Methods for recovering carbon fiber from carbon-fiber-reinforced polymer (cfrp) composites

Patent metadata

Field	Value
Publication number	US-2016115301-A1
Application number	US-201314889395-A
Country	US
Kind code	A1
Filing date	May 8, 2013
Priority date	May 8, 2013
Publication date	Apr 28, 2016
Grant date	—

Abstract

Method for recovering carbon fibers from carbon fiber reinforced polymer composites is provided. The recovered carbon fibers can be separable and can be substantially free of thermosetting resins. Compositions comprising said recovered carbon fibers are also provided.

First claim

1 . A method of recovering carbon fibers from fiber reinforced composite, the method comprising:
providing a fiber-reinforced composite comprising carbon fibers and a thermosetting resin; contacting the fiber-reinforced composite with a first organic solvent including an alcohol to form carbon fiber bundles from the fiber-reinforced composite; after contacting the composite with the first organic solvent, contacting the carbon fiber bundles with an acid solution to form acid-treated carbon fibers; and contacting the acid-treated carbon fibers with a second organic solvent.

2 . The method of claim 1 , wherein the thermosetting resin comprises an epoxy resin or a phenol resin.

3 . (canceled)

4 . The method of claim 1 , wherein the alcohol of the first organic solvent includes benzyl alcohol.

5 . The method of claim 1 , wherein the second organic solvent includes an alcohol.

6 . The method of claim 5 , wherein the second organic solvent includes benzyl alcohol.

7 . The method of claim 1 , wherein contacting the fiber-reinforced composite with the first organic solvent comprises heating the composite and the first organic solvent to a temperature of about 50° C. to about 200° C.

8 . (canceled)

9 . The method of claim 1 , wherein contacting the acid-treated carbon fibers with the second organic solvent comprises heating the acid-treated carbon fibers and the second organic solvent to a temperature of about 50° C. to about 200° C.

10 . (canceled)

11 . (canceled)

12 . The method of claim 1 , wherein the acid solution comprises nitric acid.

13 . (canceled)

14 . (canceled)

15 . The method of claim 1 , wherein contacting the carbon fiber bundles with the acid solution comprises heating the carbon fiber bundles and the acid solution to a temperature of at least about 40° C.

16 . (canceled)

17 . (canceled)

18 . The method of claim 1 , further comprising isolating carbon fibers from the second organic solvent.

19 . The method of claim 18 , wherein the carbon fibers, after isolating from the second organic solvent, are separable and substantially free of the thermosetting resin.

20 . (canceled)

21 . A method of recovering carbon fibers from fiber reinforced composite, the method comprising:
providing a fiber-reinforced composite comprising carbon fibers and a thermosetting resin; contacting the fiber-reinforced composite with a first organic solvent to form carbon fiber bundles from the fiber-reinforced composite; combining the carbon fiber bundles with a second organic solvent to form a mixture; and heating the mixture under solvothermal conditions.

22 . The method of claim 21 , wherein the thermosetting resin comprises an epoxy resin or a phenol resin.

23 . (canceled)

24 . The method of claim 21 , wherein the first organic solvent comprises one or more of chloroform, dichloromethane, tetrahydrofuran, meta-xylene, N,N-dimethylformamide, carbon tetrachloride, benzene, or toluene.

25 . (canceled)

26 . (canceled)

27 . (canceled)

28 . The method of claim 21 , wherein the second organic solvent comprises one or more of an alcohol, chloroform, dichloromethane, tetrahydrofuran, meta-xylene, N,N-dimethylformamide, carbon tetrachloride, benzene, a or nd toluene.

29 . The method of claim 28 , wherein the first organic solvent includes dichloromethane and the second organic solvent includes benzyl alcohol.

30 . The method of claim 28 , wherein the first organic solvent includes chloroform and the second organic solvent includes propanol.

31 . The method of claim 21 , wherein heating the mixture under solvothermal conditions occurs in a sealed chamber.

32 . (canceled)

33 . (canceled)

34 . The method of claim 21 , wherein heating the mixture comprises heating the mixture to a temperature of about 150° C. to 250° C.

35 . (canceled)

36 . (canceled)

37 . The method of claim 21 , further comprising isolating carbon fibers from the mixture.

38 . The method of claim 37 , wherein the carbon fibers, after isolating from the mixture, are separable and substantially free of the thermosetting resin.

39 . (canceled)

40 . A composition comprising:
a non-acidic organic solvent solution; recycled carbon fibers dispersed in the non-acidic organic solvent; and a thermosetting resin at least partially dissolved in the non-acidic organic solvent.

41 . The composition of claim 40 , wherein the non-acidic organic solvent comprises one or more of an alcohol, chloroform, dichloromethane, tetrahydrofuran, meta-xylene, N,N-dimethylformamide, carbon tetrachloride, benzene, or toluene.

42 . The composition of claim 40 , wherein the thermosetting resin comprises an epoxy resin or a phenol resin.

Assignees

• Univ East China Science & Tech

Inventors

• Zhao Chongjun
• Shitian Muzi
• Ma Weifeng
• Qian Xiuzhen
• Zhang Jinchao
• Chen Xin

Classifications

• C08J11/08 Primary

  using selective solvents for polymer components · CPC title

• D01F9/12

  Carbon filaments; Apparatus specially adapted for the manufacture thereof · CPC title

• C08K7/06 Primary

  Elements · CPC title

• C08J2361/06

  of aldehydes with phenols · CPC title

• Y02W30/62

  Plastics recycling; Rubber recycling · CPC title