Normal-temperature preparation method of slow-release polycarboxylic acid water reducing agent

Abstract

The invention discloses a normal-temperature preparation method of a slow-release polycarboxylic acid water reducing agent. The slow-release polycarboxylic acid water reducing agent is prepared by copolymerizing 20-60% of monomer methyl alkenyl polyethenoxy ether, 10-30% of monomer A, 20-60% of monomer B and 10-30% of monomer C under the action of a H2O2-vitamin C redox initiator at normal temperature. When being used for preparing concrete, the slow-release polycarboxylic acid water reducing agent prepared by the method has the advantages of uniform slow-release rate, favorable slump holding capacity and high environmental adaptability, and can overcome the slump loss in line haul. The normal-temperature polymerization method has the advantage of short technical process, shortens the production time, reduces the abrasion of production equipment, enhances the production efficiency and lowers the product cost.

Description

technical field [0001] The design of the invention belongs to the field of concrete admixtures, and in particular relates to a normal-temperature preparation method of a slow-release polycarboxylate water reducer. Background technique [0002] With the rapid development of my country's economy and the improvement of construction level, the requirements for concrete quality are getting higher and higher. However, due to the reduction of high-quality sand and gravel resources and the complexity of concrete components, in the ready-mixed concrete industry, the problem of slump loss of freshly mixed concrete has always been a problem that plagues engineering construction, especially long-term transportation will lead to concrete slump loss Too large will affect the workability of concrete. Sometimes the addition of water to reshape will make the strength and impermeability of the actual concrete less than the expected design effect. The above problems cannot be solved by using...

AI Technical Summary

Problems solved by technology

However, due to the reduction of high-quality sand and gravel resources and the complexity of concrete components, in the ready-mixed concrete industry, the problem of slump loss of freshly mixed concrete has always been a difficult problem in engineering construction, especially long-term transportation will lead to loss of concrete slump If it is too large, it will affect the workability of concrete

[0006] In the patent CN101205127 A, a formulation and manufacturing method of a slow release polycarboxylate high-performance water reducer is introduced. The formulation includes esterification reaction formulation and polymerization Reaction formula to obtain slow-release polycarboxylate superplasticizer, because allyl ether is used in this method, the polymerization activity is lower than that of methallyl polyoxyethylene ether, and the hydrolysis speed of maleic anhydride is very fast, the product Unsatisfactory performance and sustained release rate

In the patent CN101735411 A, an ether slow-release polycarboxylate water reducer and its preparation process are disclosed. In the copolymerization reaction, polyoxyethylene ether or ester containing unsaturated double bonds is firstly mixed at 40~55°C The macromonomer is prepared as a solution and added to the reaction kettle. After the temperature is raised to 60~85°C, the mixed solution of methacrylic acid or acrylic acid, sodium propylene sulfonate, hydroxyethyl acrylate, and dioxalic acid diacrylate is added dropwise, and the The sulfate initiator is added dropwise separately, the reaction time is up to 8 hours, the process is more complicated, and the reaction temperature is 85°C, which results in higher energy consumption

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