Preparation method of slump retaining ether type polycarboxylic water reducing agent

Abstract

The invention relates to a preparation method of a slump retaining ether type polycarboxylic water reducing agent. The method includes steps: (1) dissolving 80-100 parts of unsaturated polyether macromonomers into 60-85 parts of water, well stirring, and heating to 50-70 DEG C at a rate of 30-50 DEG C per hour to obtain a mixed solution; (2) keeping the temperature of the mixed solution at 50-70 DEG C, adding 0.5-1 part of an initiator, and well stirring to obtain a mixed solution; (3) keeping the temperature of the mixed solution at 50-70 DEG C while dropwise adding 15-30 parts of unsaturated carboxylic acid and unsaturated carboxylic acid derivative micromonomer solution and 20-30 parts of molecular weight regulator solution, keeping the temperature at 50-70 DEG C for 1-2h after adding is finished, and ageing to obtain a mixed solution; (4) adding 50-80 parts of water into the mixed solution, and dropwise adding sodium hydroxide solution to adjust a pH value to 6-7 to obtain the slump retaining ether type polycarboxylic water reducing agent.

Description

technical field [0001] The invention belongs to the field of building materials, and relates to a preparation method of an admixture, in particular to a preparation method of a slump-retaining ether polycarboxylate water reducer. Background technique [0002] With the continuous popularization of polycarboxylate high-performance water reducing agent and the continuous development of technology, in addition to the application of high-speed rail industry, the road of development in other industries such as expressway and commercial concrete is also getting wider and wider, and it is expected to occupy the reduction in 5 years. The water agent market, which represents the most advanced technical product of concrete water reducer, is a hot spot in the research and development of chemical admixtures. [0003] Polycarboxylate superplasticizers are polymerized by a variety of unsaturated monomers through free radical reactions. Therefore, according to molecular design, different ra...

AI Technical Summary

Problems solved by technology

[0005] Although there are several slump-retaining polycarboxylate superplasticizers with high water-reducing rate in the prior art, compound ester polycarboxylate superplasticizers or various kinds of polycarboxylate superplasticizers are still used to solve the problem of poor workability of concrete. The method of sample water retention and viscosity adjustment agent

The disadvantage of these methods is that not only the production process of ester polycarboxylic acid is complicated, but also the slump retention of concrete will be reduced, and the compatibility of water-retaining viscosity-adjusting agent and polycarboxylate superplasticizer is poor, and there will be precipitation and delamination, and even Putting it for a period of time will make the water reducing agent smelly, and it will increase the viscosity of the concrete and affect its fluidity