阅读说明：本技术 一种高效抑泥型聚羧酸减水剂及其制备方法 (Efficient mud-inhibiting type polycarboxylate superplasticizer and preparation method thereof ) 是由 唐新德 陈晓东 张翠珍 郭童新 卢晓 庞来学 董福营 于 2021-01-27 设计创作，主要内容包括：本发明公开了一种高效抗泥型聚羧酸减水剂及其制备方法,由不饱和聚醚单体与不饱和羧酸单体本体共聚,再通过与多胺类化合物的酰胺化反应制得；其中不饱和聚醚单体、不饱和羧酸单体、多胺类化合物的摩尔比为1:3～5:0.3～2.5；所述减水剂中含有的催化剂用量、引发剂用量、链转移剂用量分别为不饱和聚醚单体和不饱和羧酸单体总质量的0.03～0.3％,0.5～1.5％,0.3～1.5％。实验证实本发明的聚羧酸减水剂具有优异的减水分散效果,在较低掺量下仍能表现出较好的流动性和保持能力,在混凝土原材料含泥量较高的情况下,较普通聚羧酸减水剂具有明显优势。(The invention discloses a high-efficiency anti-mud polycarboxylic acid water reducing agent and a preparation method thereof, which is prepared by copolymerizing an unsaturated polyether monomer and an unsaturated carboxylic acid monomer and then carrying out amidation reaction with a polyamine compound; wherein the molar ratio of the unsaturated polyether monomer to the unsaturated carboxylic acid monomer to the polyamine compound is 1: 3-5: 0.3-2.5; the amount of the catalyst, the amount of the initiator and the amount of the chain transfer agent in the water reducing agent are respectively 0.03-0.3%, 0.5-1.5% and 0.3-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer. Experiments prove that the polycarboxylate superplasticizer disclosed by the invention has an excellent water reducing and dispersing effect, can still show better fluidity and retention capacity under a lower mixing amount, and has obvious advantages compared with a common polycarboxylate superplasticizer under the condition of higher mud content of a concrete raw material.)

1. A high-efficiency anti-mud polycarboxylic acid water reducing agent is prepared by copolymerizing an unsaturated polyether monomer and an unsaturated carboxylic acid monomer body and then carrying out amidation reaction with a polyamine compound; the water reducer is characterized by comprising the following main components in percentage by weight: the molar ratio of the unsaturated polyether monomer, the unsaturated carboxylic acid monomer and the polyamine compound is 1 (3-5) to 0.3-2.5; the amount of the catalyst contained in the water reducing agent is 0.03-0.3% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of the initiator is 0.5-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of the chain transfer agent is 0.3-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is one or a combination of more of 3-methyl-3-butylene-1-polyoxyethylene ether, allyl polyoxyethylene ether and 2-methylallyl polyoxyethylene ether in any molar ratio; the unsaturated carboxylic acid monomer is one or a combination of more of acrylic acid, methacrylic acid, itaconic acid and maleic acid in any molar ratio; the polyamine compound is one or a combination of more of diethylenetriamine, triethylene tetramine, tetraethylene pentamine and polyethylene polyamine in any molar ratio; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate, cumene hydroperoxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate or benzoyl peroxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptopropanol, 3-mercaptopropanol or n-dodecyl mercaptan.

2. The high-efficiency anti-mud polycarboxylic acid water reducer according to claim 1, characterized in that: the water reducing agent comprises the following main components in percentage by weight: the molar ratio of the unsaturated polyether monomer to the unsaturated carboxylic acid monomer to the polyamine compound is 1:4: 1.5; the amount of a catalyst contained in the water reducing agent is 0.1-0.3% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of an initiator is 1.0-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of a chain transfer agent is 1.0-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is 3-methyl-3-butylene-1-polyoxyethylene ether, allyl polyoxyethylene ether or 2-methylallyl polyoxyethylene ether; the unsaturated carboxylic acid monomer is acrylic acid, methacrylic acid, itaconic acid or maleic acid; the polyamine compound is diethylenetriamine, triethylene tetramine, tetraethylene pentamine or polyethylene polyamine; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate, cumene hydroperoxide, tert-butyl peroxybenzoate or benzoyl peroxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid or 3-mercaptopropanol.

