Performance Enhancement of Epoxy Glass Fiber Cores of HTLS Conductors Using Carbon Nanofillers/ATH Additives

ABSTRACT Epoxy glass fiber nanocomposites reinforced with carbon nanofillers have garnered significant attention due to their improved functional capabilities, making them a desirable choice for an array of applications. This study investigates the effect of graphene and multi‐walled carbon nanotubes combined with aluminum trihydrate fillers on the mechanical and thermal performance of epoxy glass fiber cores used in high temperature low sag conductors. The inclusion of aluminum trihydrate and nanofillers significantly enhanced the properties of the composite, as evidenced by a reduction in the coefficient of linear expansion from 2.99 × 10 − 6 to 2.05 × 10 − 6 , improved dimensional stability, and increased density from 2.2 to 2.24 g/cm 3 . Thermal endurance tests at 150°C and 200°C for 1 and 2 h demonstrated negligible discoloration and no cracking in aluminum trihydrate (ATH) ‐modified cores, while cores without ATH exhibited cracking under prolonged exposure. Mechanical testing revealed a substantial improvement in ultimate tensile strength (UTS) from 32.17 kN (400.18 MPa) to 67.68 kN (839.01 MPa), an increase in the glass transition temperature (T g ) from 119°C to 133.65°C, and enhanced flexural strength from 61.82 to 73.31 MPa. These results highlight the superior thermal and mechanical performance of epoxy glass fiber cores reinforced with carbon nanofillers and ATH, making them suitable for high‐temperature, high‐stress applications in high‐temperature low‐sag (HTLS) conductors. Further studies are needed to investigate long‐term aging effects and optimize these composites for extended service life.