A polycarboxylate water reducer with high water reducing rate and high slump retention, its synthesis method and its use

Abstract

The invention belongs to the technical field of building materials, and specifically relates to a polycarboxylic acid water reducer with a high water-reducing rate and high slump constant holding capacity, and its synthetic method and use method. The polycarboxylic acid water reducer comprises 2-methallyl polyoxyethylene ether (TPEG), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), methacrylic acid (MAA), ammonium persulfate (APS), sodium hydroxide and water. The synthetic method comprises the following steps that 1, TPEG, AMPS and MAA are prepared respectively into mixed solutions with concentrations in a range of 20 to 50%; 2, simultaneously, APS is added with a proper amount of water and is dissolved in the water; 3, the TPEG and AMPS monomer mixed solutions prepared by the step 1 are added into a reactor; nitrogen is fed into the mixture in the reactor; a condenser tube is mounted; the mixture is heated to a temperature of 60 to 100 DEG C with stirring; the MAA monomer solution prepared by the step 1 and the APS solution prepared by the step 2 are respectively added dropwisely into the heated mixture, wherein dropwise addition time of the MAA monomer solution is in a range of 1 to 5 hours and dropwise addition time of the APS solution is in a range of 1.5 to 5.5 hours; and after the dropwise addition is finished, the mixture with the MAA monomer solution and the APS solution undergoes a reaction at a constant temperature for 1 to 2 hours; 4, reaction products obtained by the step 3 are cooled and are neutralized by a NaOH solution to form desired products. The synthetic method of the polycarboxylic acid water reducer is a one-step synthetic method and has simple processes. Products prepared through the synthetic method have the advantages of stable performances, low doping quantity, high water-reducing rate, high slump constant holding capacity and good market prospects.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a polycarboxylate water-reducer with high water-reducing rate and high slump retention, a synthesis method and a use method. Background technique [0002] The polycarboxylate water reducer has a comb structure, its dosage is low, the water reducing rate is high, the slump retention is good, the degree of freedom in molecular structure design is large, there are many synthesis methods, and the development potential is great, so It has become one of the research hotspots of concrete admixtures. [0003] With the development of commercial concrete, people have higher and higher requirements for the slump retention performance of polycarboxylate superplasticizers. The loss of concrete fluidity over time not only directly affects the use effect of the water reducing agent, but also greatly restricts the service radius of the concrete mixing plant, as well a...

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Problems solved by technology

There are no domestic research results on the relevant synthesis process