for 6 h. After dropping, continue to stir for 12 h. After completion, add 18 g of water and continue to stir for 2 h. Filter to remove the white precipitate, add saturated brine, mix well and centrifuge to leave the dichloromethane phase. Repeat twice, combine the dichloromethane phases, dry with anhydrous sodium sulfate, filter, and rotary evaporate to obtain a light yellow solid. The yield is 90%.

[0088] (3) B6: Prepared by the dehydration condensation of pentaerythritol and less than equivalent methylacrylic acid, which is a mixture of products with different degrees of esterification of pentaerythritol. Add 13.62 g of pentaerythritol, 82.53 g of N,N-dicyclohexylcarbodiimide and 400 g of dichloromethane to a flask, stir to dissolve, and slowly dropwise add 21.52 g of methylacrylic acid into it under stirring at room temperature for 6 h. After dropping, continue to stir for 12 h. After completion, add 18 g of water and continue to stir for 2 h. Filter to remove the white precipitate, repeat once more, dry the organic phase with anhydrous sodium sulfate, filter, and rotary evaporate to obtain a light yellow paste. The yield is 98%.

[0089] (4) C3 is prepared by the reaction of methoxypolyethylene glycol and succinic anhydride. It is basically a stoichiometric reaction with a relatively high conversion rate. 200 g of methoxypolyethylene glycol (number-average molecular weight 2000) and 10.5 g of succinic anhydride were added to a flask, and the reaction was stirred at 100 °C for 12 h. It was dissolved in dichloromethane and then precipitated with carbon tetrachloride. This was repeated three times, and then rotary evaporation was carried out to obtain a white solid with a yield of 85%.

[0090] (5) C4 is prepared by the reaction of C2 (number-average molecular weight 2000, commercial product) and adipic anhydride. 40 g of C2 and 100 mL of anhydrous toluene were added to a flask, and the mixture was stirred and heated to dissolve. The temperature was raised to 90 °C, and 2.56 g of adipic anhydride was added thereto. The reaction was continued by heating for 6 h, and then the temperature was lowered and toluene was removed by rotary evaporation to obtain a dark yellow solid with a yield of 99%.

[0091] (6) C6 is prepared by initiating the polymerization of ethylene oxide with n-hexanol as an initiator. 51.08 g of anhydrous n-hexanol was added to a stainless steel reactor, 0.6 g of sodium hydride was added and stirred to dissolve. The air was removed under vacuum, and N 2 was charged, and this was repeated 3 times. Finally, it was evacuated again, the temperature was raised to 120 °C, and 2450 g of ethylene oxide was slowly introduced therein. The temperature was maintained, the pressure was controlled, and the cumulative reaction time was 8 - 10 h. After completion, it was poured out and cooled to obtain a white solid with a yield of 99%.

[0092] (7) C7 is prepared by initiating the polymerization of ethylene oxide with phenoxyethanol as an initiator to prepare methoxypolyethylene glycol monophenyl ether. 69.08 g of anhydrous phenoxyethanol was added to a stainless steel reactor, 0.6 g of sodium hydride was added and stirred to dissolve. The air was removed under vacuum, and N 2 was charged, and this was repeated 3 times. Finally, it was evacuated again, the temperature was raised to 120 °C, and 430 g of ethylene oxide was slowly introduced therein. The temperature was maintained, the pressure was controlled, and the cumulative reaction time was 8 - 10 h. After completion, it was poured out and cooled to obtain a white solid. The yield of methoxypolyethylene glycol monophenyl ether (number-average molecular weight 1000) was 99%.

[0093] React polyethyleneglycol phenyl ether with epichlorohydrin (refer to Imaging Science and Photochemistry, 29, 2011, 456; Synthesis, 1983, 117; J. Org. Chem. 1943, 08, 2, 189 and the cited references). Dissolve the above polyether in chloroform (100 g dissolved in 200 mL), add boron trifluoride ether complex (213 mg) thereto, heat to reflux, uniformly dropwise add epichlorohydrin (18.5 g, 2-fold equivalent) thereto, continue the reaction for 6 h after 1 h of dropping, cool down and remove the unreacted epichlorohydrin under vacuum. Adjust the temperature of the remaining reactants to 30 °C, add water (4.8 g) and flaky NaOH (4.8 g, 1.2-fold equivalent of polyether) thereto, stir for 3 h, filter off the insoluble substances, lyophilize the remaining liquid, dissolve and extract the product components with dichloromethane, filter and spin-dry dichloromethane to obtain a white paste-like solid with a yield of 74%.

[0094] The following are the specific steps of the examples (the stoichiometry of all the following reactions is based on unsaturated monomer B, and the total amount of substance of unsaturated monomer B is converted to 1 mole fraction. The following table shows the feeding ratios of the following examples). The molecular weight of the product is measured by Shimadzu GPC (LC-20A). The gel chromatography column is the TSK-GEL SW series of TOSOH Corporation. A differential refractive index detector is used, and the mobile phase is 0.1 M NaNO 3 aqueous solution, and polyethylene glycol is used as the molecular weight measurement standard.

[0095] Example 1

[0096] (1) Add N,N-dimethylformamide (925.73 parts) to the reactor, add E1 (242.28 parts), B1 (352.34 parts) and G1 (22.533 parts) thereto, stir to dissolve, adjust the reactor to 50 °C, stir evenly and react for 6 h, then stop the reaction to obtain an intermediate polymer I mixture.

[0097] (2) Add 18.14 g of sodium hydride to the intermediate I polymer mixture generated in step (1), stir well to dissolve, then add polyether C1 (1323 parts) thereto, remove the volatile small molecules under vacuum, adjust the temperature to 60 °C, stir evenly and react for 24 h, then stop the reaction.

