Method for preparing maleic anhydride type polycarboxylic acid water reducing agent and application

Abstract

The invention relates to a method for preparing a maleic anhydride type polycarboxylic acid water reducing agent and application. The method specifically comprises the following steps of: adding methyl allyl polyethenoxy ether, maleic anhydride, de-ionized water and sulfonate-containing monomer into a reaction kettle; heating the reaction kettle to 60-85 percent under the condition of continuous stirring; after the reaction kettle is stabilized at 60-85 percent, adding ammonium persulphate at one time under the condition of continuous stirring; preserving heat of the reaction kettle at 60-85 DEG C for 4-7 hours; and cooling to 50 DEG C, adding a certain amount of caustic soda liquid into the reaction kettle to keep the pH (Potential of Hydrogen) at 5.5-6 when the temperature is reduced to 50 DEG C. The invention also protects the prepared maleic anhydride type polycarboxylic acid water reducing agent and the application thereof. The prepared maleic anhydride type polycarboxylic acid water reducing agent has the advantages of proper reaction conditions, concise process, capability of reducing the operation steps, high efficiency, low cost, environmental friendliness, suitability for large-scale industrial production method, superior water reducing agent performance and good slump retaining and slow release performance.

Description

technical field [0001] The invention relates to the technical field of concrete admixtures in building materials, in particular to a "one-pot" preparation method of a polycarboxylate high-performance water reducer, and in particular to a preparation method of a maleic anhydride polycarboxylate water reducer. Background technique [0002] Polycarboxylate superplasticizer has attracted more and more attention from personnel in the industry due to its excellent performance and environmental protection characteristics. At present, the main research products in China are ester and ether polycarboxylate superplasticizers. Ester polycarboxylate superplasticizers mainly use (meth)acrylic acid and monomethoxypolyethylene glycol (MPEG) as the main materials; although these products have excellent performance, they must be esterified before polymerization, so their The cost and production process are more complicated. The main raw materials of ether polycarboxylate superplasticizers ...

AI Technical Summary

Problems solved by technology

[0003] But, the production technology of existing ether polycarboxylate superplasticizer still exists deficiency

For example, unsaturated carboxylic acids generally have certain volatility and are relatively expensive, while the patent CN101830663A developed a maleic anhydride-based polycarboxylate water-reducer on the basis of ether-based polycarboxylate water-reducers, which does not contain volatile Monocarboxylic acid, which effectively reduces the pollution to the environment during the production process, but it uses a titration process

This not only increases the cost, but also increases the difficulty of the entire process control

The patent CN101786824 adopts a one-step method to prepare a polycarboxylate water reducer, but its formula needs to add unsaturated monocarboxylic acid monomers such as acrylic acid, which not only increases the cost, but also has a certain negative impact on the environment.

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