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CN-121975105-A - Macromer for preparing polycarboxylate superplasticizer, and preparation method and application thereof

CN121975105ACN 121975105 ACN121975105 ACN 121975105ACN-121975105-A

Abstract

The application provides a macromonomer for preparing a polycarboxylate superplasticizer, a preparation method and application thereof, the large monomer for preparing the polycarboxylate water reducer is obtained by grafting sulfonate groups and quaternary ammonium salts on terminal hydroxyl groups of ethylene glycol monovinyl polyethylene glycol ether. The polycarboxylic acid water reducer prepared by copolymerizing the macromonomer with acrylic acid and hydroxyethyl methacrylate has high dispersion efficiency, strong slump retaining performance and good adaptability to complex systems.

Inventors

  • RONG HONG
  • CHEN XIANGDONG
  • XIANG HONGJUN

Assignees

  • 武汉中彭化学科技有限公司

Dates

Publication Date
20260505
Application Date
20260408

Claims (10)

  1. 1. The preparation method of the macromonomer for preparing the polycarboxylate superplasticizer is characterized by comprising the following steps of: S1, melting ethylene glycol monovinyl polyethylene glycol ether, adding epoxy chloropropane and an acidic catalyst under the protection of nitrogen, and enabling hydroxyl-terminated groups of the ethylene glycol monovinyl polyethylene glycol ether to carry out ring-opening addition reaction on the epoxy chloropropane to generate a first EPEG intermediate with beta-chlorohydrin ether structure at the end groups; s2, adding an alkaline catalyst into the first EPEG intermediate to enable beta-chlorohydrin ether to undergo intramolecular dehydrochlorination reaction to generate a second EPEG intermediate with an epoxy group at the end group; s3, adding a dimethylformamide solution of 2-acrylamide-2-methylpropanesulfonic acid and triethylamine into the molten second EPEG intermediate, and carrying out ring opening reaction on a sulfonic group of the 2-acrylamide-2-methylpropanesulfonic acid and an epoxy group of the second EPEG intermediate to obtain a third EPEG intermediate grafted with a sulfonic acid ester group; S4, adding a dimethylformamide solution of 2, 3-epoxypropyl trimethyl ammonium chloride into the molten third EPEG intermediate, and enabling epoxy groups of the 2, 3-epoxypropyl trimethyl ammonium chloride and hydroxyl groups of the third EPEG intermediate to carry out ring-opening addition reaction to obtain the EPEG macromonomer grafted with sulfonate groups and quaternary ammonium salts as a macromonomer for preparing the polycarboxylate water reducer.
  2. 2. The method for preparing a macromonomer for preparing a polycarboxylate superplasticizer according to claim 1, comprising the steps of: S1, heating 100 parts by weight of ethylene glycol monovinyl polyethylene glycol ether to 70-90 ℃ to enable the ethylene glycol monovinyl polyethylene glycol ether to be completely melted, adding 10-20 parts by weight of epichlorohydrin and 0.5-1 part by weight of an acid catalyst under the protection of nitrogen, and stirring and reacting for 4-6 hours to generate a first EPEG intermediate with a beta-chlorohydrin ether structure at the end group; s2, adding 1-3 parts by weight of an alkaline catalyst into 100 parts by weight of the first EPEG intermediate, stirring and reacting for 2-4 hours to enable the beta-chlorohydrin ether structure of the first EPEG intermediate to generate intramolecular dehydrochlorination reaction, so as to generate a second EPEG intermediate with an end group containing epoxy groups; S3, heating 100 parts by weight of a second EPEG intermediate to 70-80 ℃ to melt the second EPEG intermediate, dissolving 10-25 parts by weight of 2-acrylamide-2-methylpropanesulfonic acid in 20-50 parts by weight of dimethylformamide, adding 2-acrylamide-2-methylpropanesulfonic acid dimethylformamide solution and 2-6 parts by weight of triethylamine into the melted second EPEG intermediate under the protection of nitrogen, and reacting for 4-8 hours at 80-90 ℃ to obtain a third EPEG intermediate grafted with sulfonate groups; S4, heating 100 parts by weight of a third EPEG intermediate to 70-90 ℃ to melt the intermediate, adding 10-30 parts by weight of 2, 3-epoxypropyl trimethyl ammonium chloride to dissolve in 20-50 parts by weight of dimethylformamide under the protection of nitrogen, and reacting 0.1-0.5 part by weight of dibutyltin dilaurate for 4-8 hours at 80-100 ℃ to obtain the EPEG macromonomer grafted with the sulfonate group and the quaternary ammonium salt as a macromonomer for preparing the polycarboxylate water reducer.
  3. 3. The preparation method of the macromonomer for preparing the polycarboxylate water reducer according to claim 1 or 2, wherein the number average molecular weight of the ethylene glycol monovinyl polyethylene glycol is 1000-2000.
  4. 4. The method for preparing a macromonomer for preparing a polycarboxylate superplasticizer according to claim 1 or 2, wherein the acidic catalyst is a supported solid acid catalyst Zn (ClO 4 ) 2 /SiO 2 .
  5. 5. The method for preparing a macromonomer for a polycarboxylate superplasticizer according to claim 1 or 2, wherein the basic catalyst is a liquid base.
  6. 6. The macromonomer for preparing the polycarboxylate superplasticizer is characterized by being prepared by the preparation method according to any one of claims 1-5.
  7. 7. Use of a macromonomer according to claim 6 for the preparation of a polycarboxylate water reducer.
  8. 8. The use according to claim 7, characterized in that the method for preparing a polycarboxylate superplasticizer comprises the following steps: Adding the macromonomer, hydroxyethyl methacrylate, acrylic acid and an initiator for preparing the polycarboxylate water reducer into a reaction kettle for reaction; And after the reaction is finished, adding liquid alkali to adjust the pH value, and obtaining the polycarboxylate water reducer.
  9. 9. The use according to claim 8, characterized in that the method for preparing a polycarboxylate superplasticizer comprises the following steps: Heating 100 parts by weight of a macromonomer for preparing a polycarboxylate water reducer to 70-80 ℃ to enable the macromonomer to be completely melted, adding 10-30 parts by weight of hydroxyethyl methacrylate and 20-40 parts by weight of acrylic acid under the protection of nitrogen, stirring and uniformly mixing, heating to 80-90 ℃, adding 0.2-0.6 part by weight of an initiator into a system, and reacting for 3-6 hours to obtain an acidic polymer solution of the polycarboxylate water reducer; And after the copolymerization reaction is finished, adding liquid alkali into the reaction system, adjusting the pH of the system to 6-7 under the stirring condition, and uniformly mixing to obtain the finished product of the polycarboxylate superplasticizer.
  10. 10. The use according to claim 9, wherein the initiator is any one of ammonium persulfate, sodium persulfate, potassium persulfate.