[0098] (3) Add 2910 parts of tetrahydrofuran to another reactor, then add 44.71 parts of phosphorus pentoxide and 5.67 parts of water thereto. Adjust the temperature to 60 °C and stir for 2 h until completely dissolved. Then add 252 parts of succinic anhydride, and then add all the samples prepared in step (2) thereto at one time. After stirring evenly at 60 °C and reacting for 12 h, stop the reaction. Remove volatile organic small molecules under vacuum to obtain the product superplasticizer sample (solid) ME01, with a weight-average molecular weight of 33.5 kDa.

[0099] Example 2

[0100] (1) Add chloroform (406.7 parts) to the reactor, add E2 (105.14 parts) thereto, stir to dissolve, adjust the reactor to 50 °C, and add B2 (154.17 parts) and G2 (11.824 parts) thereto in three batches at intervals of 0.5 h. After adding, continue to stir evenly and react for 6 h, then stop the reaction to obtain the intermediate polymer I mixture.

[0101] (2) Add potassium tert-butoxide (2.24 parts) and polyether C1 (70 parts) to the intermediate polymer I mixture generated in step (1), remove volatile small molecules under vacuum, adjust the temperature to 100 °C, stir evenly and react for 6 h. Then add polyether C3 (1680 parts) thereto, and add 17.95 parts of potassium tert-butoxide to the reaction system. Adjust the temperature to 180 °C, stir evenly and continue the vacuum dehydration reaction for 12 h, then stop the reaction.

[0102] (3) Add 18.93 parts of phosphorus pentoxide, 6.53 parts of anhydrous phosphoric acid and 100 parts of succinic anhydride to another reactor, adjust the reactor temperature to 100 °C, then add all the samples prepared in step (2) thereto at one time. After stirring and mixing evenly, react for 6 h, then stop the reaction. Remove volatile organic small molecules under vacuum to obtain the product superplasticizer sample (solid) ME02, with a weight-average molecular weight of 40.3 kDa.

[0103] Example 3

[0104] (1) Add dimethyl sulfoxide (447.85 parts) to the reactor, add E3 (38.575 parts), E4 (148.2 parts), F2 (87.59 parts) and B1 (352.34 parts) thereto, stir to dissolve, adjust the reactor to 90 °C, and continuously and evenly dropwise add G1 (45.066 parts) thereto under stirring conditions for 6 h. Then continue to stir evenly and react for 18 h, then stop the reaction to obtain the intermediate polymer I mixture.

[0105] (2) Add sodium hydroxide (2.16 parts) and polyether C7 (1140.48 parts) to the intermediate polymer I mixture generated in step (1), remove volatile small molecules under vacuum, adjust the temperature to 120 °C, stir evenly and react for 12 h. Then add 4.8 parts of sodium hydride, stir well and mix. Then add polyether C2 (2000 parts) to it at one time, adjust the temperature to 160 °C, and continuously introduce N 2 Dehydrate, stir evenly and react for 12 h, then stop the reaction.

[0106] (3) Add 208.97 parts of polyphosphoric acid and 21.35 parts of water to another reactor, adjust the temperature to 80 °C and stir for 1 h until evenly mixed. Then add all the samples prepared in step (2) to it at one time, stir evenly and react for 12 h, then stop the reaction. Remove volatile organic small molecules under vacuum to obtain the product superplasticizer sample (solid) ME03 with a weight-average molecular weight of 75.2 kDa.

[0107] Example 4

[0108] (1) Add dimethyl sulfoxide (1344.35 parts) to the reactor, add E4 (148.2 parts), F1 (188.325 parts), F4 (196.755 parts), B5 (556.65 parts) and G3 (262.85 parts) to it, stir well and dissolve. Add 22.5 parts of acetic acid (catalyst) to it, adjust the reactor to 95 °C, stir evenly and react for 24 h, then stop the reaction to obtain the intermediate polymer I mixture.

[0109] (2) Add polyether C7 (2112 parts) to the intermediate polymer I mixture generated in step (1), remove volatile small molecules under vacuum, add 14.85 parts of sodium methoxide, adjust the temperature to 150 °C, stir evenly and react for 3 h. Then add polyether C3 (1050 parts) and C5 (6000 parts) to it, continue to stir and react under vacuum at 150 °C for 24 h, then stop the reaction.

[0110] (3) Add 7004 parts of N,N-dimethylformamide to another reactor, then add 337.11 parts of phosphorus pentoxide and 42.75 parts of water to it, adjust the temperature to 60 °C and stir for 1 h until completely dissolved. Add 475 parts of succinic anhydride to it, then add all the samples prepared in step (2) to it at one time, stir evenly and react for 12 h, then stop the reaction. Remove volatile organic small molecules under vacuum to obtain the product superplasticizer sample (solid) ME04 with a weight-average molecular weight of 94.1 kDa.

[0111] Example 5

[0112] (1) Add N,N-dimethylformamide (1386.99 parts) to the reactor, and add E5 (154.25 parts), B4 (183.2 parts) and G5 (31.244 parts) thereto. Stir well to mix and dissolve. Adjust the reactor to 75 °C, add 44.52 parts of triethylamine (catalyst) thereto, stir evenly, react for 12 h, then stop the reaction to obtain an intermediate polymer I mixture.

[0113] (2) Add 4.488 parts of potassium tert-butoxide and polyether C7 (422.4 parts) to the intermediate polymer I mixture generated in step (1). Remove volatile small molecules under vacuum. Adjust the temperature to 120 °C, stir evenly and react for 12 h. Then add polyether C4 (851.2 parts) thereto, adjust the temperature to 100 °C, stir evenly and continue the vacuum dehydration reaction for 24 h, then stop the reaction.

[0114] (3) Add 547.4 parts of dimethyl sulfoxide to another reactor, then add 116.09 parts of polyphosphoric acid and 11.86 parts of water thereto. Adjust the temperature to 60 °C and stir for 0.5 h to mix evenly. Adjust the reactor temperature to 100 °C, then add all the samples prepared in step (2) thereto at one time. Stir evenly and react for 8 h, then stop the reaction. Remove volatile organic small molecules under vacuum to obtain a product superplasticizer sample (solid) ME05 with a weight-average molecular weight of 17.3 kDa.

