Electrical and Thermal Properties of Boron Nitride Filled Poly Aryl Ether Ketone Composites for Electrical Insulation Applications

ABSTRACT Poly(aryl ether ketone) (PAEK) composites incorporating boron nitride (BN) fillers at varying loadings of 10, 20, and 30 wt.% were fabricated and systematically examined for their dielectric and thermal performance, targeting electrical insulation applications. The impact of BN content on the microstructural features, thermal transport, and electrical characteristics of the composites was analyzed. Scanning electron microscopy (SEM) was employed to study the filler dispersion within the PAEK matrix. At higher filler loadings, BN particles with smaller sizes exhibited noticeable agglomeration, whereas larger BN particles demonstrated more uniform distribution throughout the matrix. Composites reinforced with larger BN particles exhibited greater enhancement in thermal conductivity. The dielectric constant ( ε r ) exhibited a progressive rise with increasing BN content, while the dissipation factor (tan δ ) initially decreased up to 10 wt.% loading and showed a slight rise thereafter up to 20 wt.%. A maximum improvement of approximately 34% in dielectric strength was recorded at 30 wt.% BN relative to PAEK. Across the temperature range of 30°C to 230°C, the dissipation factor and electrical conductivity were observed in the ranges of 0.001–0.310 and 3.0 × 10 −11 to 0.5 × 10 −16 S/cm, respectively. The composite containing 30 wt.% BN exhibited a substantial increase in thermal conductivity, rising from 0.3 to 0.6 W/m K, alongside superior dielectric properties ( ε r ≈5.5 and tan δ ≈0.01) and lower volatile content. These findings highlight the potential of BN‐filled PAEK systems as promising candidates for electrical insulation in winding systems, rotating machines, and cable sheathing applications.