Viscosity-reducing type polycarboxylic acid water reducing agent preparation method

Abstract

The invention discloses a viscosity-reducing type polycarboxylic acid water reducing agent preparation method, which comprises: (1) preparing an esterification monomer; (2) carrying out a copolymerization reaction; and (3) carrying out a neutralization reaction. According to the present invention, the viscosity-reducing type polycarboxylic acid water reducing agent is prepared by co-polymerizing 2-allyloxyethanol, a blend, VPEG, 2-methacryloyloxyethyl phosphorylcholine and an unsaturated acid, such that the phosphate radical, the carboxylate radical, the quaternary ammonium salt and the estergroup are introduced into the molecular structure of the polymer while the polymer structure is lightly cross-linked, wherein the product obtained by the esterification of the single carboxy in 2-phosphonobutane-1,2,4-tricarboxylicacid prepared by a 2-phosphonobutane-1,2,4-tricarboxylicacid esterification reaction, the product obtained by the esterification of the two carboxy in a small amount of2-phosphonobutane-1,2,4-tricarboxylicacid and the product obtained by the esterification of the three carboxy in a small amount of 2-phosphonobutane-1,2,4-tricarboxylicacid form the blend; and the prepared viscosity-reducing type polycarboxylic acid water reducing agent has advantages of viscosity reducing, water reducing, slump retaining and mud resistance, and can solve the problems of high viscosity, poor workability and rapid loss due to the high mud content in the current concrete raw materials.

Description

Technical field [0001] The invention belongs to the technical field of building admixtures, and specifically relates to a preparation method of a viscosity-reducing type polycarboxylic acid water reducer. Background technique [0002] Polycarboxylic acid water reducing agent 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 super 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. In order to achieve a higher level of strength, it is generally possible to reduce water ash However, these measures will also increase the viscosity of the concrete and decrease the fluidity of the concrete. At present, it is generally achieved through the use of compound anti-mud agents and air-entraining agents. Or use viscosity-redu...

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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. 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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