Investigation of the Physical and Chemical Nature of the Surface of Recently Developed Fibers.
UNITED AIRCRAFT RESEARCH LABS EAST HARTFORD CT
Pagination or Media Count:
The purpose of this study was to provide information to guide the development of improved fiber reinforced composites. Various instrumental and analytical procedures were used to characterize graphite fiber surfaces, determine fiber and fiber surface composition and to study the interaction between fiber surfaces and epoxy resin, resin components, coupling agents and model compounds. Surface tension and adhesion tension results showed that high temperature 1200C hydrogen treatment or evacuation markedly improved the adhesion between the treated graphite surfaces and certain coupling agents and organic compounds and also that the adsorbed films were retained even after consecutive treatment with toluene, ethyl acetate and boiling water. Electron micrographs of graphite fibers, treated in a manner similar to the coupons, supported the adhesion tension results on graphite coupons. The surface reactivity of graphite yarn, employing gas phase chromatographic techniques using graphite yarn as the column substrate was studied. Retention time as a function of temperature indicates only a relatively weak physical adsorption of organic materials on as received water sized graphite yarn. In general, air oxidation and high temperature treatments 1200C in hydrogen, argon, and in vacuo activate the surface of as received graphite yarns as is shown by the increased affinity of the treated graphite surfaces for certain organic compounds and for water. Author
- Laminates and Composite Materials