Design and development of thermally conductive hybrid nano-composites in polysulfone matrix

A percolating network of hybrid fillers can provide significant synergic enhancement of thermal conductivity in polymer matrix composites. Especially, when platelets and fibers of high aspect ratios are mixed to form a percolating network, the percolation thresholds are small. However, the optimum ratio of platelets to fibers must be acquired for the maximum synergic enhancement. In this work, polysulfone (PSU) matrix-hybrid fillers composite is designed with high thermal conductivity using a computational model. The calibration of computational model with several experimentally measured thermal conductivities of polymer matrix-hybrid nanocomposites leads to the composition where maximum synergic effect/maximum thermal conductivity is expected. For the specific PSU–Graphene nano-platelets (GNPs)/Carbon nano-tubes (CNTs) hybrid composites synthesized in this study, the composition with maximum thermal conductivity as designed by the model is PSU/8.4% GNPs/1.6% CNTs. The samples produced experimentally around this composition have shown close agreement with the predictions of the model. Sensitivity analyses and parametric studies conducted on the model highlight that the dimensional parameters and the interface resistance of the fillers are the most sensitive to enhance the effective thermal conductivity. POLYM. COMPOS., 40:1419–1432, 2019.