A kind of anti-mud slow-release type slump retaining agent containing cyclodextrin side group and preparation method thereof

Abstract

The invention discloses an anti-mud slow-release slump retaining agent containing cyclodextrin side groups and a preparation method thereof. The invention introduces a structural unit of β-cyclodextrin with proper steric hindrance and better water solubility, and is combined with rich Maic acid undergoes esterification reaction to synthesize anti-mud ester monomers; in the alkaline environment of cement hydration, with the slow release of anti-mud ester monomers, the β-ring introduced into the molecular structure of the water reducer Because the dextrin particles are distributed between 0.53-1.78nm, which is similar to the interlayer spacing of bentonite 1.44-1.86nm, it can effectively weaken the interpenetration between the molecules of the water-reducer and the clay layer, making the polycarboxylate water-reducer play a role. Good anti-mud and slump-preserving effect; at the same time, phosphoric acid monomers are introduced into the molecular structure of the superplasticizer to further improve its anti-mud effect. The anti-slump polycarboxylate superplasticizer containing cyclodextrin side groups prepared by the invention has the advantages of low dosage, long slump retention time and strong anti-sludge performance, and the synthesis process is simple, safe and environmentally friendly, and the production cost is relatively low. Low.

Description

technical field [0001] The invention relates to the technical field of concrete admixture synthesis, and specifically provides a mud-resistant slow-release slump retaining agent containing cyclodextrin side groups and a preparation method thereof. Background technique [0002] Polycarboxylate superplasticizer is a high-performance concrete admixture. It has been widely used in the medium and low grade ready-mixed concrete industry due to its advantages of low mixing, high water reduction, environmental protection and strong functionality. However, polycarboxylate superplasticizers are more sensitive to aggregate clay content. With the gradual reduction of high-quality sand and gravel aggregate resources and the continuous increase of aggregate mud content, the adaptability of polycarboxylate superplasticizers to cement becomes worse, the fluidity of concrete is poor, and the slump loss becomes faster, etc. series of questions. Simply increasing the amount of water reducing...

AI Technical Summary

Problems solved by technology

Although the problem of concrete fluidity can be improved, the loss of concrete slump is relatively fast, and further research is needed

[0004] Patent CN 103819637 A discloses a polycarboxylic acid-based water reducer containing β-cyclodextrin and lignin. The invention improves the water retention and cohesion of concrete by introducing β-cyclodextrin, and to a certain extent It improves the strength of concrete, but its slump protection and anti-mud effects are poor

[0005] Patent CN 102153711 A discloses a preparation method of a retarding polycarboxylate superplasticizer. The polycarboxylate superplasticizer prepared by the invention has stable performance, strong cement adaptability and good compatibility, and the water-reducing rate of concrete It can reach 30-40%, and the slump retention time is 3-5 hours, but its anti-mud effect is poor

[0006] Patent CN 105837738 A discloses a polycarboxylate cationic anti-mud agent and its preparation method and application. The polycarboxylate water reducer product prepared by the invention has a strong dispersion effect under the same aggregate mud content. It can improve the strength of concrete, but its anti-mud effect is limited, and the effect of slump protection is insufficient

[0007] Patent CN 102229479 A discloses a water-retaining polycarboxylate water reducer containing β-cyclodextrin and its preparation and use method. The water reducer has good water reduction and water retention performance, but its slump retention effect Poor, not to mention its anti-mud effect

[0008] In recent years, people have improved the mud resistance of the water reducer by introducing β-cyclodextrin, but this will affect the slump retention effect of the water reducer, resulting in a faster loss of the slump of the water reducer or the dispersibility of the water reducer. reduce

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