Preparation method of polyacrylonitrile-based carbon fiber precursor

A technology of polyacrylonitrile-based carbon fiber and polyacrylonitrile, which is applied in the field of preparation of polyacrylonitrile-based carbon fiber precursors, which can solve problems such as deterioration of the performance of the precursors, decrease in molecular weight, poor spinnability, etc., and achieve good technical effects

Active Publication Date: 2015-04-29
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved in the present invention is that the carbon fiber spinning stock solution prepared by using azobisisoheptanonitrile as an initiator in the prior art has too high viscosity and poor spinnability, and the carbon fiber precursor obtained by spinning has low strength and unstable performance. Solving the problems of polyacrylonitrile spinning dope molecular weight decrease, molecular weight distribution broadening, and precursor performance deterioration after chain transfer agent, a preparation method of polyacrylonitrile-based carbon fiber precursor is provided, which has the ability to maintain high solid content , molecular weight and molecular weight distribution are almost unchanged, so that the viscosity of the spinning stock solution is reduced, and the spinnability of the stock solution is improved, so that the advantages of high density and high strength carbon fiber precursor can be obtained

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] 1. Preparation of stock solution: Distilled acrylonitrile (AN) and itaconic acid (IA) in a ratio of 97:3, with a solid content of 20%, azobisisoheptanonitrile (ABVN) accounting for 0.4wt% of the comonomer, Regulator dimethyl acetamide accounts for 0.4wt% of the total amount of feed, dimethyl sulfoxide (DMSO) is added to the reactor as a solvent, and under the protection of nitrogen, it is reacted at a constant temperature of 38 ° C for 20 hours to obtain Binary acrylonitrile copolymer spinning solution. Then the spinning solution is decompressed to remove residual monomers and air bubbles, and then filtered through a 5 μm filter material to obtain a high-performance polyacrylonitrile copolymer spinning solution. After testing, the molecular weight is 120021, the molecular weight distribution is 2.34, and the viscosity is 57 Pa·S at 60°C.

[0019] 2. Coagulation forming: The spinning dope is metered by a metering pump, filtered again at 3 μm, extruded through a spinnere...

Embodiment 2

[0027] 1. Preparation of stock solution: Distilled acrylonitrile (AN) and itaconic acid (IA) in a ratio of 98:2, with a solid content of 20%, azobisisoheptanonitrile (ABVN) accounting for 0.6wt% of the comonomer, Regulator N,N-dimethylformamide (DMF) accounted for 0.2wt% of the total amount of feed, dimethyl sulfoxide (DMSO) was added to the reactor as a solvent, under the protection of nitrogen, at a constant temperature of 38 ° C Reaction at high temperature for 20 hours to obtain binary acrylonitrile copolymer spinning solution. Then the spinning solution is decompressed to remove residual monomers and air bubbles, and then filtered through a 5 μm filter material to obtain a high-performance polyacrylonitrile copolymer spinning solution. After testing, the molecular weight is 121451, the molecular weight distribution is 2.21, and the viscosity is 64Pa·S at 60°C.

[0028] The remaining steps are according to Example 1.

[0029] The denier of the obtained precursor was 1.21...

Embodiment 3

[0032] 1. Stock solution preparation: Distilled acrylonitrile (AN) and itaconic acid (IA) in a ratio of 98:2, with a solid content of 22%, azobisisoheptanonitrile (ABVN) accounting for 0.6wt% of comonomers, Regulator N,N-dimethylacetamide (DMAc) accounted for 0.8wt% of the total amount of feed, dimethyl sulfoxide (DMSO) was added to the reactor as a solvent, under the protection of nitrogen, at a constant temperature of 38 ° C Reaction at high temperature for 20 hours to obtain binary acrylonitrile copolymer spinning solution. Then the spinning solution is decompressed to remove residual monomers and air bubbles, and then filtered through a 5 μm filter material to obtain a high-performance polyacrylonitrile copolymer spinning solution. After testing, the molecular weight is 146837, the molecular weight distribution is 2.09, and the viscosity is 75 Pa·S at 60°C.

[0033] The remaining steps are according to Example 1.

[0034] The denier of the obtained precursor was 1.21 dte...

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Abstract

The invention relates to a preparation method of a polyacrylonitrile-based carbon fiber precursor, and mainly aims at solving the problems that a carbon fiber spinning solution prepared from azobisisoheptonitrile as an initiator in the prior art is over-large in viscosity, and poor in spinnability, and the carbon fiber precursor obtained by spinning is low in strength and unstable in property. Through the technical scheme, the preparation method of the polyacrylonitrile-based carbon fiber precursor comprises the following steps: by taking azobisisoheptonitrile as an initiator, polymerizing a first monomer acrylonitrile and a second monomer itaconic acid through initation of a solvent dimethyl sulfoxide to obtain the spinning solution; carrying out vacuum removal on residual monomer and bubbles from the spinning solution; filtering to obtain a high-property polyacrylonitrile copolymer spinning solution; and carrying out solidifying, drafting, washing, oiling, compacting by drying, steam drafting and steam heat setting on the spinning solution, and then rolling to obtain the carbon fiber precursor with high compactness and high strength, the problems are relatively well solved, and the method can be applied to industrial production of the carbon fiber precursor.

Description

technical field [0001] The invention relates to a method for preparing polyacrylonitrile-based carbon fiber precursors. Background technique [0002] Monomer polymerization, the molecular weight of the obtained copolymer is between 100,000 and 900,000, and the molecular weight distribution is below 2.3 (patent number 200710056083.6), but the molecular weight of the spinning dope obtained from this system is too large, and the viscosity of the system is too large during the spinning process , it is not easy to control the polymerization process, and the spinnability is relatively poor. In the production of conventional spinning dope, mercaptans based on dodecyl mercaptan or isopropanol are used as chain transfer agents for free radical polymerization, which can effectively adjust the molecular weight of acrylonitrile, but will reduce the conversion rate of monomers . In addition, mercaptan has a strong pungent smell and strong toxicity, while isopropanol has no pungent smel...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F6/38D01F9/22C08F220/46C08F2/38C08F4/40D01D13/00D01D5/06D01D5/14D01D10/06D01D5/096
Inventor 屠晓萍沈志刚王贺团张静
Owner CHINA PETROLEUM & CHEM CORP
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