Method for preparing ester and ether copolymerized viscosity-reducing polycarboxylic acid water reducing agent

Abstract

The invention discloses a method for preparing an ester and ether copolymerized viscosity-reducing polycarboxylic acid water reducing agent. The method comprises the following steps: (1) esterified monomer preparation; (2) copolymerization; and (3) neutralization. According to the method disclosed by the invention, the ester and ether copolymerized viscosity-reducing polycarboxylic acid water reducing agent is obtained by the copolymerizationan of an esterified monomer, an ester macromonomer, 2-methacryloyl ethyl phosphocholine and unsaturated acid, wherein the esterified monomer is obtained by carrying out esterification on unsaturated polyether and 2-phosphate butane-1, 2, 4-tricarboxylic acid and mainly comprises products obtained by esterifying singe carboxyl in the 2-phosphate butane-1, 2, 4- tricarboxylic acid and esterifying double and three carboxyl in small amount of 2-phosphate butane-1, 2, 4- tricarboxylic acid; and while phosphate radical, carboxylate radical, quaternary ammonium salt and ester group are introduced into a polymer molecular structure, the polymer structure is also lightly crosslinked at the same time. The ester and ether copolymerized viscosity-reducingpolycarboxylic acid water reducing agent prepared by adopting the method disclosed by the invention has the properties of viscosity reducing, water reducing, slump loss resisting and mud resisting tosolve the problems of high viscosity, poor workability and damage rapidness caused by large mud content in conventional concrete raw materials.

Description

technical field [0001] The invention belongs to the technical field of building admixtures, and in particular relates to a preparation method of an ester-ether copolymerized viscosity-reducing polycarboxylate water-reducer. Background technique [0002] Polycarboxylate superplasticizer has the advantages of low dosage, high water reducing rate, strong designability and environmental friendliness, and has become the most widely used concrete admixture. High-rise and ultra-high-rise buildings require concrete to reach a certain level of strength. The pumping construction of high-rise building concrete also has high requirements on the workability of concrete. Ratio, increasing the amount of cementitious materials, increasing the proportion of mineral admixtures, etc., but these measures will also cause problems such as increased concrete viscosity and decreased fluidity. Additives such as air agent or use viscosity-reducing polycarboxylate superplasticizer to solve these prob...

AI Technical Summary

Problems solved by technology

High-rise and ultra-high-rise buildings require concrete to reach a certain level of strength. The pumping construction of concrete in high-rise buildings also has high requirements for the workability of concrete. Ratio, increasing the amount of cementitious materials, increasing the proportion of mineral admixtures, etc., but these measures will also cause problems such as increased concrete viscosity and decreased fluidity. Additives such as air agent or use viscosity-reducing polycarboxylate superplasticizer to solve these problems

However, with the rapid increase in the amount of infrastructure projects, the consumption of sand and gravel is huge, the resources of high-quality sand and gravel are getting less and less, and the mud content in sand and gravel is gradually increasing. The amount is very sensitive, which makes the dispersibility and dispersion retention of polycarboxylate superplasticizer decrease

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