Preparation and high thermal conductivity of 3D printed BNm@EP/EP-CNTs composites

In this paper, the high thermal conductivity of BN m @EP/EP-CNTs composites prepared by the electrostatic direct-in-writing (DIW) 3D printing method was investigated. Octadecyltrimethylammonium bromide was used as a cationic surfactant to modify h-BN, improve filler dispersion and reduce interfacial thermal resistance. The macroscopic 3D heat transfer framework was constructed and the BN m @EP/EP-CNTs composites were prepared by the 3D printing method. 25 wt% of BN m and epoxy resin to prepare the printing adhesive, DIW 3D printing method to prepare the BN m @EP 3D thermally conductive skeleton, and vacuum impregnation of epoxy resin adhesive with different mass fractions of CNTs to obtain 3D BN m @EP/EP-CNTs composites. The heat conductivity of EP was 0.12 W/(m·K), the thermal conductivity of 3D-BN m @EP/EP-0 wt% CNTs at 0.748 W/(m·K), and 3D-BN m @EP/EP-2 wt% CNTs had a heat conduction coefficient of 1.22 W/(m·K). The heat transfer coefficient of 3D-BN m @EP/EP-0 wt% CNTs increased by 0.3% compared with that of BN m /EP prepared by simple blending at 25 wt%. 3D-BN m @EP/EP-2 wt% CNTs showed an increase of 916.7 % in thermal conductivity compared with that of EP; and the heat-resistance index was improved, with the glass transition temperature (GST) of 142.98 °C and the Tg of pure EP of 132.61 °C. Therefore, it can be concluded that the 3D printing method can clearly improve the heat conductivity of epoxy composites, and the 3D heat conducting network constructed macroscopically can likewise enhance the heat dissipation performance. It also has good electrical properties. In conclusion, this research can be better adapted to high-frequency signal transmission.