A kind of thickening type functional polycarboxylate water reducer and preparation method thereof

Abstract

The invention discloses tackifying type functional polycarboxylate superplasticizer. A preparation method for the tackifying type functional polycarboxylate superplasticizer comprises the following steps: adding microcrystalline celluloses into unsaturated carboxylic acid and concentrated sulfuric acid to generate acidolysis and esterification reaction; carrying out copolymerization on cellulose nanocrystalline generated by reaction, the esterified derivative of the cellulose nanocrystalline, polyether macromonomers and other micromonomers to form a mico-crosslinking chain structure, i.e., obtain the tackifying type functional polycarboxylate superplasticizer. According to the tackifying type functional polycarboxylate superplasticizer, the microcrystalline celluloses are hydrolyzed to generate the cellulose nanocrystalline to be combined with cellulose nanocrystalline grafted esterification, and the cellulose nanocrystalline which is even in dispersion and the micro-crosslinking polycarboxylate superplasticizer which contains cellulose nanocrystalline derivatives are successfully prepared. After the tackifying type functional polycarboxylate superplasticizer is added into concrete, multiple effects of water reduction, thickening and early strength can be realized.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a viscosity-increasing functional polycarboxylate water reducer and a preparation method thereof. Background technique [0002] Modern civil engineering has higher and higher requirements for concrete technology, and more and more new concrete admixture products have been developed and successfully applied in various types of concrete. Viscosifiers and viscosified polycarboxylate superplasticizers are a new type of concrete admixture, which have good effects in inhibiting concrete bleeding and segregation, improving the segregation resistance of underwater concrete, and reducing the rebound rate of shotcrete. . In addition, during concrete construction in winter, the strength development is slow, and it is necessary to add early strength agents to accelerate the hydration speed of cement, promote the development of early strength in coagulation, and improv...

AI Technical Summary

Problems solved by technology

[0003] The tackifiers and viscosified polycarboxylate superplasticizers currently used in the market will reduce the fluidity of fresh concrete, especially the viscosity of low-grade concrete, and the viscosity of concrete is not durable enough. To maintain the same fluidity, it needs Increase the amount of water reducing agent, or increase the water-binder ratio

However, increasing the water-binder ratio will often destroy the continuity of the slurry and reduce the hardening strength of the concrete; adding more water-reducing agents will often lead to sensitivity to the dosage, especially when the temperature difference between day and night is relatively large, and it is easier to segregate and bleed

In addition, when the tackifiers and thickened polycarboxylate water-reducing agents on the market are compounded with other additives, there are often problems such as poor compatibility, serious retardation or air-entrained phenomena, and insufficient viscosity at low shear rates.

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