A kind of preparation method of amphoteric polycarboxylate clay inhibitor

Abstract

The invention discloses a preparation method of an amphoteric polycarboxylate clay inhibitor. In a reactor, unsaturated sulfonate monomer and methacryloyloxyethyl dimethylamine are dissolved in deionized water, stirred and heated To a certain temperature, add initiator and unsaturated carboxylic acid monomer at the same time, keep warm for reaction, then cool down to room temperature, carry out quaternization reaction with diol sulfate ester, and finally neutralize it to obtain a light yellow viscous Viscous transparent liquid; as an admixture to suppress the negative impact of clay on the performance of concrete polycarboxylate superplasticizers, this invention can be used in combination with polycarboxylate superplasticizers to reduce the consumption of clay on superplasticizers. Improve the anti-mud performance of the superplasticizer, its relative molecular weight is small, the diffusion is fast, and it is strongly adsorbed on the surface of the clay. Consumption, effectively alleviate the adverse effects of clay on the polycarboxylate superplasticizer.

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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