Preparation method of amphoteric clay inhibitor with low relative molecular mass

Abstract

The invention discloses a preparation method of an amphoteric clay inhibitor with low relative molecular mass. The amphoteric clay inhibitor with the low relative molecular mass is synthesized through copolymerization of unsaturated carboxylic acid or anhydride, unsaturated sulfonic acid or sulfonate and cationic monomer and is compounded with a polycarboxylate superplasticizer for use, so that consumption of the superplasticizer by clay can be reduced, and the mud resistance performance of the superplasticizer is improved. The clay inhibitor is amphoteric linear polymer with the low relative molecular mass, has low relative molecular mass, is fast in diffusion, has high adsorption performance on the clay surface and has an advantage of competitive adsorption with the polycarboxylate superplasticizer, so that consumption of the superplasticizer by the clay is reduced, and an adverse effect caused by the clay on the polycarboxylate superplasticizer is effectively relieved; used production equipment is simple and easy to operate, adopts a reasonable process, and facilitates industrial production.

Description

technical field [0001] The invention belongs to the technical field of concrete additives, in particular to a preparation method of a low relative molecular mass amphoteric 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. [0003] 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 pol...

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Problems solved by technology

[0003] 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

[0004] 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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