Electrical properties and EMI shielding characteristics of multiwalled carbon nanotubes filled carbon black-high density polyethylene nanocomposites

摘要

Electrically conducting nanocomposites were prepared by melt mixing process using high density polyethylene (HDPE) with 20 wt.% of carbon black (CB) and 0–1 wt.% of multiwalled carbon nanotubes (MWNTs). The effects of MWNTs in HDPE-CB-MWNTs composites were examined using X-ray diffraction and differential scanning calorimeter. DC resistivity (ρ_(dc)), AC conductivity (σ_(ac)), and some dielectric properties and electromagnetic interference (EMI) shielding effectiveness of these composites have been investigated. The results reveal that ρ_(dc) decreases significantly whereas σ_(ac), e′, and EMI shielding effectiveness increase with loading of MWNT. The values of ε′, ε″, and σ_(ac) are frequency dependent. Positive temperature coefficient effects are observed to be dominant over temperature range of 60–105 °C and the shielding effectiveness is frequency dependent over the X band (8.2–12.4 GHz).