Viscosity reduction type polycarboxylic acid water reducer containing dual viscosity reduction functional groups, preparation method for viscosity reduction type polycarboxylic acid water reducer and use of viscosity reduction type polycarboxylic acid water reducer

Abstract

The invention provides a viscosity reduction type active macromonomer. The invention further provides a viscosity reduction type polycarboxylic acid water reducer. According to the viscosity reductiontype polycarboxylic acid water reducer provided by the invention, all ingredients and all functional groups are in mutual synergism; compared with viscosity reduction type polycarboxylic acid water reducers synthesized in the prior art, the viscosity reduction type polycarboxylic acid water reducer has the advantages that the viscosity reduction effect is superior, and the water reducing rate isnot affected; meanwhile, a large number of hydrophobic alkyl groups and ester groups are introduced into a PEG lateral chain, so that the HLB value is lowered, the surfactivity effect is enhanced, andthe viscosity reduction type polycarboxylic acid water reducer has a good reduction effect; and concrete doped with the product provided by the invention is low in shrinkage and does not crack. The viscosity-reduction hydrophobic functional groups are located on the lateral chain, the viscosity reduction effect of the water reducer can be regulated through the content of the viscosity-reduction functional groups, however, the content of dispersion groups is not affected, the dispersion effect on cement particles is not affected, and the dispersion and water reduction effects of the water reducer are not affected.

Description

technical field [0001] The invention relates to the technical field of concrete admixtures, in particular to a viscosity-reducing polycarboxylate water-reducer containing double viscosity-reducing functional groups, a preparation method and application thereof. 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 i...

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Problems solved by technology

Since the hydrophobic alkyl 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 and ester groups, the water-reducer molecules cannot form a complete water layer film on the surface of cement particles, but form a collapsed water layer film with defects , this defective collapsed water film endows the superplasticizer with the following characteristics: (1) it can release more free water and reduce the viscosity of the cement paste; (2) the molecular weight of the superplasticizer is not subject to the requirement of viscosity reduction (3) The length of the PEG side chain is not limited by the requirement for viscosity reduction; 4. The introduction of a large number of hydrophobic alkyl groups and ester groups in the PEG side chain greatly reduces the surface tension of the product and reduces 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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