[0115] Example 6

[0116] (1) Add N,N-dimethylformamide (418.19 parts) to the reactor, and add E2 (26.285 parts), E6 (21.535 parts), F3 (69.79 parts), B3 (84.095 parts) and B2 (77.085 parts) thereto. Add 4.05 parts of acetic acid (catalyst) thereto. Stir well to mix and dissolve. Adjust the reactor to 50 °C, stir evenly and react for 12 h, then stop the reaction to obtain an intermediate polymer I mixture.

[0117] (2) Add polyether C4 (212.8 parts) to the intermediate polymer I mixture generated in step (1). Remove volatile small molecules under vacuum, then add 1.44 parts of sodium hydride. Adjust the temperature to 180 °C, stir and introduce N 2 After dehydration and uniform reaction for 6 h, add polyether C6 (1250 parts) thereto. Adjust the temperature to 150 °C, stir and continue the vacuum reaction for 8 h, then stop the reaction.

[0118] (3) Add 435.4 parts of N,N-dimethylformamide to another reactor, then add 18.93 parts of phosphorus pentoxide, 6.53 parts of anhydrous phosphoric acid and 70 parts of succinic anhydride thereto. Adjust the temperature to 80 °C and stir for 1 h to fully dissolve and mix evenly. Then add all the samples prepared in step (2) thereto at one time, stir evenly and react for 6 h, and then stop the reaction. Remove volatile organic small molecules under vacuum to obtain the product superplasticizer sample (solid) ME06 with a weight-average molecular weight of 66.3 kDa.

[0119] Example 7

[0120] (1) Add N-methylpyrrolidone (498.93 parts) to a reactor, add E7 (178.453 parts) and B2 (154.17 parts) thereto, stir and mix thoroughly to dissolve. Add 44.52 parts of tricyclohexylphosphine and 11.78 parts (catalyst) thereto. Adjust the reactor to 50 °C, stir evenly and react for 12 h, and then stop the reaction to obtain the intermediate polymer I mixture.

[0121] (2) Add 2.695 parts of concentrated sulfuric acid and polyether C4 (1170.4 parts) to the intermediate polymer I mixture generated in step (1). Remove volatile small molecules under vacuum, adjust the temperature to 150 °C, stir evenly, and continuously react under vacuum for 6 h, and then stop the reaction.

[0122] (3) Add N-methylpyrrolidone to another reactor, then add 59.86 parts of polyphosphoric acid, 19.58 parts of anhydrous phosphoric acid and 82.5 parts of succinic anhydride thereto. Adjust the temperature to 100 °C and stir to fully dissolve and mix evenly. Adjust the reactor temperature to 120 °C, then add all the samples prepared in step (2) thereto at one time, stir evenly and react for 4 h, and then stop the reaction. Remove volatile organic small molecules under vacuum to obtain the product superplasticizer sample (solid) ME07 with a weight-average molecular weight of 24.7 kDa.

[0123] Example 8

[0124] (1) Add chloroform (958.1 parts) to a reactor, add E1 (109.03 parts), B2 (146.46 parts), B5 (27.85 parts) and G3 (22.08 parts) thereto, stir and mix thoroughly to dissolve. Add 11.09 parts of lithium hydroxide (catalyst) thereto. Adjust the reactor to 60 °C, and continuously and evenly add a solution of E11 (1000 parts) dissolved in 1000 parts of chloroform to the reaction system within 4 h under stirring. After adding, continue to stir evenly and react for 4 h, and then stop the reaction to obtain the intermediate polymer I mixture.

[0125] (2) Add sodium hydroxide (6.24 parts) and polyether C1 (546 parts) to the intermediate polymer I mixture generated in step (1), remove volatile small molecules under vacuum, adjust the temperature to 150 °C, stir evenly and react for 6 h, then stop the reaction.

[0126] (3) Adjust the temperature of the reactor in step (2) to 60 °C, add 7405 parts of chloroform to it (the temperature adjustment is at the boiling point of the solvent), then add 229.32 parts of maleic anhydride, stir to dissolve and then cool down to 30 °C, react evenly for 11 h, and stop the reaction. Remove volatile organic small molecules under vacuum to obtain the superplasticizer sample (solid) ME08, with a weight-average molecular weight of 55.6 kDa.

[0127] Example 9

[0128] (1) Add N,N-dimethylformamide (1440.34 parts) to the reactor, add E4 (74.1 parts), E9 (375 parts) and B3 (168.19 parts) to it, stir well to mix and dissolve, adjust the reactor to 75 °C, stir evenly and react for 6 h, then stop the reaction to obtain the intermediate polymer I mixture.

[0129] (2) Add p-toluenesulfonic acid (monohydrate, 11.4 parts) and polyether C3 (630 parts) to the intermediate polymer I mixture generated in step (1), adjust the temperature to 120 °C, stir evenly and continuously react under vacuum for 12 h, then stop the reaction.

[0130] (3) Add 74.52 parts of phosphorus pentoxide, 40.35 parts of 85% phosphoric acid and 3.40 parts of water to another reactor, adjust the temperature to 100 °C and stir for 1 h to dissolve evenly, then add all the samples prepared in step (2) to it at one time, stir evenly and react for 8 h, then stop the reaction. Remove volatile organic small molecules under vacuum to obtain the superplasticizer sample (solid) ME09, with a weight-average molecular weight of 69.8 kDa.

[0131] Example 10

[0132] (1) Add 1,2-dichloroethane (3099.22 parts) to the reactor, add E1 (90.85 parts), E10 (500 parts), B4 (183.2 parts) and 4.05 g of triethylamine to it, stir well to mix and dissolve, adjust the reactor to 100 °C, stir evenly and react for 2 h, then stop the reaction to obtain the intermediate polymer I mixture.

