Corona Resistance Mechanism of Nano-Modified Polyimide

Area of Science:

• Materials Science
• Electrical Engineering
• Polymer Science

Background:

• Composite films are crucial in high-voltage applications but susceptible to degradation from electrical discharge (corona).
• Understanding the relationship between field strength, doping, and dielectric properties is essential for material longevity.

Purpose of the Study:

• To investigate the impact of field strength on the corona-resistant lifespan of composite films.
• To evaluate how doping affects the dielectric properties and electrical aging of composite films.
• To develop a method for predicting corona-resistant lifespan under operational electric field strengths.

Main Methods:

• Characterization of composite film morphology and structure using Scanning Electron Microscopy (SEM) after corona exposure.
• Analysis of imidiated film using Fourier Transform Infrared Spectroscopy (FT-IR).
• Determination of electrical aging threshold via conductivity current testing.

Main Results:

• Introduction of nano-silicon dioxide (SiO2) particles substantially improved the corona-resistant lifespan.
• A polyimide/nano-SiO2 three-layer composite film with 10 wt% nano-particle doping exhibited a corona-resistant lifespan of 7472.61 hours at 155 °C and an extrapolated electric field strength of 20 kV/mm.

Conclusions:

• Nano-SiO2 doping is an effective strategy to enhance the corona resistance and durability of polyimide composite films.
• The study provides a predictive approach for assessing material lifespan under working electric field conditions.