3. The high-efficiency anti-mud polycarboxylic acid water reducer according to claim 2, characterized in that: the amount of a catalyst contained in the water reducing agent is 0.2-0.25% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of an initiator is 1.0-1.35% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of a chain transfer agent is 1.0-1.35% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is 3-methyl-3-butylene-1-polyoxyethylene ether or 2-methylallyl polyoxyethylene ether; the unsaturated carboxylic acid monomer is acrylic acid or methacrylic acid; the polyamine compound is diethylenetriamine, triethylene tetramine or tetraethylene pentamine; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate or cumene hydroperoxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid or 3-mercaptopropionic acid.

4. The preparation method of the high-efficiency anti-mud polycarboxylate superplasticizer of claim 1 comprises the following steps:

adding an unsaturated polyether monomer into a reactor, heating to 50-80 ℃ to enable the unsaturated polyether monomer to be in a molten state, adding a catalyst, and uniformly stirring; dropwise adding a mixed solution consisting of an unsaturated carboxylic acid monomer, an initiator and a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is completed within 1-3 h; continuously heating the product to 140-160 ℃, dropwise adding the polyamine compound while stirring, and finishing dropping within 2-5 h; after the dropwise addition is finished, cooling to 50-70 ℃, preserving heat for 1-2 h, and then adding a sodium hydroxide solution to adjust the pH value to 5-7, so as to obtain the high-efficiency anti-mud polycarboxylic acid water reducer; wherein the molar ratio of the unsaturated polyether monomer, the unsaturated carboxylic acid monomer and the polyamine compound is 1 (3-5) to 0.3-2.5; the amount of the catalyst contained in the water reducing agent is 0.03-0.3% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of the initiator is 0.5-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of the chain transfer agent is 0.3-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is one or a combination of more of 3-methyl-3-butylene-1-polyoxyethylene ether, allyl polyoxyethylene ether and 2-methylallyl polyoxyethylene ether in any molar ratio; the unsaturated carboxylic acid monomer is one or a combination of more of acrylic acid, methacrylic acid, itaconic acid and maleic acid in any molar ratio; the polyamine compound is one or a combination of more of diethylenetriamine, triethylene tetramine, tetraethylene pentamine and polyethylene polyamine in any molar ratio; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate, cumene hydroperoxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate or benzoyl peroxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptopropanol, 3-mercaptopropanol or n-dodecyl mercaptan.

5. The preparation method of the high-efficiency anti-mud polycarboxylate superplasticizer according to claim 4 comprises the following steps:

adding an unsaturated polyether monomer into a reactor, heating to 60-70 ℃ to enable the unsaturated polyether monomer to be in a molten state, adding a catalyst, and uniformly stirring; dropwise adding a mixed solution consisting of an unsaturated carboxylic acid monomer, an initiator and a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is completed within 2-3 h; continuously heating the product to 150-160 ℃, dropwise adding the polyamine compound while stirring, and finishing dropping within 2-4 h; after the dropwise addition is finished, cooling to 50-60 ℃, preserving heat for 1.5-2 h, and then adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer; wherein the molar ratio of the unsaturated polyether monomer to the unsaturated carboxylic acid monomer to the polyamine compound is 1:4: 1.5; the amount of a catalyst contained in the water reducing agent is 0.1-0.3% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of an initiator is 1.0-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of a chain transfer agent is 1.0-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is 3-methyl-3-butylene-1-polyoxyethylene ether, allyl polyoxyethylene ether or 2-methylallyl polyoxyethylene ether; the unsaturated carboxylic acid monomer is acrylic acid, methacrylic acid, itaconic acid or maleic acid; the polyamine compound is diethylenetriamine, triethylene tetramine, tetraethylene pentamine or polyethylene polyamine; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate, cumene hydroperoxide, tert-butyl peroxybenzoate or benzoyl peroxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid or 3-mercaptopropanol.

6. The preparation method of the high-efficiency anti-mud polycarboxylate superplasticizer according to claim 5, which is characterized by comprising the following steps: the amount of a catalyst contained in the water reducing agent is 0.2-0.25% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of an initiator is 1.0-1.35% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of a chain transfer agent is 1.0-1.35% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is 3-methyl-3-butylene-1-polyoxyethylene ether or 2-methylallyl polyoxyethylene ether; the unsaturated carboxylic acid monomer is acrylic acid or methacrylic acid; the polyamine compound is diethylenetriamine, triethylene tetramine or tetraethylene pentamine; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate or cumene hydroperoxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid or 3-mercaptopropionic acid.

Technical Field

The invention relates to a high-efficiency mud-inhibiting type polycarboxylate superplasticizer and a preparation method thereof, belonging to the technical field of concrete admixtures.

