A comparative study of electrical aging of multiwalled carbon nanotubes and carbon black filled cross-linked polyethylene

In this work, XLPE/MWCNT and XLPE/CB nanocomposites have been prepared in order to investigate AC electric field and water effects on electrical aging of XLPE. The mechanical, AC breakdown strength and AC conductivity were tested and the morphologies after 30 days electrical aging were observed using an optical microscope. The results showed that all samples exhibit excellent insulation properties and mechanical properties. Compared with CB addition, the MWCNT composites exhibit better resistance to electrical aging, with the length of electrical aging-induced microcracks in the MWCNT blends decreasing from 104 to 22 µm, and the width decreasing from 87 to 17 µm, which means a reduction of ∼80% compared of values for neat XLPE in both length and width. However, the XLPE/CB composites have a tendency to promote electrical aging. The mechanism is revealed by comparing the results of the fibrous MWCNTs with the spherical CBs.