On some recent aspects of surface treatment of carbon fibres

Abstract A number of fibre surface modification methods such as exposure to gas and liquid phases, low and high temperatures, chemical, electrochemical methods have been used to improve carbon fibre adhesion to a polymeric composite matrix. The present work deals with thermal and thermochemical treatment effects on some carbon fibre characteristics, as well as on the strength of carbon fibre tows impregnated with phenolformaldehyde oligomer. This strength was taken as a criterion for improved interaction between carbon fibres and phenolformaldehyde matrix. Thermal treatment of the carbon fibres was carried out in air at temperatures of 250-400°C, for a period of 5-30 min. The thermochemical treatment was performed by impregnation of the carbon fibres with nitrocarbamide solutions, followed by drying and thermal treatment. The surface treatment effects on structural changes of carbon fibres and correlations with their physicomechanical characteristics and the impregnated cable strength were studied. The surface thermal and nitrocarbamide thermochemical treatment have improved the interaction of the carbon fibres with the matrix, which is expressed by the increased impregnated tow strength. The thermochemical treatment is more effective by a factor of 1.4. Keywords: Carbon fibressurface treatmentnitrocarbamidepolymeric composition