Preparation method of amphoteric polycarboxylate clay inhibitor

Abstract

The invention discloses a preparation method of an amphoteric polycarboxylate clay inhibitor. The preparation method comprises the following steps: dissolving unsaturated sulfonate monomer and methylpropenylacyloxy ethyldimethylamine in deionized water in a reactor, heating to a certain temperature while stirring, simultaneously adding an initiator and unsaturated carboxylic acid monomer, keeping the temperature to react, cooling to room temperature, carrying out quaternization with diol sulfate, and finally, neutralizing to obtain a light yellow viscous transparent liquid. The amphoteric polycarboxylate clay inhibitor can be compounded with a polycarboxylic acid water reducer as an additive for inhibiting negative influence of clay on the performance of the concrete polycarboxylate water reducer so as to reduce the water reducer consumption by the clay and enhance the sludge resistance of the water reducer. The amphoteric polycarboxylate clay inhibitor has small relative molecular mass and high dispersion speed, can be violently adsorbed on the clay surface, is free of chlorine ions, and has competitive adsorption advantages as compared with the polycarboxylic acid water reducer, thereby reducing the water reducer consumption by the clay and effectively relieving the adverse influence of the clay on the polycarboxylic acid water reducer.

Description

technical field [0001] The invention belongs to the technical field of concrete additives, in particular to a preparation method of an amphoteric polycarboxylate clay inhibitor. Background technique [0002] Polycarboxylate water reducer is the third generation of high-performance water reducer after wood sodium water reducer and naphthalene water reducer, which has the advantages of low dosage, high water reducing rate, small loss of concrete slump Good adaptability and low content of harmful ingredients. It has been widely used in the construction of large national infrastructure projects such as high-speed rail, bridges, airports, and nuclear power. Although polycarboxylate superplasticizer has many advantages, it also has its own defects, among which the raw materials of concrete, especially the mud content in sand and gravel, have a significant impact on the performance of polycarboxylate superplasticizer. Clay has a strong adsorption effect on polycarboxylate superpl...

AI Technical Summary

Problems solved by technology

Although polycarboxylate superplasticizer has many advantages, it also has its own defects. Among them, the raw materials of concrete, especially the mud content in sand and gravel, have a significant impact on the performance of polycarboxylate superplasticizer.

Clay has a strong adsorption effect on polycarboxylate superplasticizer, which can absorb polycarboxylate superplasticizer into its interlayer structure, so that the superplasticizer that interacts with concrete is greatly reduced; and clay has a strong water absorption effect , after mixing, the free water in the slurry will decrease, which will seriously affect the fluidity and slump retention of concrete; increase the shrinkage of concrete, increase the risk of cracking, reduce the strength and durability, and greatly restrict its promotion and application

The impact of clay on concrete can be improved by increasing the amount of polycarboxylate water-reducing agent added, but this will greatly increase the cost of concrete, and the addition of too much water-reducing agent will affect the later strength of concrete, and may also cause concrete to set The time is too long; Chinese patent application CN102358763A proposes a preparation method of an anionic copolymer, which has a certain inhibitory effect on clay, but because the overall clay is electronegativity, the copolymer only contains anionic functional groups, so the shielding effect on clay The effect is limited; although the Chinese patent application CN102617811A proposes a preparation method of an amphoteric anti-mud agent, macromonomer polyethylene glycol monohexyl ether is introduced in the molecular design, which not only has high production cost, but also has a relatively large relative molecular weight of the synthesized molecule. Competitive adsorption to clay is not strong enough compared to superplasticizers

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