Preparation method of solid flake polycarboxylate slump retention agent for bulk polymerization

Abstract

The invention provides a preparation method of a solid flake polycarboxylate slump retention agent for bulk polymerization. The method comprises the following steps: adding a certain amount of liquidpolyether macromonomer into a reaction kettle, stirring and heating; controlling the temperature to be 100-105 DEG C, and starting to add a certain amount of a solubilizer, a chain transfer agent, anorganic peroxy-initiator, an initial initiator and a penetrant; after 5 minutes, starting to dropwise add a small monomer solution, wherein the dropwise adding time of the small monomer solution is 0.5-2h, and the small monomer solution is prepared from a fluoro-functional monomer, alkyl acrylate and acrylic acid according to a certain proportion; after the body solution is added dropwise for 10min, firstly adding a certain amount of the organic peroxy-initiator into the kettle, then adding at a time every 10min, and adding for the last time until the time before the completion of the dropwiseaddition of the small monomer solution; after the dropwise addition is finished, heating up to 110-115 DEG C, maintaining the temperature to be constant, curing for 1-3h, then cooling, slicing and packaging to obtain the finished product. The final solid flake polycarboxylic acid slump retention agent prepared by the method is convenient to store, so that the transportation cost is greatly lowered.

Description

technical field [0001] The invention belongs to the technical field of building materials, and relates to the field of concrete admixtures, in particular to a preparation method of bulk-polymerized solid sheet polycarboxylic acid slump-retaining agent. Background technique [0002] In the production of ready-mixed high-performance concrete, the slump-retaining agent is an indispensable and important part just like the water-reducing agent. Like common polycarboxylate superplasticizers, the solid content of common polycarboxylate slump-retaining agents is generally about 40%, because it contains a large amount of water as a solvent, resulting in higher storage and transportation costs. With the continuous advancement of engineering construction, the use and demand of polycarboxylate water reducer and polycarboxylate slump retaining agent are increasing, especially now that many engineering projects are far away from the production place of water reducer, long-distance transpo...

AI Technical Summary

Problems solved by technology

[0003] In the current bulk polymerization process, a big problem is the high viscosity of the anhydrous environment, which leads to the low efficiency of the collision reaction between molecules. Therefore, reducing the viscosity of the reaction solution is the most important thing to make the reaction go smoothly. The solid polycarboxylate slump-retaining agent prepared by appropriate viscosity-reducing means and reasonable process can meet the requirements of use

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