Preparation method of tannic acid-based star-shaped polycarboxylate superplasticizer

Abstract

The invention discloses a preparation method of a tannic acid-based star-shaped polycarboxylate superplasticizer. The preparation method comprises the following steps: adding tannic acid, sodium hydroxide and water into a reaction kettle, dropwisely adding glycidyl methacrylate, and reacting to obtain modified tannic acid; reacting the modified tannic acid, an unsaturated polyether macromonomer, an unsaturated fatty acid micromonomer, an initiator, a chain transfer agent and water at 50-80 DEG C for 3-6 hours; and adjusting the pH value of an obtained star-shaped copolymer to 6.0-7.0 by usingan alkaline substance to obtain a reddish brown solution, namely the tannic acid-based star-shaped polycarboxylate superplasticizer. The tannic acid-based star-shaped polycarboxylate superplasticizerdisclosed by the invention has the advantages of multiple molecular branched chains, low viscosity, small hydrodynamic volume, rich surface functional groups; the tannic acid molecules have a large number of hydroxyl groups, the rich polar groups have a strong hydrophilic effect with the polar surfaces of cement particles, and hydration films can be generated on the surfaces of the cement particles, so that the cement particles are fully dispersed and wetted.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a preparation method of a tannic acid-based star polycarboxylate water reducer. Background technique [0002] In recent years, with the continuous expansion of the scale of civil engineering and the continuous improvement of the level of science and technology, some important buildings with high-rise, long-span and special functional requirements continue to appear, such as skyscrapers, super-long-span bridges, high-speed railways and giant water conservancy projects. Construction, etc. , requiring concrete to have higher strength, better durability, and better stability. Water reducing agent is one of the indispensable important components of high performance concrete. Water reducing agent can reduce the water consumption of concrete during use, improve its durability, improve the collapse retention, change the properties of concrete, and improve the perfo...

AI Technical Summary

Problems solved by technology

Carboxylic acid-based high-performance water reducers have only a few decades of development history, and neither the molecular structure nor the product range is rich enough to fully meet the current theoretical and application needs of concrete.

At present, researchers mainly focus on preparing comb-type polycarboxylate superplasticizers to solve the problems of concrete dispersion and dispersion retention through molecular structure design, but there are often problems such as single molecular structure and uncontrollable structure, complex preparation process, and high production cost.

Images