Improved Dielectric-Breakdown Property of POSS-Filled Epoxy

Overview

The document titled "Improved Electrical Properties of Epoxy Resin with Nanometer-Sized Inorganic Fillers" presents research conducted by a team from the Air Force Research Laboratory and the University of Dayton Research Institute. The study focuses on enhancing the electrical properties of epoxy resins by incorporating nanometer-sized inorganic fillers, specifically polyhedral oligomeric silsesquioxane (POSS).

Epoxy resins are widely used in high-voltage applications, such as potting materials in power supplies and insulation systems for mobile communications and aerospace vehicles. The research highlights that while these fillers are commonly known for improving mechanical and thermal properties, they can also significantly enhance electrical properties, including dielectric breakdown voltage and corona endurance.

The study investigates the effects of a 5% by weight POSS loading in epoxy resin, specifically using EPON 828 as the base resin and an aliphatic diamine (Jeffamine D400) as the curing agent. The samples were cured under controlled conditions to ensure uniformity and consistency. The research employed various testing methods, including short-term dielectric withstand tests, to evaluate the performance of the POSS-loaded epoxy compared to a control epoxy without fillers.

Key findings indicate that the incorporation of POSS resulted in a 34% increase in the average dielectric breakdown voltage compared to the unfilled epoxy. Scanning electron microscopy revealed a uniform dispersion of the POSS filler at the nanoscale, which is critical for achieving the desired enhancements in electrical properties. Additionally, surface analysis through infrared spectroscopy confirmed the formation of a silicon-rich layer on the surface of the POSS-epoxy samples after corona exposure, suggesting a mechanism for improved performance.

The document emphasizes the importance of filler dispersion uniformity in achieving property enhancements and discusses the implications of these findings for the design of robust insulation systems in high-voltage applications. The research contributes valuable insights into the development of advanced epoxy materials that can withstand harsh electrical environments, thereby enhancing the reliability and performance of electronic devices and systems.

In conclusion, this study provides a significant advancement in the understanding of how nanometer-sized inorganic fillers can improve the electrical properties of epoxy resins, paving the way for future innovations in material science and engineering applications.