Background

The polycarboxylate superplasticizer has the advantages of low mixing amount, high water reducing rate, good slump retaining performance, strong molecular structure adjustability, large high-performance potential and the like, and becomes a third-generation high-performance concrete water reducer. The polycarboxylate water reducing agent is a comb-shaped high molecular polymer and consists of a main chain rich in carboxylic acid groups and polyoxyethylene side chains, wherein the carboxyl groups on the main chain can be directionally adsorbed on the surface of positively charged cement or cement hydrate, and the polyoxyethylene side chains extend in a solution to form a hydration layer to provide a spatial repulsive force to avoid preventing cement agglomeration, so that good fluidity is given to cement slurry.

The aggregate is the main component of the concrete, and the quality of the aggregate directly influences the performance (such as workability, strength, durability and the like) of the concrete after being newly mixed and hardened. The polycarboxylate superplasticizer is very sensitive to the mud content of concrete aggregate, influences the slump and slump loss of concrete, and has great influence on strength when the mud content of the aggregate exceeds 3%. It is generally believed that the mechanism of action of the polycarboxylate water reducer with the clay includes adsorption and intercalation. The interlayer structure of the silt particle can adsorb a large amount of water reducing agent molecules, so that the part of the water reducing agent used for dispersing cement particles after being adsorbed by the silt particle is reduced, and the dispersibility is poor. Under the condition of high sand and stone content, the condition of fresh concrete can be improved, and the requirements of strength, durability and the like of hardened concrete can be met, so that the method is a hot and difficult point in the field of research and development and application of the polycarboxylic acid water reducing agent in recent years.

Cation is introduced into the molecular structure of the traditional polycarboxylic acid water reducing agent to play a role in inhibiting mud. Patent CN104119482A discloses a mud-inhibiting type polycarboxylate water reducer, and its main design thought is to introduce unsaturated quaternary ammonium salt constitutional unit in the polycarboxylate structure, reduces the absorption of clay to polycarboxylate water reducer through the effect of cation constitutional unit, and cation constitutional unit adsorbs on the clay surface, and the polycarboxylate main chain adsorbs on cement and hydration product surface, and anti mud type polycarboxylate connects on clay and cement-based material surface and realizes its anti mud purpose through the bridging. Patent CN103467670 discloses a mud-resistant polycarboxylic acid water reducing agent, which adopts self-synthesized quaternary ammonium salt oligomer to polymerize with TPEG and monounsaturated carboxylic acid, etc. free radicals, and provides cation structural units through the quaternary ammonium salt oligomer to realize mud resistance. The patent CN111892685A discloses a mud-resistant polycarboxylate superplasticizer and a preparation method thereof, which is a copolymer prepared by polymerizing unsaturated polyether macromonomer, unsaturated cationic functional monomer containing glucosyl group and acrylic acid serving as raw materials through free radical copolymerization reaction in the presence of an initiator and a chain transfer agent, wherein the molecular side chain of the polycarboxylate superplasticizer contains glucosyl group and quaternary ammonium salt group, and has stronger adsorption capacity than the existing polycarboxylate superplasticizer. Patent CN105199032A provides a super early strength polycarboxylate water reducing agent, which is synthesized by taking an active macromonomer as a raw material, and when the steric effect of the water reducing agent is further improved, cations are introduced into molecules, so that the water reducing rate, the mud resistance and the adaptability to cement of the water reducing agent are improved. Patent CN104177561A discloses a preparation method of a polycarboxylate water reducer with slow release property and mud resistance, which synthesizes a mud-resistant ether ester copolymerized polycarboxylate water reducer product capable of slowly releasing anions and cations non-ions, the molecular structure of the product contains an ester group and an amide group which are unstable in a cement strong alkali environment, and amine cations generated by hydrolysis of the amide group have a sealing effect on mud with negative charges, so that a mud-resistant effect is achieved.

