Experimental evaluation and comparison of silica/biocarbon particulate-epoxy composites for high-strength applications

Abstract

Biowaste utilization and management are of primary concern in the current scenario for a sustainable environment. One way to enable this is to replace commercial fillers with composite materials. In the present study, the fillers, that is, silica and biocarbon are extracted from rice husk and processed further as biofillers for processing composites. With inherent processing challenges involved in biofiller-based composites, this study investigated and compared the influence of dispersed silica and biocarbon particles independently on the mechanical and tribological properties of epoxy composites. The composites were fabricated by a hand lay-up process. The composites were fabricated with three different filler loadings each of silica and biocarbon separately (2, 4 and 6 wt%). The mechanical characterization results illustrate that tensile, flexural, compression, and erosion wear showed superior properties compared to neat epoxy. It is also evident that there was an enhancement of 19% in compressive strength in composites compared to neat epoxy at 2 wt% silica and biocarbon filler composites. The tensile strength increased by 2.6 times when compared to neat epoxy at 2 wt% silica filler addition. Alongside, erosion results confirm that the properties of pure epoxy change from semi-brittle to ductile due to the addition of silica and biocarbon fillers. This semi-brittle to ductile nature is important for marine applications as propellers are subject to extreme cold and warm temperatures with very little transition time, leading to ductile to brittle failure. Finally, it can be inferred that silica extracted from rice husk has versatile applications when compared to the carbon extract.