[0133] (2) Add sodium methoxide (0.169 parts) and polyether C1 (21.875 parts) to the intermediate polymer I mixture generated in step (1), remove volatile small molecules under vacuum, adjust the temperature to 90 °C, stir evenly and react for 12 h. Then add polyether C3 (1050 parts) and potassium tert-butoxide 11.22 parts, adjust the temperature to 120 °C, stir evenly and continuously pass N 2 After the dehydration reaction for 12 h, stop the reaction.

[0134] (3) Add 74.52 parts of phosphorus pentoxide, 13.45 parts of 85% phosphoric acid and 7.43 parts of water to another reactor, adjust the temperature to 100 °C and stir for 0.5 h to fully dissolve and mix evenly. Adjust the reactor temperature to 120 °C, then add all the samples prepared in step (2) at one time, stir evenly and react for 2 h, then stop the reaction. Remove volatile organic small molecules under vacuum to obtain the product superplasticizer sample (solid) ME10, with a weight-average molecular weight of 19.7 kDa.

[0135] Example 11

[0136] (1) Add dichloromethane (3099.22 parts) to the reactor, add E8 (32.243 parts), E3 (23.15 parts), B6 (351.37 parts) and G6 (18.08 parts) and n-hexylamine 7.79 parts (catalyst), stir well to mix and dissolve, stir evenly at room temperature and react for 24 h, then stop the reaction to obtain the intermediate polymer I mixture.

[0137] (2) Add polyether C4 (1085.28 parts) to the intermediate polymer I mixture generated in step (1), remove volatile small molecules under vacuum, then add sodium acetate (8.364 parts), adjust the temperature to 180 °C, stir evenly and continuously pass N 2 After the dehydration reaction for 12 h, stop the reaction.

[0138] (3) Adjust the temperature of the reactor in step (2) to 90 °C, add 97.92 parts of adipic anhydride and 74.97 parts of maleic anhydride, stir to dissolve evenly and react for 8 h, then stop the reaction. Remove volatile organic small molecules under vacuum to obtain the product superplasticizer sample (solid) ME11, with a weight-average molecular weight of 12.6 kDa.

[0139] Example 12

[0140] (1) Add acetonitrile (666.59 parts) to the reactor, add B2 (154.17 parts) and G4 (19.826 parts) thereto, stir well to dissolve, and continuously and uniformly dropwise add a solution of E4 (148.2 parts) dissolved in 300 parts of acetonitrile thereto within 6 h under stirring conditions at room temperature. After the dropping is completed, continue stirring and reacting for 18 h, and then stop the reaction to obtain an intermediate polymer I mixture.

[0141] (2) Add sodium methoxide (1.64 parts) and polyether C3 (840 parts) to the intermediate polymer I mixture generated in step (1), adjust the temperature to 200 °C, stir evenly, and after continuously reacting under vacuum for 3 h, stop the reaction.

[0142] (3) Add 29.02 parts of polyphosphoric acid and 20.35 parts of anhydrous phosphoric acid to another reactor, then add 120 parts of succinic anhydride, adjust the temperature to 120 °C and stir for 1 h to mix evenly, and then add all the samples prepared in step (2) thereto at one time. Adjust the temperature of the reactor to 90 °C, stir to dissolve evenly and react for 6 h, and then stop the reaction. Vacuum remove volatile organic small molecules to obtain a product superplasticizer sample (solid) ME12 with a weight average molecular weight of 46.1 kDa.

[0143] Application Example

[0144] The following uses ordinary cement paste experiments and concrete experiments in different states to illustrate the use effect of the superplasticizer of the present invention.

[0145] All materials are kept at a constant temperature to the required temperature before the experiment. The comparative samples are ordinary commercially available polycarboxylate superplasticizers (commercially available 1 is an ester type, commercially available 2 is an ether type, and the side chain length is 2400). It should be noted that all the percentages expressed below are compared with the better corresponding indicators in the commercially available samples.

[0146] The following experiments measure the fluidity of cement paste in accordance with GB / T8077-2000 "Test Methods for the Homogeneity of Concrete Admixtures", and the relevant test indexes of concrete experiments (slump, spread, bleeding rate, segregation rate, etc.) are measured in accordance with GB50080-2016 "Standard Test Methods for Performance of Ordinary Concrete Mixtures" and JGJ283-2012 "Technical Specification for Application of Self-Compacting Concrete".

[0147] (1) Cement paste

[0148] All dosages of the dispersants are percentages by weight (wt%) of the pure solid relative to the mass of the cement. To characterize the dispersion / dispersion retention performance of the samples at different water-cement ratios, the neat cement paste was prepared with 300 g of cement. The water consumption in Group A was 87 g, and the dosage of the water reducer was fixed to be the same as that of the commercially available product No. 1. The fluidity and its change were compared. The water consumption in Group B was 60 g, and the dosage of the superplasticizer was adjusted to make the initial fluidity of the neat cement paste (240 ± 10) mm. The differences in dosage and fluidity change were compared. The cement was mixed with a mixer to ensure uniformity.

[0149] Based on the standard mixing process of the neat cement paste, the fluidity of the neat cement paste with different superplasticizers was tested, and the fluidity of the neat cement paste after standing for 30 min was also tested. The samples prepared in the examples were compared with the commercially available polycarboxylate superplasticizer samples, and the results are as follows:

[0150] Table 2 Test results of the neat cement paste (20 °C)

[0151]

[0152]

[0153] As can be seen from the results in Table 2, the dispersion ability of the superplasticizers prepared in the examples of the present invention is related to the structural parameters, and there are high and low values. Compared with the commercially available samples, under the condition of a higher water-cement ratio (lower dosage, Group A), the initial water-reducing and slump-retention abilities of ME08 are comparable to those of the commercially available product, and the initial dispersion abilities of ME01, ME02, and ME11 are basically comparable to those of the commercially available samples. The fluidity retention ability is improved to varying degrees. The other samples lead the commercially available samples to varying degrees in terms of initial water reduction. Under the condition of a lower water-cement ratio (higher dosage, Group B), the situation is slightly different from that of Group A. The water-reducing ability of ME01 is still comparable to that of the commercially available sample. The water reduction of the ME04 sample changes from leading in Group A to being comparable to that of the commercially available sample in Group B. All other samples lead the commercially available samples to varying degrees, and the dosage savings can reach 3.4 - 15.5% when the same fluidity is achieved. The fluidity retention ability of all samples is not weaker than that of the commercially available samples.