The clay inhibiting effect can also be realized by compounding the compound with the clay inhibiting effect and the polycarboxylic acid water reducing agent. The patent CN108997146A discloses a novel gemini quaternary ammonium salt anti-mud agent and a preparation method and application thereof, and the novel gemini quaternary ammonium salt anti-mud agent has the structural characteristics that two symmetrical alkyl tertiary amines are connected at two ends of dibromide benzyl through quaternization reaction, the anti-mud property of cement can be improved by compounding the novel gemini quaternary ammonium salt anti-mud agent with a polycarboxylic acid water reducing agent, the anti-mud time is long, the stability is good, the safety and the environmental protection are realized, and the novel gemini quaternary ammonium salt anti-mud. CN103723941A discloses a clay inhibitor used in combination with a polycarboxylic acid water reducing agent, which is a cationic nitrogen-containing low molecular weight copolymer prepared by the free radical copolymerization reaction of a quaternary ammonium type cationic monomer, a monomer containing primary, secondary or tertiary amine and a crosslinking type monomer in an aqueous solution. The clay inhibitor can effectively ensure or improve the initial dispersing ability and the dispersion maintaining ability of the polycarboxylate superplasticizer under the condition of higher mud content, and simultaneously does not influence the setting time, the gas content, the strength and other properties of concrete.

The steric hindrance effect can be utilized to play a role in inhibiting mud. Patent CN107652376A discloses a reticular mud-resistant quaternary ammonium salt polycarboxylate water reducer, which is prepared by adding quaternary ammonium salt containing epoxy group into polymer containing amino group, then adding dianion compound and quaternary ammonium salt cation to form ion pair to obtain reticular intermediate, and then adding polycarboxylate water reducer to form reticular mud-resistant quaternary ammonium salt polycarboxylate water reducer with semi-interpenetrating reticular structure. CN109265052A discloses a preparation method of a cross-linking viscosity-reduction type polycarboxylate superplasticizer, which is characterized in that phosphate radicals, carboxylate radicals, quaternary ammonium salts and ester groups are introduced into a polymer molecular structure, and the polymer structure is also lightly cross-linked.

The mud-inhibiting type polycarboxylate superplasticizer achieves the mud-inhibiting effect by introducing a functional monomer with the mud-inhibiting effect or compounding the mud-inhibiting agent and the conventional polycarboxylate superplasticizer, but the mud-inhibiting effect is difficult to meet the requirement due to the limited density or charge of mud-inhibiting groups, and particularly has more prominent effect on sand and stone with high mud content. The introduction of polycation groups into the polycarboxylate superplasticizer is expected to effectively solve the negative influence of clay minerals in the high-mud content sandstone material on the service performance of the polycarboxylate superplasticizer. The patent CN108047396A discloses a polycation anti-mud type polycarboxylate water reducer and a preparation method thereof, the polycation anti-mud type polycarboxylate water reducer is formed by polymerizing a polyether macromonomer, unsaturated carboxylic acid/unsaturated carboxylic anhydride and an unsaturated anti-mud type monomer in an aqueous solution, wherein the unsaturated anti-mud type monomer is prepared by reacting unsaturated hydroxy ester with a hydrochloric acid solution of tetraethylenepentamine, the anti-mud type polycarboxylate water reducer can be hydrolyzed under an alkaline condition to release polycation long-chain organic matters, the physicochemical properties of clay minerals can be changed, the expansion of the expanded clay minerals is inhibited, and the consumption of polycarboxylic acid and water by the surfaces and crystal layers of the minerals is reduced, so that the service performance of the polycarboxylate water reducer under a high mud content material is ensured, and the anti-mud effect is achieved. However, the preparation method still needs to prepare the mud inhibiting monomer, and has complex steps and limited application.

The polycarboxylic acid water reducing agent is a macromolecular surfactant with a long side chain comb-shaped molecular structure, and the good designable characteristic of the molecular structure is the development basis of the multifunctional polycarboxylic acid water reducing agent. Therefore, through the innovative molecular structure design of the polycarboxylate superplasticizer, the mud content of the polycarboxylate superplasticizer in adapting to sand can be obviously improved, and the slump retaining performance and the soil resistance of the polycarboxylate superplasticizer are further improved. Through retrieval, the traditional method for preparing the polycarboxylate superplasticizer by an aqueous solution method is broken through, and the conventional polycarboxylate superplasticizer is obtained by copolymerization of an unsaturated polyether monomer and an unsaturated carboxylic acid monomer under the condition of no solvent; the patent or related literature of the amphoteric polycarboxylic acid water reducing agent which forms a molecular structure and simultaneously contains carboxyl anions and amino cations through the amidation reaction of carboxyl and polyamine compounds in the polycarboxylic acid water reducing agent has not been reported.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a high-efficiency mud-inhibiting type polycarboxylate superplasticizer and a preparation method thereof.

