A viscosity-reducing polycarboxylate water-reducer containing three viscosity-reducing functional groups, its preparation method and application

Abstract

The invention provides a viscosity-reducing active macromonomer, and the invention also provides a viscosity-reducing polycarboxylate water-reducer. The viscosity-reducing polycarboxylate water-reducer synthesized by the invention has a The functional groups cooperate with each other, and compared with the viscosity-reducing polycarboxylate superplasticizer synthesized in the prior art, the viscosity-reducing effect is superior and the water-reducing rate is not affected. At the same time, due to the introduction of a large number of hydrophobic alkyl groups, ester groups and phenyl groups in the PEG side chain, the HLB value is effectively reduced, the surface activity effect is enhanced, and the shrinkage effect is good. The concrete added with the product of the present invention has a shrinkage Low rate, no cracking. The viscosity-reducing hydrophobic functional group is located on the side chain, and the viscosity-reducing effect of the water reducer can be adjusted through the content of the viscosity-reducing functional group, but it does not affect the content of the dispersing group and the dispersion effect on cement particles, so it does not affect the water reducing effect. agent dispersion and water-reducing effect.

Description

technical field [0001] The invention relates to the technical field of concrete admixtures, in particular to a viscosity-reducing polycarboxylate water reducer containing three viscosity-reducing functional groups and its preparation method and application. Background technique [0002] In recent years, with the increase of my country's infrastructure construction, high-grade concrete is gradually entering the building material market due to its high strength, good integrity and low weight, especially in bridge engineering. However, due to the use of a large amount of gel material and low water-binder ratio, high-grade concrete has the problems of high viscosity and slow flow speed, which in turn causes problems in concrete mixing, transportation, pumping and construction, which largely limits high-strength super Promotion and application of high-strength concrete. [0003] For engineers and technicians, the high-strength ultra-high-strength concrete viscosity problem is a ...

AI Technical Summary

Problems solved by technology

Since the hydrophobic alkyl group, phenyl group and ester group are located on the PEG side chain, the water reducer of the present invention has the following four main advantages: 1. Its content does not affect the adsorption and dispersion of the copolymer-COO - 2. The content of hydrophobic alkyl groups and ester groups can be adjusted at will according to the actual needs of the viscosity-reducing effect, so as to effectively solve the problem of high viscosity and flow rate in high-grade concrete. The purpose of the slow problem; 3. Since the PEG side chain contains a large number of hydrophobic viscosity-reducing alkyl groups, phenyl groups and ester groups, the water-reducer molecules cannot form a complete water film on the surface of the cement particles, but form a collapsed one with defects. Water layer film, this defective collapsed water layer film endows the water reducer with the following characteristics: (1) It can release more free water and reduce the viscosity of cement paste; (2) The molecular weight of the water reducer molecules is not reduced (3) The length of the PEG side chain is not limited by the viscosity reduction requirement; 4. A large number of hydrophobic alkyl groups, phenyl groups and ester groups introduced in the PEG side chain greatly reduce the surface tension of the product, Reduce the shrinkage force of water evaporation, thereby reducing the shrinkage and cracking of concrete, and has a good shrinkage reduction effect

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