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Mud-proof slump-retaining type polycarboxylate superplasticizer and preparation method thereof

A slump-preserving, polycarboxylic acid technology, applied in the field of concrete functional additives, can solve the problems of esterification end-capping reaction requiring high temperature and catalysis, increasing the adaptability of concrete materials, prone to side reactions, etc., to avoid side reactions, The effect of improving slump retention performance and mild reaction conditions

Active Publication Date: 2019-07-02
JIANGSU WANBANG BUILDING MATERIALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method prevents polyether side chains from being embedded in the interlayer of clay, but there are problems such as esterification capping reaction requires high temperature and catalysis, and side reactions are prone to occur.
[0004] On the other hand, introducing an amide or imide structure into the polycarboxylate superplasticizer molecule can significantly improve the dispersion ability and slump retention performance of the polycarboxylate superplasticizer, and increase the adaptability of the polycarboxylate superplasticizer to concrete materials. The typical example is the amide / imide type polycarboxylate water reducer known as the third generation polycarboxylate water reducer (see: Journal of Building Materials, 2012, 15(1): 22-26; silicon Acta Sinica Sinica, 2013, 41(8): 1079-1086), but its production cost is too high to enter the practical stage

Method used

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  • Mud-proof slump-retaining type polycarboxylate superplasticizer and preparation method thereof
  • Mud-proof slump-retaining type polycarboxylate superplasticizer and preparation method thereof
  • Mud-proof slump-retaining type polycarboxylate superplasticizer and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] (1) Reflux to remove water: methallyl polyoxyethylene ether (HPEG, number average molecular weight M n = 2400) After being heated to all melting, add toluene accounting for 10% of the mass of the polyether monomer to carry out refluxing with water, and after the water is removed, the remaining toluene is distilled off under reduced pressure at 60°C;

[0028] (2) Furfuryl isocyanate blocking: Add furfuryl isocyanate to the dehydrated HPEG monomer in step (1) (the ratio of the amount of furfuryl isocyanate to HPEG monomer is 1:1), Stir and react for 3 hours at 70°C;

[0029] (3) N-carbamoyl maleimide end-capping: Add N-carbamoyl maleimide (N-carbamoyl maleimide and HPEG monomer) to the product obtained in step (2). The ratio of the amount of the substance to the substance is 1:1), the reaction is stirred at 70°C for 4 hours to obtain the functionally terminated polyether monomer; the specific reaction route is as follows figure 1 Shown.

[0030] (4) The functional end-capped po...

Embodiment 2

[0032] (1) Reflux to remove water: methallyl polyoxyethylene ether (HPEG, number average molecular weight M n =2400) After heating to complete melting, add toluene accounting for 15% of the mass of the polyether monomer to carry out refluxing with water, and after carrying out without water, the remaining toluene is distilled off under reduced pressure at 60°C;

[0033] (2) Furfuryl isocyanate blocking: add furfuryl isocyanate to the dehydrated HPEG monomer in step (1) (the ratio of the amount of furfuryl isocyanate to HPEG monomer is 0.9:1), Stir and react at 80°C for 2 hours;

[0034] (3) N-carbamoyl maleimide end-capping: Add N-carbamoyl maleimide (N-carbamoyl maleimide and HPEG monomer) to the product obtained in step (2). The ratio of the amount of the substance to the substance is 0.9:1), and the reaction is stirred at 80°C for 3 hours to obtain a functionally terminated polyether monomer.

[0035] (4) The functional end-capped polyether monomer obtained in step (3) is mixed w...

Embodiment 3

[0037] (1) Reflux to remove water: the isopentenyl polyoxyethylene ether (TPEG, number average molecular weight M n = 2400) After being heated to all melting, add toluene accounting for 10% of the mass of the polyether monomer to carry out refluxing with water, and after the water is removed, the remaining toluene is distilled off under reduced pressure at 60°C;

[0038] (2) Blocking of furfuryl isocyanate: add furfuryl isocyanate to the dehydrated TPEG monomer in step (1) (the ratio of the amount of furfuryl isocyanate to TPEG monomer is 1:1), Stir and react at 80°C for 2 hours;

[0039] (3) N-carbamoyl maleimide capping: Add N-carbamoyl maleimide (N-carbamoyl maleimide and TPEG monomer) to the product obtained in step (2). The ratio of the amount of the substance to the substance is 1:1), and the reaction is stirred at 80° C. for 3 hours to obtain a functionally terminated polyether monomer.

[0040] (4) The functional end-capped polyether monomer obtained in step (3) is mixed wit...

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Abstract

The invention discloses a mud-proof slump-retaining type polycarboxylate superplasticizer and a preparation method thereof. The preparation method comprises the following steps: methylbenzene is firstly used for water-bringing refluxing of a polyether monomer, and residual methylbenzene is steamed out by reduced pressure distillation; the dehydrated polyether monomer is subjected to an end-cappingreaction with furfuryl isocyanate, and the product is then subjected to an end-capping reaction with N-carbamylmaleimide so as to obtain a functional terminated polyether monomer; the monomer is mixed with water, an initiator, a chain transfer agent and acrylic acid, followed by heating and reacting; and then aqueous alkali is added for neutralization until pH value is 6-7, so as to obtain motherliquor of the polycarboxylate superplasticizer. The The terminal end of the functional terminated polyether monomer prepared by the invention has a cyclic structure having a large physical size and an amide / imide structure. When the functional terminated polyether monomer is used for preparation of the polycarboxylate superplasticizer, the cyclic structure having a large physical size at the terminal end of the polyether side-chain can prevent the polyether side-chain from being embedded in the interlayer of mud, thus achieving the mud-proof effect. The amide / imide structure at the terminal end of the polyether side-chain can help enhance dispersibility and slump-retaining property of the polycarboxylate superplasticizer.

Description

Technical field [0001] The invention relates to a sludge-resistant polycarboxylic acid water reducer and a preparation method thereof, and belongs to the field of concrete functional additives. Background technique [0002] Polycarboxylic acid water reducing agent is a water-soluble polymer with comb-shaped structure composed of a main chain rich in carboxylic acid groups and sulfonic acid groups and polyethylene oxide side chains. It has a designable structure, low dosage, and water reduction rate. High advantages are more and more widely used in concrete engineering. With the rapid development of my country's construction industry, sand and gravel consumption is large, high-quality sand and gravel resources are scarce, and the sand and gravel content is relatively high. A large number of engineering examples and studies have shown that polycarboxylic acid water reducer is very sensitive to the mud content in concrete aggregates. When the mud content in the concrete system is h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F283/06C08F220/06C08G65/333C04B24/26C04B103/30
CPCC04B24/2605C04B2103/30C08F283/065C08G65/33334C08G65/33362C08F220/06
Inventor 刘斌李本刚
Owner JIANGSU WANBANG BUILDING MATERIALS CO LTD