Strategy for Constructing Epoxy Composites with High Effective Thermal Conductive Capability Based on Three-Dimensional Cellulose and Multiwalled Carbon Nanotube Network

High effective thermal management materials have become a crucial factor for the reliability and lifetime of devices. Herein, epoxy resin (EP) composites with superior thermal conductive efficiency were fabricated via the homogeneous dispersion of carboxylated multiwalled carbon nanotubes (CMWCNTs) in cellulose nanofiber (CNF) aerogels, and then the EP precursors were impregnated and cured. The thermal conductivity of EP/CNF/CMWCNT thermosets containing only 0.65 wt % CMWCNTs increased from 0.19 W·m–1·k–1 for pristine EP to 0.93 W·m–1·k–1 and increased by 389.5%. As a result, the composites presented excellent heat absorption and dissipation performance, which are demonstrated by the infrared thermal camera tests. Besides, the composites showed highly electric insulating performance, and its volume electrical resistivity was as high as 6.48 × 1015 Ω·cm–1 due to the low content of CMWCNTs in thermosets. The glass-transition temperature of EP/CNF/CMWCNT composites increased from 132.6 °C for neat EP thermosets to 153.3 °C, as indicated by the dynamic mechanical analysis. Moreover, thermal mechanical analysis demonstrated that the resultant EP composites possessed excellent dimensional stability. The obtained EP/CNF/CMWCNT composites were allowed to work at a higher temperature environment. This presented research work provided an alternative approach for preparing EP composites with highly efficient thermal management and electrical insulation performance, which allowed their application in electronic packaging, devices, and other electronic applications.