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Shrinkage reducing type polycarboxylic acid water reducer and preparation method thereof

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

Active Publication Date: 2019-11-19
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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  • Shrinkage reducing type polycarboxylic acid water reducer and preparation method thereof
  • Shrinkage reducing type polycarboxylic acid water reducer and preparation method thereof
  • Shrinkage reducing type polycarboxylic acid water reducer and preparation method thereof

Examples

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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 at 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 invention relates to the technical field of building admixtures, and especially relates to a shrinkage reducing type polycarboxylic acid water reducer and a preparation method thereof. The preparation method of the shrinkage reducing type polycarboxylic acid water reducer includes the following steps: adding a shrinkage reducing function macromonomer and water into a reaction kettle, controlling the temperature at 20-60 DEG C, respectively adding an aqueous solution of an initiator, an aqueous solution of a chain transfer agent and an aqueous solution of an unsaturated acid, performing a reaction to obtain a reaction product, and adjusting the pH value of the reaction product to 6.0-7.0 by using an alkaline substance in order to obtain the shrinkage reducing type polycarboxylic acid water reducer. The molecular structure of the shrinkage reducing type polycarboxylic acid water reducer prepared in the invention has a hyperbranched shrinkage-reducing functional segment, a steric hindrance segment and an adsorption group segment, so the water reducer of the invention achieves the unification of shrinkage reduction and dispersion performance at a low dosage, and can prevent concrete from shrinking and cracking in order to improve the durability of the 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 Applications(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