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A shrinkage-reducing polycarboxylate water reducer and its preparation method

A technology of polycarboxylic acid and water reducing agent, applied in the field of building admixtures, can solve the problems of small plastic shrinkage, insufficient reduction range, increase early shrinkage and total shrinkage of high-strength concrete, and achieve good dispersion performance and improve dispersion performance. Effect

Active Publication Date: 2021-10-08
KZJ NEW MATERIALS GROUP CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Under the condition of ensuring the same slump of the mixture, different admixtures have obvious effects on the plastic shrinkage and crack resistance of concrete. Naphthalene-based, sulfamate-based and aliphatic-based water reducers all increase the early shrinkage and total Shrinkage, compared with naphthalene-based water reducers and sulfamic acid-based water reducers, high-strength concrete mixed with polycarboxylate water-reducers has less plastic shrinkage and better crack resistance, but the reduction is far from enough, and the shrinkage reduction effect Difficult to compare with shrink reducer

Method used

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  • A shrinkage-reducing polycarboxylate water reducer and its preparation method
  • A shrinkage-reducing polycarboxylate water reducer and its preparation method
  • A shrinkage-reducing polycarboxylate water reducer and its preparation method

Examples

Experimental program
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Effect test

Embodiment 1

[0032] (1) Preparation of polyphosphate: under the protection of nitrogen, add 10mol trimethylolpropane to the first reaction device, cool in an ice-water bath for 1h, add 500ml triethylamine, and drop 100ml dichlorophosphoric acid under rapid stirring The dichloromethane solution of ethyl ester (solution concentration: 100mol / L), the dropwise addition time is 1h, after the dropwise addition is completed, the temperature is slowly raised to 45°C for 24h reaction. After standing for 12 hours, filter with suction, collect the filtrate, and distill off the solvent to obtain polyphosphate.

[0033] (2) Preparation of shrinkage-reducing functional macromonomer: Polyethylene glycol monomethyl ether, 4.1g maleic anhydride, 19g polyphosphate prepared in step (1), 0.5g SnCl with 100g molecular weight of 2400 2 2H 2 O and 0.6 g of o-tert-butylphenol were added to the second reaction device, and under the protection of nitrogen, they were reacted at a constant temperature of 90° C. for ...

Embodiment 2

[0037] (1) Preparation of polyphosphate: under the protection of nitrogen, add 10mol trimethylolpropane to the first reaction device, cool in an ice-water bath for 1h, add 500ml triethylamine, and drop 100ml dichlorophosphoric acid under rapid stirring The dichloromethane solution of ethyl ester (solution concentration: 100mol / L), the dropwise addition time is 1h, after the dropwise addition is completed, the temperature is slowly raised to 45°C for 24h reaction. After standing for 12 hours, filter with suction, collect the filtrate, and distill off the solvent to obtain polyphosphate.

[0038] (2) Preparation of shrinkage functional macromonomer: 100g of polyethylene glycol monomethyl ether with a molecular weight of 3000, 3.3g of maleic anhydride, 25g of polyphosphate prepared in step (1), 1g of NaHSO 4 ·H 2 O and 0.8 g of phenothiazine were added to the second reaction device, and under the protection of nitrogen, they were reacted at a constant temperature of 100° C. for ...

Embodiment 3

[0042] (1) Preparation of polyphosphate: under the protection of nitrogen, add 10mol trimethylolpropane to the first reaction device, cool in an ice-water bath for 1h, add 500ml triethylamine, and drop 100ml dichlorophosphoric acid under rapid stirring The dichloromethane solution of ethyl ester (solution concentration: 100mol / L), the dropwise addition time is 1h, after the dropwise addition is completed, the temperature is slowly raised to 45°C for 24h reaction. After standing for 12 hours, filter with suction, collect the filtrate, and distill off the solvent to obtain polyphosphate.

[0043] (2) Preparation of shrinkage-reducing functional macromonomer: 100 g of polyethylene glycol monomethyl ether with a molecular weight of 4000, 2.45 g of maleic anhydride, 15 g of polyphosphate prepared in step (1), 1.2 g of FeCl 3 ·6H 2 O and 1.0 g of phenothiazine were added to the second reaction device, and under the protection of nitrogen, they were reacted at a constant temperature...

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Abstract

The present invention relates to the technical field of construction admixtures, in particular to a shrinkage-reducing polycarboxylate water-reducer and a preparation method thereof, wherein the preparation method of the shrinkage-reduction polycarboxylate water-reducer comprises the following steps: Add the body and water into the reaction kettle, control the temperature at 20-60°C, then add the initiator aqueous solution, the chain transfer agent aqueous solution and the unsaturated acid aqueous solution to react respectively to obtain the reaction product, and adjust the pH to 6.0-6.0 through alkaline substances 7.0, that is, a shrinkage-reducing polycarboxylate superplasticizer is obtained. The molecular structure of the shrinkage-reducing polycarboxylate superplasticizer prepared by the present invention has hyperbranched shrinkage-reducing functional segments, steric hindrance segments and adsorption group segments, and realizes uniform shrinkage reduction and dispersion performance at low dosage, and It can prevent concrete shrinkage and cracking, thereby improving the durability of concrete.

Description

technical field [0001] The invention relates to the technical field of building admixtures, in particular to a shrinkage-reducing polycarboxylate water reducer and a preparation method thereof. Background technique [0002] The brittleness and shrinkage of concrete are important factors affecting its performance. Shrinkage leads to cracks inside the concrete, which reduces the strength of the concrete and adversely affects its durability. According to survey results, from bridges, roads and other transportation facilities to coastal areas Seaport engineering structures, from civil buildings, commercial buildings to industrial buildings, are affected by cracking problems extremely widely. Therefore, reducing the shrinkage of concrete and controlling the internal defects of concrete are very important to improve the application performance of concrete. [0003] How to reduce the shrinkage of concrete has become the focus of current engineering research. At home and abroad, a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F283/06C08F220/06C08F222/02C08G65/335C04B24/26C04B103/30
CPCC04B24/246C04B2103/302C08F283/065C08G65/3355C08F220/06C08F222/02
Inventor 林艳梅赖华珍方云辉李格丽钟丽娜郭元强麻秀星林添兴
Owner KZJ NEW MATERIALS GROUP CO LTD