The high-efficiency anti-mud polycarboxylic acid water reducing agent is prepared by copolymerizing an unsaturated polyether monomer and an unsaturated carboxylic acid monomer body and then carrying out amidation reaction with a polyamine compound; the water reducer is characterized by comprising the following main components in percentage by weight: the molar ratio of the unsaturated polyether monomer, the unsaturated carboxylic acid monomer and the polyamine compound is 1 (3-5) to 0.3-2.5; the amount of the catalyst contained in the water reducing agent is 0.03-0.3% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of the initiator is 0.5-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of the chain transfer agent is 0.3-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is one or a combination of more of 3-methyl-3-butylene-1-polyoxyethylene ether, allyl polyoxyethylene ether and 2-methylallyl polyoxyethylene ether in any molar ratio; the unsaturated carboxylic acid monomer is one or a combination of more of acrylic acid, methacrylic acid, itaconic acid and maleic acid in any molar ratio; the polyamine compound is one or a combination of more of diethylenetriamine, triethylene tetramine, tetraethylene pentamine and polyethylene polyamine in any molar ratio; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate, cumene hydroperoxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate or benzoyl peroxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptopropanol, 3-mercaptopropanol or n-dodecyl mercaptan.

In the above high-efficiency anti-mud polycarboxylic acid water reducing agent: the water reducing agent comprises the following main components in a preferable ratio: the molar ratio of the unsaturated polyether monomer to the unsaturated carboxylic acid monomer to the polyamine compound is 1:4: 1.5; the amount of a catalyst contained in the water reducing agent is 0.1-0.3% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of an initiator is 1.0-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of a chain transfer agent is 1.0-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; among them, the unsaturated polyether monomer is preferably 3-methyl-3-butene-1-polyoxyethylene ether, allyl polyoxyethylene ether or 2-methylallyl polyoxyethylene ether; the unsaturated carboxylic acid monomer is acrylic acid, methacrylic acid, itaconic acid or maleic acid; the polyamine compound is preferably diethylenetriamine, triethylene tetramine, tetraethylene pentamine or polyethylene polyamine; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is preferably azobisisobutyronitrile, dimethyl azobisisobutyrate, cumene hydroperoxide, tert-butyl peroxybenzoate or benzoyl peroxide; the chain transfer agent is preferably thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid or 3-mercaptopropanol.

The most preferred embodiment of the high-efficiency anti-mud polycarboxylic acid water reducing agent is as follows: the amount of a catalyst contained in the water reducing agent is 0.2-0.25% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of an initiator is 1.0-1.35% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of a chain transfer agent is 1.0-1.35% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is 3-methyl-3-butylene-1-polyoxyethylene ether or 2-methylallyl polyoxyethylene ether; the unsaturated carboxylic acid monomer is acrylic acid or methacrylic acid; the polyamine compound is diethylenetriamine, triethylene tetramine or tetraethylene pentamine; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate or cumene hydroperoxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid or 3-mercaptopropionic acid.

The preparation method of the high-efficiency anti-mud polycarboxylate superplasticizer comprises the following steps:

adding an unsaturated polyether monomer into a reactor, heating to 50-80 ℃ to enable the unsaturated polyether monomer to be in a molten state, adding a catalyst, and uniformly stirring; dropwise adding a mixed solution consisting of an unsaturated carboxylic acid monomer, an initiator and a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is completed within 1-3 h; continuously heating the product to 140-160 ℃, dropwise adding the polyamine compound while stirring, and finishing dropping within 2-5 h; after the dropwise addition is finished, cooling to 50-70 ℃, preserving heat for 1-2 h, and then adding a sodium hydroxide solution to adjust the pH value to 5-7, so as to obtain the high-efficiency anti-mud polycarboxylic acid water reducer; wherein the molar ratio of the unsaturated polyether monomer, the unsaturated carboxylic acid monomer and the polyamine compound is 1 (3-5) to 0.3-2.5; the amount of the catalyst contained in the water reducing agent is 0.03-0.3% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of the initiator is 0.5-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of the chain transfer agent is 0.3-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is one or a combination of more of 3-methyl-3-butylene-1-polyoxyethylene ether, allyl polyoxyethylene ether and 2-methylallyl polyoxyethylene ether in any molar ratio; the unsaturated carboxylic acid monomer is one or a combination of more of acrylic acid, methacrylic acid, itaconic acid and maleic acid in any molar ratio; the polyamine compound is one or a combination of more of diethylenetriamine, triethylene tetramine, tetraethylene pentamine and polyethylene polyamine in any molar ratio; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate, cumene hydroperoxide, tert-butyl peroxybenzoate, tert-butyl peroxypivalate, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate or benzoyl peroxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptopropanol, 3-mercaptopropanol or n-dodecyl mercaptan.

