COMPOSITIONS INCLUDING ESTERIFIED LIGNIN AND POLY(LACTIC ACID) AND CARBON FIBERS PRODUCED THEREFROM

• US 20140099505A1
• Filed: 10/08/2013
• Published: 04/10/2014
• Est. Priority Date: 10/09/2012
• Status: Active Grant

• Current Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Original Assignee: Iowa State University Research Foundation Incorporated (Iowa State University)
• Inventors: Thunga, Mahendra, Chen, Keke, Kessler, Michael Richard
• Granted Patent: US 9,340,425 B2
• Time in Patent Office: Days
• US Class Current: 428/373
• CPC Class Codes: C08H 6/00 Macromolecular compounds derived from lignin, e.g. tannins, humic acids
• CPC Class Codes: C08L 2203/12 used for fibers
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: C08L 97/005 Lignin
• CPC Class Codes: D01F 6/625 derived from hydroxy-carboxylic acids, e.g. lactones
• CPC Class Codes: D01F 6/92 of polyesters
• CPC Class Codes: D01F 8/14 with at least one polyester as constituent
• CPC Class Codes: D01F 8/18 from other substances
• CPC Class Codes: D01F 9/00 Artificial filaments or the like of other substances; Manufacture thereof; Apparatus specially adapted for the manufacture of carbon filaments
• CPC Class Codes: D01F 9/17 from lignin
• CPC Class Codes: D01F 9/26 from polyesters
• CPC Class Codes: Y10T 428/2929 Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]
• CPC Class Codes: Y10T 428/298 Physical dimension

Abstract

The present invention relates to compositions comprising esterified lignin and poly(lactic acid). In various embodiments, the present invention provides fibers comprising the esterified lignin and poly(lactic acid) blend, carbon fibers made therefrom, and methods of making the fiber and the carbon fibers.

Claims

1. A composition comprising:

lignin comprising at least one esterified —

OH group, wherein the esterified —

OH group has the structure —

OC(O)R, wherein each R is independently a C₁-C₃₀ hydrocarbyl group; and

poly(lactic acid).

2. The composition of claim 1, wherein the weight ratio of the esterified lignin to the poly(lactic acid) is about 1:

1 to about 9;

1.

3. The composition of claim 1, wherein about 50 mol % to about 100 mnol % of the —

OH groups on the lignin are esterified.

4. The composition of claim 1, wherein each R group is independently a C₁-C₁₀ alkyl group.

5. The composition of claim 1, wherein the composition has a glass transition temperature of about 40°

C. to about 70°

C. and a melting temperature of about 150°

C. to about 170°

C.

6. A fiber comprising the blend of claim 1.

7. The fiber of claim 6, wherein the fiber has a diameter of about 1 μ

m to about 300 μ

m.

8. The fiber of claim 6, comprising a plurality of smaller fibers within a larger fiber, wherein each of the plurality of smaller fibers independently have a diameter that is about 1/10 to about 1/1,000,000 the diameter of the larger fiber.

9. A carbon fiber derived from the fiber of claim 6.

10. The carbon fiber of claim 9, wherein the carbon fiber has a diameter of about 1 μ

m to about 300 μ

m.

11. The carbon fiber of claim 9, comprising pores occupying about 0.01% to about 50% of the volume of the carbon fiber, wherein the carbon fiber has an average pore volume of about 0.100 cm³/g to about 0.500 cm³/g.

12. The carbon fiber of claim 9, wherein the carbon fiber has an average surface area of about 300 m²/g to about 700 m²/g, as determined using BET.

13. Carbon fibers made by a method comprising:

spinning fibers from the composition of claim 1;

heating the spun fibers to obtain carbon fibers.

14. A process comprising:

thermally treating the fiber of claim 6 to yield a carbon fiber.

15. A method of making spun fibers, comprising:

spinning fibers from the composition of claim 1, to give spun fibers.

16. A method of making carbon fibers, comprising the method of claim 15, further comprising:

heating the spun fibers to obtain carbon fibers.

17. The method of claim 16, wherein heating the spun fibers to obtain carbon fibers comprises heating to a temperature of about 500°

C. to about 3000°

C. with a heating rate of about 10°

C. /h to about 3000°

C. /h, wherein the temperature of about 500 to about 3000°

C. is maintained in an oxygen atmosphere for about 1 min to about 30 h.

18. The method of claim 16, wherein the method of making carbon fibers further comprises thermostabilizing the spun fibers prior to the heating step.

19. The method of claim 18, wherein thermostabilizing the spun fibers comprises at least one of a) heating to a temperature of about 120°

C. to about 500°

C. with a heating rate of about 0.01°

C./min to about 10°

C./min, and b) heating to about 100°

C. to about 120°

C. with a heating rate of about 0.1°

C./min to about 5°

C./min.

20. A carbon fiber, comprising:

an average surface area of about 300 m²/g to about 700 m²/g; and

an average pore volume of about 0.100 cm³/g to about 0.500 cm³/g.