STUDYING THE EFFECT OF CHEMICAL TREATMENT AND ORIENTATION ON FRACTURE TOUGHNESS OF KENAF FIBRE EPOXY COMPOSITES

Abstract

In this paper, the effect of surface modification and fibre arrangements of kenaf fibers on fracture toughness of epoxy composite was investigated. The chemical treatment of kenaf fibers (KFs) with 6 % NaOH was achieved, and composites with two different fibre arrangements (X and Y) directions were fabricated. Values of fracture toughness (KIc) measured of the compact tension (CT) specimens for both untreated kenaf fibre-reinforced epoxy (ut-KFRE) composites and treated kenaf fibre-reinforced epoxy (treated-KFRE) were much better than the neat epoxy. The KIc value of the treated-KFRE composite in Y-fibre direction was the highest of 2.74 MPa.m1/2 while it was 1.45 MPa.m1/2 for the neat epoxy. Different toughening mechanisms were noticed in the fracture surfaces of the composites in relation to the fibre reinforcement planar, they are shear yielding and fibre splaying with the X-direction and broken fibers, fibre pullout and fibre delamination with the Y-fibre orientation.