Optimizing dielectric, mechanical, and thermal properties of epoxy resin through molecular design for multifunctional performance.

Epoxy resins are widely used as dielectric materials in electrical and electronic systems. However, the trend of miniaturization of electronic devices and increasing power output of electrical equipment have created new challenges for dielectric materials, necessitating low dielectric constants, high breakdown strength, and high electrical resistivity. This study introduces three molecular modifications to epoxy resin systems using facile synthesis procedures, including modifiers with bulky groups and crosslinking potential to reduce the dielectric constant while enhancing mechanical and thermal reliability, along with deep traps to increase breakdown strength.

Unravelling the role of filler surface wettability in long-term mechanical and dielectric properties of epoxy resin composites under hygrothermal aging.

Epoxy resin (EP) incorporating inorganic fillers has garnered significant attention in the electrical and electronic industries due to its enhanced dielectric and mechanical properties, but its long-term performance under harsh conditions remains a critical concern. This study investigates the effects of filler surface wettability on the durability of EP-SiO composites. Micro-sized SiO with hydrophilic (HP) and hydrophobic (HB) surfaces are prepared via surface treatment, before they are incorporated into epoxy resin and subjected to hygrothermal aging at 95 °C and 95 % relative humidity for up to 1200 h.

Degradation and Lifetime Prediction of Epoxy Composite Insulation Materials under High Relative Humidity.

Insulation failure of composite epoxy insulation materials in distribution switchgear under the stress of heat and humidity is one of the leading causes of damage to switchgear components. This work prepared composite epoxy insulation materials by casting and curing a diglycidyl ether of bisphenol A (DGEBA)/anhydride/wollastonite composite system, and performed material accelerated aging experiments under three conditions: 75 °C and 95% relative humidity (RH), 85 °C and 95% RH, and 95 °C and 95% RH. Material, mechanical, thermal, chemical, and microstructural properties were investigated.

Electrical Properties and Lifetime Prediction of an Epoxy Composite Insulation Material after Hygrothermal Aging.

In this study, we conducted the hygrothermal aging of an epoxy composite insulation material at 95% relative humidity (RH) and temperatures of 95 °C, 85 °C, and 75 °C. We measured electrical properties, including volume resistivity, electrical permittivity, dielectric loss, and breakdown strength. It was found to be impossible to estimate a lifetime based on the IEC 60216 standard, because it uses breakdown strength as its criterion even though breakdown strength hardly changes in response to hygrothermal aging.

A Reactive Molecular Dynamics Study on Crosslinked Epoxy Resin Decomposition under High Electric Field and Thermal Aging Conditions.

To reveal the microscopic mechanism of synergetic thermal-electrical degradation during a partial discharge process in epoxy insulation materials, the decomposition of crosslinked epoxy resin is investigated using reactive molecular dynamics simulations under high electric field and thermal degradation conditions. Bond-boost acceleration method is employed in reactive molecular dynamics simulations to successfully establish epoxy polymer models with a crosslink degree of 93%. Active molecular species derived from electrical partial discharges are considered in the current work.