Effect of Grafting Maleimide on the DC Electrical Properties XLPE at Various Temperatures

Maleimide (MAI) with both electron donor group and electron acceptor group was selected as graft monomer. cross-linked polyethylene (XLPE) and XLPE-g-MAI were prepared by peroxide initiation. The DC properties of XLPE and XLPE-g-MAI were investigated at wide temperatures range. The FTIR results show that MAI has been grafted onto PE molecules. XLPE-g-MAI shows a decreased conductivity and enhanced DC breakdown strength. Space charge distribution shows that even at elevated temperature, there is no single polar charges accumulated in the material. No serious positive and negative charge boundary appeared in the material, and the electric field distribution is relatively uniform. Molecular simulation results indicate that MAI can introduce both electron and hole traps to form a balanced trap distribution, which can assist to prevent single-polarity space charge accumulation and avoid the ameliorate electric field distortion cause by the single-polar space charge accumulation.