Interfacial studies on surface modified Kevlar fibre epoxy matrix composites

Kevlar fibre/epoxy composites with superior interfacial strength were developed, by chemical treatment of the fibre surface with organic solvents. Multiple fibre pullout tests revealed that it is possible to raise the interfacial strength to 63 MPa from a value of 39 MPa normally exhibited by untreated Kevlar fibre/epoxy composites. A physicochemical and morphological characterization of the chemically treated fibre surface by microscopic and spectroscopic techniques, aids in the understanding of the observed interfacial properties. The importance of surface oxygen content in matrix bonding and mechanical interlocking of the fibre and matrix was established. Failure analysis of the pullout specimens reveals a strong correlation between the fracture features and the observed test data. (C) 1999 Elsevier Science Ltd. All rights reserved.