Structural Insights into Space Charge Control: The Impact of Monomer Variations in Epoxy Resins

This study explores how molecular structures affect epoxy resin materials, focusing on space charge and electrical properties. Bisphenol A-type epoxy resin is used as the base material. Three curing agents are tested: low molecular weight polyamide (651), phenolic amine (T-31), and diethyl-diamino-diphenyl methane (ME-DDM). The research compares space charge distribution, conductivity current, and DC breakdown strength across these materials. Using space charge data, they analyze electric field distribution, charge carrier movement, and the distribution of charge traps. Results show that ME-DDM forms a conjugated system in the material. This system reduces space charge buildup significantly. It also creates a more uniform internal electric field. ME-DDM increases shallow charge traps, which improves charge mobility and helps charges move and disperse faster. Additionally, ME-DDM enhances electron attraction, boosting DC breakdown strength and overall insulation performance.