Reduced shrinkage early strength polycarboxylic acid water reducing agent mother liquid and preparation process thereof

Abstract

The invention discloses a reduced shrinkage early strength polycarboxylic acid water reducing agent mother liquid and a preparation process thereof. The water reducing agent mother liquid is preparedby the free radical copolymerization reaction of a polyether macro-monomer, an anionic active monomer, a cationic active monomer, a shrinkage reducing monomer, a chain transfer agent and an initiator;wherein the polyether macro-monomer is isopentenyl polyoxyethylene ether and / or methyl allyl polyoxyethylene ether; the anionic active monomer is acrylic acid; the cationic active monomer is methacrylatoethyl trimethyl ammonium chloride; the shrinkage reducing monomer is an esterification reaction product of a phenyl alcohol or a methyl phenyl alcohol with acrylic acid; the chain transfer agent is 2-methyl-2-propene-1-sulfonic acid sodium salt; and the initiator comprises an initiator system A and an initiator system B, the initiator system A comprises organic hydrogen peroxide and vitamin C,and the initiator system B comprises sodium bisulfite and a ferrous salt. According to the preparation process, different functional monomers are grafted to the high-performance polycarboxylic acid water reducing agent, and the length of the main chain is adjusted, so that the polycarboxylic acid water reducing agent has excellent water reducing rate, and also has early strength and reduced shrinkage.

Description

technical field

[0001] The invention relates to the technical field of concrete admixtures, in particular to a shrinkage-reducing early-strength polycarboxylate water-reducer mother liquor and a preparation process. Background technique

[0002] Polycarboxylate superplasticizer is a high-performance concrete admixture, its main function is to reduce the amount of mixing water, change the rheological properties and construction performance of concrete, etc. Polycarboxylate high-performance water reducer is a macromolecular compound composed of functional groups such as sulfonic acid groups, carboxyl groups, amino groups, and polyoxyethylene side chains. It is usually synthesized in aqueous solution by the principle of free radical copolymerization with a comb-shaped structure. polymeric surfactants. Compared with the high-efficiency superplasticizers with straight-chain structures such as naphthalene and aliphatic, which were widely used before, polycarboxylate high-performa...

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