A kind of preparation method of tannic acid-based star polycarboxylate water reducer

Abstract

The invention discloses a preparation method of a tannic acid-based star-shaped polycarboxylate water reducer. The method is to first add tannic acid, sodium hydroxide and water into a reaction kettle, and then add glycidyl methacrylate dropwise. , and react to obtain modified tannic acid; then react modified tannic acid, unsaturated polyether macromonomer, unsaturated fatty acid small monomer, initiator and chain transfer agent and water at 50-80°C for 3-6 hours , to obtain a star-shaped copolymer, and then adjust the pH value in the range of 6.0-7.0 with an alkaline substance to obtain a reddish-brown solution, which is the tannic acid-based star-shaped polycarboxylate superplasticizer. The tannic acid-based star-shaped polycarboxylate superplasticizer of the present invention has many molecular branches, low viscosity, small hydrodynamic volume, rich surface functional groups, and a large number of hydroxyl groups on the tannic acid molecule. These abundant polar groups and The polar surface of cement particles has a strong hydrophilic effect, which can form a hydration film on the surface of cement particles, so that the cement particles can be 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