A kind of preparation method of high performance water reducer

Abstract

A preparation method of a polycarboxylate high-performance water reducer, under the protection of an inert gas and under the action of an oxidation-reduction initiation system and a chain transfer agent, the active macromonomer A (methallyl poly Oxyethylene ether), small molecule monomer B (methacrylic acid or acrylic acid) and small molecule monomer C (sodium methacrylate, sodium propylene sulfonate or sodium styrene sulfonate) are prepared by copolymerization in water. The invention adopts a highly active oxidation-reduction initiation system, which can increase the polymerization reaction rate, lower the polymerization temperature and shorten the reaction time, and the polymer has an ideal molecular structure. The water reducing agent prepared by the invention has excellent properties such as high water reducing rate, good dispersibility, no loss of slump over time, and high concrete strength; at the same time, the method of the invention adopts copolymerization reaction in water, the preparation process is simple, and it also has green Environmental protection, low energy consumption, low cost and other characteristics.

Description

technical field [0001] The invention relates to a preparation method of a concrete water reducer, in particular to a preparation method of a polycarboxylate high-performance water reducer. Background technique [0002] Water reducer is the most important admixture used in concrete. It can greatly improve the performance of freshly mixed concrete, improve the slump retention, workability and fluidity of the concrete mixture, and at the same time reduce the water consumption of the mixture to increase the strength and durability of the concrete. [0003] The first-generation common water reducer represented by wood calcium and the second-generation high-efficiency water reducer represented by naphthalene series and melamine have high dosage, low water reducing rate, large slump loss, Low concrete strength, poor adaptability with cement and other admixtures; at the same time, traditional water reducers such as naphthalene and melamine are formaldehyde condensates. During produ...

AI Technical Summary

Problems solved by technology

The disadvantages of the above preparation method are: the initiator persulfate and hydrogen peroxide have low initiating activity, high reaction temperature (70-90°C), long reaction time (6-8 hours), difficult polymerization control, and low conversion rate , the polymer cannot obtain the ideal comb-shaped molecular structure, and the performance of the prepared water reducer is poor; the use of mercapto compounds as chain transfer agents is highly toxic and has a strong pungent smell, which is likely to cause environmental pollution during production and application.