Endurance Analysis of Electrical Insulating Materials for Ionic Propulsion Systems in Stratosphere

This study examines the impact of DC corona discharge on the electrical and chemical properties of polyethylene (PE), epoxy resin (EP), and polyimide (PI). The discharge process induces surface modifications, primarily through the formation of carbonyl and hydroxyl functional groups, resulting from the dissociation of environmental oxygen and moisture due to ion acceleration effects. The extent of these chemical transformations is material-dependent, with PE exhibiting the most pronounced variations due to its lower binding energy. In contrast, E P and P I demonstrate greater structural stability owing to the presence of aromatic and imide functionalities, respectively. Changes in surface conductivity suggest nonuniform charge accumulation dynamics, likely influenced by surface reorganization mechanisms. Surface erosion is observed across all samples. These findings provide essential insights into the degradation mechanisms associated with dielectric materials under sustained corona exposure, contributing to the optimization of material selection and engineering strategies in high-voltage applications.