Preparation method for polycarboxylic acid high-performance water reducer

Abstract

The invention discloses a preparation method of a poly-carboxylic acid water reducing agent with high performance, the water reducing agent is made in simple process with low mixing amount and high dispersive property. The technical proposal is as the follow: A) methacrylic acid and methoxy polyethylene glycol with a mole ratio of 1 to 1.2: 1 are put into a reactor with catalyst, polymerization inhibitor and water carrying agent being added to be mixed and heated to 100 to 150 DEG C and kept reacting within 8 to 12 hours to obtain polyoxyethylene methacrylate; B) water and initiator are added into the reactor, then a mixing solution containing sodium allylsulfonate, the polyoxyethylene methacrylate and the methacrylic acid is added drop by drop slowly into the reactor, wherein the weight proportion of the water and the mixing solution is 2: 1 to 1.2, the solution is mixed and heated to the temperature of 80 to 120 DEG C. Chain transfer agent is added after reaction of 4 to 6 hours and the adding drop by drop being finished, and the solution is discharged after being kept mixing with heat preserved for 1 to 2 hours, the poly-carboxylic acid water reducing agent with high performance is obtained.

Description

technical field [0001] The invention relates to a preparation method of a water reducer, more specifically to a preparation method of a polycarboxylic acid high-performance water reducer. Background technique [0002] High-performance water reducer is one of the important products in the pillar industry of new building materials, and has become an indispensable fifth component in concrete besides sand, stone, cement and water. With the development of concrete technology, the durability index of concrete is getting higher and higher, and the water-binder ratio of concrete is often reduced to a lower level, but the fluidity of concrete still needs to meet the needs of pumping construction, and the performance of water reducing agent has higher requirements. In addition to the water-reducing effect, it is also necessary to control the slump loss of concrete, and better solve the problems of air-entrainment, retardation, and bleeding of concrete. High performance water reducer ...

AI Technical Summary

Problems solved by technology

However, due to the constraints of the molecular structure, the problem of slump cannot be fundamentally solved, so people turned their attention to carboxylic acid polymers, which are called the third generation of new polymer water reducers, and achieved great results.

[0004] However, the molecular design of high-performance polycarboxylate water-reducers needs to be realized through preparation methods. The synthesis process of such water-reducers is generally cumbersome, and the shortcomings of free-radical polymerization products such as unstable quality still exist.