Room-temperature preparation method of early strength type polycarboxylate superplasticizer

Abstract

The invention discloses a room-temperature preparation method of an early strength type polycarboxylate superplasticizer. The early strength type polycarboxylate superplasticizer is prepared from three water soluble monomers including 80wt%-90wt% of methyl allyl polyethenoxy ether, 6wt%-13wt% of acrylic acid and 4wt%-7wt% of acrylamide, sodium methallyl sulfonate is preferably taken as a chain transfer agent, the monomers are copolymerized by a hydrogen peroxide-vitamin C redox initiation system with a single-tank segmented dripping method at the room temperature, and the early strength type polycarboxylate superplasticizer is prepared. The early strength type polycarboxylate superplasticizer is produced with a room-temperature one-step method, the production technology is simple, requirements for production equipment are low, and the method is suitable for production of zero-heat-source early strength type polycarboxylate superplasticizers. The early strength type polycarboxylate superplasticizer prepared with the method has high water reducing rate and good early strength effect and is suitable for production of concrete for metro segments, other prefabricated parts and the like requiring for the early strength performance.

Description

technical field [0001] The invention relates to the field of concrete admixtures, in particular to a preparation method of a normal-temperature early-strength polycarboxylate water reducer. Background technique [0002] As a commonly used building material, concrete has been widely used in various fields with the rapid development and continuous improvement of its technology. Followed by the continuous improvement of the performance requirements of concrete. It has excellent and easy performance, convenient pumping construction, super early strength, high strength, high durability and other properties have attracted widespread attention. Early-strength and ultra-early-strength concrete have broad market application prospects in prestressed high-strength pipe columns, bridges, highways, ports and their maintenance and reinforcement. In traditional concrete design, the strength of concrete is generally increased by reducing the water-binder ratio, increasing the strength gra...

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Problems solved by technology

This method requires esterification at 100-140°C and polymerization at 65-80°C. It is produced by a high-temperature two-step method. The production process is complicated and it is not suitable for large-scale promotion of industrial production.

In the patent CN103450408A, a preparation method of an ether early-strength polycarboxylate water reducer is disclosed, which consists of unsaturated ester, diethanol monoisopropanolamine, 2-acrylamido-methylpropanesulfonic acid and methyl Allyl polyoxyethylene polyoxypropylene ether is used as the main chemical synthesis raw material, under the action of catalyst, initiator, chain transfer agent, etc., it is prepared by amidation and copolymerization under certain conditions. The amidation reaction is carried out at ~100°C, and the copolymerization reaction is carried out at 50~70°C. The polymerization process is complicated and the production cycle is long, which is not suitable for industrial production.

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