Preparation method of delayed coagulation type ester polycarboxylate water reducing agent

Abstract

The invention discloses a preparation method of a delayed coagulation type ester polycarboxylate water reducing agent. The preparation method comprises the following steps: (1) preparing an esterification monomer; (2) performing a copolymerization reaction; and (3) performing a neutralization reaction. The preparation method utilizes a saccharide compound and crotonic acid to prepare the esterification monomer, and has the advantages of low costs and simple and convenient operation; the prepared saccharide esterification product participates in the next step of the copolymerization reaction, so that the main chain of the polycarboxylate water reducing agent has a polyhydroxy structure, and the prepared polycarboxylate water reducing agent has a better delayed coagulation effect, effectively prolongs the initial setting and final setting time of cement, and can reduce negative effects caused by using a retarder; and the polyhydroxy structure of the saccharide compound enables the polycarboxylatewater reducing agent to have better slump loss resistance, so that the pumping construction of concrete in summer is facilitated.

Description

technical field [0001] The invention belongs to the technical field of building admixtures, and in particular relates to a preparation method of a retarding type ester polycarboxylate water reducer. Background technique [0002] With the construction of national large-scale infrastructure nuclear power, water conservancy, bridges and various large-scale projects, the performance requirements of concrete are constantly improving, which will inevitably lead to higher requirements for the performance of concrete admixtures. [0003] Although the excellent water-reducing performance of polycarboxylate superplasticizers has been widely recognized by the industry, due to factors such as changes in cement, mud content in sand, and stone materials, polycarboxylate superplasticizers have also appeared in practical applications. Problems such as excessive slump loss and poor workability. For some concrete that is transported over long distances in summer and constructed in hot weathe...

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Problems solved by technology

[0003] Although the excellent water-reducing performance of polycarboxylate superplasticizers has been widely recognized by the industry, due to factors such as changes in cement, mud content in sand, and stone materials, polycarboxylate superplasticizers have also appeared in practical applications. Problems such as excessive slump loss and poor workability

For some concrete that is transported over long distances in summer and constructed in hot weather, compound retarders are often used to prolong the setting time. The retarder components contained in the layer superplasticizer are different, which will cause some problems of short or long setting time in the actual application process, which will affect the engineering construction. Water agent is of great significance

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