Investigation of the influence of surface-activated carbon fibres on debonding energy and frictional stress in polymer-matrix composites by the micro-indentation technique

The influence on fibre/matrix adhesion of the acidic and basic nature of surface-activated carbon fibres in epoxy and PPS matrices has been investigated by means of the micro-indentation method. The fibre ‘push-out’ and ‘push-in’ techniques were used for this study. The debonding energy and frictional stress are calculated, and the adhesion behaviour is compared with the calculated thermodynamical work of adhesion (as derived from the fibre surface tension) and surface oxygen content. Influence of surface activation on the interfacial frictional stress is discussed.