Mechanical and morphological characterization of glass fiber reinforced epoxy composites with fire-retardant fillers for electrical applications

Glass fiber reinforced epoxy (GFRP) composites are extensively employed in electrical industries for their high strength, insulation properties and good corrosion resistance. But their combustion properties present a safety concern for high-temperature and fire hazards. In this research, the mechanical, thermal, morphological and electrical properties of GFRP composites filled with fire-retardant fillers such as aluminum trihydrate (ATH) and magnesium hydroxide (Mg(OH)₂) at different weight percentages (0-15%) are studied. The findings of this study reveal that filler incorporation leads to improved tensile, flexural and impact strength at a critical loading of 10%, after which a marginal decrease in properties is observed due to filler agglomeration and poor adhesion. Thermal gravimetric analysis (TGA) shows enhanced thermal stability and increased char yield with filler loading. Flame retardancy tests show a significant increase in limiting oxygen index (LOI) and UL-94 ratings, indicating improved flame resistance. SEM studies reveal better interfacial bonding and filler dispersion at low concentrations, but onset of micro-cracks and filler agglomeration at higher concentrations. Moreover, the dielectric strength and volume resistivity of the composites are enhanced, suggesting their potential for electrical insulation. In conclusion, these composites have a combination of mechanical, thermal and fire-retardant properties, and are suitable for use in high-end electrical and structural components.