CN-121974946-A - Early-strength functional monomer, early-strength polycarboxylate superplasticizer and preparation method and application thereof

CN121974946ACN 121974946 ACN121974946 ACN 121974946ACN-121974946-A

Abstract

The invention belongs to the technical field of building materials, and provides an early-strength functional monomer, an early-strength polycarboxylate superplasticizer and application thereof. The chemical structural formula of the early-strength functional monomer is shown as a formula (I). The preparation method of the early-strength polycarboxylate superplasticizer comprises the step of carrying out free radical polymerization reaction on an unsaturated polyether macromonomer, an early-strength functional monomer shown in a formula (I), unsaturated carboxylic acid and polysaccharide-based graft copolymer. The early-strength functional monomer provided by the invention is prepared by reacting N- (beta-aminoethyl) -alpha-aminopropyl trimethoxy silane and an acrylic monomer, has the advantages of readily available raw materials, low cost, simple synthesis process, convenient post-treatment and mild reaction conditions, can be prepared by only one-step reaction, and can be applied to a polycarboxylic acid water reducer to have synergistic effect with an unsaturated polyether macromonomer, unsaturated carboxylic acid and polysaccharide-based graft copolymer, so that the polycarboxylic acid water reducer has excellent early-strength effect and cementing material environmental adaptability. Formula (I).

Inventors

CHEN HAO
GUO YUANQIANG
FANG YUNHUI
KE YULIANG
LAI HUAZHEN

Assignees

科之杰新材料集团有限公司

Dates

Publication Date: 20260505
Application Date: 20251229

Claims (12)

1. The early strength functional monomer is characterized in that the chemical structural formula of the early strength functional monomer is shown as the formula (I): The compound of formula (I), R is H or C1-C5 alkyl.
2. The method for preparing the early-strength functional monomer according to claim 1, wherein the method comprises the steps of carrying out dehydration condensation reaction on N- (beta-aminoethyl) -alpha-aminopropyl trimethoxysilane and an acrylic monomer with a chemical structural formula shown as a formula (II): Formula (II).
3. The method for producing an early-strength functional monomer according to claim 2, wherein the molar ratio of N- (beta-aminoethyl) -alpha-aminopropyl trimethoxysilane to acrylic monomer is 1.2 to 1.3.
4. The method for producing an early-strength functional monomer according to claim 2, wherein the conditions for the dehydration condensation reaction include a temperature of 45 ℃ to 70 ℃ for a time of 2 hours to 5 hours.
5. The preparation method of the early-strength polycarboxylate superplasticizer is characterized by comprising the step of carrying out free radical polymerization on an unsaturated polyether macromonomer, an early-strength functional monomer, unsaturated carboxylic acid and a polysaccharide-based graft copolymer, wherein the early-strength functional monomer is the early-strength functional monomer as claimed in claim 1.
6. The method for preparing an early-strength polycarboxylate superplasticizer as recited in claim 5, wherein the unsaturated polyether macromonomer is at least one of ethylene glycol monovinyl polyethylene glycol ether, 4-hydroxybutyl vinyl polyoxyethylene ether, isopentenyl alcohol polyoxyethylene ether and methallyl polyoxyethylene ether.
7. The method for producing an early-strength polycarboxylate superplasticizer as defined in claim 5, wherein said unsaturated carboxylic acid is at least one of acrylic acid, methacrylic acid and maleic anhydride.
8. The method for preparing the early-strength polycarboxylate superplasticizer as claimed in claim 5, wherein the polysaccharide-based graft copolymer is polysaccharide-based polyacrylamide, and the polysaccharide-based polyacrylamide is at least one of starch grafted polyacrylamide, cellulose grafted polyacrylamide and dextran grafted polyacrylamide.
9. The method for preparing an early-strength polycarboxylate superplasticizer as claimed in claim 5, wherein the amount of said unsaturated polyether macromonomer is 200-208 parts by mass, the amount of said early-strength functional monomer is 6-12 parts by mass, the amount of said unsaturated carboxylic acid is 8-16 parts by mass, and the amount of said polysaccharide-based graft copolymer is 4-12 parts by mass.
10. The method for preparing the early-strength polycarboxylate superplasticizer according to claim 5, wherein the reaction of the free radical polymerization reaction comprises uniformly mixing an unsaturated polyether macromonomer, a chain transfer agent, an initiator and water, simultaneously dropwise adding an A solution formed by mixing an early-strength functional monomer, an unsaturated carboxylic acid, a polysaccharide-based graft copolymer and water and a B solution formed by mixing a reducing agent and water into the obtained mixed solution, continuing the polymerization reaction after the dropwise adding, adding a neutralizing agent after the reaction is finished, and adjusting the pH value of the solution to 5.5-7.0 to obtain the early-strength polycarboxylate superplasticizer.
11. An early strength polycarboxylate superplasticizer prepared by the method of any one of claims 5-10.
12. The use of the early-strength polycarboxylate superplasticizer of claim 11 in the construction field.

