Heat conductive h-BN/CTPB/epoxy with enhanced dielectric properties for potential high-voltage applications

• Main Authors: Ying Gong, Wenying Zhou, Yujia Kou, Li Xu, Hongju Wu, Wei Zhao
• Format: Article
• Language: English
• Published: Wiley 2017-06-01
• Series: High Voltage
• Subjects: heat conduction; dielectric properties; epoxy insulation; rubber; permittivity; electric breakdown; heat conductive epoxy; enhanced dielectric properties; cured epoxy; carboxyl-terminated polybutadiene; CTPB liquid rubber; thermal conductivity; hexagonal boron nitride; dielectric permittivity; dissipation factor; electrical resistivity; dielectric breakdown strength; mechanical toughness; electrical insulation
• Online Access: https://digital-library.theiet.org/content/journals/10.1049/hve.2017.0053

To enhance the toughness and electrical insulation properties of cured epoxy, carboxyl-terminated polybutadiene (CTPB) liquid rubber was used to modify epoxy in this study, and the thermal conductivity, mechanical and dielectric properties of modified epoxy were investigated. The results indicate that the CTPB-epoxy exhibits higher impact strength and lower dielectric constant and loss compared with pure epoxy. Further, hexagonal boron nitride (hBN) was used to reinforce epoxy modified with 20 phr CTPB. It is found that compared with the hBN/epoxy under the same filler loading, the heat conductive hBN/CTPB/epoxy possesses a lower dielectric permittivity and dissipation factor in all frequency ranging from 10^2–10^7 Hz, a higher electrical resistivity and dielectric breakdown strength, and improved mechanical toughness. Therefore, the prepared hBN/CTPB/epoxy composites are potentially useful in practical electrical insulation applications.