Processing and Characterization of Almond Shell Powder Filled Flax Fiber Reinforced Epoxy Composites

Abstract

The present-day demand for environmentally sustainable and low-density materials in structural applications have attracted research on lightweight bio-based composite systems. In view of this, this study is focused on the preparation and property assessment of flax-epoxy hybrid composite filled with a bio-waste filler, i.e., almond shell powder (ASP). These composites are fabricated with fixed fiber fraction (20 wt%) and varying ASP filler content (0, 10 and 20 wt%) by conventional hand lay-up technique. The composites are subjected to different physico-mechanical tests for property evaluation. The experimental results indicate an increase in void fraction with ASP content due to filler agglomeration and incomplete wetting. Mechanical tests reveal that while the tensile, flexural, and interlaminar shear strength decrease with increasing ASP, impact strength and micro-hardness improve due to the energy absorption capacity and hardness of the filler particles. Stereo-microscopic and scanning electron microscopic images reveal the shape, size, and dispersion of ASP particles and confirm uniform dispersion of filler in the composite. The X-ray diffractograph of filler shows the presence of phases like silica, calcite, and magnesia. FTIR spectra show the presence of carbon functional groups in fiber, filler, and composite. The inclusion of ASP can improve mechanical properties of flax-epoxy composites.