Development of modified h-BN/UPE resin for insulation varnish applications

Abstract The objective of this study is to explore the impact of a nanofiller, hexagonal boron nitride (h-BN), on the main physical, electrical, and thermal characteristics of unsaturated polyester (UPE) resin. To obtain a homogeneous dispersion, h-BN nanoparticles were surface-modified using 3-glycidoxypropyltrimethoxysilane to give S/h-BN nanoparticles. UPE-S/h-BN composites were prepared by using various ratios (1, 5, 10 wt%) of these modified nanoparticles. Thermogravimetric analysis studies showed that the presence of S/h-BN nanoparticles boosted the thermal stability of the UPE resin. The electrical volume resistivity value increased from 1.3 × 1013 to 1.38 × 1014 Ω cm with the addition of 10 wt% S/h-BN. The contact angle results indicated that the hydrophobicity of UPE-S/h-BN composites increased and the value of 110° was obtained for UPE-S/h-BN10. The findings revealed that incorporating S/h-BN nanoparticles into UPE resin, in specific ratios, improved its properties and the resulting product has the potential to be used as an insulation varnish.