CARBON FIBRE EPOXY COMPOSITES - EFFECT OF EPOXY NETWORK AND SURFACE-TREATMENT OF FIBERS ON INTERFACIAL SHEAR-STRENGTH/

The paper deals with studies on interfacial shear strength (tau) of ca rbon fibre composite using single fibre fracture test. Surface modific ation of desized carbon fibres has been done by argon or oxygen plasma . The effect of network structure on tau has been studied by using dif unctional or multifunctional epoxy resins. Interfacial shear strength depends on (i) chemical structure of the epoxy resin (ii) nature of ga s used in plasma generation and (iii) duration of plasma treatment. An increase in cross-link density resulted in a decrease in tau, thereby indicating that a more flexible interface is superior for better adhe sion with fibres. Oxygen plasma treated carbon fibres gave highest val ues of tau.