Description

Early-strength functional monomer, early-strength polycarboxylate superplasticizer and preparation method and application thereof Technical Field The invention belongs to the technical field of building materials, and relates to an early-strength functional monomer and an early-strength polycarboxylate superplasticizer as well as a preparation method and application thereof. Background Modern concrete technology is designed to take account of both cost and performance, and is commonly designed by adopting a large amount of mineral admixture (such as fly ash and slag powder). The mixing ratio can reduce hydration heat, improve crack resistance and long-term durability, and has good environmental benefit. However, the technical path also brings about the remarkable challenges that the cement consumption in the cementing material system is relatively reduced, so that the early hydration rate of the concrete is slow, the early strength development is insufficient, and the construction progress and the formwork turnover efficiency are seriously affected. This problem is particularly pronounced in low temperature or winter construction conditions, not only increasing the setting time, but also increasing the energy costs. The polycarboxylate water reducer has the advantages of high water reducing rate, low slump loss, strong designability of molecular structure, environmental protection, no pollution and the like, and is widely applied to concrete materials at present, but the early strength of the traditional polycarboxylate water reducer is slow to develop, especially under the low-temperature or winter construction conditions. Therefore, in order to improve early performance of concrete, a method for compounding early strength components in a polycarboxylate water reducer is generally adopted at present. For example, CN103304181a discloses that several early strength components of calcium chloride, sodium nitrite and triethanolamine are compounded with a polycarboxylate water reducer to form an early strength polycarboxylate high performance water reducer. CN109665737A discloses that silicate cement, a polycarboxylate water reducer, calcium formate, aluminum nitrate and triethanolamine are formed into a nano cement early-strength water reducer for sulphoaluminate cement, and the prepared nano cement early-strength water reducer is doped into the sulphoaluminate cement according to the doping amount of 2-4%, so that the early strength of the sulphoaluminate cement can be increased, the hardening time can be shortened, and the later strength is not affected. However, the above patent does not essentially design and improve the molecular structure of the polycarboxylate water reducer, and only relies on physical mixing, so that the adaptability of the product to different cements and admixtures is generally poor, and the performance adjustment and lifting space is very limited. Therefore, development of an early-strength polycarboxylate superplasticizer capable of synchronously improving the early-strength effect and the environmental adaptability of a cementing material from a molecular source has become a main research direction in the field. The early-strength polycarboxylate water reducer is usually prepared by reacting polyether macromonomer, unsaturated carboxylic acid, early-strength functional monomer and the like, wherein the early-strength functional monomer has important influence on the early-strength performance of the early-strength polycarboxylate water reducer. CN113248663a discloses an early-strength functional monomer, an early-strength polycarboxylate water reducer and a preparation method thereof, wherein the early-strength functional monomer is prepared by reacting an amino azo compound and unsaturated alcohol under the action of an inlet polymerization inhibitor and a catalyst, the early-strength polycarboxylate water reducer containing the early-strength functional monomer can remarkably improve the early strength of concrete without influencing the later strength under normal environment, can reduce the viscosity of the concrete and improve the water retention property of the concrete, but the synthesis step of the early-strength functional monomer is complicated, involves complex post-treatment such as reflux reaction (100 ℃), repeated extraction, drying, distillation and the like, has high energy consumption, and adopts an aromatic azo compound as a special chemical as a raw material, is unstable in supply and is not suitable for industrial application. CN114316163A discloses a mud-resistant early-strength functional monomer, a mud-resistant early-strength polycarboxylate water reducer and a preparation method thereof, wherein the mud-resistant early-strength functional monomer is prepared by non-covalent modification of graphene oxide and quaternary ammonium salt and grafting of a silane coupling agent, the mud-resistant early-strength polycarboxylate water reducer containing the mud-re