Fabrication of Curdlan connected honeycomb-like 3D BN-CNT network for enhancing the thermal conductivity of epoxy composites

Abstract

Polymer composites have excellent properties and become important materials in the field of microelectronic devices and wireless communication technology. In this paper, BNNS-CNT (mass ratio of BNNS:CNT = 10:1) was prepared by grafting treated carbon nanotubes (CNT) onto exfoliation-modified boron nitride nanosheets (BNNS-OH). Then BNNS-CNT is constructed into a honeycomb-like 3D BNNS-CNT using gel polysaccharide (Curdlan). Finally, the epoxy (EP) was poured on the surface of 3D BNNS-CNT to obtain 3D BNNS-CNT/EP composites. The 3D BNNS-CNT structure is characterized by light weight (0.61 g/cm³), high strength (can withstand 2217 times higher than its own weight) and high thermal conductivity. The thermal conductivity of the 3D BNNS-CNT/EP composites reach 1.05 W·m⁻¹·K⁻¹ when containing 20 wt% 3D BNNS-CNT, which increase 425 % compared to that of the pure EP. Meanwhile, the electrical insulation properties are still excellent (surface resistance of 1.3 × 10¹⁵ Ω and volume resistance of 1.2 × 10¹⁵ Ω·cm). The EP composites prepared in this paper have excellent thermal management properties and great potential applications in electronic devices.