[0154] (2) Conventional concrete

[0155] The concrete mix proportion is as follows:

[0156] Table 3 Concrete mix proportion (kg / m 3 )

[0157] Cement Fly ash Sand Crushed stone Water 280 70 780 1060 170

[0158] Onoeda Cement (P II 52.5), Class F Grade I fly ash from Nanjing Thermal Power Plant is used, natural river sand is used as sand, with a fineness modulus of 2.6 and a mud content of 1.8%, and continuously graded basalt gravel with a particle size range of 5 - 25 mm is used as crushed stone. The dosages of superplasticizer PCE - ME01 - 12, commercially available product 1, and commercially available product 2 are calculated based on the solid content with respect to the cementitious materials (unit: mass per thousand, ‰bwoc). During the test, the slump flow of the concrete is controlled to be equivalent ((60 ± 2) cm) by adjusting the dosage of the superplasticizer. This fluidity is close to bleeding for many conventional mix - proportioned concretes.

[0159] The defoamer used is the commercially available ordinary conventional PXP - I concrete defoamer from Jiangsu Sobute New Materials Co., Ltd., and the air content of each group of concrete is controlled to be basically the same by the defoamer.

[0160] After adding all the materials into the mixer, the slump, slump flow, and the emptying time of the slump cone (T f ) of the concrete after mixing for 2 minutes are respectively tested. The slump and slump flow of the concrete are respectively tested and recorded as "initial / out - of - machine" and the dosage of the superplasticizer used. The state of the concrete is observed and recorded. After the out - of - machine concrete is left standing for 60 minutes, its slump and slump flow are measured. The results are shown in the following table:

[0161] Table 4 Concrete test results

[0162]

[0163]

[0164] As can be seen from the results in Table 4, compared with the commercially available samples, the water - reducing and fluidity - retaining abilities of ME01 - ME12 are equivalent to or slightly better than those of the commercially available samples. Importantly, the workability of the commercially available samples is significantly worse under the test conditions, and there are obvious separation conditions of different degrees between the paste and the gravel. Commercially available product 2 is better than commercially available product 1, but during the slump flow test, the gravel cannot be evenly carried by the paste to flow, resulting in a pile of stones in the middle of the concrete. The homogeneity of the concrete of samples ME01 - ME12 is significantly improved, and the bleeding rate is reduced by 25% - 72%.

[0165] Due to the significant improvement in the homogeneity of the concrete, when testing the emptying time of the slump cone, the time of the concrete prepared with ME01 - ME12 is significantly shortened. For the commercially available samples, the gravel in the concrete is prone to sedimentation and aggregation, so the emptying time of the slump cone is significantly prolonged.

[0166] (3) Manufactured - sand concrete

[0167] The concrete mix - proportion is as follows:

[0168] Table 5 Concrete mix - proportion (kg / m 3 )

[0169]

[0170] Conch Cement (P·O42.5), Class F Grade I fly ash from Nanjing Thermal Power Plant, the sand is limestone manufactured sand (fineness modulus 3.1, MB value 0.8, powder content 4.4%), and the crushed stone uses continuously graded basalt crushed stone with a particle size range of 5 - 25 mm. The dosages of superplasticizer PCE - ME01 - 12, Commercial 1, and Commercial 2 are calculated based on the solid content by weight of the binder (unit: per thousand by weight of binder, ‰bwoc). During the test, the slump flow of the concrete (55 - 60 cm) is controlled to be equivalent by adjusting the dosage of the superplasticizer.

[0171] The defoamer used is the commercially available ordinary conventional PXP - I concrete defoamer from Jiangsu Sobute New Materials Co., Ltd., and the air content of each group of concrete is controlled to be basically the same by the defoamer.

[0172] After adding all the materials into the mixer, the initial slump, slump flow, bleeding rate, and segregation rate of the concrete after stirring for 2 min are respectively tested. After the concrete discharged from the mixer is left standing for 40 min, its slump and slump flow are measured.

[0173] Table 6 Concrete test results

[0174]

[0175] * indicates almost no bleeding.

[0176] In this concrete, manufactured sand is used, which contains 4.4% of fine powder. At the same time, the binder content is increased and the aggregate content is decreased. The state of the concrete has been improved compared with the previous group of experiments, but the loss of the concrete is slightly accelerated. The segregation rate is used to represent the stability of the concrete. Similarly, in the presence of a small amount of stone powder, when ME01 - ME12 reaches the same initial slump flow, the dosage of the water - reducing agent is basically equivalent to or slightly less than that of the commercial products. The fluidity retention of a few samples has an obvious advantage, and the fluidity retention level of most samples is basically the same as that of Commercial 1.

[0177] Comparing the bleeding rate of the concrete, the bleeding rate of the concrete prepared with ME01 - ME12 decreases by more than 70%, and the segregation rate decreases by 27 - 55%. Here, the segregation rate reflects the ability of the paste to adhere to the aggregate under forced conditions. When the segregation rate decreases, the degree of non - uniformity of the concrete caused by the settlement of the aggregate is significantly reduced, proving that the stability of the concrete is significantly improved.

[0178] All the superplasticizers tested have no negative impact on the strength, and are at the same level as the commercial samples, with the deviation within the test error range.

