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Preparation method for lignin and acrylonitrile copolymer and preparation method for lignin based carbon fiber

A technology of lignin and acrylonitrile, which is applied to the chemical characteristics of fibers, textiles and papermaking, etc., can solve the problems of low copolymerization reaction efficiency, limited lignin usage ratio, and large hole defects in fibers, so as to improve the copolymerization reaction efficiency and avoid large Pore ​​defects, the effect of improving mechanical properties

Active Publication Date: 2015-09-30
NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the disadvantage of this technology is that when the lignin content in the blend exceeds 20%, the lignin will phase-separate from the PAN and be lost in the solvent during the solidification molding process, resulting in the formation of large pores inside the fiber. Defects, which limit the proportion of lignin used, and lead to a substantial decline in the performance of carbon fibers (see literature: Baker D A. et al. Journal of Applied Polymer Science, 2013, 130:713-728.)
However, this method firstly produces a viscous PAN oligomer solution, which is difficult to mix evenly with lignin; in addition, a large number of phenolic hydroxyl groups contained in lignin molecules will capture active free radicals to form stable phenolic oxygen free radicals , so that it loses its reactivity, resulting in a very low efficiency of the copolymerization reaction between PAN oligomers and lignin, and the proportion of lignin in the copolymer is very small, which fails to realize the efficient utilization of lignin

Method used

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  • Preparation method for lignin and acrylonitrile copolymer and preparation method for lignin based carbon fiber
  • Preparation method for lignin and acrylonitrile copolymer and preparation method for lignin based carbon fiber
  • Preparation method for lignin and acrylonitrile copolymer and preparation method for lignin based carbon fiber

Examples

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Effect test

Embodiment 1

[0028] In this example, the following steps are used to prepare the copolymer of esterified lignin and acrylonitrile:

[0029] (1) Add dimethyl sulfoxide, lignin and acryloyl chloride sequentially in the reactor at a weight ratio of 100:30:1, stir the esterification reaction at 45°C for 4 hours, and add a small amount of triethylamine (TEA) after the reaction is completed Neutralize the HCl produced by the esterification reaction, then add ether to precipitate the modified lignin, then filter, wash with absolute ethanol several times, remove TEA hydrochloride, and obtain esterified lignin modified with acryloyl chloride;

[0030] (2) Add dimethyl sulfoxide, acryloyl chloride-modified esterified lignin, acrylonitrile, and azobisiso Butyronitrile, carry out the homogeneous solution free radical copolymerization reaction at 60°C under the protection of nitrogen for 20 hours, remove the unreacted acrylonitrile monomer in the polymerization solution under vacuum after the reaction,...

Embodiment 2

[0039] In this example, the following steps are used to prepare the copolymer of esterified lignin and acrylonitrile:

[0040] (1) Add dimethyl sulfoxide, lignin and methacryloyl chloride sequentially in the reactor at a weight ratio of 100:30:3, stir the esterification reaction at 30°C for 3 hours, and add a small amount of triethylamine ( TEA) neutralizes the HCl produced by the esterification reaction, then adds ether to precipitate the modified lignin, then filters it, and washes it with absolute ethanol several times to remove TEA hydrochloride to obtain methacryloyl chloride-modified esterified Lignin;

[0041] (2) Add dimethylformamide, methacryloyl chloride-modified esterified lignin, acrylonitrile, azo Diisobutyronitrile. Carry out homogeneous solution free radical copolymerization reaction at 63°C under the protection of nitrogen for 18 hours. After the reaction, the unreacted acrylonitrile monomer in the polymerization liquid is removed under vacuum, and then stan...

Embodiment 3

[0044] In this example, the following steps are used to prepare the copolymer of esterified lignin and acrylonitrile:

[0045] (1) In the reactor, dimethyl sulfoxide, lignin and methacryloyl chloride are sequentially added in a weight ratio of 100:30:30, and the esterification reaction is stirred at 25° C. for 1 hour. After the reaction, a small amount of triethylamine ( TEA) neutralizes the HCl produced by the esterification reaction, then adds ether to precipitate the modified lignin, then filters it, and washes it with absolute ethanol several times to remove TEA hydrochloride to obtain methacryloyl chloride-modified esterified Lignin;

[0046] (2) Add dimethyl sulfoxide, methacryloyl chloride-modified esterified lignin, acrylonitrile, azo Diisoheptanonitrile. Homogeneous solution free radical copolymerization was carried out at 58°C under the protection of nitrogen for 15 hours. After the reaction was over, the unreacted acrylonitrile monomer in the polymerization soluti...

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Abstract

The invention provides a preparation method for a lignin and acrylonitrile copolymer. The preparation method comprises the following steps: at first, an esterification reaction is conducted on unsaturated acyl chloride and lignin, lignin is modified with unsaturated acyl chloride, so that a hydroxide radical in a lignin molecule is converted into an ester group, and meanwhile, an unsaturated carbon-carbon double bond is introduced to obtain esterified lignin; then a homogeneous solution free radical copolymerization reaction is conducted on an esterified lignin and acrylonitrile copolymer. The preparation method has the advantages that the copolymerization efficiency of lignin and acrylonitrile is effectively improved; when carbon fibers are prepared through pre-oxidation and carbonization, not only can lignin be prevented from running away in the process of wet spinning and consolidation forming processes, and big hole defects are avoided, but also the utilization efficiency of lignin can be improved.

Description

technical field [0001] The invention belongs to the technical field of lignin and carbon fiber, and in particular relates to a preparation method of lignin and acrylonitrile copolymer and a preparation method of lignin-based carbon fiber. Background technique [0002] Lignin is a natural polymer material second only to cellulose in nature. Industries such as pulping and papermaking in the world produce hundreds of millions of tons of lignin by-products every year, but only a very small part is utilized, and most of them are directly discharged into rivers or concentrated and burned as "black liquor", which not only wastes precious resources, but also It also caused serious environmental pollution. Carbon fiber is a high-performance fiber material composed of carbon elements. It has a series of excellent properties such as high strength, high modulus, high temperature resistance, corrosion resistance, high thermal conductivity, and high electrical conductivity. It is widely ...

Claims

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Application Information

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IPC IPC(8): C08F290/00C08F220/44C08H7/00D01F9/17
Inventor 欧阳琴夏克强汪绪兰黄显雯马洪波杨建行
Owner NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI