Filtern
Erscheinungsjahr
- 2007 (5) (entfernen)
Dokumenttyp
- Zeitschriftenartikel (2)
- Jahresbericht (1)
- Vortrag (1)
- Posterpräsentation (1)
Sprache
- Deutsch (2)
- Englisch (2)
- Mehrsprachig (1)
Schlagworte
- Adhesion (2)
- A. Carbon fibres (1)
- B. Debonding (1)
- B. Interfacial strength (1)
- Carbon fibers (1)
- Contact angle (1)
- Fiber properties (1)
- Fluorination (1)
- Interface (1)
- Surface area (1)
Eingeladener Vortrag
- nein (1)
Mikromechanische Methoden zur Messung der Faser-Matrix-Haftung in Polymermatrix-Verbundwerkstoffen
(2007)
The interaction between direct fluorinated carbon fibres and various fluoropolymers (ethylene-chlorotrifluoroethylene, poly vinylidene fluoride, fluorinated ethylene propylene copolymer and tetrafluoroethylene-perfluoro alkoxy vinyl ether copolymer) was studied by means of direct wetting measurements between fibres and the polymer melts and single fibre pull-out tests. The results of both techniques allow the adhesion behaviour between the fibres and the matrices to be predicted. The results obtained show that a low degree of surface fluorination of carbon fibres leads to an improved wettability between the fibres and fluoropolymer melts and this is an indicator for an improved thermodynamic work of adhesion. The apparent interfacial shear strength as measure of practical adhesion, determined by the single fibre pull-out test, increases with increasing degree of surface fluorine content up to a maximum, which depends on the degree of fluorination of the matrix used. The improved interaction between the fibre and the matrix is due to an enhanced compatibility at the fibre/matrix interface.
Atmospheric-plasma fluorination was used to introduce fluorine functionalities onto the surface of carbon fibers without affecting their bulk properties. The interfacial adhesion between atmospheric-plasma-fluorinated carbon fibers and poly(vinylidene fluoride) (PVDF) was studied by means of direct wetting measurements and single fiber pullout tests. Measured contact angles of PVDF melt droplets on modified carbon fibers show that short exposure times of carbon fibers to atmospheric-plasma fluorination (corresponding to a degree of surface fluorination of F/C = 0.01 (1.1%)) leads to improved wettability of the fibers by PVDF melts. The apparent interfacial shear strength as a measure of practical adhesion, determined by the single-fiber pullout test, increases by 65% under optimal treatment conditions. The improved practical adhesion is not due to the formation of transcrystalline regions around the fibers or a change of the bulk matrix crystallinity or to an increased surface roughness; it seems to be due to the compatibilization of the interface caused of the atmospheric-plasma fluorination of the carbon fibers.
Jahresbericht 2006
(2007)