A kind of preparation method of anti-mud type polycarboxylic acid slump retaining agent adopting carboxyl functional monomer

Abstract

The invention provides a method for preparing a mud-resistant polycarboxylic acid slump inhibitor from a carboxyl functional monomer. The preparation method comprises the followings steps: adding a polyether macromonomer, the carboxyl functional monomer, a phosphate functional monomer and water into a reaction kettle according to a certain proportion, stirring and heating the mixture till the mixture is dissolved; controlling the temperature at 55 to 60 DEG C, and starting to add a certain amount of penetrant and chain transfer agent; starting to dropwise add a solution A and a solution B simultaneously for (a+0.5) hours 5 minutes later, and starting to dropwise add a solution C for a hour 10 minutes later, wherein the solution A is prepared from an initiator, an ethanol organic solvent and water, the solution B is prepared from hydrogen peroxide and water, and the solution C is prepared from carboxylic ester, acrylic acid and water; heating to 70 to 75 DEG C after finishing of dropwise adding, keeping the temperature constant, curing for b hour, adding a neutralizing agent after the reaction solution is lower than 30 DEG C, and adding water to 1000 parts to obtain the mud-resistant polycarboxylic acid slump inhibitor. By adopting the method, the polycarboxylic acid water reducing agent with high mud resistance and adsorption resistance can be prepared.

Description

Technical field [0001] The invention belongs to the technical field of building materials, relates to the field of concrete admixtures, and specifically relates to a preparation method of an anti-sludge type polycarboxylic acid slump retaining agent using a carboxyl functional monomer. Background technique [0002] With the continuous construction of high-speed railways, highways and various landmark buildings, the amount of high-performance concrete is increasing. As an important part of high-performance concrete, sand and gravel and admixtures affect the performance of concrete. However, high-quality sand and gravel resources continue to decrease, and in many areas, machine-made sand or river sand are used as alternative materials. Compared with high-quality sand, the mud content of machine-made sand and river sand is generally higher. The traditional polycarboxylic acid slump protection agent is easy to be absorbed and wrapped by the clay layer. The main components of the clay...

AI Technical Summary

Problems solved by technology

Compared with high-quality sand, machine-made sand and river sand generally have higher mud content. Traditional polycarboxylate slump-retaining agents are easily absorbed and wrapped by clay layers. The main components of clay in sand are montmorillonite, kaolin and illite Soil, etc., its layered structure is easy to cause intercalation adsorption and end surface adsorption on the slump-preserving agent molecules. Even after the later hydrolysis and release, its carboxyl group cannot act on the surface of cement particles, and it is difficult to exert the effect of slump-preserving agent

Images