Preparation method of polycarboxylic acid water reducer containing paw type short side chains

Abstract

The invention discloses a preparation method of a polycarboxylic acid water reducer containing paw type short side chains. The preparation method comprises following specific steps: cis-hexadiene diacid and a small monomer containing an active double bond and polycarboxylic acid groups are subjected to Diels-Alder reaction in an alcohol solution at 40 to 50 DEG C so as to obtain a claw type unsaturated small monomer; the claw type unsaturated small monomer, and a unsaturated carboxylic acid small monomer and an unsaturated large monomer are subjected to free radical polymerization under the co-effect of an initiator, a reducing agent, and a chain transferring agent at 10 to 50 DEG C for 3 to 5h so as to obtain a copolymerization product, an alkali is added to adjust the pH value to 5 to 7,and water is added so as to obtain the polycarboxylic acid water reducer containing paw type short side chains with a mass concentration of 20 to 50%. The adsorption groups of conventional polycarboxylic acid water reducers are increased, the reaction is simple and convenient, the claw type adsorption groups are stable in performance, finished product yield is high, and the polycarboxylic acid water reducer containing paw type short side chains prepared using the preparation method is a functional polycarboxylic acid water reducer with both sludge resistance and plasticity maintenance performance.

Description

technical field [0001] The invention relates to the technical field of polycarboxylate water-reducer for building materials cement concrete, in particular to a method for preparing a polycarboxylate water-reducer containing claw-shaped short side chains. Background technique [0002] Polycarboxylate superplasticizer has become a new generation of concrete admixture because of its high water reducing rate, strong dispersion of cement particles, good slump retention performance, low dosage and strong molecular design. The polycarboxylate water reducer mainly plays the role of dispersion and water reduction through the electrostatic repulsion of the functional groups that can be adsorbed on the surface of cement particles and the steric hindrance of the long side chain of PEO. [0003] However, with the continuous development of the concrete industry and the increasing depletion of raw material resources, more and more concrete mixing plants in cities have to use gradually dete...

AI Technical Summary

Problems solved by technology

[0010] Aiming at the deficiencies of the prior art, the present invention provides a method for preparing a polycarboxylate-based water reducer with claw-type short side chains, and provides a claw-type water-reducer with a simple production process in order to enrich and improve the deficiencies of the prior art. The preparation method of polycarboxylic acid-based water reducer solves the problems that the synthesis process is generally complicated, the cost is relatively high, and its mud resistance is relatively general

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