Amphoteric betaine-type polycarboxylate superplasticizer and preparation method thereof

Patent metadata

Field	Value
Publication number	US-9718733-B2
Application number	US-201615063531-A
Country	US
Kind code	B2
Filing date	Mar 8, 2016
Priority date	Mar 18, 2014
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

An amphoteric betaine-type polycarboxylic acid water reducer and a preparation method therefor are provided in the present invention. An unsaturated betaine-type monomer A and an acrylic acid-type polyethylene glycol monomer B are placed in a reaction container, stirred until uniform and then an acrylic acid-type monomer C is added, the stirring is continued and water is added to make adjustments so as to make the total mass of the monomers account for 10%-20% of the total mass of the aqueous solution; and under the protection of an inert gas, the temperature is raised to 60° C.-100° C., an aqueous initiator solution is added, maintaining the temperature and reacting for 4-6 h, and after the reaction is completed, the solution is cooled to room temperature, and the pH value thereof is adjusted to 5-7 to prepare the amphoteric betaine-type polycarboxylic acid water reducer.

First claim

What is claimed is:

1. A superplasticizer for concrete, wherein the superplasticizer is obtained through aqueous solution polymerization of a monomer A, a monomer B and a monomer C at a weight ratio of (1-30%):(20-50%):(20-50%) in the presence of an initiator;
wherein the monomer A has a general formula of

in which R 1 is H or CH 3 , R 2 is O or NH, R 3 is any one of CH 3 , CH 2 CH 3 , and CH 2 CH 2 CH 3 , and Y is any one of COO, SO 3 , and PO 3 ;
the monomer B has a general formula of

in which R 4 is H or CH 3 , and m is the average addition moles of oxyethylene and is an integer selected from 1 to 100; and
the monomer C has a general formula of

in which R 5 is H or CH 3 .

2. A method for preparing a the superplasticizer for concrete according to claim 1 , comprising:
placing a monomer A and a monomer B in a reaction vessel, adding water, and stirring;
then adding a monomer C to the reaction vessel, stirring, and adding water to adjust in such a manner that the total weight of the monomers accounts for 10-20% of the total weight of the aqueous solution, in which the weight ratio of the monomer A, the monomer B, and the monomer C is (1-30%):(20-50%):(20-50%);
under an inert atmosphere, adding an initiator when the temperature is raised to 60-100° C.; and
reacting for 4-6 hrs with thermal insulation, and after the reaction is complete, adjusting the pH to 5-7, to obtain an aqueous solution of the superplasticizer;
wherein the monomer A has a general formula of

in which R 1 is H or CH 3 , R 2 is O or NH, R 3 is any one of CH 3 , CH 2 CH 3 , and CH 2 CH 2 CH 3 , and Y is any one of COO, SO 3 , and PO 3 ;
the monomer B has a general formula of

in which R 4 is H or CH 3 , m is the average addition moles of oxyethylene, and is an integer selected from 1 to 100; and
the monomer C has a general formula of

in which R 5 is H or CH 3 .

3. The method for preparing a the superplasticizer for concrete according to claim 2 , wherein the initiator is a water soluble free radical initiator, and has a total amount accounting for 0.5-2.0% of the total weight of the monomers.

4. The method for preparing a the superplasticizer for concrete according to claim 2 , wherein the initiator is at least one of ammonium persulfate, potassium persulfate, or a redox initiator.

5. The method for preparing a the superplasticizer for concrete according to claim 2 , wherein the initiator is formulated into an aqueous solution before addition, and is added in a manner such that ⅓ of the total weight of the aqueous initiator solution is added dropwise per hour.

6. The method for preparing a the superplasticizer for concrete according to claim 2 , wherein the adjusting of the pH to 5-7 is achieved by adding 1-3 mol/L of a basic aqueous NaOH solution.

7. The method for preparing a the superplasticizer for concrete according to claim 2 , wherein the water is deionized water.

Assignees

• Univ Shenzhen

Inventors

• Chen Shaojun
• Chen Shiguo
• Ge Zaochuan
• Chen Chengbin
• Gu Lidan

Classifications

• C04B2103/32

  Superplasticisers · CPC title

• C08F220/08

  Anhydrides · CPC title

• C08F290/062

  Polyethers · CPC title

• C04B28/02

  containing hydraulic cements other than calcium sulfates · CPC title

• C04B24/165 Primary

  containing polyether side chains · CPC title