Macroscopic fiber comprising single-wall carbon nanotubes and acrylonitrile-based polymer and process for making the same

• US 6,852,410 B2
• Filed: 06/30/2003
• Issued: 02/08/2005
• Est. Priority Date: 07/01/2002
• Status: Expired due to Fees

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Kumar, Satish, Veedu, Sreekumar T.
• Primary Examiner(s): Edwards, N.
• Application Number:
  US10/609,724
• Publication Number:
  US 20040180201A1
• Time in Patent Office: 589 Days
• Field of Search: 428/367, 428/372, 428/394, 423/447.1, 423/447.2
• US Class Current: 428/367
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: D01F 1/09 for making electroconductive or anti-static filaments
• CPC Class Codes: D01F 1/10 Other agents for modifying properties
• CPC Class Codes: D01F 6/18 from polymers of unsaturated nitriles, e.g. polyacrylonitrile, polyvinylidene cyanide
• CPC Class Codes: D01F 6/38 comprising unsaturated nitriles as the major constituent
• CPC Class Codes: D01F 9/225 from stabilised polyacrylonitriles
• CPC Class Codes: Y10S 977/75 Single-walled
• CPC Class Codes: Y10S 977/788 Of specified organic or carbon-based composition
• CPC Class Codes: Y10T 428/2918 including free carbon or carbide or therewith [not as steel]
• CPC Class Codes: Y10T 428/2927 including structurally defined particulate matter
• CPC Class Codes: Y10T 428/2967 Synthetic resin or polymer

Abstract

The present invention relates to a high modulus macroscopic fiber comprising single-wall carbon nanotubes (SWNT) and an acrylonitrile-containing polymer. In one embodiment, the macroscopic fiber is a drawn fiber having a cross-sectional dimension of at least 1 micron. In another embodiment, the acrylonitrile polymer-SWNT composite fiber is made by dispersing SWNT in a solvent, such as dimethyl formamide or dimethyl acetamide, admixing an acrylonitrile-based polymer to form a generally optically homogeneous polyacrylonitrile polymer-SWNT dope, spinning the dope into a fiber, drawing and drying the fiber. Polyacrylonitrile/SWNT composite macroscopic fibers have substantially higher modulus and reduced shrinkage versus a polymer fiber without SWNT. A polyacrylonitrile/SWNT fiber containing 10 wt % SWNT showed over 100% increase in tensile modulus and significantly reduced thermal shrinkage compared to a control fiber without SWNT. With 10 wt % SWNT, the glass transition temperature of the polymer increased by more than 40° C.

Claims

1. A macroscopic fiber comprising single-wall carbon nanotubes (SWNT) and an acrylonitrile-containing polymer, wherein the fiber has a cross-sectional dimension in the range of about 1 micron and about 100 microns.

2. The fiber or claim 1 wherein the polymer is selected from the group consisting of polyacrylonitrile, poly(acrylonitrile-methyl acrylate), poly(acrylonitrile-methacrylic acid), poly(acrylonitrile-acrylic acid), poly(acrylonitrile-itaconic acid), poly(acrylonitrile-methyl methacrylate), poly(acrylonitrile-itaconic acid-methyl acrylate), poly(acrylonitrile-methacrylic acid-methyl acrylate), poly(acrylonitrile-vinyl pyridine), poly(acrylonitrile-vinyl chloride), poly(acrylonitrile-vinyl acetate), and combinations thereof.

3. The fiber of claim 1 wherein the polymer is poly(acrylonitrile-methyl acrylate).

4. The fiber of claim 1 wherein the polymer is poly(acrylonitrile-itaconic acid-methyl acrylate).

5. The fiber of claim 1 wherein the polymer is poly(acrylonitrile-methyl methacrylate).

6. The fiber of claim 1 wherein the single-wall carbon nanotubes are derivatized with a functional group.

7. The fiber of claim 1 wherein the single-wall carbon nanotubes are present in the macroscopic fiber in a range of about 0.001 wt % and about 50 wt %.

8. The fiber of claim 1 wherein the single-wall carbon nanotubes are present in the macroscopic fiber in a range of about 1 wt % and about 25 wt %.

9. The fiber of claim 1 wherein the single-wall carbon nanotubes are present in the macroscopic fiber in the range of about 5 wt % and about 15 wt %.

10. The fiber of claim 1 wherein the fiber further comprises an anti-gelling agent.

11. The method of claim 10 wherein the anti-gelling agent comprises oxalic acid.

12. The fiber of claim 1 wherein the macroscopic fiber has a glass transition temperature that is higher than the glass transition temperature of tho polymer without SWNT.

13. The fiber of claim 1 wherein the macroscopic fiber has less shrinkage than a drawn fiber of the polymer without SWNT.

14. The fiber of claim 1 wherein the macroscopic fiber has a greater tensile modulus than a drawn fiber of the polymer without SWNT.

15. A drawn macroscopic fiber comprising a mixture of single wall carbon nanotubes (SWNT) and acrylonitrile-containing polymer, the fiber having a tensile strength of 0.25-3.52 GPa, an elongation of 9.9% to 14.3% and an initial tensile modulus of 8.0 to 16.3 GPa, wherein the fiber has a cross-section.