Preparation method of slump retaining agent containing ether type polycarboxylic acid

Abstract

The invention discloses a preparation method of a slump retaining agent containing ether type polycarboxylic acid. The preparation method comprises the following steps: (1) esterification reaction; (2) copolymerization reaction; (3) neutralization reaction. According to the preparation method disclosed by the invention, aliphatic hydroxyl ester and esterification products from unsaturated anhydride are used in copolymerization of a polycarboxylic acid slump retaining agent, and a structure with carboxyl groups and double ester groups is introduced into a molecular chain structure of polycarboxylic acid, so that electronegative carboxylate radicals cannot influence the electrostatic repulsive force of a water reducing agent, and the problems of workability and sensibility of concrete can be improved. The double ester groups are hydrolyzed under an alkaline condition of cement paste, so that more carboxyl groups are slowly released, and the slump retaining property of the concrete can be improved; meanwhile, the polycarboxylic acid slump retaining agent in the structure can adapt to various materials and has lower sensibility.

Description

technical field [0001] The invention belongs to the technical field of building admixtures, and in particular relates to a preparation method of an ether polycarboxylic acid slump-retaining agent. Background technique [0002] At present, polycarboxylate slump-retaining agents are more and more widely used in the market, and the products can solve some slump problems to a certain extent, but in the face of factors such as high mud content, high stone powder content, and cement changes, polycarboxylate In actual application, the slump retaining agent has defects such as insufficient slump retaining performance, too fast loss, poor sensitivity, hysteresis bleeding, etc., especially in the medium and low grade concrete mix, the rapid loss and poor sensitivity are particularly obvious. Therefore, it is of great significance to develop a slump-retaining agent that can satisfy the use of various materials and has good slump-retaining effect, workability and sensitivity. Contents...

AI Technical Summary

Problems solved by technology

[0002] At present, polycarboxylate slump-retaining agents are more and more widely used in the market, and the products can solve some slump problems to a certain extent, but in the face of factors such as high mud content, high stone powder content, and cement changes, polycarboxylate In actual application, the slump retaining agent has defects such as insufficient slump retaining performance, too fast loss, poor sensitivity, hysteresis bleeding, etc., especially in the medium and low grade concrete mix, the rapid loss and poor sensitivity are particularly obvious