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Prepn process of polyimide fiber

A technology of polyimide fiber and polyamic acid, which is applied in the direction of wet spinning, can solve the problems of low fiber strength, low production efficiency, and no practical value, and achieve the effect of good chemical corrosion resistance

Inactive Publication Date: 2007-03-21
DONGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition US5840828, WO9800590 and JP2000129535 adopt the melting method to spin polyimide fiber, but the intensity of fiber is relatively small, basically has no practical value
[0003] The wet spinning route not only has a slow spinning speed and low production efficiency, but also the coagulation bath is mixed with a large amount of solvent after spinning, making separation difficult; in contrast, the dry spinning technology does not use a coagulation bath , the solvent in the spinning slurry volatilizes at high temperature and condenses at low temperature, so the recovery is relatively simple

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Add 200g of 4,4'-diamine diphenyl ether into 2000ml of dimethylacetamide and stir until completely dissolved. Afterwards, 222 g of pyromellitic dianhydride was added to the solution in batches, and stirred at room temperature for 8 hours to obtain a light yellow viscous polyamic acid spinning solution.

[0019] After defoaming the polyamic acid spinning solution prepared above, dry spinning is carried out on a dry spinning machine. The length of the tunnel is 10 meters, and the temperature of the upper section of the tunnel is 170°C, the middle section is 200°C, and the lower section is 220°C, and then winding and forming A polyamic acid fiber is obtained. The polyamic acid fiber is made of polyimide fiber by thermal imidization, and the two-stage treatment temperature is 270°C and 370°C respectively; stretching 5 times at 430°C, the high-performance polyimide fiber can be obtained.

Embodiment 2

[0021] Add 108g of phenylenediamine into 1000ml of dimethylformamide and stir until completely dissolved. Afterwards, 344 g of dimethylmethylene diphenylamine was added to the solution in batches, and stirred at room temperature for 10 hours to obtain a pale yellow viscous polyamic acid spinning solution.

[0022] After defoaming the polyamic acid spinning solution prepared above, dry spinning is carried out on a dry spinning machine. The length of the tunnel is 12 meters. The temperature of the upper section of the tunnel is 150 ° C, the middle section is 200 ° C, and the lower section is 210 ° C. After that, it is wound into shape A polyamic acid fiber is obtained. The polyamic acid fiber is made of polyimide fiber by thermal imidization, the two-stage treatment temperature is 185°C and 330°C respectively; stretching 3 times at 350°C, the high-performance polyimide fiber can be obtained.

Embodiment 3

[0024] Stir 246g of 4,3'-diaminodiphenylene in a mixed solvent of 2000ml dimethylformamide and dimethylacetamide (1:1) until completely dissolved. Afterwards, 302 g of biphenyl dianhydride was added to the solution in batches, and stirred at room temperature for 6 hours to obtain a light yellow viscous polyamic acid spinning solution.

[0025] After defoaming the polyamic acid spinning solution prepared above, carry out dry spinning on a dry spinning machine. The length of the tunnel is 10 meters. The temperature of the upper section of the tunnel is 170°C, the middle section is 210°C, and the lower section is 230°C, and then it is wound into shape A polyamic acid fiber is obtained. Polyamic acid fibers are chemically imidized in a mixture of acetic anhydride / pyridine to obtain polyimide fibers; the fibers are stretched 6 times at 430°C to obtain high-performance polyimide fibers.

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Abstract

The preparation process of polyimide fiber includes the following steps: 1. preparing polyamic acid solution as the spinning precursor through polycondensing maleic anhydride monomer and diamine monomer; 2. dry spinning to prepare polyamic acid fiber; 3. imidating polyamic acid fiber to form polyimide fiber; and 4. hot stretching polyimide fiber at 350-470 deg.c for 3-8 times. Thus prepared polyimide fiber has high strength, high modulus, high heat resistance, high chemical corrosion resistance and relatively high limiting oxygen index, and may be used widely as reinforcing material of composite material and cable, rope for vehicle and ship, filter material, etc.

Description

technical field [0001] The present invention relates to a preparation method for fiber production, in particular to a preparation method for polyimide fibers, specifically to prepare polyamic acid fibers through the dry spinning process technical route of polyamic acid spinning slurry , and then polyimide fibers were prepared after imidization and thermal stretching. Background technique [0002] Polyimide fiber is a new type of special fiber with many superior properties such as high strength, high modulus, high temperature resistance, flame resistance, radiation resistance, and chemical corrosion resistance. There are two main wet production routes for polyimide fibers. One is the one-step technical route: polyimide is directly spun as a raw material, and polyimide fibers are obtained after thermal stretching. The spinning process of this method is relatively simple, but the choice of solvent is difficult and often has a high Toxicity, so the type of polyimide is very li...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F6/74D01D5/06
Inventor 张清华李静陈大俊罗伟强
Owner DONGHUA UNIV
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