Modified carbon nanotubes and their compatibility

Patent metadata

Field	Value
Publication number	US-9284398-B2
Application number	US-201113702106-A
Country	US
Kind code	B2
Filing date	Jun 10, 2011
Priority date	Jun 11, 2010
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

Modified carbon nanotubes are provided having carbon nanotube core covalently bound through C—C bonds to a polymer shell surrounding the carbon nanotube core. The polymer shell is a polymer having functional groups pointing outwardly from the shell. The functional groups are compatible with or able to covalently connect to another polymer. Such modified carbon nanotubes are more readily dispersed in a homogeneous manner in another polymer and may be used as a reinforcing filler in a polymer matrix. The modified carbon nanotubes with a core-shell structure in which the core has a substantially unidirectional orientation within the shell are produced by reacting neutral carbon nanotubes with 4-vinylaniline through a diazonium reaction in presence of one or more types of multifunctional monomers carrying a vinyl moiety and one or more functional groups for compatibilization with or connection to another polymer. The reaction is conducted at an elevated temperature without isolation of intermediates and without addition of any extra initiator or catalyst to form a polymer shell in situ around the carbon nanotube. The polymer shell is covalently bound to CNT sidewall through C—C bonds and has functional groups outwardly pointing from the shell for compatibilization with or connection to another polymer.

First claim

The invention claimed is:

1. Modified carbon nanotube comprising a carbon nanotube core covalently bound to a polymer shell surrounding the carbon nanotube core, wherein said covalent bond consists of a bond between a carbon atom on the carbon nanotube core and a carbon atom on the polymer shell, and wherein the polymer shell comprises a homopolymer of 4-vinylaniline or a copolymer of 4-vinylaniline and one or more other types of multifunctional monomers having one or more functional groups compatible with or able to covalently connect to another polymer.

2. The modified carbon nanotube according to claim 1 , wherein the carbon nanotube core comprises single-walled or multi-walled carbon nanotube.

3. The modified carbon nanotube according to claim 1 , wherein the functional groups comprise amino, hydroxyl, sulfonato, oxycarbonyl, halo, acetyl, epoxy, amido, diazo, anhydride or carboxyl functional groups or mixtures thereof.

4. The modified carbon nanotube according to claim 1 , wherein the multifunctional monomer comprises a vinylaniline, vinyl alcohol, a vinyl alkyl alcohol, a vinyl phenol, a styrene derivative, vinyl ester, vinyl chloride, vinyl acetate, methacrylic acid, a methacrylate, acrylic acid, an acrylate, acrylamide, acrylonitrile or any mixture thereof.

5. The modified carbon nanotube according to claim 1 , wherein the multifunctional monomer comprises vinyl alcohol, 4-penten-1-ol, 2-methoxy-4-vinylphenol, styrene sodium sulfonate, vinyl ester, vinyl chloride, vinyl acetate, methacrylic acid, glycidyl methacrylate, methyl methacrylate, acrylic acid, methyl acrylate, acrylamide, acrylonitrile or mixtures thereof.

6. The modified carbon nanotube according to claim 1 wherein the multifunctional monomer comprises glycidyl methacrylate.

7. The modified carbon nanotube according to claim 1 , further comprising a secondary compatibilizer.

8. The modified carbon nanotube according to claim 7 , wherein the secondary compatibilizer comprises polyethylene-graft-glycidyl methacrylate, polypropylene-graft-glycidyl methacrylate, polyethylene-graft-maleic anhydride, polypropylene-graft-maleic anhydride or any mixture thereof.

9. The modified carbon nanotube according to claim 1 , wherein the polymer shell has a uniform thickness in a range of 10-400 nm.

10. The modified carbon nanotube according to claim 1 , wherein the carbon nanotube core has a substantially unidirectional orientation along the longitudinal axis of CNT within the polymer shell.

11. The modified carbon nanotube according to claim 1 for use as a reinforcing filler in a polymer matrix.

12. A polymeric nanocomposite comprising modified carbon nanotubes as defined in claim 1 .

13. The polymeric nanocomposite according to claim 12 , wherein the modified carbon nanotubes are mixed with another polymer.

14. The polymeric nanocomposite according to claim 13 , wherein the modified carbon nanotubes are homogeneously distributed in a matrix of the other polymer.

15. The polymeric nanocomposite according to claim 13 , wherein the other polymer comprises a polyethylene, a polypropylene, a polystyrene, a polybutadiene, a poly(acetylene), a poly(pyrrole), a poly(thiophene), a polyaniline, a polythiophene, a poly(p-phenylene sulfide), a poly(p-phenylene vinylene), a polycarbonate, polymethylmethacrylate, a polyisoprene, a single component epoxy resin, an epoxy resin system, an epoxy vinyl ester resin or any mixture thereof.

16. A process of producing modified carbon nanotube, the process comprising: reacting neutral carbon nanotube with 4-vinylaniline in an organic solvent through a diazonium reaction in presence of one or more types of multifunctional monomers carrying a vinyl moiety and one or more functional groups for compatibilization with or connection to another polymer, the reaction conducted at least in part at a temperature of from 25° C. to 120° C. without isolation of intermediates and without addition of any extra initiator or catalyst to form a polymer shell in situ around the carbon nanotube, the polymer shell covalently bound to carbon nanotube sidewall through C—C bonds and wherein the polymer shell comprises a homopolymer of 4-vinylaniline or a copolymer of 4-vinylaniline and one or more other types of multifunctional monomers having one or more functional groups compatible with or able to covalently connect to another polymer.

17. The process according to claim 16 , wherein the diazonium reaction is effected with a diazotization agent comprising isoamyl nitrite.

18. The process according to claim 16 , wherein the functional groups comprise amino, hydroxyl, sulfonato, oxycarbony, halo, acetyl, epoxy, amido, diazo, anhydride or carboxyl functional groups or mixtures thereof.

19. The process according to claim 16 , wherein the multifunctional monomers comprise a vinylaniline, vinyl alcohol, a vinyl alkyl alcohol, a vinyl phenol, a styrene derivative, vinyl ester, vinyl chloride, vinyl acetate, methacrylic acid, a methacrylate, acrylic acid, an acrylate, acrylamide, acrylonitrile or any mixture thereof.

20. The process according to claim 16 , wherein the multifunctional monomers comprise vinyl alcohol, 4-penten-1-ol, 2-methoxy-4-vinylphenol, styrene sodium sulfonate, vinyl ester, vinyl chloride, vinyl acetate, methacrylic acid, glycidyl methacrylate, methyl methacrylate, acrylic acid, methyl acrylate, acrylamide, acrylonitrile or mixtures thereof.

Assignees

• Guan Jingwen
• Fraser Robin
• Simard Benoit
• Nat Res Council Canada

Inventors

• Guan Jingwen
• Fraser Robin
• Simard Benoit

Classifications

• C08F226/02 Primary

  by a single or double bond to nitrogen · CPC title

• C01P2002/88

  by thermal analysis data, e.g. TGA, DTA, DSC · CPC title

• C09C1/44

  Carbon · CPC title

• C01B2202/02

  Single-walled nanotubes · CPC title

• C01B2202/06

  Multi-walled nanotubes · CPC title