Mechanical Engineering Faculty Research

Title

Electrical Conductivity and Dielectric Properties of PMMA/Expanded Graphite Composites

Document Type

Article

Publication Date

2-2003

Abstract

PMMA/expanded graphite (EG) composites were prepared by direct solution blending of PMMA with the expanded graphite filler. Electrical conductivity and dielectric properties of the composites were measured by a four-point probe resistivity determiner and a dielectric analyzer (DEA). Interestingly, only 1 wt.% filler content was required to reach the percolation threshold (φ) of transition in electrical conductivity from an insulator to a semiconductor using PMMA/EG. The thickness of the interlayer of the expanded graphite was shown to be close to the nanometer scale. The reported filler content was much lower than that required for conventional PMMA/carbon black (8 wt.% carbon) and PMMA/graphite (3.5 wt.% graphite) composites. The improvements in both electrical conductivity and structural integrity were attributed to the difference in filler geometry (aspect ratio and surface area) and the formation of conductive networks in the composites.

Publication Title

Composites Science and Technology

Volume

63

Issue

2

First Page

225

Last Page

235