Preparation method of novel polycarboxylic acid type water-reducer

A technology of polycarboxylic acid series and water reducing agent, which is applied in the field of polycarboxylic acid series water reducing agent, can solve the problems of inability to form a homogeneous phase, oxidative cracking of polyether molecular weight, poor compatibility, etc., and achieves simple and convenient operation steps and improved Reaction efficiency, the effect of shortening the reaction time

Inactive Publication Date: 2015-09-30
JIANGSU CHINA RAILWAY ARIT NEW MATEIRALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are still many problems to be solved urgently in the post-esterification method, such as the poor compatibility between polyacrylic acid and polyethylene glycol macromolecules, which cannot form a homogeneous phase and cannot be directly esterified; the reaction system has a high viscosity and low mass and heat transfer efficiency. It is greatly affected, which is not conducive to the increase of the esterification rate of the product; at the same time, there are side reactions at the esterification temperature, which may easily cause the molecular weight of the polyether to be oxidized and broken, and then crosslinking occurs, affecting product quality, etc.

Method used

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  • Preparation method of novel polycarboxylic acid type water-reducer

Examples

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Embodiment 1

[0027] 1) Preparation of amine copolymerization products: 9.9 mol acrylic acid, 0.1 mol sodium methoxy allyl sulfonate and 1 mol acrylamide were mixed at 6°C in 0.1 mol tert-butyl hydroperoxide, 0.3 mol diabolite, 0.1 mol mercapto Oxidation-reduction radical polymerization was carried out under the action of acetic acid for 30 minutes to obtain a copolymer product with a molecular weight of 2000;

[0028] 2) Preparation of polyethylene glycol monomethyl ether monoisocyanate: 10 mol of polyethylene glycol monomethyl ether with a molecular weight of 350 was added dropwise to 10.1 mol of excess toluene diisocyanate (TDI) at 0°C. Reaction under the effect of methylcyclohexylamine for 10min and distillation under reduced pressure obtain polyethylene glycol monomethyl ether monoisocyanate;

[0029] 3) Preparation of a new type of water reducer: add 10 mol of the amine copolymer product obtained in step 1) into step 2) and react with 10 mol of polyethylene glycol monomethyl ether mon...

Embodiment 2

[0031] 1) Preparation of amine copolymerization products: 10mol methacrylic acid, 1mol potassium allyl sulfonate and 2mol methacrylamide were mixed at 45°C in 0.3mol cumene hydroperoxide, 0.5mol tetraethyleneimine, 1mol 2-mercapto Oxidation-reduction radical polymerization was carried out under the action of propionic acid for 40 minutes to obtain a copolymer product with a molecular weight of 2500;

[0032] 2) Preparation of polyethylene glycol monomethyl ether monoisocyanate: 10 mol polyethylene glycol monomethyl ether with a molecular weight of 450 was added dropwise to 10.2 mol excess hexamethylene diisocyanate (HDI) at 8°C, and in 0.5 mol bis Under the effect of (2-dimethylaminoethyl) ether, reaction under reduced pressure distillation obtains polyethylene glycol monomethyl ether monoisocyanate after 40min;

[0033] 3) Preparation of a new type of water reducer: add 10 mol of the amine copolymer product obtained in step 1) into step 2) and react with 20 mol of polyethylen...

Embodiment 3

[0035] 1) Preparation of amine-containing copolymers: 10 mol sodium acrylate, 1 mol sodium allyl sulfonate and 3 mol N-ethylacrylamide at 45°C in 0.5 mol ammonium persulfate, 1 mol sodium bisulfite, 0.5 mol 3-mercapto Oxidation-reduction radical polymerization was carried out under the action of propionic acid for 50 minutes to obtain a copolymer product with a molecular weight of 3000;

[0036]2) Preparation of polyethylene glycol monomethyl ether monoisocyanate: Add 10 mol of polyethylene glycol monomethyl ether with a molecular weight of 500 dropwise into 10.3 mol of excess isophorone diisocyanate (IPDI) at 6°C, in 0.7 mol N , N,N',N'-Tetramethylalkylenediamine reacted for 30min and then distilled under reduced pressure to obtain polyethylene glycol monomethyl ether monoisocyanate;

[0037] 3) Preparation of a new type of water reducer: add 10 mol of the amine copolymer product obtained in step 1) into step 2) and react with 20 mol of polyethylene glycol monomethyl ether mo...

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Abstract

The invention discloses a preparation method of a novel polycarboxylic acid type water-reducer. The novel polycarboxylic acid type water-reducer is prepared by the following steps: 1) a unsaturated acid monomer and an amine unsaturated monomer react under the action of a chain transfer agent, an initiator and a reducing agent to obtain a copolymer containing an amino group; 2) excessive diisocyanate is dropwise added into methoxy polyethylene glycol to react under the action of a catalyst so as to obtain methoxypolyethylene glycol mono-isocyanate; 3) the copolymer containing the amino group is added into the methoxypolyethylene glycol mono-isocyanate to react and then pH value is adjusted so as to obtain a novel polycarboxylic acid water-reducer. According to the method, product performance is adjusted by controlling molecular structure / molecular weight of the amine copolymer and molecular weight of methoxy polyethylene glycol. Reactions are fast and efficiency is high. In addition, no organic solvent is used; the water-reducer is nontoxic and pollution-free; and operation is simple. The polycarboxylic acid type water-reducer prepared by the method is a functional polycarboxylic acid type high-efficiency water-reducer, and product performance is stable.

Description

technical field [0001] The invention relates to the technical field of a polycarboxylate water reducer for cement concrete, in particular to a preparation method of a novel polycarboxylate water reducer using amidation reaction of isocyanate and amines and free radical polymerization. Background technique [0002] Water reducer is currently the most widely studied and used concrete admixture, and water reducer is one of the admixtures that can improve the rheological properties of concrete mixing. Water reducer is an admixture that has the effects of water reduction and retardation under the condition that the concrete slump is basically the same and does not affect the workability; it also has the effect of increasing the rheology of the mixture or saving the amount of cement. The main purpose of using water reducing agent in engineering is to reduce the water consumption of concrete, reduce the water-cement ratio, save the amount of single cement, and improve its workabili...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G81/02C08G65/48C08F220/06C08F228/02C08F220/56C04B24/16C04B103/30
Inventor 钱珊珊石宇丁蓓王毅姜海东郑春扬
Owner JIANGSU CHINA RAILWAY ARIT NEW MATEIRALS CO LTD
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