Method for ultralow-temperature preparation of polycarboxylic acid type high slump keeping water reducer by utilizing ethoxyethanol vinyl polyoxyethylene ether

Abstract

The invention relates to a polycarboxylate water reducer, in particular to a method for ultralow-temperature preparation of a polycarboxylic acid type high slump keeping water reducer by utilizing ethoxyethanol vinyl polyoxyethylene ether. The method comprises the steps that water, the ethoxyethanol vinyl polyoxyethylene ether, acrylic acid, acrylic alkyl ester and amide monomers are put in a reaction kettle, heating is not needed, and stirring is conducted until the mixture is dissolved; an oxidizing agent solution is added, a prepared solution A and a prepared solution B are dropwise added to the mixed solution, and after 0.5 hour, the solution A and the solution B are dropwise added completely at the same time; after the temperature is preserved for 0.5 h, an alkali solution is added for neutralizing until the pH value is 6-8, and after water supply, the polycarboxylic acid type high slump keeping water reducer with the concentration of 40% is obtained; the solution A is prepared from acrylic acid, a chain transfer agent and water; the solution B is a reductive catalyst. According to the method, the ethoxyethanol vinyl polyoxyethylene ether of high polymerization activity, acrylic alkyl ester hydrophobic side chains and the amide monomers are taken as raw materials for preparing the high slump keeping water reducer, the reaction period is short, the normal temperature reaction time is only one hour, and the production efficiency is high.

Description

technical field [0001] The invention relates to a polycarboxylate water reducer, in particular to a method for preparing a polycarboxylate high slump retention water reducer by using ethylene glycol monovinyl polyoxyethylene ether at ultra-low temperature. Background technique [0002] Polycarboxylate admixture is an extremely important component in modern concrete, which can significantly improve the performance of concrete. With the rapid development of national construction and the remarkable progress of construction technology, the building structure is developing towards large-scale, complex and functional directions, and the performance requirements of concrete in the construction process are also getting higher and higher. Important work for high performance concrete needs. [0003] As the third generation of concrete water reducer, polycarboxylate water reducer has the advantages of high water reducing rate, low dosage, large degree of freedom in molecular structure...

AI Technical Summary

Problems solved by technology

[0004] During the use of polycarboxylate superplasticizer, the hydration of cement will cause the molecules of the superplasticizer to be covered by hydrolysis products, resulting in the loss of concrete slump, which cannot meet the construction requirements of concrete under specific application requirements.

Aiming at the problem of rapid loss of concrete slump, the current patent discloses some improvement methods, such as changing the length and density of the hydrophilic side chain in the water reducer molecule, using esterified products as macromonomers for synthesis, and introducing retarding However, the above methods are still difficult to improve the problem of rapid loss of concrete slump in the case of cement diversification and poor sand and gravel materials.

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