Encapsulation of Graphite Nanoflakes for Improving Thermal Conductivity of Mesogenic Epoxy Composites

Abstract

Graphite nanoflake (GN) is the most prominent filler for thermally conductive polymeric composites. However, the aggregation problem of GN has an adverse effect on the improvement of thermal conductivity of the composites. In this study, GR is decorated with melamine-formaldehyde (MF) by in situ polymerization, which successfully solves the well-known aggregation problem of GN. GN@MF is used as nanofillers for improving the thermal conductivity of the biphenyl mesogenic epoxy resin (MEP). Photomicrograph observations of MEP/GN@MF composites exhibit that GN@MF flakes are evenly dispersed in the polymer matrix, which demonstrate that GN@MF has excellent dispersion in the MEP matrix. The homogeneous dispersion of GN@MF in MEP favors the formation of the consecutive thermal conductive paths or networks. As a result, the MEP/GN@MF composite has a higher thermal conductivity than MEP/GN with the same content of loading.