Preparation method of esters retarding polycarboxylic acid slump retaining agent

Abstract

The invention discloses a preparation method of an esters retarding polycarbocylic acid slump retaining agent. The method comprises the following steps that 1, unsaturated carboxylic acid and / or anhydride, alkoxy poly alkylene glycol, hydroxy ethidene diphosphonic acid and / or 2-hydroxyphosphonoacetic acid and polymerization inhibitor are mixed, under the protection of nitrogen, the temperature is increased to range from 40 DEG C to 60 DEG C, a catalyst is added, the temperature is increased to 100-140 DEG C, thermal reaction is conducted for 0.5-3 h, water is removed during the reaction, after reaction is finished, the temperature is cooled to room temperature, and a first mixture is obtained; 2, the first mixture and unsaturated carboxylic acid hydroxyl esters are mixed, and a comonomer mixture solution is obtained; 3, the comonomer mixture solution, an initiator aqueous solution and a molecular weight regulator aqueous solution are dropped in water to conduct reaction, and a copolymer product is obtained; 4, pH of the copolymer product is adjusted to 5-7 through alkali, and the esters retarding polycarbocylic acid slump retaining agent is obtained. According to the preparation method of the esters retarding polycarbocylic acid slump retaining agent, a structure of the hydroxy ethidene diphosphonic acid and / or the 2-hydroxyphosphonoacetic acid is introduced into the esters polycarbocylic acid slump retaining agent, and a finally obtained product has the effects of retardation and slump retaining.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a preparation method of an ester retarding polycarboxylate slump retaining agent. Background technique [0002] In recent years, due to changes in concrete raw materials, problems such as rapid loss of concrete slump, poor workability, and delayed bleeding have become more and more prominent. However, most of these slump-preventing agents are ether-based polycarboxylic acid-based slump-preserving agents, which often have problems such as poor workability and delayed bleeding in practical applications. In summer, in order to make the concrete meet the construction requirements, it is often necessary to compound slump retaining agent and retarder in the water reducer to obtain suitable slump retention and setting time, and in order to solve the problem of poor workability and delayed bleeding For water problems, it is often necessary to compound a certain am...

AI Technical Summary

Problems solved by technology

The compatibility of these additives in the admixture is not very ideal, and often there will be abnormal concrete properties caused by poor compatibility, such as: due to the poor compatibility of the retarder in the admixture, the retarder will be in the admixture The content of the bottom layer of the primer is too high. If you don’t notice it when you use it, the use of admixtures that exceed the standard of the bottom layer retarder will make the concrete set for a long time or even not set, which will bring hidden dangers to engineering applications.