Preparation method of slump-retaining polycarboxylic acid type water-reducer

A polycarboxylic acid-based, slump-preserving technology, applied in the field of polycarboxylic acid-based water reducing agents, can solve the problem that the grafting rate of maleic anhydride grafted β-cyclodextrin macromonomer is not high and cannot be fundamentally solved. Concrete slump loss, the preparation process is not environmentally friendly and other problems, to achieve the effect of excellent and stable product performance, simple and convenient operation steps, and shortened reaction time

Active Publication Date: 2015-09-30
JIANGSU CHINA RAILWAY ARIT NEW MATEIRALS CO LTD
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  • Application Information

AI Technical Summary

Problems solved by technology

CN103613308B has reported a kind of preparation method of polycarboxylate high slump retention agent: itaconic acid introduced in molecular structure delays cement hydration, and benzene ring is introduced in molecular structure to produce steric hindrance effect, enhances the dispersion stability of water reducing agent, but The conversion rate of this invention is not high, and the preparation process is not environmentally friendly, which is not conducive to large-scale production and application
CN102153711A reports a kind of allyl sulfonate monomer, acrylic monomer, polyethylene glycol monomethyl ether methacrylate macromonomer and maleic anhydride grafted β-cyclodextrin macromonomer through A retarded polycarboxylate superplasticizer is obtained by free radical copolymerization, so that the obtained polycarboxylate superplasticizer has better retarding performance, micro-air-entraining performance and better flow performance, but this invention The grafting rate of maleic anhydride grafted β-cyclodextrin macromonomer is not high, and it is greatly affected by temperature, which cannot fundamentally solve the problem of concrete slump loss under different conditions, which is not conducive to large-scale production and application

Method used

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  • Preparation method of slump-retaining polycarboxylic acid type water-reducer
  • Preparation method of slump-retaining polycarboxylic acid type water-reducer

Examples

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Embodiment 1

[0027] 1) Preparation of amine-containing copolymers: 10mol 2-methallyl alcohol and 10mol acrylamide at 25°C in 0.1mol tert-butyl hydroperoxide, 0.3mol Glycyrrhiza, 0.01mol sodium methallyl sulfonate Carrying out oxidation-reduction radical polymerization reaction 30min to obtain the copolymerization product that molecular weight is 3000;

[0028] 2) Preparation of epoxy-based polyethylene glycol monomethyl ether: add 10.1 mol of sodium hydride to 10 mol of polyethylene glycol monomethyl ether with a molecular weight of 5000 at 0°C, add 10.1 mol of epichlorohydrin for 40 minutes, and stir for 90 minutes Desalination obtains epoxy group polyethylene glycol monomethyl ether;

[0029] 3) Preparation of slump-preserving water reducer: add 10 mol of amine-containing copolymer to 10 mol of epoxy polyethylene glycol monomethyl ether for 10 minutes, add potassium hydroxide to neutralize and adjust the pH value to 6 to obtain a slump-preserving type Polycarboxylate superplasticizer. ...

Embodiment 2

[0031] 1) Preparation of amine-containing copolymers: 10 mol of allyl alcohol and 9 mol of allylamine were subjected to oxidation-reduction free radical polymerization under the action of 0.2 mol of tert-butyl hydroperoxide, 0.4 mol of sodium metabisulfite, and 0.02 mol of thioglycolic acid at 30°C for 35 minutes to obtain the molecular weight Be the copolymerization product of 3500;

[0032] 2) Preparation of epoxy-based polyethylene glycol monomethyl ether: Add 10.2 mol of sodium hydride to 10 mol of polyethylene glycol monomethyl ether with a molecular weight of 400 at 25°C, add 11 mol of epichlorohydrin for 10 minutes of reaction, stir for 90 minutes, and desalt to obtain Epoxy polyethylene glycol monomethyl ether;

[0033] 3) Preparation of slump-preserving water reducer: add 10 mol of amine-containing copolymer to 5 mol of epoxy polyethylene glycol monomethyl ether for 50 minutes, add calcium hydroxide to neutralize and adjust the pH value to 7 to obtain a slump-preservi...

Embodiment 3

[0035] 1) Preparation of amine-containing copolymers: 10mol hydroxymethyl acrylate and 8mol methacrylamide at 35°C in 0.3mol benzoyl peroxide, 0.6mol N,N-dimethylaniline, 0.03mol 2-mercaptopropionic acid Carrying out oxidation-reduction radical polymerization reaction 40min to obtain the copolymerization product that molecular weight is 5000;

[0036] 2) Preparation of epoxy-based polyethylene glycol monomethyl ether: add 10.5 mol of sodium hydride to 10 mol of polyethylene glycol monomethyl ether with a molecular weight of 2000 at 20°C, add 10.2 mol of epichlorohydrin for 10 minutes of reaction, and desalt after stirring for 40 minutes Obtain epoxy group polyethylene glycol monomethyl ether;

[0037] 3) Preparation of slump-preserving water reducer: add 10 mol of amino group-containing copolymer to 9 mol of epoxy polyethylene glycol monomethyl ether for 10 minutes, add sodium hydroxide to neutralize and adjust the pH value to 6.5 to obtain a slump-preserving type Polycarboxy...

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Abstract

The invention discloses a preparation method of a slump-retaining polycarboxylic acid type water-reducer. The preparation method comprises the following steps: 1) a hydroxyl-containing unsaturated monomer, an amine unsaturated monomer, an initiator, a reducing agent and a chain transfer agent are subjected to an oxidation-reduction free radical polymerization reaction to obtain a copolymerization product containing an amino group; 2) excessive sodium hydride is added into methoxypolyethylene glycol to react, epoxy chloropropane is added after the reaction, and desalination is carried out after stirring and reacting so as to obtain epoxy methoxy polyethylene glycol; 3) the copolymerization product containing an amino group is added into the epoxy methoxy polyethylene glycol to react, and pH value is adjusted by alkaline neutralization after the reaction so as to prepare the slump-retaining polycarboxylic acid type water-reducer. According to the method, product performance is adjusted by controlling molecular structure / molecular weight of the copolymerization product containing an amino group and molecular weight of methoxy polyethylene glycol. Reaction is 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 prepared polycarboxylic acid type water-reducer is a slump-retaining polycarboxylic acid type water-reducer, has stable product performance and especially has a good slump-retaining effect on a mud sandy stone material.

Description

technical field [0001] The present invention relates to the technical field of a polycarboxylate water-reducer for cement concrete, in particular to a slump-preserving polycarboxylate water-reducer that adopts amine-epoxy reaction and oxidation-reduction free radical polymerization Preparation. Background technique [0002] In today's world, social economy is developing vigorously, urban construction is advancing by leaps and bounds, followed by the rapid rise of construction related to transportation, water and electricity, municipal administration, etc., the continuous emergence of high-rise buildings and the improvement of construction material construction requirements, the reliability of concrete The requirements for pumpability are getting higher and higher, and high-efficiency water reducers are an essential part of pumping, and polycarboxylate water reducers have become an important part of it. However, for a long time, the use of concrete has been troubled by how t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B24/24C04B103/30
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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