Preparation method of wet-process high-strength polyacrylonitrile-based carbon fiber

A polyacrylonitrile-based carbon fiber and high-strength technology, which is applied in the fields of fiber chemical characteristics, textiles and papermaking, can solve the problems of gelation and time-consuming spinning solution system, and achieve less hole-type defects, reduce devitrification and impermeability Homogeneity, the effect of improving the uniformity of solidification diffusion

Inactive Publication Date: 2014-07-30
BEIJING UNIV OF CHEM TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

(2) When ammonia gas is used in the existing carbon fiber preparation process, gas-liquid reaction is involved, which takes a long time
(3) When ammonia water is used in the existing carbon fiber preparation process, the water may be introduced into the gel of the spinning solution system

Method used

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  • Preparation method of wet-process high-strength polyacrylonitrile-based carbon fiber
  • Preparation method of wet-process high-strength polyacrylonitrile-based carbon fiber
  • Preparation method of wet-process high-strength polyacrylonitrile-based carbon fiber

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] Example 1: Using azobisisobutyronitrile (AIBN) as the initiator and dimethyl sulfoxide (DMSO) as the solvent, acrylonitrile solution copolymerization was carried out. Based on the total mass of the comonomers, put the monomers and comonomers methyl acrylate and itaconic acid into the polymerization kettle at the ratio of 97.2% of acrylonitrile, 1.6% of methyl acrylate and 1.2% of itaconic acid, and then add Solvent DMSO, control the monomer acrylonitrile to account for 22% of the total mass of the polymerization system, react at 65°C for 24 hours, and the resulting polymerization solution is defoamed and subjected to wet spinning. The spinning solution enters the coagulation bath through the metering pump, candle filter, and spinneret. In the three coagulation baths with the concentration of the good solvent DMSO solution of 67%, 45%, and 15%, the corresponding coagulation bath temperature is 60. Under the conditions of ℃, 20℃, and 20℃, perform gradient gelation coagulat...

Embodiment 2

[0042] Example 2: According to the polymerization formula and quantity of Example 1, it was charged into the polymerization kettle, and the same process conditions were used to carry out polymerization reaction, de-sizing and defoaming. The spinning solution passes through a metering pump, a candle filter, and a spinneret. The DMSO solution concentration in the coagulation bath is 74.5%, 45%, and 15% respectively. The three coagulation baths are gradient gelled and coagulated. The coagulation bath temperature is 20. ℃, 20℃, 20℃, in the first coagulation bath, add diethylamine solution, adjust the pH of the coagulation bath = 10.5, and prepare PAN-based precursor yarn through the same follow-up spinning process as the comparative example. The fineness of the raw silk is 1.24dtex, and the bulk density is 1.190g / cm 3 The pore volume content determined by the SAXS method is 0.43%. The precursor is pre-oxidized in an air atmosphere at 200-280°C, carbonized at a low temperature in a n...

Embodiment 3

[0043] Example 3: According to the polymerization formula and quantity of Example 1, polymerization, de-ordering, and defoaming were performed. The spinning solution enters the coagulation bath through the metering pump, candle filter, and spinneret. The coagulation bath contains ethylenediamine, adjusted to pH=10.3, and the concentration in the coagulation bath is 64%, 45%, and 15% respectively. The medium gradient gelation coagulation molding, the coagulation bath temperature is 60°C, 20°C, and 20°C, respectively, and the PAN-based precursor yarn is prepared through the same follow-up spinning process as the comparative example. The fineness of the prepared raw yarn is 1.25dtex, and the bulk density is 1.191g / cm 3 The pore volume content determined by the SAXS method is 0.32%. The raw silk is pre-oxidized under 200-280℃ air atmosphere, low-temperature carbonization treatment under 350-800℃ nitrogen atmosphere, and 800-1600℃ nitrogen atmosphere Under high temperature carboniza...

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Abstract

The invention relates to a preparation method of a wet-process high-strength polyacrylonitrile-based carbon fiber. The preparation method sequentially comprises the following steps: step1. preparing a PAN (Polyacrylonitrile) copolymer; step 2. removing monomers and removing foams; step 3. filtering and metering; step 4. carrying out consolidation forming; step 5. carrying out primary-drafting, washing, drying and compacting, re-drafting and thermally setting to prepare precursor fibers; and step 6. carrying out pre-oxidizing, low-temperature carbonizing and high-temperature carbonizing to finally obtain carbon fibers, wherein the coagulating bath system used in the step 4 consists of a good solvent of polyacrylonitrile, precipitator water and water soluble low carbon fatty amine. According to the preparation method provided by the invention, contact between the polymer and the precipitator water is alleviated by means of the appetency of the low carbon fatty amine and the polymer component to accelerate the solution trickle to precipitate with a slow speed phase so as to effectively reduce hole defects and skin cores of the precursor fibers in the conventional wet-process solidification forming process, so that the shape structure of the precursor fibers is improved, devitrification and non-uniformity of the precursor fibers are reduced, radial solidification and dispersion uniformity of the solution trickle are expanded and strands far from the bath are compact and transparent.

Description

technical field [0001] The present invention relates to a method for preparing wet-process high-strength polyacrylonitrile-based carbon fibers, in particular to a method for improving the wet-process gel fiber-forming process of polyacrylonitrile to prepare high-performance carbon fibers, which can prepare a diameter of 6-8 μm. Polyacrylonitrile-based carbon fiber with tensile strength>4.9GPa and tensile modulus>240MPa. Background technique [0002] Carbon fiber is a new material developed to meet the needs of cutting-edge industries such as aerospace, aviation, and atomic energy. It has a series of excellent properties such as high specific strength, high specific modulus, high electrical and thermal conductivity, low thermal expansion, low density, high temperature resistance, ablation resistance, fatigue resistance, creep resistance, self-lubrication, etc. It is the most advanced composite material. important reinforcing material. The performance of carbon fiber m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F9/22
Inventor 徐樑华李常清李书乡王文义童元建张大勇曹维宇
Owner BEIJING UNIV OF CHEM TECH
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