[0179] (4) Self - compacting concrete

[0180] The concrete mix proportion is as follows:

[0181] Table 7 Concrete Mix Ratio (kg / m 3 )

[0182] Cement Fly ash Ground granulated blast-furnace slag Sand Gravel Water 312 96 72 790 967 163

[0183] Conch Cement (P·O 42.5), S95 slag powder, and fly ash are Class F Grade I fly ash from Nanjing Thermal Power Plant. The sand is ordinary river sand with a fineness modulus of 2.6, and the basalt gravel has a continuous gradation of 5 - 20 mm (mud content 1.8%). The dosages of superplasticizer PCE - ME01 - 12, Commercial 1, and Commercial 2 are calculated based on the solid content with respect to the binder (unit: mass per thousand, ‰bwoc). During the test, the slump flow of the concrete was controlled to be equivalent (62 - 67 cm) by adjusting the dosage of the superplasticizer. The defoamer used was the commercially available ordinary conventional PXP - I concrete defoamer from Jiangsu Sobute New Materials Co., Ltd., and the air content of each group of concrete was controlled to be basically the same by the defoamer.

[0184] After adding all the materials into the mixer, the slump flow and the slump cone evacuation time (T f ) of the concrete were measured after stirring for 2 min, and the slump flow, air content, bleeding rate, and segregation rate of the concrete were measured respectively. The initial homogeneity of the concrete was mainly concerned.

[0185] Table 8 Concrete Test Results

[0186]

[0187]

[0188] * indicates almost no bleeding.

[0189] In this case, the dosage of the concrete binder was significantly increased, and the dosage of the aggregate was further decreased. To improve the state of the concrete itself and ensure its self - compacting ability, the slump flow of the concrete can reach about 65 cm. The overall bleeding rate of the concrete in this case was significantly reduced. Compared with the commercially available reference samples, for most samples with the same fluidity, the dosage of ME01 - ME12 can be saved by 2 - 9%. Under the condition of equivalent air content, the bleeding rate of the concrete can be reduced by more than 80%, and the segregation rate can be reduced by 29 - 61%. The 28 - day strength of the concrete prepared from all the test samples was basically the same.

Claims

1. A superplasticizer, characterized in that, the superplasticizer comprises a main chain and grafted side chains, the main chain of which contains a branched structure generated by the addition of active H sites to unsaturated esters or unsaturated amides, and polyether side chains are grafted through the end functional groups of the main chain, and adsorption groups are connected to the main chain structure by an acidifying reagent; the main chain of the superplasticizer is a structure containing functional groups and branched structures represented by the following general formulas (0-1), (0-2) and (0-3), wherein R 51 , R 52 , R 53 and R 54 each independently represents H or -CH 3 , X 21 , X 22 , X 23 and X 24 each independently represents an -O- or -NH- functional group; " " means covalently connected to other structures; the main chain of the superplasticizer is connected with carboxyl groups and phosphate groups, formed by the reaction of hydroxyl groups and amino groups with an acidifying reagent; the grafted side chains of the superplasticizer are poly(ethylene glycol-isopropoxy) ether structures substituted with saturated alkyl groups or phenyl groups at the ends, and are connected to the main chain of the superplasticizer through ring-opening of epoxy groups, transesterification of hydroxyl groups, esterification or amidation of carboxyl groups; the weight-average molecular weight range of the superplasticizer is 10,000 - 100,000.

2. A preparation method of the superplasticizer according to claim 1, characterized in that, the superplasticizer is prepared through three steps, including Michael addition, side-chain grafting and adsorption group modification, and the preparation method is as follows: (1) Michael addition: A small molecule A containing active functional groups reacts with an unsaturated monomer B under the action of a catalyst to carry out a Michael addition reaction to form an intermediate polymer I containing multiple branched structures with multiple hydrogen-bond-forming functional groups; the small molecule A containing active functional groups is an amine, polyhydroxyamine, polythiol or amino acid ester with carboxyl esterified containing two or more active H sites; the active H site refers to the -NH- or -SH functional group structure, and a primary amine functional group is regarded as containing two active H sites; the unsaturated monomer B contains no less than two unsaturated ester or unsaturated amide bond functional groups; (2) Side-chain grafting: A polyether C with functional groups reacts with the intermediate polymer I prepared in step (1) and connects the polyether side chain to the intermediate polymer I to obtain a polymer II; the polyether C is one or any mixture of more than one conforming to general formula (5-1) or (5-2) or (5-3), wherein R 6 , R 7 and R 8 each independently represents a saturated alkyl group having 1 to 6 carbon atoms or a phenyl group, R 9 represents -OH or -NH 2 , X represents -(CH 2 ) n -CO-, n is an integer from 2 to 4, Y represents -O- or -NH-; in the structures shown, c, e, g and d, f, h respectively independently represent the number of repeating units of ethoxy and isopropoxy in their respective general formulas, the sum of the number of repeating units of ethoxy and isopropoxy in each of the above general formulas is 8 to 114, and the proportion of the number of repeating units of isopropoxy in the sum of the number of repeating units of ethoxy and isopropoxy is not more than 1 / 3. The structures shown in general formula (5-1) or (5-2) or (5-3) do not limit the connection order of the repeating units of ethoxy and isopropoxy, and they are block or random; (3) Adsorption group modification: The remaining surplus hydroxyl groups or amino groups in the polymer II prepared in step (2) react with an acidifying reagent D to connect the adsorption group to the polymer II to obtain the superplasticizer; the acidifying reagent D is any one or any mixture of more than one of dianhydrides or phosphorylating reagents.

3. According to the preparation method of the superplasticizer according to claim 2, characterized in that, the unsaturated ester bond in the unsaturated monomer B is derived from acrylate or methacrylate monomers, and the unsaturated amide bond is derived from acrylamide or methacrylamide monomers.

