Curing treatment method of carbon fiber precursor polyacrylonitrile fiber

A technology of polyacrylonitrile fiber and processing method, which is applied in the direction of fiber chemical characteristics, textiles and papermaking, etc., can solve the problems of failure to improve fiber molecular orientation, cost increase, lack of drafting means, etc., achieve good application prospects, improve Degree of Orientation, Effect of High Tensile Strength

Inactive Publication Date: 2011-09-14
DONGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Wu Gang et al improved the homogeneous pre-oxidation of fibers by adjusting the humidity of the oxidizing atmosphere [6, 7], but the use of a water-containing atmosphere in the entire non-melting process inhibited the subsequent non-melting speed, increased the cost, and lacked proper The means of drafting failed to further improve the degree of molecular orientation in the fiber

Method used

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  • Curing treatment method of carbon fiber precursor polyacrylonitrile fiber
  • Curing treatment method of carbon fiber precursor polyacrylonitrile fiber

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] The polyacrylonitrile fiber precursors pass through five temperature zones in the continuous non-melting furnace successively under normal pressure conditions, the first temperature zone is the pre-cyclization stage, and the second temperature zone is the cyclization plastic drawing stage, the third, fourth, and fifth temperature zones are oxidation crosslinking stages. Then enter the carbonization furnace for carbonization treatment:

[0022] The first temperature zone is 190, 210°C, nitrogen gas is fed in, the tension is 16MPa, and the residence time is 15min; The ratio is 5%, the tension is 26MPa, and the residence time is 15min.

[0023] The third, fourth, and fifth temperature zones are respectively 200, 210°C, 230, 240°C, 260, and 280°C. Preheating air is introduced, and the tension of the fiber in the third temperature zone is 26MPa. The tension is 28MPa; the residence time of each temperature zone is 15min. The obtained bulk density is 1.38g / cm 3 , the degre...

Embodiment 2

[0027] The first temperature zone is 190, 210°C, nitrogen gas is fed in, the tension is 17MPa, and the residence time is 15min; The ratio is 10%, the tension is 33MPa, and the residence time is 15min.

[0028] The third, fourth, and fifth temperature zones are respectively 200, 210°C, 230, 240°C, 260, and 280°C. Preheating air is introduced, and the tension of the fiber in the third temperature zone is 29MPa. The tension is 28MPa; the residence time of each temperature zone is 15min. The obtained bulk density is 1.38g / cm 3 , the degree of orientation is 76.2%, and the cyclization rate is 85.0% of the preoxidized fiber.

[0029] The pre-oxidized fiber enters the low-temperature carbonization furnace, and performs low-temperature carbonization treatment on the temperature distribution gradient of 350°C, 500°C, 650°C, and 900°C. The time is 15 minutes, and the tension is controlled at 12MPa; finally, it enters the high-temperature carbonization furnace at 1300°C. For high-temp...

Embodiment 3

[0032] The first temperature zone is 190, 210°C, nitrogen gas is fed in, the tension is 18MPa, and the residence time is 15min; The ratio is 5%, the tension is 27MPa, and the residence time is 15min.

[0033] The third, fourth, and fifth temperature zones are respectively 205, 215°C, 230, 240°C, 260, and 280°C. Preheating air is introduced, and the tension of the fiber in the third temperature zone is 26MPa. The tension is 28MPa; the residence time of each temperature zone is 15min. The obtained bulk density is 1.38g / cm 3 , the degree of orientation is 75.3%, and the cyclization rate is 85.2% of the preoxidized fiber.

[0034] The pre-oxidized fiber enters the low-temperature carbonization furnace, and performs low-temperature carbonization treatment on the temperature distribution gradient of 350°C, 500°C, 650°C, and 900°C. The time is 15 minutes, and the tension is controlled at 12MPa; finally, it enters the high-temperature carbonization furnace at 1300°C. For high-tempe...

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Abstract

The invention relates to a curing treatment method of a carbon fiber precursor polyacrylonitrile fiber. The method comprises the following steps: pre-cyclizing the polyacrylonitrile fiber precursor in the atmosphere of inert gas; carrying out cyclizing and plastic drawing in the atmosphere of inert gas and water vapor; and carrying out oxidation crosslinking in the atmosphere of air, thus obtaining a pre-oxidized polyacrylonitrile fiber. The method has the following beneficial effects: carrying out heat treatment on the fiber in the inert atmosphere is beneficial to implementation of cyclization reaction in the molecules to form rigid ladderlike molecules with regular structure and strong heat resistance, and at the same time, a defined amount of water vapor is introduced to obtain a higher drawing ratio by enhancing the plasticity of the molecular chains in the fiber, thus improving the orientation degree of the rigid molecules along the fiber axis.

Description

technical field [0001] The invention belongs to the field of polyacrylonitrile fibers, in particular to a non-melting treatment method for carbon fiber precursor polyacrylonitrile fibers. Background technique [0002] Carbon fiber is a fiber material mainly composed of carbon atoms, and the carbon content is generally more than 90%. Due to a series of advantages such as high strength, high modulus, low thermal expansion coefficient, high temperature resistance, and corrosion resistance, it has become an irreplaceable material in the fields of aerospace and national defense. Before carbonization, carbon fiber precursor fibers must undergo non-melting treatment, also known as stabilization or pre-oxidation, to obtain a stable heat-resistant structure, thereby ensuring the smooth progress of the carbonization process and obtaining carbon fiber products with excellent performance. [0003] Most of the non-melting methods of the carbon fiber precursor polyacrylonitrile fibers re...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01F9/22
Inventor 吕永根秦显营肖浩郝宇晨
Owner DONGHUA UNIV
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