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Preparation method of polyimide fiber

A technology of polyimide fiber and polyamic acid, applied in dry cleaning fiber products, fiber treatment, fiber type, etc., can solve the problems of unstable spinning, unstable viscosity of polyamic acid solution, difficult filtration, etc., and achieve control System molecular weight and viscosity, the effect of improving spinnability

Active Publication Date: 2019-10-11
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The invention relates to a method for preparing polyimide fibers, which mainly solves the problems caused by unstable viscosity of polyamic acid solution, excessively high molecular weight, and excessively large viscosity when polyimide fibers are prepared by a two-step method in the prior art. Difficult filtration and unstable spinning

Method used

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  • Preparation method of polyimide fiber

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] 1. Stock solution preparation: mix p-phenylenediamine with 3,3′,4,4′-biphenyltetraacid dianhydride at a total molar ratio of 1:0.99, and mix 10.0807g (0.1mol) of terephthalic Add amine, 203.3g N,N-dimethylacetamide and 22.3g 1-methyl-2-pyrrolidone into a four-neck flask (water content 410ppm), stir at room temperature and under nitrogen protection, after completely dissolving, stir at 20°C Add 29.1080g (0.099mol) 3,3′,4,4′-biphenyltetraacid dianhydride powder at a speed of 250 rpm, and continue stirring for 0.5 hours to obtain the desired polyamic acid solution with a solid content of 14.8%. . Then the spinning solution was left to stand under reduced pressure to remove air bubbles, and then filtered through an 8 μm filter material to obtain a polyamic acid spinning stock solution. The solution was tested by filtration without gel generation, the apparent viscosity of the solution was 108 Pa·s at 25°C, and the intrinsic viscosity was 1.43dL / g at 25°C.

[0030] 2. Coag...

Embodiment 2

[0037] 1. Stock solution preparation: mix 4,4′-diphenyl ether diamine with 3,3′,4,4′-biphenyltetraacid dianhydride at a total molar ratio of 1:1.005, mix 20.0090g (0.1 mol) of 4,4′-diphenyl ether diamine, 100.5g of N,N-dimethylacetamide and 15.1g of 1-methyl-2-pyrrolidone into a four-necked flask (water content 700ppm), stirred at room temperature and Under argon protection, after complete dissolution, adjust the temperature to 40°C, add 29.5470g (0.1005mol) of 3,3′,4,4′-biphenyltetraacid dianhydride powder at a stirring speed of 250 rpm, and continue After stirring for 10 hours, the desired polyamic acid solution with a solid content of 30% was obtained. Then the spinning solution was left to stand under reduced pressure to remove air bubbles, and then filtered through an 8 μm filter material to obtain a polyamic acid spinning stock solution. The solution was tested by filtration without gel formation, the apparent viscosity of the solution was 269 Pa·S at 25°C, and the intr...

Embodiment 3

[0041] 1. Stock solution preparation: mix 4,4′-diphenyl ether diamine with 3,3′,4,4′-biphenyltetraacid dianhydride at a total molar ratio of 1:0.98, mix 20.0090g (0.1 mol) of 4,4′-diphenyl ether diamine, 773.0g N,N-dimethylacetamide and 154.6g 1-methyl-2-pyrrolidone into a four-necked flask (water content 450ppm), stirred at room temperature and Under the protection of N2, after completely dissolving, cool in an ice-water bath to -10°C, and add 28.8120g (0.098mol) of 3,3',4,4'-biphenyltetraacid dianhydride powder at a stirring speed of 250 rpm, Stirring was continued for 8 hours to obtain the desired polyamic acid solution with a solid content of 5%. Then the spinning solution was left to stand under reduced pressure to remove air bubbles, and then filtered through an 8 μm filter material to obtain a polyamic acid spinning stock solution. The solution was filtered and tested to have no gel. The apparent viscosity of the solution was 53 Pa·S at 25° C., and the intrinsic viscos...

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Abstract

The invention relates to a preparation method of polyimide fiber. The method mainly solves the problem in the prior art that when a two-step method is used for preparing polyimide fiber, filtering is difficult and spinning is not stable due to polyamide acid solution viscosity which is not stable and the molecular weight which is too high, and viscosity which is too high. The preparation method of polyimide fiber comprises the following steps: polymer raw material diamine, a solvent and a conditioning agent are added into a reactor, dissolving is carried out with the protection of nitrogen, tetracarboxylic dianhydride is added at -10-40 DEG C in order to carry out a reaction for 2-10 hours, and a polyamide acid stock solution is obtained; pressure of the stock solution is reduced, bubbles are removed, and filtering is carried out in order to obtain a polyamide acid spinning stock solution; the stock solution employs a wet method spinning process for carrying out spinning; solidification, washing, oiling, and densification by drying are carried out in order to obtain precursor; imidization and hot-stretching of the precursor are carried out, in order to obtain the polyimide fiber with high compactness and high strength. The technical scheme better solves the problem, and can be applied to industrial production of polyimide fiber.

Description

technical field [0001] The invention relates to a preparation method of polyimide fiber. Background technique [0002] As a variety of high-performance fibers, polyimide fibers have a large number of nitrogen-containing five-membered heterocycles and benzene rings in the main chain of the macromolecules, and the carbon and oxygen in the aromatic rings are connected by double bonds. The heterocyclic ring produces a conjugation effect, which makes the bond energy of the main chain large and the intermolecular force is also large. In this way, when the polyimide fiber is subjected to high-energy radiation, the energy absorbed by the fiber macromolecules is difficult to exceed the energy required to break the molecular chain, so that the fiber exhibits many excellent properties. In addition to the characteristics of high strength and high modulus, It also has excellent heat resistance, dielectric properties, low temperature resistance, radiation resistance, etc., making it suit...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): D01F6/74C08G73/10D06L1/16D06M15/643D01D5/12D01D10/02D06M101/30
Inventor 崔晶刘京妮孙旭阳陈雪周文乐
Owner CHINA PETROLEUM & CHEM CORP