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Modified lignin concrete air entraining agent and preparation method thereof

A concrete and lignin technology, applied in the field of concrete admixtures, can solve the problems of wasting resources and failing to realize high-value utilization of lignin, and achieve the effects of increasing air-entraining capacity, high cost performance, and good adaptability

Active Publication Date: 2020-06-26
重庆天耀建材有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Industrial lignin mainly comes from the waste liquid produced by the pulp and paper industry. The world's annual output is about 50 million tons, of which less than 10% is used efficiently, and most of the rest is concentrated by the alkali recovery system and then incinerated to produce steam and generate electricity. , did not realize the high-value utilization of lignin, wasting resources

Method used

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Examples

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Effect test

preparation example Construction

[0024] The present invention provides a method for preparing a modified lignin concrete air-entraining agent. The specific steps are as follows, and the following parts are all parts by mass:

[0025] Step 1. Oxidatively degrade lignin. Take 23~33 parts of lignin, 3~3.5 parts of sodium hydroxide, 45~56 parts of water, 1.6~2.3 parts of hydrogen peroxide solution, 1.1~1.6 parts of copper sulfate according to mass parts. In the reactor, mix evenly and react at 85-95°C for 2 to 3 hours to obtain oxidatively degraded lignin.

[0026] Step 2. Sulfite modified lignin and the above-mentioned degraded lignin solution are kept at 80~90℃, 11.3~15.6 parts of formaldehyde solution and 23.6~28.5 parts of sodium metabisulfite are sequentially added, and the reaction is stirred for 4.5~5.5 hours to obtain sulfitation Modified lignin.

[0027] Step three: Preparation of modified lignin air-entraining agent by grafting modified lignin with polyoxyethylene allyl alcohol, adding 21~32 parts of polyoxye...

Embodiment 1

[0040] Step 1. Oxidatively degrade lignin. Take 23 parts of lignin, 3 parts of sodium hydroxide, 45 parts of water, 1.6 parts of hydrogen peroxide solution, and 1.1 parts of copper sulfate in the reactor according to the mass parts, and mix them evenly. It is reacted for 2 hours at ℃ to obtain oxidatively degraded lignin.

[0041] Step 2: The sulfite-modified lignin and the degraded lignin solution are kept at 80° C., 11.3 parts of formaldehyde solution and 23.6 parts of sodium metabisulfite are sequentially added, and the reaction is stirred for 4.5 hours to obtain the sulfite-modified lignin.

[0042] Step 3. Allyl alcohol polyoxyethylene ether grafted modified lignin to prepare modified lignin air-entraining agent, 21 parts of allyl alcohol polyoxyethylene ether were added to the above sulfite modified lignin solution, stirred and heated At 40℃, add 5 parts of buffer solution to adjust the pH of the system to 6.5, while adding 9 parts of horseradish peroxidase solution with mass...

Embodiment 2

[0045] Step 1. Oxidatively degrade lignin. Take 33 parts of lignin, 3.5 parts of sodium hydroxide, 56 parts of water, 2.3 parts of hydrogen peroxide solution, and 1.6 parts of copper sulfate in the reactor according to the mass parts, and mix them evenly. It is reacted for 3 hours at ℃ to obtain oxidatively degraded lignin.

[0046] Step 2: The sulfite-modified lignin and the degraded lignin solution are kept at 90° C., and 15.6 parts of formaldehyde solution and 28.5 parts of sodium metabisulfite are sequentially added, and the reaction is stirred for 5.5 hours to obtain the sulfite-modified lignin.

[0047] Step 3. Allyl alcohol polyoxyethylene ether grafted modified lignin to prepare modified lignin air-entraining agent. Add 32 parts of allyl alcohol polyoxyethylene ether to the above sulfite modified lignin solution, stir and heat At 50°C, add 8 parts of buffer solution to adjust the pH of the system to 7.0, while adding 15 parts of horseradish peroxidase solution with mass fra...

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Abstract

The invention belongs to the field of concrete admixtures, and particularly discloses a modified lignin concrete air entraining agent and a preparation method thereof. The modified lignin concrete airentraining agent is obtained by firstly performing oxidative degradation on natural polymer material that is lignin, then performing sulfitation modification, and finally performing graft modification on the modified lignin through allyl alcohol polyoxyethylene ether. According to the invention, the natural polymer material lignin is selected as a base material and is subjected to oxidative degradation, sulfitation and free radical graft polymerization modification on allyl alcohol polyoxyethylene ether under the catalysis of enzyme to obtain the air entraining agent with good adaptability. The preparation process is free of pollution, the conversion rate is high, the cost is low, the cost performance is high, the compatibility with a water reducing agent is good, the doping amount is small, and the foaming and air entraining effects are good.

Description

Technical field [0001] The invention belongs to the field of concrete admixtures, and specifically relates to a modified lignin concrete air-entraining agent and a preparation method thereof. Background technique [0002] Concrete air-entraining agent is an admixture that can introduce a large number of fine and uniform bubbles during the concrete mixing process. By introducing appropriate size and appropriate bubbles, it can significantly improve the workability of the concrete mixture and reduce the slump loss. Improve the strength and durability of hardened concrete such as frost resistance, impermeability and carbonation resistance. Modern concrete engineering puts forward higher requirements for mixing performance such as water reduction rate, workability, fluidity, and hardening performance such as strength and durability. At present, the air-entraining agents actually used in concrete engineering include rosin soaps and triterpene saponins modified natural product air-ent...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G81/00C08H7/00C12P11/00C04B24/18C04B103/30
CPCC04B24/18C04B2103/304C08G81/00C08H6/00C12P11/00
Inventor 吕生华刘相高党国李宁国杨震
Owner 重庆天耀建材有限公司