Method for preparing high-strength polyacrylonitrile-based precursor for carbon fiber

A technology of polyacrylonitrile-based carbon fiber and acrylonitrile, which is applied in the direction of spinning solution preparation, fiber treatment, wet spinning, etc., can solve the problem of insufficient high-performance carbon fiber, and achieve low production cost of raw silk, small fineness, and high production process compact effect

Active Publication Date: 2012-09-05
ZHONGFU SHENYING CARBON FIBER
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] At present, the polyacrylonitrile-based carbon fiber precursor prepared by domestic wet spinning technology has a monofilament strength of only 6-8cN / dtex, a fineness of 0.8-1.2dtex, and a density of 1.170-1.178g / cm3, which is very important for the preparation of high-performance Carbon fiber is clearly not enough

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0033] A method for preparing high-strength polyacrylonitrile-based precursor for carbon fiber, the specific steps are as follows: (wherein the percentage concentration is the mass ratio percentage)

[0034] 1) With 99wt% of acrylonitrile and 1wt% of itaconic acid as comonomers, azobisisobutyronitrile was used to initiate homogeneous solution polymerization of acrylonitrile and comonomers in DMSO (DMSO). Obtain spinning dope, and control the temperature of the spinning dope to 40~70℃ and the solid content of 18~24%;

[0035] 2) The raw solution after polymerization is stripped under a pressure of -60 ~ -78KPa, and then subjected to a 3um primary filtration treatment.

[0036] 3) The stock solution after the primary filtration is subjected to defoaming treatment under a pressure of -78~-100KPa, and then sent to the spinning unit through a secondary filtration of 1um.

[0037] 4) The refined spinning dope is extruded from the spinneret into the first coagulation bath through a metering ...

Embodiment 1

[0053] It is composed of 99% (wt) of acrylonitrile, 1% (wt) of itaconic acid, and the solid content of 20.5% (wt) of dimethyl sulfoxide solution for solution polymerization to obtain a polymer with intrinsic viscosity [ η] is 1.78.

[0054] The polymer is removed from the single reactor at a pressure of -76KPa, and then subjected to a 3um level primary filtration treatment. Then, after defoaming treatment in a defoaming tank with a pressure of -97KPa, it is sent to a 1um second

[0055] Grade filtration system, the stock solution after the refining treatment is transported to the spinning unit, and the stock solution temperature is controlled to 55°C.

[0056] The spinning dope passes through a 0.5um candle wick filter and is extruded from the spinneret to the coagulation bath. The total number of holes in the spinneret is 12000, the hole diameter is 0.07mm, and the hole length is 0.25mm.

[0057] The coagulation liquid in the coagulation bath is composed of 70% (wt) DMSO and 30% (w...

Embodiment 2

[0063] The traction speed of the traction roller outside the coagulation bath in Example 1 was changed to 4m / min, and the draft ratio of the pre-draft was reduced, so that the total draft ratio of the fiber in the whole process was about 12 times. In addition, the same apparatus and method as in Example 1 were used to produce polyacrylonitrile-based carbon fiber precursors.

[0064] The monofilament in the obtained fiber bundle has a fineness of 0.67dtex, a monofilament strength of 8.7cN / dtex, an elongation of 10.4%, a density of 1.181g / cm3, a small amount of "waist type" in the cross section of the fiber bundle, and fiber silicone oil content It is 0.78%.

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Abstract

The invention discloses a method for preparing a high-strength polyacrylonitrile-based carbon fiber precursor. The method comprises the steps of: using azodiisobutyronitrile to trigger acrylonitrile and a comonomer to perform homogeneous solution polymerization in dimethyl sulfoxide to obtain spinning solution, and controlling the temperature of the spinning solution to be between 40 and 70 DEG C and the solid content to be between 18 and 24 percent; performing monomer removal on the spinning solution under the pressure of between -60 and -78KPa, and performing deaeration treatment under the pressure of between -78 and -97KPa; then extruding the spinning solution into a spin duct in a coagulation bath with a temperature of between 35 and 65 DEG C and a dimethyl sulfoxide concentration of between 50 and 70 percent for molding through a spinneret, and obtaining PAN-based as-spun fiber through 45 to 75 percent of minus stretch in the coagulation bath; then molding and stretching through a secondary coagulation bath, a third coagulation bath, a fourth coagulation bath and a fifth coagulation bath; and obtaining the high-strength polyacrylonitrile-based carbon fiber precursor through solvent removal by water scrubbing, hot water stretch, oiling, drying and densification, steam stretch, and hot air setting. The tensile strength of the high-strength polyacrylonitrile-based carbon fiber precursor reaches 10.2cN / dtex.

Description

Technical field [0001] The invention relates to a preparation technology of carbon fiber, in particular to a preparation method of high-strength polyacrylonitrile-based precursor yarn for carbon fiber. Background technique [0002] Carbon fiber is a high-tech fiber material that developed rapidly in the 1960s. It is a fibrous carbon material whose chemical composition accounts for more than 90% of the total mass. Carbon fiber has a series of excellent properties such as high specific strength, high specific modulus, high temperature resistance, chemical corrosion resistance, fatigue resistance, thermal shock resistance, radiation resistance, electrical conductivity, heat transfer and small specific gravity, and is a typical high-performance fiber. The main purpose of carbon fiber is to composite with resin, metal, ceramic and carbon as a reinforcing material to form a composite material. Now it is not only widely used in aerospace fields such as spacecraft, artificial satellites...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): D01D5/06D01D1/02D01D1/10D01D10/02D01D10/06
Inventor 张国良李怀京刘宣东陈秋飞
Owner ZHONGFU SHENYING CARBON FIBER
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