Method to produce high-quality carbon fiber using lignin

Patent metadata

Field	Value
Publication number	US-2024141560-A1
Application number	US-202318495185-A
Country	US
Kind code	A1
Filing date	Oct 26, 2023
Priority date	Oct 27, 2022
Publication date	May 2, 2024
Grant date	—

Abstract

The present application is directed to a method of producing a lignin-based carbon fiber. This method comprises providing a lignin-containing material; producing a lignin fiber from the lignin-containing material; stabilizing the lignin fiber under tension, where the tension is adjusted during said stabilizing such that the maximum bearable tension is applied to the lignin fiber; and carbonizing the lignin fiber under tension to produce a carbon fiber, where said carbonizing is carried out at a temperature below 1200° C. and where the tension during said carbonizing is adjusted to avoid shrinkage. The present application is also directed to a lignin-based carbon fiber and molded articles containing such fibers.

First claim

What is claimed:

1 . A method of producing a lignin-based carbon fiber, said method comprising:
providing a lignin-containing material; producing a lignin fiber from the lignin-containing material; stabilizing the lignin fiber under tension, wherein the tension is adjusted during said stabilizing such that a maximum bearable tension is applied to the lignin fiber; and carbonizing the lignin fiber under tension to produce a carbon fiber, wherein said carbonizing is carried out at a temperature below 1200° C. and wherein the tension during said carbonizing is adjusted to avoid shrinkage.

2 . The method of claim 1 , further comprising:
purifying the lignin-containing material prior to said producing a lignin fiber.

3 . The method of claim 1 , wherein said producing a lignin fiber is carried out by spinning the lignin-containing material.

4 . The method of claim 3 , wherein the lignin-containing material is spun using melt-spinning, wet-spinning, dry-spinning, or gel-spinning techniques.

5 . The method of claim 3 , wherein the lignin-containing material is spun at a temperature from about −60° C. to about 250° C.

6 . The method of claim 1 , wherein said stabilizing the lignin fiber is carried in an inert environment.

7 . The method of claim 1 , wherein said stabilizing the lignin fiber is carried in an oxidative environment.

8 . The method of claim 1 , wherein the tension applied during said stabilizing stretches fibers to a length greater than its length prior to said stabilizing.

9 . The method of claim 1 , wherein, during said stabilizing, the fiber is heated from a temperature of about 25° C. to a temperature of about 300° C. over 2-28 hours.

10 . The method of claim 1 , wherein said stabilizing is carried out while subjecting the lignin fiber to thermal treatment, plasma treatment, UV light treatment, or microwave radiation.

11 . The method of claim 1 , wherein said stabilizing is carried out at a tension of about 1.5 kPa to about 1250 kPa per fiber.

12 . The method of claim 1 , wherein said stabilizing is carried out at a temperature of about 105° C. to about 300° C.

13 . The method of claim 1 , wherein said carbonizing is carried out at a temperature of about 500° C. to about 1200° C.

14 . The method of claim 13 , wherein said carbonizing is carried out at a temperature of about 500° C. to about 1000° C.

15 . The method of claim 1 , wherein the carbon fiber has an average diameter of 2 μm to about 20 μm.

16 . The method of claim 1 , wherein the carbon fiber has an average tensile strength of about 2.0 GPa to about 4.0 GPa.

17 . The method of claim 1 , wherein the carbon fiber has an average tensile modulus of about 200 GPa to about 400 GPa.

18 . The method of claim 1 , wherein the carbon fiber has inner pores having an average radius of about 0.2 nm to about 4.0 nm.

19 . A carbon fiber prepared by the method of claim 1 .

20 . The carbon fiber of claim 19 , wherein the carbon fiber has an average diameter of 2 μm to about 20 μm.

21 . The carbon fiber of claim 19 , wherein the carbon fiber has an average tensile strength of about 2.0 GPa to about 4.0 GPa.

22 . The carbon fiber of claim 19 , wherein the carbon fiber has an average tensile modulus of about 200 GPa to about 400 GPa.

23 . The carbon fiber of claim 19 , wherein the carbon fiber has inner pores having an average radius of about 0.8 nm to about 2.2 nm.

24 . A lignin-based carbon fiber comprising:
an elemental oxygen content of at least 1 wt %; an elemental carbon content of at least 65 wt %; an average diameter of about 0.1 μm to about 20 μm; an average tensile strength of from about 2.0 GPa to about 4.0 GPa; and an average tensile modulus of from about 200 GPa to about 400 GPa.

25 . The lignin-based carbon fiber of claim 24 , wherein the elemental oxygen content is from about 1 wt % to about 30 wt %.

26 . The lignin-based carbon fiber of claim 24 , wherein the elemental carbon content is from about 65 wt % to about 88 wt %.

27 . A molded article for a machine part, electric and electronic part, or automotive part, said article comprising:
a matrix material; and the carbon fiber of claim 24 dispersed in said matrix material.

28 . The molded article of claim 27 , wherein the molded article is an automotive part.

29 . The molded article of claim 28 , where the automotive part is selected from the group consisting of a hood, a pillar, a panel, a structural panel, a door panel, a door component, an interior floor, a floor pan, a roof, an exterior surface, an underbody shield, a wheel component, a storage area, a glove box, a console box, a trunk, a trunk floor, a truck bed, a lamp pocket, a shock tower cap, a control arm, a suspension component, a crush can, a bumper, a structural rail, a structural frame, a cross car beam, an undercarriage component, a drive train component, and combinations thereof.

30 . The method of claim 1 , wherein the carbon fiber has an average tensile modulus of about 50 GPa to about 500 GPa.

31 . The carbon fiber of claim 19 , wherein the carbon fiber has an average tensile modulus of about 50 GPa to about 500 GPa.

Assignees

• Univ Iowa State Res Found Inc

Inventors

• Bai Xianglan
• Luo Yixin
• Razzaq Moham Ed Abdur

Classifications

• D06M11/84

  combined with mechanical treatment (combined with mechanical tension, e.g. mercerising D06M11/40) · CPC title

• D06M11/34

  with oxygen, ozone or ozonides · CPC title

• D06M10/025

  Corona discharge or low temperature plasma · CPC title

• D06M10/003

  Treatment with radio-waves or microwaves · CPC title

• D06M10/001

  Treatment with visible light, infrared or ultraviolet, X-rays · CPC title