Efficient polycarboxylate superplasticizer as well as preparation method and application thereof

Abstract

According to the high-efficiency polycarboxylate superplasticizer and the preparation method thereof provided by the invention, the low-activity small monomer is added into the reaction substrate, so that the reaction resistance is increased, and the initial reaction rate is better inhibited; low-activity small monomers are added into the material A, so that the overall reaction activity of small monomer acrylic acid in the material A is reduced; and a certain amount of low-activity small monomers are regularly added in the reaction process, so that the reaction rate of the whole polymerization reaction process is further effectively regulated and controlled. Through the steps, the monomer activity in the reaction system is always controlled at a certain level, so that the polymerization reaction is uniformly and continuously carried out, the conversion rate of the synthesis reaction is improved, and the performance of the water reducer is improved. Meanwhile, after the reaction process is controlled by the method, the polymerization reaction does not need to be carried out under a low-temperature condition (8-12 DEG C), the reaction rate can be effectively controlled, and the production cost of the water reducing agent is reduced.

Description

technical field [0001] The invention belongs to the field of concrete admixture industry, and in particular relates to a high-efficiency polycarboxylate water reducer and its preparation method and application. Background technique [0002] EPEG type polyether monomer (ethylene glycol monovinyl polyoxyethylene ether) is a new type of polyether monomer that has appeared in recent years. Due to its special molecular structure design, the double bond electron cloud density is relatively large, and the space position low resistance and high reactivity. When used in the synthesis of polycarboxylate superplasticizers, it can greatly shorten the polymerization reaction time and improve the production efficiency of superplasticizers. At the same time, the double bond in the molecule is a substitution structure, which reduces the steric resistance of the swing of the polyether side chain, makes the swing of the polyether side chain more flexible, improves the encapsulation and entan...

AI Technical Summary

Problems solved by technology

It is worth noting that low temperature conditions will undoubtedly increase the production cost of water reducing agent products and increase the difficulty of large-scale industrial production of products

At the same time, although the low temperature condition can improve the initial reaction rate of the superplasticizer synthesized by EPEG type polyether monomer to a certain extent, the problem of too fast initial reaction rate, but judging from the monitoring results of the conversion rate change during the synthesis reaction, the use under low temperature conditions When the EPEG type polyether monomer synthetic water reducer is added more than half of the time, the GPC test result of the reaction is relatively close to the GPC test result after the reaction is complete, which shows that when the drop time reaches half, the synthesis reaction may have tended to Termination, the subsequent acrylic acid entering the reaction system may not effectively participate in the polymerization reaction, so low temperature conditions cannot well solve the problems of fast early polymerization rate and early termination

Images