METHOD FOR PREPARING POLYCARBOXYLIC ACID-BASED WORKABILITY REGULATOR Russian patent published in 2021 - IPC C04B24/26 C04B24/24 C04B103/30 C08F220/10 C08F220/06 

FIELD: chemical industry.

SUBSTANCE: present invention relates to a method for preparing a polycarboxylic acid-based workability regulator. The method includes a copolymerization step followed by a neutralization step. Copolymerization involves mixing a polymerizable reducing agent, a macromonomer of an unsaturated polyether and water in a reaction vessel, dripping a mixed solution of an unsaturated acid and an unsaturated ether, an aqueous solution of an oxidizing agent and an aqueous solution of a chain transfer agent into a reaction vessel, obtaining a reaction mixture for 0.5-6 hours at a temperature of 50°С. Neutralization involves adding an alkaline solution after the completion of the reaction and adjusting the pH of the reaction mixture to 6-7. A polymerizable reducing agent is obtained by transesterification of compounds A and B in an organic solvent with a catalyst and a polymerization inhibitor at a temperature of 80-120°С for 5-24 hours. Compound A is a compound of the formula: where R₁ is a linear or branched C₁-C₅ alkyl group, R₂ is -(CH₂)_n-, phenylene or ethoxyphenylene, where n is an integer from 1 to 10 and R₃ is a linear or branched C₁-C₅ alkyl group. Compound B is a compound of the formula in which R is H, linear or branched C₁-C₅ alkyl, -CH₂CH₂OH, or and n is an integer from 1 to 300.

EFFECT: obtained, in accordance with the presented method, workability regulator based on polycarboxylic acid can not only significantly improve the insulating characteristics and mobility of concrete, reduce the likelihood of water separation and mortar separation, but also increase the dispersibility and cohesion of concrete.

9 cl, 1 tbl, 10 ex