In the preparation method of the high-efficiency anti-mud polycarboxylic acid water reducing agent, the preferable embodiment is as follows:

adding an unsaturated polyether monomer into a reactor, heating to 60-70 ℃ to enable the unsaturated polyether monomer to be in a molten state, adding a catalyst, and uniformly stirring; dropwise adding a mixed solution consisting of an unsaturated carboxylic acid monomer, an initiator and a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is completed within 2-3 h; continuously heating the product to 150-160 ℃, dropwise adding the polyamine compound while stirring, and finishing dropping within 2-4 h; after the dropwise addition is finished, cooling to 50-60 ℃, preserving heat for 1.5-2 h, and then adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer; wherein the molar ratio of the unsaturated polyether monomer to the unsaturated carboxylic acid monomer to the polyamine compound is 1:4: 1.5; the amount of a catalyst contained in the water reducing agent is 0.1-0.3% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of an initiator is 1.0-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of a chain transfer agent is 1.0-1.5% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; wherein the unsaturated polyether monomer is 3-methyl-3-butylene-1-polyoxyethylene ether, allyl polyoxyethylene ether or 2-methylallyl polyoxyethylene ether; the unsaturated carboxylic acid monomer is acrylic acid, methacrylic acid, itaconic acid or maleic acid; the polyamine compound is diethylenetriamine, triethylene tetramine, tetraethylene pentamine or polyethylene polyamine; the catalyst is N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is azobisisobutyronitrile, dimethyl azobisisobutyrate, cumene hydroperoxide, tert-butyl peroxybenzoate or benzoyl peroxide; the chain transfer agent is thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid or 3-mercaptopropanol.

The preparation method of the high-efficiency anti-mud polycarboxylate superplasticizer comprises the following steps: the amount of the catalyst contained in the water reducing agent is more preferably 0.2-0.25% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, the amount of the initiator is more preferably 1.0-1.35% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer, and the amount of the chain transfer agent is more preferably 1.0-1.35% of the total mass of the unsaturated polyether monomer and the unsaturated carboxylic acid monomer; among them, the unsaturated polyether monomer is further preferably 3-methyl-3-butene-1-polyoxyethylene ether or 2-methylallyl polyoxyethylene ether; the unsaturated carboxylic acid monomer is further preferably acrylic acid or methacrylic acid; the polyamine compound is further preferably diethylenetriamine, triethylene tetramine or tetraethylene pentamine; the catalyst is further preferably N, N-dimethylaniline or 2-hydroxy-2-sulfonic acid dipotassium acetate; the initiator is further preferably azobisisobutyronitrile, dimethyl azobisisobutyrate or cumene hydroperoxide; the chain transfer agent is further preferably thioglycolic acid, mercaptoethanol, 2-mercaptopropionic acid or 3-mercaptopropionic acid.

The invention discloses a mud-inhibiting type polycarboxylate superplasticizer which effectively solves the problems that in the prior art, the polycarboxylate superplasticizer has poor adaptability, is easy to have the defect of insufficient slump retaining performance on concrete with high mud content, has poor segregation bleeding and workability and the like, thereby ensuring the service performance of the polycarboxylate superplasticizer under a high mud content material and realizing a high-efficiency mud inhibiting effect. The invention breaks through the traditional method for preparing the polycarboxylate superplasticizer by using an aqueous solution method, and obtains the conventional polycarboxylate superplasticizer by copolymerizing an unsaturated polyether monomer and an unsaturated carboxylic acid monomer under the condition of no solvent; the amphoteric polycarboxylate superplasticizer with a molecular structure containing carboxyl anions and amino cations is formed by carrying out amidation reaction on carboxyl in the polycarboxylate superplasticizer and polyamine compounds. Wherein, the carboxyl has good adsorption capacity to cement particles, while the amino has strong adsorption to clay particles.

