Next-generation high-performance sustainable hybrid composite materials from silica-rich granite waste particulates and jute textile fibres in epoxy resin

In recent years, extensive efforts have been made to prepare composite materials using renewable and sustainable raw materials. Albeit significant advancements in bio-based fibre-reinforced composites, high water absorption and eventual degradation in properties remain a persistent issue the needs to be addressed. In this study, the epoxy-based hybrid green composites were prepared, where granite waste particulates were used as filler in synergy with jute fibre reinforcement. Milled granite particulates were characterized for their physical, chemical, mineralogical, and morphological aspects. Composites were prepared using hand layup followed by compression moulding techniques with high filler percentages (30, 50, and 60 wt%) and jute fibre content (2 and 4 layers). The influence of filler and fibres on physical properties (water absorption, thickness swelling, and density), mechanical properties (tensile, flexural, and impact), electrical resistivity, and thermal conductivity of the prepared composites were studied. Loading with 60 wt% of granite waste filler and 4 layers of jute fibres resulted in composites with around 5% higher flexural strength, 16% higher tensile strength, 148% higher impact strength, and almost 150% higher thermal conductivity as compared to neat epoxy. The composites also exhibited very low water absorption (0.1%) with a nominal increase in density while containing electrical insulation property despite decreasing volume resistivity. Due to the high amount of mineral waste and natural fibre usage, these materials have very low embodied energy content, thus making them cost-effective, sustainable, and environment-friendly materials for structural and architectural applications. Additionally, the study also provides a potentially viable route for the effective utilization of mineral wastes, such as granite, whose growing accumulation has serious ramifications for the environment, living organisms, and the economy.