Viscosity reduction type polycarboxylate water reducing agent with three viscosity reduction functional groups, method for preparing viscosity reduction type polycarboxylate water reducing agent and application thereof

Abstract

The invention provides a viscosity reduction type active macromonomer, and further provides a viscosity reduction type polycarboxylate water reducing agent. Compared with synthetic viscosity reductiontype polycarboxylate water reducing agents in the prior art, the viscosity reduction type polycarboxylate water reducing agent has the advantages that synergistic effects can be realized between various components and between various functional groups in the synthetic viscosity reduction type polycarboxylate water reducing agent, excellent viscosity reduction effects can be realized by the viscosity reduction type polycarboxylate water reducing agent, but influence on the water reducing ratio is prevented; large quantities of hydrophobic alkyl, ester and phenyl are led into PEG (polyethyleneglycol) side chains, accordingly, the HLB (hydrophile-lipophile balance) value can be effectively lowered, surface activity effects can be enhanced, good shrinkage reducing effects can be realized, and concrete with the added viscosity reduction type polycarboxylate water reducing agent is low in shrinkage and free of cracking; the viscosity reduction hydrophobic functional groups are positioned on the side chains, the viscosity reduction effects of the viscosity reduction type polycarboxylate water reducing agent can be adjusted by the aid of the contents of the viscosity reduction functionalgroups, but the influence on the contents of dispersion groups and influence on cement particle dispersion effects can be prevented, and accordingly influence on dispersion and water reducing effectsof the viscosity reduction type polycarboxylate water reducing agent can be prevented.

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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