A kind of preparation method of cross-linked polycarboxylate water reducer using carboxyl functional monomer

Abstract

The invention provides a preparation method for a cross-linking type polycarboxylate water reducer by adopting carboxyl functional monomers. The preparation method includes adding polyether macromonomers, hydroxyl functional monomers, phosphate functional monomers and water into a reaction kettle, and performing stirring and heating until a mixture is dissolved; controlling a temperature at 55-60DEG C, and starting adding an initial initiator, an osmotic agent and a chain transferring agent; simultaneously dropping a solution A and a solution B after 5 min, and starting dropping a solution Cwithin 10 min after the solution A and the solution B start dropping, the dropping time of the solution C being a hour, the dropping time of the solution A and the solution B being a+0.5 hours, the solution C consisting of carboxyl functional monomers and water, the solution A consisting of ascorbic acid, a cross-linking agent and water, and the solution B consisting of hydrogen peroxide and water; heating to 70-75 DEG C after the dropping is finished, keeping the temperature constant, performing curing for b hour, adding a neutralizer when the temperature of a to-be-reacted solution is less than 30 DEG C, and replenishing water to 1,000 parts so that a water reducer can be obtained. The polycarboxylate water reducer with high dispersibility and keeping slump can be obtained through the preparation method.

Description

technical field [0001] The invention belongs to the technical field of building materials and relates to the field of concrete admixtures, in particular to a preparation method of a cross-linked polycarboxylate water reducer using carboxyl functional monomers. Background technique [0002] With the rapid development of high-performance concrete technology, the requirements for the performance of water reducers in engineering applications are also increasing. In practical applications, due to factors such as changes in cement and unreasonable sand and gravel materials, polycarboxylate superplasticizers are prone to problems such as poor slump retention and segregation and bleeding of concrete, which have a great impact on construction and later performance of concrete. big negative impact. The current method to deal with this situation is to use compound slump-preserving agent and retarder and other chemical reagents to improve the working performance, but there are problems...

AI Technical Summary

Problems solved by technology

In practical applications, due to factors such as changes in cement and unreasonable sand and gravel materials, polycarboxylate superplasticizers are prone to problems such as poor slump retention and segregation and bleeding of concrete, which have a great impact on construction and later performance of concrete. big negative impact

At present, the way to deal with this situation is to use other chemical reagents such as compound slump-preserving agent and retarder to improve the working performance, but there are problems such as the high cost of slump-retaining agent and the excessive prolongation of setting time by retarder.

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