The invention has the beneficial effects that:

1. the polycarboxylic acid water reducing agent prepared by the invention has excellent water reducing and dispersing effects, and can still show good fluidity and holding capacity under a low mixing amount;

2. the polycarboxylic acid water reducing agent prepared by the invention contains a plurality of amino groups, can be adsorbed on the surface of an anion solid phase (such as clay minerals), improves the physicochemical property of the polycarboxylic acid water reducing agent, inhibits the adsorption of non-expansive clay minerals to the polycarboxylic acid and the water swelling of expansive clay minerals, and can effectively reduce the ineffective consumption of the clay minerals to the polycarboxylic acid and water. Moreover, as the positive charge density is high, the efficiency of neutralizing the double electric layers on the clay mineral surface is high, which shows that the mud inhibiting efficiency is high;

3. the mud-inhibiting type polycarboxylate superplasticizer disclosed by the invention has the advantage that the advantages of the mud-inhibiting type polycarboxylate superplasticizer are obviously higher than those of a common polycarboxylate superplasticizer under the condition that the mud content of a concrete raw material is higher.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples are merely illustrative of the preferred embodiments of the present invention and are not intended to limit the present invention in any way, and any simple modifications, equivalent changes and modifications made to the embodiments according to the technical spirit of the present invention fall within the scope of the technical solution of the present invention.

The processes described in the examples of the present invention are conventional unless otherwise specified, and the starting materials are commercially available from public sources unless otherwise specified.

Example 1

Adding 240g (0.1mol, molecular weight 2400g/mol) of allyl polyoxyethylene ether into a reactor, heating to 60 ℃ to enable the allyl polyoxyethylene ether to be in a molten state, adding 0.26g of catalyst N, N-dimethylaniline, and uniformly stirring; dropwise adding a mixed solution consisting of 21.6g (0.3mol) of acrylic acid, 1.3g of azodiisobutyronitrile as an initiator and 1.5g of thioglycolic acid as a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is finished within 2 hours; continuously heating the product to 150 ℃, dropwise adding 4.38g (0.03mol) of triethylene tetramine while stirring, and finishing dropwise adding within 3 hours; and after the dropwise addition is finished, cooling to 60 ℃, preserving the heat for 1.5h, and adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer.

Example 2

Adding 240g (0.1mol, molecular weight 2400g/mol) of allyl polyoxyethylene ether into a reactor, heating to 65 ℃ to enable the allyl polyoxyethylene ether to be in a molten state, adding 0.27g of catalyst N, N-dimethylaniline, and uniformly stirring; dropwise adding a mixed solution consisting of 28.8g (0.4mol) of acrylic acid, 1.5g of initiator azobisisobutyronitrile and 1.5g of chain transfer agent 2-mercaptopropionic acid into the obtained product, stirring at the same time, and completing dropwise addition within 2.5 hours; continuously heating the product to 160 ℃, dropwise adding 14.6g (0.1mol) of triethylene tetramine while stirring, and finishing dropwise adding within 3 hours; and after the dropwise addition is finished, cooling to 50 ℃, preserving the heat for 2h, and adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer.

Example 3

Adding 240g (0.1mol, molecular weight 2400g/mol) of allyl polyoxyethylene ether into a reactor, heating to 70 ℃ to enable the allyl polyoxyethylene ether to be in a molten state, adding 0.3g of catalyst N, N-dimethylaniline, and uniformly stirring; dropwise adding a mixed solution consisting of 28.8g (0.4mol) of acrylic acid, 2.0g of azodiisobutyronitrile serving as an initiator and 2.5g of thioglycolic acid serving as a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is finished within 2.5 hours; continuously heating the product to 160 ℃, dropwise adding 20.6g (0.2mol) of diethylenetriamine while stirring, and finishing dropping within 3 hours; and after the dropwise addition is finished, cooling to 70 ℃, preserving the heat for 1.5h, and adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer.

Example 4

Adding 240g (0.1mol, molecular weight 2400g/mol) of 2-methylallyl polyoxyethylene ether into a reactor, heating to 65 ℃ to enable the 2-methylallyl polyoxyethylene ether to be in a molten state, adding 0.4g of catalyst N, N-dimethylaniline, and uniformly stirring; dropwise adding a mixed solution consisting of 36.0g (0.5mol) of acrylic acid, 2.5g of cumene hydroperoxide as an initiator and 2.7g of mercaptoethanol as a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is finished within 2 hours; continuously heating the product to 160 ℃, dropwise adding 14.6g (0.1mol) of triethylene tetramine while stirring, and finishing dropwise adding within 3 hours; and after the dropwise addition is finished, cooling to 60 ℃, preserving the heat for 2h, and adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer.

