Method for preparing carbon fiber spinning solution

A technology of spinning liquid and carbon fiber, which is applied in the fields of fiber chemical characteristics, textiles and papermaking, and can solve problems such as uneven distribution of copolymerization units, molecular defects, and difficulty in industrial production

Inactive Publication Date: 2003-03-12
ZHONGJIAN TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when the free radical copolymerization method is used, due to the different reactivity ratios of different monomers and the constant change of the monomer concentration during the polymerization process, etc., the copolymerization units will be unevenly distributed on the macromolecular chain, resulting in molecular defects.
Although controlling the polymerization conversion rate and continuously adding monomer can weaken this uneven distribution, it cannot fundamentally solve this problem, and it is not easy for industrial production.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0006] Example 1: 1. Weigh acrylonitrile, dimethylformamide, distilled water, and azobisisobutyronitrile according to the weight ratio of 200:790:10:1, and react at 50°C for 15 hours under nitrogen protection after mixing . 2. Introduce ammonia gas into the system to adjust the pH value to 9, and the polymerization reaction is terminated. 3. Keep the pH at 9, raise the temperature of the system to 80°C, hydrolyze for 2 hours, remove the single and defoam, and obtain the spinning solution.

[0007] The spinning liquid is analyzed by infrared and nuclear magnetic resonance, and the spectrogram shows that the product contains a small amount of carboxyl and amido groups, 0.2% of carboxyl groups and 0.9% of amido groups.

Embodiment 2

[0008] Example 2: 1. Acrylonitrile, dimethylformamide, distilled water, and azobisisobutyronitrile were weighed in a weight ratio of 400:1500:150:1, and reacted at 70° C. for 1 hour under nitrogen protection. 2. Introduce ammonia gas into the system to make the pH value to 8.5, and the polymerization reaction is terminated. 3. Adjust the pH to 12 with ammonia gas, raise the temperature of the system to 95°C, hydrolyze for 20 minutes, remove the single and defoam, and obtain the spinning solution.

[0009] The spinning liquid is analyzed by infrared and nuclear magnetic resonance, and the spectrogram shows that the product contains a small amount of carboxyl and amido groups, 0.2% of carboxyl groups and 1.3% of amido groups.

Embodiment 3

[0010] Example 3: 1. Weigh acrylonitrile, dimethylformamide, distilled water, and azobisisobutyronitrile according to the mass ratio of 200:700:50:2, and react at 60° C. for 6 hours under nitrogen protection. 2. Introduce ammonia gas into the system to make the pH value to 8.7, and the polymerization reaction is terminated. 3. Adjust the pH to 14 with ammonia gas, raise the temperature of the system to 100° C., hydrolyze for 5 minutes, remove the single and defoam, and obtain the spinning solution.

[0011] The spinning liquid is analyzed by infrared and nuclear magnetic resonance, and the spectrogram shows that the product contains a small amount of carboxyl and amido groups, 0.1% of carboxyl groups and 0.8% of amido groups.

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PUM

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Abstract

A process for preparing spinning dope of carbon fibres includes homopolymerization of acrylonitrile in the mixture of dimethyl formamide and water, introducing ammonia gas to stop reaction, regulating pH value with ammonia gas and homogenous hydrolysis. Its advantage is high uniformity of function groups in chain or between chains of polymer.

Description

[0001] Field: [0002] The invention belongs to a method for preparing a carbon fiber spinning solution, in particular to a method for preparing a spinning solution for preparing high-performance polyacrylonitrile-based carbon fibers. Background technique: [0003] Polyacrylonitrile macromolecular chain structure is an important factor affecting the quality of raw silk. Acrylonitrile homopolymer is a highly crystalline polymer with poor solubility and difficult spinning; during pre-oxidation, the peak temperature is high, the heat release is concentrated, and the process It is not easy to control, and high-performance carbon fibers cannot be obtained. This problem is generally solved by binary or ternary copolymerization with less than 2% comonomer. Commonly introduced comonomers are: acrylic acid, methacrylic acid, itaconic acid, methyl methacrylate, acrylamide, etc. Mitsubishi Viscose Company uses solution polymerization to synthesize acrylonitrile / itaconic acid / acrylamide...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F9/12
Inventor 凌立成杨永岗温月芳张寿春吕春祥
Owner ZHONGJIAN TECH CO LTD
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