4. According to the preparation method of the superplasticizer according to claim 3, characterized in that, the specific steps are as follows: (1) Add a solvent S1, a small molecule A containing active functional groups, an unsaturated monomer B, a regulator G and a catalyst M1 to a reactor, and stir and react under certain conditions to obtain a mixture of the intermediate polymer I; The regulator G is a mixture of component G-A and G-B in any proportion, where component G-A is an organic small molecule containing only 2-6 carbon atoms, without unsaturated bonds, and having only one active H site, and component G-B is any one small molecule or a mixture of more than one small molecule conforming to the following general formula (4): Among them, R 10 represents H or -CH 3 , R11 represents a functional group containing no more than 6 carbon atoms, no unsaturated bonds, no active H sites, no elements other than carbon, hydrogen, oxygen, and nitrogen, and the terminal is connected to the carbonyl group in the structure shown by the general formula (4) through -O- or -NH- or a tertiary amine functional group; The total mass of the small molecule A with active functional groups, the unsaturated monomer B, and the regulator G accounts for 20-60% of the total mass of the reaction system, and the dosage of the regulator G accounts for 0-50% of the total molar amount of the small molecule A with active functional groups and the unsaturated monomer B; the molar ratio range of the small molecule A with active functional groups and the unsaturated monomer B is 0.25-4; (2) Add the polyether C with functional groups and the catalyst M2 to the mixture of the intermediate polymer I generated in step (1), vacuum-remove the volatile components, and then stir and react under certain conditions to obtain a mixture of polymer II; (3) In the presence or absence of the solvent S2, add the acidifying reagent D to the reactor, add all of the product in step (2), i.e., the mixture of polymer II, stir and react under certain conditions, and then vacuum-remove the volatile organic small molecules to obtain the superplasticizer sample; or dissolve in water after removing the small molecules, and neutralize to obtain the superplasticizer solution of the product.

5. The preparation method of a superplasticizer according to claim 4, characterized in that, The small molecule A with active functional groups in step (1) is a composition of E and F in any proportion, and the sum of the average molar number of hydroxyl groups and the molar number of ester functional groups per molecule of A is not less than 1; and the amount of component E cannot be 0, and the average molar number of hydroxyl groups per molecule of component E is not less than 1; Wherein component E is an organic small molecule containing 2-8 carbon atoms, without unsaturated bonds, containing two or more active H sites, and not containing any other elements except carbon, hydrogen, oxygen, nitrogen, and sulfur, or an amino polyether molecule conforming to the structure shown in the following general formula (1), or any mixture of more than one of the above organic small molecules and amino polyethers: Where a and b respectively represent the number of repeating units of ethoxy and isopropoxy, which are or are not integers, the value range of (a + b) is 8-114, and b / (a + b) is not greater than 1 / 3. The structure shown in general formula (1) does not limit the connection order of the repeating units of ethoxy and isopropoxy, which is block or random; The component F is any one small molecule conforming to the following general formula (2) or a mixture of one or more of its hydrochloride or sulfate salts: Among them, R 1 represents a saturated alkyl group containing 1 to 4 carbon atoms, and R 2 represents the functional group structure of H, the R group of natural amino acid I, or the methyl ester, ethyl ester, or propyl ester formed by the R group of natural amino acid II. The R group is the remaining group after removing -CH- connected to both the amino group and the carboxyl group and the directly connected amino group and carboxyl group in the natural amino acid. When the R group contains a carboxyl group, the carboxyl group contained in the R group of the natural amino acid is esterified to form the functional group structure of the methyl ester, ethyl ester, or propyl ester; the natural amino acid I is a natural amino acid whose R group does not contain a carboxyl group, and the natural amino acid II is a natural amino acid whose R group contains a carboxylic acid; any carbon atom in the small molecule represented by the general formula (2) is not limited in chirality.

6. The preparation method of a superplasticizer according to claim 5, characterized in that, The organic small molecules in component E are selected from saturated thiols or polythiols, saturated amines or polyamines.

7. The preparation method of a superplasticizer according to claim 4, characterized in that, The unsaturated monomer B is any one small molecule or a mixture of more than one small molecule conforming to the structure shown in the following general formula (3): where m represents a positive integer with a value range of 2 - 6, R 3 represents H or -CH 3 ; R 4 The functional group represented does not contain any elements other than carbon, hydrogen, oxygen, and nitrogen, contains 2 - 10 carbon atoms, does not contain unsaturated bonds, does not contain active H sites, and the -O- or -NH- or tertiary amine functional group is directly connected to each carbonyl group within the parentheses of the general formula (3). At the same time, in each small molecule represented by the general formula (3), the functional group within the parentheses connected to R 4 is the same or different.

8. The preparation method of a superplasticizer according to claim 7, characterized in that, The organic small molecule represented by the general formula (3) is a commercially available product or is prepared by dehydration condensation of acrylic acid, methacrylic acid and an organic small molecule containing 2-10 carbon atoms, without unsaturated bonds, and the total number of hydroxyl groups, primary amine groups and secondary amine groups is between 2-6 and does not contain any other elements except carbon, hydrogen, oxygen and nitrogen, and a dehydrating condensing agent is used for the dehydration condensation reaction.

9. The preparation method of a superplasticizer according to claim 5, wherein, in step (2), the dosage of polyether C needs to meet the following conditions: the molar amount of the polyether conforming to the structures shown in the general formula (5-1) and the general formula (5-2) accounts for no less than 10% and no more than 60% of the total molar amount of hydroxyl groups in the active functional group small molecule A, the unsaturated monomer B and the regulator G; the molar amount of the polyether conforming to the structure shown in the general formula (5-3) is not higher than 1.1 times the total molar amount of ester bonds in the component F and the regulator G.

10. The preparation method of a superplasticizer according to claim 4, wherein, the dianhydride is selected from one or a mixture of more than one of succinic anhydride, glutaric anhydride, adipic anhydride and maleic anhydride; the phosphorylation reagent is one or a mixture of more than one of phosphoric acid, polyphosphoric acid, pyrophosphoric acid, phosphorus pentoxide and water, which is a mixture prepared by the reaction of the acid anhydride of phosphoric acid with water, and the ratio of the total molar amount of H to the total molar amount of P in the phosphorylation reagent is between 1-1.5; the molar amount of hydrogen element in the phosphorylation reagent is denoted as n(H), the molar amount of phosphorus element is denoted as n(P), and its effective phosphorylation equivalent is calculated as [1.5n(P) - 0.5n(H)], then the sum of the molar amount of the dianhydride and the effective phosphorylation equivalent, that is, the dosage of the acidifying reagent D is equivalent to 0.5-1.5 times the difference between the total molar amount of hydroxyl groups in the active functional group small molecule A, the unsaturated monomer B and the regulator G and the molar amount of the polyether conforming to the structure shown in the general formula (5-2).

11. The preparation method of a superplasticizer according to any one of claims 4 to 8, wherein, the temperature range of the stirring reaction in step (1) is 0-100 °C, the reaction time is 1-24 h, and the dosage of the catalyst M1 used accounts for 0-20% of the total molar amount of all reactants; the catalyst M1 is selected from formic acid, acetic acid, lithium hydroxide, sodium hydroxide, the alcohol sodium corresponding to the organic alcohol with a saturated alkyl group containing 1-12 carbon atoms, or any one of the structures shown in the following general formula (6-1) or general formula (6-2): In general formula (6-1), R 16 , R 17 , R 18 each independently represents H or a saturated alkyl group having 1 to 6 carbon atoms. In general formula (6-2), R 13 , R 14 , R 15 each independently represents H, a saturated alkyl group having 1 to 6 carbon atoms, phenyl, cyclohexyl, cyclopentyl, phenyl substituted with a saturated alkyl group having 1 to 3 carbon atoms, cyclohexyl substituted with a saturated alkyl group having 1 to 3 carbon atoms, or cyclopentyl substituted with a saturated alkyl group having 1 to 3 carbon atoms; the solvent S1 is dichloromethane, chloroform, tetrahydrofuran, dioxane, N,N-dimethylformamide, N,N-dimethylacetamide, 1,2-dichloroethane, dimethyl sulfoxide, acetonitrile or N-methylpyrrolidone.

12. The preparation method of a superplasticizer according to claim 4 or 9, wherein, in step (2), when the polyether C is the component shown in the general formula (5-1), the reaction temperature is 60-150 °C and the reaction time is 2-24 h; When the polyether C is a component having the structure shown in the general formula (5-2), the "certain conditions" are that N is continuously introduced in the presence of the catalyst M2 2 or a vacuum is maintained, the reaction temperature is 100-200 °C, and the reaction time is 3-24 h; the catalyst M2 is a Lewis acid, a Bronst acid or a Lewis base; When the polyether C is a component having the structure shown in the general formula (5-3), the "certain conditions" are that N is continuously introduced in the presence of a catalyst 2 or a vacuum is maintained, the reaction temperature is 80-200 °C, and the reaction time is 3-24 h; the catalyst M2 is an acid or a base; When the polyether C contains both the component with the structure shown in the general formula (5-1) and the component with the structure shown in the general formula (5-2) or the general formula (5-3), the catalyst M2 used in step (2) is unified as a strong base, and the reaction is carried out in two stages. In the first stage, the reaction of the component with the structure shown in the general formula (5-1) is carried out at a temperature of 60-150 °C for a reaction time of 2-24 h; then the reaction of the component with the structure shown in the general formula (5-2) or the general formula (5-3) is carried out. The reaction of the components with the structures shown in the general formula (5-2) and the general formula (5-3) can be carried out in stages or simultaneously. When the reaction is carried out simultaneously, the above reaction conditions need to be satisfied simultaneously. The total amount of the catalyst M2 used in step (2) accounts for 0-20% of the total molar amount of the polyether C used in step (2); the amount of the catalyst used in each stage accounts for 0-20% of the molar amount of the corresponding polyether.

13. A method for preparing a superplasticizer according to claim 12, characterized in that, when the polyether C is the component with the structure shown in the general formula (5-1), the catalyst M2 is sodium metal, sodium hydride, sodium methoxide, sodium hydroxide, potassium hydroxide, or sodium alkoxide or potassium alkoxide corresponding to an organic alcohol with a saturated alkyl group having 1-12 carbon atoms; when the polyether C is the component with the structure shown in the general formula (5-2), the catalyst M2 is any one of p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, sodium acetate, potassium acetate, sodium hydroxide, potassium hydroxide, or sodium alkoxide or potassium alkoxide corresponding to an organic alcohol with a saturated alkyl group having 1-12 carbon atoms; when the polyether C is the component with the structure shown in the general formula (5-3), the catalyst M2 is any one of p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, sodium acetate, potassium acetate, sodium hydroxide, potassium hydroxide, or sodium alkoxide or potassium alkoxide corresponding to an organic alcohol with a saturated alkyl group having 1-12 carbon atoms; when the polyether C contains both the component with the structure shown in the general formula (5-1) and the component with the structure shown in the general formula (5-2) or the general formula (5-3), the catalyst M2 is any one of sodium metal, sodium hydride, sodium methoxide, sodium hydroxide, potassium hydroxide, or sodium alkoxide or potassium alkoxide corresponding to an organic alcohol with a saturated alkyl group having 1-12 carbon atoms.

14. A method for preparing a superplasticizer according to claim 4 or 10, characterized in that, the amount of the solvent S2 used in step (3) needs to meet the following conditions: at the reaction temperature, ensure that the acidifying reagent D and the entire reaction system are in a solution or liquid state rather than a frozen or insoluble other state; the solvent S2 used in step (3) is chloroform, tetrahydrofuran, dioxane, N,N-dimethylformamide, acetonitrile, N,N-dimethylacetamide, dimethyl sulfoxide, or N-methylpyrrolidone; the reaction conditions in step (3) are 20-120 °C, the reaction time is 2-12 h, and this reaction is carried out under anhydrous conditions.

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