High-water-reducing slump-retaining type polycarboxylate superplasticizer and preparation method and application thereof

A technology of polycarboxylic acid and water reducing agent, which is applied in the field of concrete water reducing agent, can solve the problems of affecting the performance of concrete, the decrease of water reducing ability, and the increase of initial dosage of water reducing agent, so as to prolong the slump retention time and good initial expansion degree and slump retention ability, and the effect of improving water-reducing dispersion ability

Active Publication Date: 2020-11-13
GUANGZHOU INSTITUTE OF BUILDING SCIENCE CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method is to drop acrylic acid and slump-inhibiting monomers into the polymerization system at the same time. The slump-inhibiting monomers are randomly distributed in the acrylic acid chain through random polymerization, which affects the carboxylate group to a certain extent. RCOO- effectively complexes metal cations in cement particles, resulting in a decrease in water-reducing capacity, which can easily lead to an increase in the initial dosage of water-reducing agent, and bleeding, segregation, etc., will easily occur in the later stage, affecting the performance of concrete

Method used

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  • High-water-reducing slump-retaining type polycarboxylate superplasticizer and preparation method and application thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0028] A high water-reducing and slump-preserving polycarboxylate water-reducer is prepared by the following method:

[0029] (1) Mix 300 parts of methallyl polyoxyethylene ether with 300 parts of water to obtain substrate solution A; mix 25 parts of acrylic acid monomer with 25 parts of water to obtain solution B; mix 50 parts of hydroxyethyl acrylate 12 parts of polyethylene glycol diacrylate (molecular weight 400Da) were mixed with 38 parts of water to obtain solution C; 0.45 parts of ascorbic acid and 2.0 parts of thioglycolic acid were mixed with 50 parts of water to obtain solution D;

[0030] (2) Add 3.0 parts of hydrogen peroxide to the substrate solution A, stir evenly, start to add solution B and solution D dropwise, set the solution B and solution D dropping time for 3h, and start dropping solution B and solution D after 0.5h Add solution C, and control solution B and solution C to drop at the same time;

[0031] (3) After the dropwise addition, keep warm for 1.0 h...

Embodiment 2

[0033] A high water-reducing and slump-preserving polycarboxylate water-reducer is prepared by the following method:

[0034] (1) Mix 320 parts of methallyl polyoxyethylene ether with 320 parts of water to obtain substrate solution A; mix 23 parts of acrylic acid monomer with 27 parts of water to obtain solution B; mix 48 parts of hydroxyethyl acrylate 10 parts of polyethylene glycol diacrylate (molecular weight 200Da) were mixed with 42 parts of water to obtain solution C; 0.48 parts of ascorbic acid and 2.2 parts of mercaptopropionic acid were mixed with 50 parts of water to obtain solution D;

[0035] (2) Add 2.8 parts of hydrogen peroxide to the substrate solution A, stir evenly, start to add solution B and solution D dropwise, set the solution B and solution D dropping time for 3h, and start dropping solution B and solution D after 0.75h Add solution C, and control solution B and solution C to drop at the same time;

[0036] (3) After the dropwise addition, keep warm for...

Embodiment 3

[0038] A high water-reducing and slump-preserving polycarboxylate water-reducer is prepared by the following method:

[0039] (1) Mix 360 parts of methallyl polyoxyethylene ether with 360 parts of water to obtain substrate solution A; mix 20 parts of acrylic acid monomer with 30 parts of water to obtain solution B; mix 46 parts of hydroxyethyl acrylate , 9 parts of polyethylene glycol diacrylate (molecular weight 600Da) were mixed with 45 parts of water to obtain solution C; 0.47 parts of ascorbic acid and 2.4 parts of sodium methacrylate were mixed with 50 parts of water to obtain solution D;

[0040] (2) Add 3.0 parts of hydrogen peroxide to the substrate solution A, stir evenly, start to add solution B and solution D dropwise, set the time for adding solution B and solution D to 3.5h, and start after adding solution B and solution D for 1.0h Add solution C dropwise, and control solution B and solution C to finish dripping at the same time;

[0041](3) After the dropwise ad...

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Abstract

The invention provides a high-water-reducing slump-retaining type polycarboxylate superplasticizer and a preparation method and application thereof, and relates to the technical field of concrete superplasticizers. The high-water-reducing slump-retaining type polycarboxylate superplasticizer is prepared by the following method: S1, mixing methyl allyl polyoxyethylene ether with water to obtain a substrate solution A; mixing an acrylic monomer with water to obtain a solution B; mixing a slump-retaining monomer, a cross-linking monomer and water to obtain a solution C; mixing a reducing agent, achain transfer agent and water to obtain a solution D; S2, adding hydrogen peroxide into the substrate solution A, uniformly mixing, dropwise adding the solution B and the solution D at the same time, dropwise adding the solution C at the same time after dropwise adding for preset time, and controlling the solution B and the solution C to be completely dropwise added at the same time; and S3, after dropwise adding is finished, keeping the temperature, and adding an alkaline solution to adjust the pH value to 7.0 + / -1.0, thereby obtaining the high-water-reducing slump-retaining polycarboxylatesuperplasticizer. The water reducing agent disclosed by the invention is applied to concrete and has relatively good initial dispersion capability and slump retention capability.

Description

technical field [0001] The invention relates to the technical field of concrete water-reducing agents, in particular to a high water-reducing and slump-retaining polycarboxylate water-reducing agent and its preparation method and application. Background technique [0002] Polycarboxylate superplasticizer, as the third generation superplasticizer, has the advantages of low dosage, high water reducing rate, good workability, etc., and the production process is simple, green and environmentally friendly. It has been widely used in the ready-mixed concrete industry. In the current application, with the reduction of natural aggregates and the decline in the quality of fly ash and mineral powder, more and more stringent requirements are put forward for the water reducing and slump retention performance of polycarboxylate superplasticizers. In the prior art, ester type slump-retaining monomers are usually added to the water reducer and copolymerized with acrylic acid monomers to ob...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F283/06C08F220/06C08F220/20C08F222/20C04B24/26C04B103/30
CPCC08F283/065C04B24/2694C04B2103/302C08F220/06C08F220/20C08F222/1063Y02W30/91
Inventor 张金龙陈胜利熊旭峰孙申美钟开红
Owner GUANGZHOU INSTITUTE OF BUILDING SCIENCE CO LTD
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