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CN-119661787-B - Polycarboxylate superplasticizer for high-micropowder regenerated masonry mortar, and preparation method and application thereof

CN119661787BCN 119661787 BCN119661787 BCN 119661787BCN-119661787-B

Abstract

The invention relates to a polycarboxylate superplasticizer for high-micropowder regenerated masonry mortar, and a preparation method and application thereof. The method comprises the steps of mixing and dissolving IPEG and water, heating to a certain temperature, adding an oxidant to prepare a solution A, mixing a reducing agent and a chain transfer agent, adding water to prepare a solution B, mixing an unsaturated acid monomer and a phosphoric acid group-containing monomer, adding water to prepare a solution C, adding the solution B and the solution C into the solution A, stirring at a constant temperature until the reaction is completed, and cooling to room temperature to obtain the polycarboxylic acid water reducer, wherein the reaction is completed. Compared with the prior art, the method has the advantages of reducing the adsorption of the polycarboxylate water reducer to the micro powder, improving the dispersion effect of the polycarboxylate water reducer, improving the working performance of the high micro powder regenerated masonry mortar and the like.

Inventors

  • XU LINGLIN
  • YANG KEN
  • WU KAI
  • XIAO JIANZHUANG
  • DUAN ZHENHUA

Assignees

  • 同济大学

Dates

Publication Date
20260512
Application Date
20241230

Claims (10)

  1. 1. The preparation method of the polycarboxylate water reducer for the high micro powder regenerated masonry mortar is characterized by comprising the following steps of: Mixing and dissolving isopentenol polyoxyethylene ether and water, heating to 25-35 ℃, and adding an oxidant to prepare a solution A; Mixing a reducing agent and a chain transfer agent, and adding water to prepare a solution B; Mixing unsaturated acid monomer and monomer containing phosphate group, and adding water to prepare solution C; Adding the solution B and the solution C into the solution A, stirring at constant temperature until the reaction is completed, and cooling to room temperature to obtain a polycarboxylate water reducer, wherein the reaction is completed; The mole ratio of the isopentenyl alcohol polyoxyethylene ether to the unsaturated acid monomer to the phosphoric acid group-containing monomer is 1:3-5:0.01-0.2; The chain transfer agent is beta-mercaptopropionic acid; The unsaturated acid monomer is acrylic acid; The phosphoric acid group-containing monomer is 2- (methacryloyloxy) ethyl phosphate.
  2. 2. The preparation method of the polycarboxylate water reducer for the high-micropowder regenerated masonry mortar, which is characterized by mixing and dissolving isopentenol polyoxyethylene ether and water, heating to 25-35 ℃, and stirring at a constant temperature of 25-35 ℃.
  3. 3. The method for preparing the polycarboxylate superplasticizer for the high micro powder recycled masonry mortar according to claim 1, wherein, The mass ratio of the oxidant to the reducing agent to the total mass of the chain transfer agent to the isopentenyl alcohol polyoxyethylene ether to the total mass of the unsaturated acid monomer to the total mass of the phosphate group-containing monomer is 1-1.2:0.15-0.2:0.35-0.4:100.
  4. 4. The preparation method of the polycarboxylate water reducer for the high micro-powder regenerated masonry mortar, which is characterized by comprising the following steps of, according to the preparation method, 30% -80% of the mass concentration of isopentenol polyoxyethylene ether in the solution A; The mass concentration of the reducing agent in the solution B is 1% -5%; The mass concentration of the unsaturated acid monomer in the solution C is 30% -80%.
  5. 5. The method for preparing the polycarboxylate water reducer for the high micro-powder regenerated masonry mortar according to claim 1, wherein the oxidant is ammonium persulfate; the reducing agent is ascorbic acid.
  6. 6. The preparation method of the polycarboxylate superplasticizer for the high micro powder regenerated masonry mortar according to claim 1, wherein the solution B and the solution C are added into the solution A through a peristaltic pump, the total adding time is 3-3.5 h, and the constant-temperature stirring time is 0.5-2 h after adding.
  7. 7. A polycarboxylate water reducer for high micro-powder recycled masonry mortar, which is prepared by the preparation method of any one of claims 1-6.
  8. 8. The polycarboxylate water reducer for high-micropowder recycled masonry mortar of claim 7, wherein the weight average molecular weight of the polycarboxylate water reducer is 4000-45000.
  9. 9. Use of a polycarboxylate water reducer for high micro-powder recycled masonry mortar according to claim 7 in the field of high micro-powder recycled masonry mortar, wherein the polycarboxylate water reducer is used for preparing high micro-powder recycled masonry mortar.
  10. 10. The use according to claim 9, wherein said Gao Weifen recycled masonry mortar comprises micropowder, recycled aggregate, cement, polycarboxylate water reducer, water.

