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

A polyacrylonitrile-based carbon fiber and acrylonitrile technology, which is applied in 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, wool little effect

Active Publication Date: 2010-06-09
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,

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0034] A method for preparing high-strength polyacrylonitrile-based precursors for carbon fibers, the specific steps are as follows: (wherein the percentage concentration is mass ratio percentage)

[0035] 1) Using acrylonitrile and itaconic acid as comonomers, using azobisisobutyronitrile to initiate homogeneous solution polymerization of acrylonitrile and comonomers in dimethyl sulfoxide (DMSO) to obtain spinning dope, control The temperature of the spinning stock solution is 40-70°C, and the solid content is 18-24%;

[0036] 2) The raw liquid after polymerization is separated under the pressure of -60~-78KPa, and then treated by 3um primary filtration.

[0037] 3) The stock solution after primary filtration is degassed under the pressure of -78~-100KPa, and then sent to the spinning unit through secondary filtration of 1um.

[0038]4) The refined spinning stock solution is extruded from the spinneret through the metering pump and the three-stage filter of 0.5um into the fi...

Example Embodiment

[0053] Example 1

[0054] It is composed of 99% (wt) acrylonitrile and 1% (wt) itaconic acid, and the solid content is 20.5% (wt) in a dimethyl sulfoxide solution for solution polymerization to obtain a polymer with an intrinsic viscosity of [ η] was 1.78.

[0055] The polymer is singled out under the pressure of -76KPa through the single removal tank, and then undergoes a 3um level primary filtration treatment. Then, after degassing treatment in a defoaming tank with a pressure of -97KPa, it is sent to a 1um-level secondary filtration system, and the stock solution after refining treatment is transported to the spinning unit, and the temperature of the stock solution is controlled at 55°C.

[0056] The spinning stock solution is extruded from the spinneret to the coagulation bath through a 0.5um candle wick filter. 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 coagulat...

Example Embodiment

[0062] Example 2

[0063] Change the drawing speed of the pulling roll outside the coagulation bath in embodiment 1 to 4m / min, reduce the draw ratio of pre-drawing simultaneously, make the total draw ratio of fiber in the whole operation be about 12 times, except this In addition, using the same apparatus and method as in Example 1, polyacrylonitrile-based carbon fiber precursors were produced.

[0064] The fineness of the monofilament in the obtained fiber bundle is 0.67dtex, the monofilament strength is 8.7cN / dtex, the elongation is 10.4%, and the density is 1.181g / cm3, there is a small amount of "waist type" in the fiber bundle section, and the fiber silicone oil content was 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 technology for preparing carbon fibers, in particular to a method for preparing high-strength polyacrylonitrile-based precursors for carbon fibers. Background technique [0002] Carbon fiber is a high-tech fiber material developed rapidly in the 1960s. It is a fibrous carbon material, and the carbon element in its 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 be used as a reinforcing material to compound with resin, metal, ceramic and carbon matrix to form a composite material. Now it is not only widely used in aerospace fields suc...

Claims

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Application Information

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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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