Carbon fiber surface treatments for improved adhesion to thermoplastic polymers

The effect of anodization in NaOH, H₂SO₄, and amine salts on the surface chemistry of carbon fibers was examined by x-ray photoelectron spectroscopy (XPS). The surfaces of carbon fibers after anodization in NaOH and H₂SO₄ were examined by scanning transmission electron microscopy (STEM). angular dependent XPS, ultraviolet (UV) absorption spectroscopy of the anodization bath, secondary ion mass spectrometry, and polar/dispersive surface energy analysis. Hercules AS-4, Dexter Hysol XAS, and Union Carbide T-300 fibers were examined by STEM, angular dependent XPS, and breaking strength measurement before and after commercial surface treatment. The fibers from the three companies were anodized to create similar surface chemistry on each fiber. XPS was used to compare the surface chemistry after anodization. Adhesion of carbon fibers to polysulfone, polycarbonate, and polyetherimide was studied using the fiber critical length test. Oxygen and nitrogen were added to the fiber surfaces by anodization in amine salts. Analysis of the plasmon peak in the carbon 1s signal indicated that H₂SO₄ anodization affected the morphological structure of the carbon fiber surface. UV absorption spectra of the anodization bath, SIMS, and angular dependent XPS indicate that NaOH anodization removes amorphous carbon from the fiber. The oxygen and nitrogen content on the fiber surfaces were affected by commercial surface treatment. The Union Carbide fiber had much lower oxygen content after laboratory anodization than the Hercules or Dexter Hysol fibers. The breaking strength of all three fibers was increased by anodization. Laboratory anodization resulted in better fiber/matrix adhesion than the commercial surface treatment for the Hercules and Dexter Hysol fibers. Fiber/matrix adhesion was better for the commercially treated Union Carbide fiber than for the laboratory treated fiber. The work of adhesion of carbon fibers to thermoplastic resins was calculated using the geometric mean relationship. A correlation was observed between the dispersive component of the work of adhesion and the interfacial adhesion.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Materials Engineering Science

Department dc:contributor.department

Materials Engineering Science

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1987

Author dc:creator

• DeVilbiss, Thomas Alexander

Chair dc:contributor.committeechair

• Wightman, James P.

Committee members dc:contributor.committeemember

• Dillard, John G.
• Ward, Thomas C.
• Brinson, Halbert F.
• Duke, John C. Jr.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Handle dc:identifier.uri

http://hdl.handle.net/10919/49844

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/49844