Selectively distributed graphene in 1,6-hexanediol diacrylate/epoxy composites via digital light processing 3D printing for enhanced thermal conductivity

Abstract

A 3D-printer based on digital-light-processing (DLP) was used to build a 3D foam containing graphene nanopowder (GNP) as a thermally conductive filler. 1,6-hexanediol diacrylate (HDDA) was used as a UV-curable resin because of its low viscosity and high fidelity during printing. Foam-shaped GNP-containing HDDA was placed in a disc-shaped Teflon mold, followed by infiltration of epoxy and thermal curing. The construction of a 3D heat path was achieved by selective GNP particle distribution on the HDDA matrix. According to the GNP filler fraction of the foam-shaped composite, epoxy composite with random GNP filler distribution was also fabricated, to investigate the effect of selective to random GNP distribution and the presence of a 3D heat path on thermal conductivity enhancement. When 1.93 wt% GNP was selectively distributed, the composite exhibited about 14.6% higher thermal conductivity compared to samples with random GNP distribution. The enhanced thermal conductivity could be attributed to efficient heat transfer through the heat path constructed inside the polymer matrix. © 2021 Elsevier B.V.