A kind of preparation method of ultra-retarded polycarboxylate water reducer

Abstract

The invention discloses a preparation method of a super-retarding type polycarboxylate superplasticizer. The super-retarding type polycarboxylate superplasticizer comprises a copolymer and water serving as a solvent, wherein the copolymer comprises an unsaturated polyether macromonomer, an unsaturated carboxylic acid / anhydride mini-monomer, an unsaturated sulfonic acid mini-monomer and an unsaturated phosphonic acid mini-monomer; the pH is 6-7. According to the preparation method, a phosphonate structure capable of retarding is introduced into a water reducer molecular structure; the prepared super-retarding type polycarboxylate superplasticizer can be directly applied to the concrete which needs a relatively long setting time, and thus the process of compounding a retarder can be saved, the production efficiency can be improved, the obtained product is uniform and stable, and abnormal concrete setting time can be avoided.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a preparation method of an ultra-retarding polycarboxylate water reducer. Background technique [0002] Due to the designability of its molecular structure, polycarboxylate superplasticizers have been a hot spot in the research of concrete superplasticizers in recent years. At present, they have been successfully developed by introducing different functional units into the molecular structure of polycarboxylate superplasticizers. High water-reducing polycarboxylate superplasticizer, slump-preserving polycarboxylate superplasticizer, low air-entraining polycarboxylate superplasticizer, early-strength polycarboxylate superplasticizer and ultra-retarding polycarboxylate superplasticizer Water agent and other polycarboxylate superplasticizers with different special functions. Among them, the ultra-slow coagulation carboxylic acid superplasticizer has two funct...

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Problems solved by technology

For example, CN102241489A discloses a super-retarding polycarboxylate water reducer and its preparation and use method. The super-retarding polycarboxylate water reducer is based on allyl polyethylene glycol (number average ), methyl acrylate, maleic anhydride, sodium lignosulfonate, and sucrose fatty acid esters are directly synthesized under the action of ammonium persulfate and neutralized by sodium hydroxide. The raw materials are cheap, but sodium lignosulfonate reacts The activity is low, and unreacted sodium lignosulfonate is easy to form precipitation, which may affect the use of the product to a certain extent; another example is CN102153711A discloses a preparation method of retarded polycarboxylate superplasticizer, the patent by β-cyclodextrin is introduced into the main chain of carboxylic acid superplasticizer to improve its retarding effect, but cyclohexane is needed in the preparation of MPEG-MAA in the synthesis process, and the introduction of organic solvents increases the production cost At the same time, it will also bring certain dangers to production and cause certain pollution to the environment.