Changes in the properties of kenaf/silica/epoxy hybrid composites by variations in silica particle sizes and contents

Abstract

Silica micro-/nanoparticle reinforced composites have been extensively investigated. This study was carried out in two stages. In the first stage, 25 vol.% untreated kenaf fiber, 2 vol.% silica microparticles (>100, 74, 37 μm), and 73 vol.% epoxy resin were fabricated to be the composites by cold-press molding for 24 hours, then subjected to the tensile test to identify the highest composite's tensile strength corresponding to SEM of the fracture surface. The highest value from the first stage was used in the second stage to determine the influence of the silica particle contents of 1, 3, and 5 vol.% on the composite's tensile properties and water absorption rate. These results achieved an optimum kenaf/silica/epoxy composite's tensile properties (64.10 MPa for tensile strength and 6.60 MPa for tensile modulus) by 37 μm silica particle size and 2 vol.% silica content. However, the composite containing 5 vol.% silica reached the lowest water absorption rate of 7.40%.