A novel polymer composites with high thermal conductivity by Zn2+interfacial intensification and 3D network construction

Polymer-based composites with high thermal conductivity (TC) have attracted broad attention in electronics and heat exchange fields. However, obtaining desirable TC enhancement at low filler loading by a simple preparation strategy remains challenging. In this study, a simple one-pot method was proposed to fabricate high TC composites with low filler loading. Here, Zn2+ was introduced into the curing agent to directly strengthen the interface of expanded graphite (EG)-epoxy (EP), as opposed to the common method of modifying the filler with interfacial reinforcements. Meanwhile, a connectivity network as the main heat transfer medium was constructed with micro-3D EG by the pre-filling method. Results showed that the TC of the prepared composite with only 30 wt% filler loading was up to 55.49 W/(m & sdot;K), which was about 241 times higher than that of pure epoxy. After the experimental data analysis, the key to effectively improving TC was that the dual effect of the effective facilitation of Zn2+ and the presence of a dense and high-quality 3D EG network.