Method for preparing concrete water reducing agents from polycarboxylic acid modified acyl halide grafted composite side chains

Abstract

The invention discloses a method for preparing concrete water reducing agents from polycarboxylic acid modified acyl halide grafted composite side chains, and belongs to the field of water reducing agents. By the aid of the method for polymerizing main chains, modifying acyl halide, polymerizing cationic side chains and then carrying out grafting reaction, polycarboxylic acid modified acyl halide grafted composite side chain type concrete reducing agent materials which are excellent in performance can be prepared. The method includes carrying out free radical polymerization on unsaturated carboxylic acid monomers to obtain the polycarboxylic acid main chains; modifying carboxylic acid groups on the main chains to obtain acyl halide groups; forming oxidation-reduction initiation systems from high-valence ceric salt and alcohol, initiating polymerization of unsaturated cationic quaternary ammonium salt monomers by the aid of the oxidation-reduction initiation systems to obtain the hydroxyl-terminated cationic side chains; carrying out the grafting reaction on the polycarboxylic acid main chains with the acyl halide groups, the hydroxyl-terminated cationic side chains and polyethylene glycol compounds to obtain the concrete water reducing agents. The method has the advantages that owing to modes for modifying the acyl halide by polycarboxylic acid and grafting the cationic side chains and polyethylene glycol side chains, composite side chain structures can be synthesized, reaction procedures are simple and are easy to control, energy can be saved, the method is high in efficiency, and excellent water reduction slump retaining and high-resistant clay composite effects can be realized.

Description

technical field [0001] The present invention relates to the technical field of a composite side chain type concrete water reducer, in particular to a method that adopts an unsaturated carboxylic acid monomer to first polymerize the main chain, then modify the acyl halide group, then polymerize the cationic side chain, and then graft the main side chain. The specific preparation method of reaction synthesis composite side chain type concrete water reducer. Background technique [0002] As the third generation of water reducer, polycarboxylate water reducer with polycarboxylic acid as the main molecular structure has become an indispensable and important component in concrete. It makes an important contribution to the preparation and realization of the excellent characteristics of high-performance concrete. With the widening of various auxiliary materials in concrete, the adaptability of concrete superplasticizers to various raw materials has become the focus of researchers. ...

AI Technical Summary

Problems solved by technology

Therefore, this requires a fundamental innovation in the molecular structure of the synthesized water reducing agent. It does not stick to the traditional synthesis method, and innovatively uses carboxylic acid modified acid halides, high-valent cerium salts to initiate long chains of polycations, and acid halides. The synthesis route and characteristics of grafted polycation side chains and polyether side chains not only have the composite work performance of water-reducing and slump-resistance, but also are conducive to industrial production and popularization and application. There are no reports on this aspect at home and abroad.

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