A kind of viscosity-reducing composite polycarboxylate water reducer and preparation method thereof

Abstract

The invention provides a viscosity reduction type composite polycarboxylic acid water reducing agent. The viscosity reduction type composite polycarboxylic acid water reducing agent is prepared from a polycarboxylic acid water reducing agent A, a polycarboxylic acid water reducing agent B, a polycarboxylic acid water reducing agent C, a beta-cyclodextrin derivative, methyl-beta-cyclodextrin and de-ionized water, wherein the polycarboxylic acid water reducing agent A is prepared from the following preparation raw materials: isopentenyl polyoxyethylene ether, acrylic acid, an initiator 1, a chain transferring agent 1 and de-ionized water; the polycarboxylic acid water reducing agent B is prepared from the following preparation raw materials: methylallyl polyethylene glycol ether, acrylic acid, sodium methallyl sulfonate, an initiator 2, a chain transferring agent 2 and de-ionized water; the polycarboxylic acid water reducing agent C is prepared from the following preparation raw materials: diallyl capped polyether, acrylic acid, methylallyl polyethylene glycol ether, an initiator 3, a chain transferring agent 3 and de-ionized water; the diallyl capped polyether is prepared by carrying out allylation capping on the methoxy polyethylene glycol through allyl bromide; the beta-cyclodextrin derivative is beta-cyclodextrin modified by sodium dodecyl sulfonate and carbon nanotubes.

Description

technical field [0001] The invention relates to the field of concrete admixtures, in particular to a viscosity-reducing composite polycarboxylate water reducer and a preparation method thereof. Background technique [0002] At present, concrete is still the main and largest building material in the construction industry. In recent years, with the development of my country's construction industry, high-grade concrete is gradually entering the construction market because of its high strength, good integrity and low weight, especially in bridge engineering. However, due to the use of a lower water-binder ratio and a larger amount of cementitious material, high-grade concrete has the problems of high viscosity and slow flow speed in application. [0003] Polycarboxylate superplasticizer has the advantages of low dosage, high water reducing rate, strong plasticity, small slump loss, low shrinkage, green environmental protection and environmental friendliness, and has become an e...

AI Technical Summary

Problems solved by technology

[0004] The excessive decrease of concrete slump over time has always been a problem that plagues normal construction

The amount of polycarboxylate superplasticizer itself is very low, and a large amount of superplasticizer will be consumed in the early stage of concrete mixing, resulting in the lack of actual effective ingredients in the later concrete, resulting in a decline in its application performance, especially the serious loss of slump in the later stage , cannot meet the requirements of normal construction

[0005] In addition, polycarboxylic acid has a structure with polyether as the main chain and polyether as the side chain. The molecular thermal stability of this structure is poor, and the molecular structure is easily destroyed under the condition of high temperature for a long time, so that the performance is greatly reduced.

[0006] Therefore, in view of the above problems, the present invention provides a viscosity-reducing composite polycarboxylate water-reducer, which solves the problems of high viscosity and slow flow rate in concrete, and also has low dosage, high water-reducing rate, strong plasticity, and slump. Small sag loss, low shrinkage, good thermal stability, green and environmentally friendly, etc.

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