Method for solid-phase synthesis of polycarboxylate water reducer by virtue of microwave assistance

Abstract

The invention discloses a method for solid-phase synthesis of a polycarboxylate water reducer by virtue of microwave assistance, belonging to the technical field of concrete admixtures in building materials. All the existing polycarboxylate water reducer synthesis processes need to be performed in a reaction medium that takes water as a solvent, the production time is 6-10 hours, only a water product of which the solid content is 20-45 percent is obtained, and the transportation cost is relatively high during use, so the invention provides a method for the solid-phase synthesis of the polycarboxylate water reducer by virtue of microwave assistance, the synthesis time is short, and a solid product can be directly obtained. Specifically the method comprises the steps: putting a pasty mixture consisting of a polyether monomer, an initiating agent, a small-molecular monomer, a reducing agent, a chain transfer agent and water of which the mass is 50% of the mass of the small-molecular monomer into a power-adjustable microwave oven, and reacting for a certain time to obtain a solid or pasty polycarboxylate water reducer. The method is wide in application range, and all the polyether type polycarboxylate water reducers in the current markets can be prepared by the method.

Description

technical field

[0001] The invention belongs to the technical field of concrete admixtures in building materials, and in particular relates to a preparation method of a polycarboxylic acid-based high-performance water reducer. Background technique

[0002] Concrete admixture is one of the essential components of modern concrete, and water reducing agent is the most widely used admixture. After adding water reducer to concrete, it can improve the workability of concrete, increase the strength of concrete and save cement. Among many water reducers, polycarboxylate water reducer is considered to be the most promising high-performance water reducer due to its high water reducing rate, simple synthesis process, safety and environmental protection.

[0003] At present, there are two main production processes for polycarboxylate high-performance water reducers: 1. Two-step synthesis of esterified macromonomers; 2. One-step synthesis of ether macromonomers. Both synthesis process...

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