Preparation method of graft copolymerization carboxylate high-performance dehydragent

A technology of co-polymerized carboxylate and water-reducer, which is applied in the specific preparation field of graft-copolymerized carboxylic acid-based high-performance water-reducers, which can solve the problem of poor fluidity retention of comb polymer water-reducing rate, cumbersome intermediate separation and purification process, The feeding speed should not be controlled, etc., to achieve the effect of shortening the reaction time, short reaction time, and no environmental pollution

Inactive Publication Date: 2007-09-26
BEIJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The present invention proposes a new preparation process of polycarboxylic acid-based water reducer, which effectively solves the problems of the previous two-step preparation method of esterification and then polymerization, which are low esterification conversion rate and long reaction time. Dropping method, the feeding speed should not be controlled, and there is an intermediate separation and purification process in the preparation method, which is cumbersome and costly. Toluene is used as a solvent, which does not meet environmental protection requirements and cannot be recycled. The water-reducing rate of the prepared comb polymer is low Poor property retention and poor adaptability to cement

Method used

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  • Preparation method of graft copolymerization carboxylate high-performance dehydragent
  • Preparation method of graft copolymerization carboxylate high-performance dehydragent

Examples

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Embodiment 1

[0020] Add 80g of methoxypolyethylene glycol with a molecular weight of M1000 to the reaction vessel equipped with a stirring, condensing, and effluent reflux device, fully melt, the temperature is at 95°C, add 0.14g of polymerization inhibitor hydroquinone, and react for 15 minutes 14.4g of acrylic acid, 1.98g of concentrated sulfuric acid, and 14.4g of cyclohexane were added to the reaction vessel in sequence, and the temperature was kept constant for 4 hours. The esterification rate reached 97.6%, and the cyclohexane was removed by vacuuming to obtain methoxypolyethylene Alcohol acrylate (macromonomer). The recovered water-carrying agent is treated with 3A molecular sieve and can be recycled. During the second step of polymerization, all the macromonomers were prepared by adding esterification reaction into the four-necked flask, 55.19 g of water was stirred continuously, and the temperature was raised to 50° C. in a water bath. Add 1.26 g of mercaptoacetic acid, 4.54 g of...

Embodiment 2

[0022] Add 90 g of methoxypolyethylene glycol with a molecular weight of M1300 to a reaction vessel equipped with a stirring, condensing, and effluent reflux device, fully melt, and add 0.89 g of a polymerization inhibitor phenothiazine at a temperature of 120 ° C, and react for 15 minutes. Add 29.76g of methacrylic acid, 4.55g of concentrated sulfuric acid, 4.55g of p-toluenesulfonic acid, and 37g of cyclohexane to the reaction vessel in sequence. After a constant temperature reaction time of 3.5 hours, the esterification rate reaches 96.6%. Hexane to give methoxypolyethylene glycol methacrylate (macromonomer). The recovered water-carrying agent is treated with 3A molecular sieve and can be recycled in the next production. During the second step of polymerization, all macromonomers were prepared by adding esterification reaction into a four-necked flask, 27.17g of water, stirring continuously, heating in a water bath to 60°C, adding 5.87g of mercaptopropionic acid, 8.86g of b...

Embodiment 3

[0024]Add 100g of methoxypolyethylene glycol with a molecular weight of M1000 to the reaction vessel equipped with a stirring, condensing, and effluent reflux device, and fully melt it at a temperature of 130°C. Add 0.014g of a polymerization inhibitor hydroquinone, and react for 15 minutes 14.40g of acrylic acid, 1.14g of p-toluenesulfonic acid, and 23g of cyclohexane were added to the reaction vessel in sequence. After 4.5 hours of constant temperature reaction, the esterification rate reached 97.2%, and the cyclohexane was removed by vacuuming to obtain methane Oxy-polyethylene glycol acrylate (macromonomer). The recovered water-carrying agent is treated with 3A molecular sieve and can be recycled. During the second step of polymerization, all the macromonomers were prepared by adding esterification into the four-necked flask, 150.52 g of water was continuously stirred, and the temperature was raised to 65° C. in a water bath. 7.9 g of sodium allyl sulfonate, 32.4 g of an ...

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Abstract

The invention discloses a preparing method of graft copolymerization carboxylate high-performance dehydragent belonging to dehydragent domain, which comprises the following steps: choosing methoxy carbowax with molecular weight distributing between 1000-2000 and acroleic acid or methacrylic acid as main raw material; adopting total acid method esterified priority method; preparing intermediate (big monomer) with polymerization activity; adding third monomer into polymerization reaction; adjusting polymerization activity of copolymerization system; proceeding technique route synthesis of main chain polymerization in the water solution. The getting big monomer possesses merits of high conversion rate, short reacting time, simple process flow and strong controlling property.

Description

technical field [0001] The invention relates to the technical field of preparing a high-performance water-reducer for concrete, in particular to a specific preparation method of a graft-copolymerized carboxylic acid-based high-performance water-reducer. Background technique [0002] In recent years, with the vigorous development of the domestic construction industry, the demand for concrete performance water reducers has increased year by year. my country's construction industry urgently needs high-quality polycarboxylate water reducers that adapt to the domestic construction market and high-performance concrete technology. [0003] The synthesis reaction of graft copolycarboxylate water reducer can be divided into two steps: the first step is to generate polymerizable structural units or "building blocks", and the second step is to generate polycarbonate by condensation or addition polymerization A co-polycarboxylate polymer with a certain structure and molecular weight, so...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B24/04C08F283/06C08G65/48C04B103/30
CPCC04B2103/302C04B24/32C04B2103/0059
Inventor 王子明郝利炜刘俊元兰明章崔素萍王亚丽王晓丰
Owner BEIJING UNIV OF TECH
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