A bio‐based compatibilizer for improved interfacial compatibility in thermally conductive and electrically insulating graphite/high density poly(ethylene) composites

Abstract

Abstract Graphite is a thermally conductive filler. However, when dispersed into high density poly(ethylene) (HDPE) resin, graphite particles tend to agglomerate and requires a compatibilizer to achieve desired thermal/physical properties. In this study, oleic acid (OA), a bio‐based additive and polyethylene‐polyamines (PEPA) were used to synthesize a new compatibilizer, PEPA‐g‐OA, containing numerous NR 2 groups. The experimental results showed that PEPA‐g‐OA can significantly improve the compatibility between graphite particles and the HDPE matrix due to uniform dispersion of graphite in the HDPE matrix. When the graphite content was 25 wt%, the thermal conductivity of the composite recorded 1.2 W m −1 K −1 (three times that of neat HDPE) and the volume resistivity was 1.8 × 10 9 Ω cm, indicating excellent electrical insulation. Compared to the composites with no graphite content, the properties of the composites with 25 wt% graphite content exhibited narrower melting and crystallization peaks, more stable mechanical properties, and higher ultraviolet aging resistance. Synthesized new bio‐based compatibilizer and thermally conductive and electrically insulating composites developed in this study can be useful in different industrial fields for the preparation of the next generation composites.