Method of improving adhesion of carbon fibers with a polymeric matrix

• US 9,365,685 B2
• Filed: 02/28/2012
• Issued: 06/14/2016
• Est. Priority Date: 02/28/2012
• Status: Active Grant

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Vautard, Frederic, Ozcan, Soydan, Paulauskas, Felix Leonard
• Primary Examiner(s): Chriss, Jennifer
• Assistant Examiner(s): THOMPSON, CAMIE S
• Application Number:
  US13/406,732
• Publication Number:
  US 20130224470A1
• Time in Patent Office: 1,568 Days
• Field of Search: 423/408, 252/500, 252/501, 252/502
• US Class Current: 1/1
• CPC Class Codes: C08J 2333/04 esters
• CPC Class Codes: C08J 2363/00 Characterised by the use of epoxy resins; Derivatives of epoxy resins
• CPC Class Codes: C08J 2463/00 Characterised by the use of epoxy resins; Derivatives of epoxy resins
• CPC Class Codes: C08J 5/06 using pretreated fibrous materials
• CPC Class Codes: C08L 63/10 Epoxy resins modified by unsaturated compounds
• CPC Class Codes: Y10T 428/249948 Fiber is precoated
• CPC Class Codes: Y10T 428/2918 including free carbon or carbide or therewith [not as steel]

Abstract

A functionalized carbon fiber having covalently bound on its surface a partially cured epoxy or amine-containing sizing agent, wherein at least a portion of epoxide or amine groups in the sizing agent are available as uncrosslinked epoxide or amine groups, which corresponds to a curing degree of epoxide or amine groups of no more than about 0.6. Composites comprised of these functionalized carbon fibers embedded in a polymeric matrix are also described. Methods for producing the functionalized carbon fibers and composites thereof are also described.

Claims

1. A carbon fiber having covalently bound on its surface a partially cured sizing agent comprised of an epoxy resin, wherein said epoxy resin is covalently attached to a linking group that contains an accessible unsaturated group capable of reacting with a carbon-carbon double bond via a vinyl addition reaction, and at least a portion of epoxide groups in the sizing agent are available as uncrosslinked epoxide groups, which corresponds to a curing degree of epoxide groups of no more than about 0.6.

2. The carbon fiber of claim 1, wherein said epoxy resin possesses a curing degree of epoxide groups of no more than about 0.5.

3. The carbon fiber of claim 1, wherein said epoxy resin possesses a curing degree of epoxide groups of no more than about 0.4.

4. The carbon fiber of claim 1, wherein said epoxy resin is comprised of a difunctional epoxy resin.

5. The carbon fiber of claim 4, wherein said difunctional epoxy resin is selected from one or both of bisphenol A diglycidyl ether and ethylene glycol diglycidyl ether.

6. The carbon fiber of claim 1, wherein said epoxy resin is a trifunctional or a higher functional epoxy resin.

7. The carbon fiber of claim 1, wherein said partially cured sizing agent is a flexible gel.

8. A carbon fiber having covalently bound on its surface a partially cured amine-containing sizing, wherein at least a portion of amine groups in the sizing agent are available as uncrosslinked amine groups, which corresponds to a curing degree of amine groups of no more than about 0.6.

9. The carbon fiber of claim 8, wherein said amine-containing sizing agent possesses a curing degree of amine groups of no more than about 0.5.

10. The carbon fiber of claim 8, wherein said amine-containing sizing agent possesses a curing degree of amine groups of no more than about 0.4.

11. The carbon fiber of claim 8, wherein said amine-containing sizing agent is comprised of an organoamine moiety containing at least two amine groups selected from primary and secondary amine groups.

12. The carbon fiber of claim 8, wherein said partially cured amine-containing sizing agent is a flexible gel.

13. The carbon fiber of claim 8, wherein said amine-containing sizing is covalently attached to a linking group that contains an accessible unsaturated group capable of reacting with a carbon-carbon double bond via a vinyl addition reaction.