Description

Polycarboxylate superplasticizer for high-micropowder regenerated masonry mortar, and preparation method and application thereof Technical Field The invention relates to the field of concrete admixture preparation, in particular to a polycarboxylate superplasticizer for high-micropowder regenerated masonry mortar, and a preparation method and application thereof. Background The output scale of the construction waste in China is increased, and a great deal of accumulation of the construction waste is derived to be negatively tired in a plurality of environments. The utilization of construction waste to regenerate construction materials to protect the environment, save energy and reduce emissions has become a common industry. The crushed concrete contained in the construction waste can be converted into recycled aggregate for masonry mortar production after secondary crushing. In addition, the construction waste also contains a large amount of micro powder, and the strength of the mortar can be obviously improved by doping a proper amount of micro powder into the mortar. The recycled aggregate and the micropowder are compositely applied to prepare the high micropowder recycled masonry mortar, so that the utilization rate of construction waste resources can be greatly improved, and the accumulation dilemma of the construction waste resources can be relieved. However, recycled aggregate and micropowder cause a significant decrease in mortar workability due to the characteristics of high water absorption and the like. In practice, it is necessary to incorporate a polycarboxylate water reducer to improve the workability of the high micropowder recycled masonry mortar. However, the micro powder and the cement have similar particle sizes, and the micro powder and the cement compete to adsorb the molecules of the water reducer, so that the dispersing effect of the water reducer is greatly reduced. The elbow is pulled by the current situation, the engineering and the industrialization of the high-micro-powder regenerated masonry mortar are applied, and the development of the high-efficiency polycarboxylate water reducer specially adapted to the high-micro-powder regenerated masonry mortar is needed. Patent publication No. CN117903378A discloses a polycarboxylic acid water reducer containing a phosphate group, a preparation method and application thereof, and the preparation method comprises the following steps of adding isopentenyl alcohol polyoxyethylene ether into a reaction kettle, adding deionized water, automatically stirring at normal temperature to enable the isopentenyl alcohol polyoxyethylene ether to be completely dissolved, adding an aqueous solution of an unsaturated carboxylic acid small monomer, a chain transfer agent, an aqueous solution of an initiator and a small monomer containing the phosphate group into the reaction kettle, regulating the temperature of the reaction kettle to 65-70 ℃, reacting for 2-2.5h at the temperature, then raising the temperature to 70-75 ℃, preserving heat for 3-3.5h, and cooling to room temperature to obtain the polycarboxylic acid water reducer containing the phosphate group. However, in the preparation process of the water reducer, the initiator containing the oxidant is added after the isopentenyl alcohol polyoxyethylene ether, so that the problems of uneven reaction rate and the like are easy to occur, the reaction process temperature is higher, and the water reducer has certain uncontrollable reaction and danger. Disclosure of Invention The invention aims to overcome the defects of poor adaptability and poor dispersion effect of the polycarboxylate superplasticizer in the high-micro-powder recycled mortar in the prior art, and provides the polycarboxylate superplasticizer for the high-micro-powder recycled masonry mortar, and the preparation method and application thereof, so that the adsorption of the polycarboxylate superplasticizer to micro-powder is reduced, the dispersion effect of the polycarboxylate superplasticizer is improved, and the working performance of the high-micro-powder recycled masonry mortar is improved. The aim of the invention can be achieved by the following technical scheme: the invention provides a preparation method of a polycarboxylate water reducer for high-micropowder regenerated masonry mortar, which comprises the following steps: mixing and dissolving isopentenyl alcohol polyoxyethylene ether (IPEG) and water, heating to a certain temperature, and adding an oxidant to prepare a solution A; Mixing a reducing agent and a chain transfer agent, and adding water to prepare a solution B; Mixing unsaturated acid monomer and monomer containing phosphate group, and adding water to prepare solution C; And adding the solution B and the solution C into the solution A, stirring at constant temperature until the reaction is completed, and cooling to room temperature to obtain the polycarboxylate water reducer, wherein the reaction is completed. Furthe