Example 5

Adding 240g (0.1mol, molecular weight 2400g/mol) of 2-methylallyl polyoxyethylene ether into a reactor, heating to 70 ℃ to enable the 2-methylallyl polyoxyethylene ether to be in a molten state, adding 0.5g of catalyst N, N-dimethylaniline, and uniformly stirring; dropwise adding a mixed solution consisting of 28.8g (0.4mol) of acrylic acid, 2.5g of initiator azobisisobutyronitrile and 2.0g of chain transfer agent 3-mercaptopropionic acid into the obtained product, and stirring at the same time, wherein the dropwise adding is completed within 3 hours; continuously heating the product to 160 ℃, dropwise adding 29.2g (0.2mol) of triethylene tetramine while stirring, and finishing dropwise adding within 3 hours; and after the dropwise addition is finished, cooling to 65 ℃, preserving the heat for 2h, and adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer.

Example 6

Adding 240g (0.1mol, molecular weight 2400g/mol) of 2-methylallyl polyoxyethylene ether into a reactor, heating to 60 ℃ to enable the 2-methylallyl polyoxyethylene ether to be in a molten state, adding 0.6g of catalyst 2-hydroxy-2-sulfonic acid acetic acid dipotassium salt, and uniformly stirring; dropwise adding a mixed solution consisting of 36.0g (0.5mol) of acrylic acid, 2.8g of cumene hydroperoxide as an initiator and 3.0g of 3-mercaptopropionic acid as a chain transfer agent into the obtained product, and stirring the mixture at the same time, wherein the dropwise adding is finished within 3 hours; continuously heating the product to 160 ℃, dropwise adding 15.5g (0.15mol) of diethylenetriamine while stirring, and finishing dropping within 2.5 h; and after the dropwise addition is finished, cooling to 50 ℃, preserving the heat for 1.5h, and adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer.

Example 7

Adding 240g (0.1mol, molecular weight 2400g/mol) of 3-methyl-3-butylene-1-polyoxyethylene ether into a reactor, heating to 70 ℃ to enable the mixture to be in a molten state, adding 0.7g of catalyst N, N-dimethylaniline, and uniformly stirring; dropwise adding a mixed solution consisting of 36.0g (0.5mol) of acrylic acid, 3.0g of cumene hydroperoxide as an initiator and 3.0g of thioglycolic acid as a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is finished within 3 hours; the temperature of the product is continuously raised to 160 ℃, 18.9g (0.1mol) of tetraethylenepentamine is added dropwise and stirred at the same time, and the dropwise addition is finished within 2 hours; and after the dropwise addition is finished, cooling to 60 ℃, preserving the heat for 2h, and adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer.

Example 8

Adding 240g (0.1mol, molecular weight 2400g/mol) of 3-methyl-3-butene-1-polyoxyethylene ether into a reactor, heating to 70 ℃ to enable the mixture to be in a molten state, adding 1.0g of catalyst 2-hydroxy-2-sulfonic acid dipotassium acetate, and uniformly stirring; dropwise adding a mixed solution consisting of 34.0g (0.4mol) of methacrylic acid, 3.0g of cumene hydroperoxide as an initiator and 2.8g of 3-mercaptopropionic acid as a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is finished within 3 hours; the temperature of the product is continuously raised to 160 ℃, 18.9g (0.1mol) of tetraethylenepentamine is added dropwise and stirred at the same time, and the dropwise addition is finished within 2 hours; and after the dropwise addition is finished, cooling to 50 ℃, preserving the heat for 2h, and adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer.

Example 9

Adding 240g (0.1mol, molecular weight 2400g/mol) of 3-methyl-3-butene-1-polyoxyethylene ether into a reactor, heating to 65 ℃ to enable the mixture to be in a molten state, adding 1.0g of catalyst 2-hydroxy-2-sulfonic acid dipotassium acetate, and uniformly stirring; dropwise adding a mixed solution consisting of 34.0g (0.5mol) of methacrylic acid, 2.5g of azodiisobutyronitrile as an initiator and 2.8g of thioglycolic acid as a chain transfer agent into the obtained product, and stirring at the same time, wherein the dropwise adding is finished within 3 hours; continuously heating the product to 160 ℃, dropwise adding 37.8g (0.2mol) of tetraethylenepentamine while stirring, and finishing dropping within 2 h; and after the dropwise addition is finished, cooling to 60 ℃, preserving the heat for 1.5h, and adding a sodium hydroxide solution to adjust the pH value to 5-7 to obtain the high-efficiency anti-mud polycarboxylic acid water reducer.

Also to be reviewed: the above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.