Description

Macromer for preparing polycarboxylate superplasticizer, and preparation method and application thereof Technical Field The application relates to the technical field of polycarboxylate water reducers, in particular to a macromonomer for preparing a polycarboxylate water reducer, and a preparation method and application thereof. Background The water reducing agent is a concrete admixture capable of reducing the mixing water consumption under the condition of maintaining the slump of the concrete basically unchanged. The water reducer belongs to anionic surfactant, and has dispersing effect on cement particles after being added into concrete mixture, and can improve the workability, reduce the unit water consumption, improve the fluidity of the concrete mixture, or reduce the unit cement consumption and save cement. The water reducer is generally classified into lignin sulfonate type water reducer, naphthalene type high-efficiency water reducer, melamine type high-efficiency water reducer, sulfamate type high-efficiency water reducer, fatty acid type high-efficiency water reducer and polycarboxylate type high-efficiency water reducer according to chemical composition. The polycarboxylic acid water reducer is used as the most widely used high-performance additive in modern concrete, and the dispersion performance of the polycarboxylic acid water reducer mainly depends on the adsorption effect of carboxyl groups in polymer molecules on the surfaces of cement particles and the steric hindrance effect formed by polyether side chains. In the prior art, a polycarboxylic acid water reducer is generally prepared by copolymerizing a polyether vinyl macromonomer (EPEG) and a functional monomer such as acrylic acid, and the product can obtain a certain water reducing effect in a conventional cement system. However, as the adsorption mode of the polymer mainly depends on a single carboxyl-calcium ion bridging mechanism, the dispersion behavior of the polymer is sensitive to the composition of cement minerals, the alkalinity and the ionic strength of a system, and the problems of insufficient initial dispersion, reduced dispersion stability, quicker slump loss and the like are easy to occur under the condition of high electrolyte. Therefore, improving the initial dispersion speed of the polycarboxylate water reducer under the high electrolyte condition and improving the dispersion stability of the water reducer are technical problems to be solved in the field. Disclosure of Invention The application provides a macromonomer for preparing a polycarboxylate water reducer, a preparation method and application thereof, wherein the macromonomer is obtained by grafting a glycol monovinyl polyethylene glycol ether with a sulfonate group and a quaternary ammonium salt, and the polycarboxylate water reducer prepared by matching with functional monomers such as acrylic acid, hydroxyethyl methacrylate and the like has stronger adaptability under a high electrolyte system. In a first aspect, the application provides a method for preparing a macromonomer for preparing a polycarboxylate superplasticizer, comprising the steps of: S1, melting ethylene glycol monovinyl polyethylene glycol ether, adding epoxy chloropropane and an acidic catalyst under the protection of nitrogen, and enabling hydroxyl-terminated groups of the ethylene glycol monovinyl polyethylene glycol ether to carry out ring-opening addition reaction on the epoxy chloropropane to generate a first EPEG intermediate with beta-chlorohydrin ether structure at the end groups; s2, adding an alkaline catalyst into the first EPEG intermediate to enable beta-chlorohydrin ether to undergo intramolecular dehydrochlorination reaction to generate a second EPEG intermediate with an epoxy group at the end group; s3, adding a dimethylformamide solution of 2-acrylamide-2-methylpropanesulfonic acid and triethylamine into the molten second EPEG intermediate, and carrying out ring opening reaction on a sulfonic group of the 2-acrylamide-2-methylpropanesulfonic acid and an epoxy group of the second EPEG intermediate to obtain a third EPEG intermediate grafted with a sulfonic acid ester group; S4, adding a dimethylformamide solution of 2, 3-epoxypropyl trimethyl ammonium chloride into the molten third EPEG intermediate, and enabling epoxy groups of the 2, 3-epoxypropyl trimethyl ammonium chloride and hydroxyl groups of the third EPEG intermediate to carry out ring-opening addition reaction to obtain the EPEG macromonomer grafted with sulfonate groups and quaternary ammonium salts as a macromonomer for preparing the polycarboxylate water reducer. According to the preparation method of the macromonomer for preparing the polycarboxylate superplasticizer, nucleophilic ring-opening addition reaction is carried out on epoxy groups of epoxy chloropropane by EPEG molecular terminal hydroxyl (-OH) under the action of an acid catalyst to generate a first intermediate with a beta-chlorohydrin ether stru