Preparation method of ether viscosity reduction type polycarboxylate superplasticizer

Abstract

The invention discloses a preparation method of an ether viscosity reduction type polycarboxylate superplasticizer, which comprises the following steps: (1) copolymerization reaction; and (2) neutralization reaction. According to the preparation method disclosed by the invention, amide groups are connected to superplasticizer molecules, and then a polycarboxylate molecular chain has anion and cation groups, so that adsorbability on the surfaces of cement particles can be increased, the electrostatic repulsion effect between the cement particles can be increased, and a better viscosity reduction effect on concrete is achieved. Moreover, the amide groups are hydrolyzed under alkaline conditions so as to release potential carboxyl groups again, thereby being favorable for improving the dispersibility and slump retentivity of the superplasticizer and realizing high adaptability to cement of different varieties.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a preparation method of an ether viscosity-reducing polycarboxylate water reducer. Background technique [0002] With the vigorous development of my country's construction industry, high-rise and super-high-rise concrete structures and important buildings with special functional requirements continue to appear, such as skyscrapers, super-long-span bridges and giant water conservancy projects, etc., requiring concrete to have higher strength , better durability, and better stability. These demands have led to the gradual development of concrete from ordinary to high-performance and even ultra-high-performance. At present, the strength of concrete is mainly improved by reducing the water-cement ratio and increasing the amount of cementitious materials, but these methods will increase the viscosity of concrete and reduce the fluidity, which largely limits the p...

AI Technical Summary

Problems solved by technology

The added organic admixture is mainly air-entraining agent. The incorporation of air-entraining agent will form a large number of tiny closed spherical bubbles in the concrete mixture. These micro-bubbles are like balls, reducing the frictional resistance between aggregate particles, thereby reducing the viscosity. , but the viscosity-reducing effect of the air-entraining agent is limited, and the air bubbles introduced will have an adverse effect on the strength of high-strength concrete

However, by adding a large amount of fly ash to improve the performance of concrete, the effect of reducing viscosity for high-rise, high-strength or ultra-high-strength concrete is very limited.

At present, the research on the viscosity-reducing polycarboxylate superplasticizer is still relatively lacking, and there are few good products on the market.

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