Hot pressing-induced alignment of hexagonal boron nitride in SEBS elastomer for superior thermally conductive composites

Abstract

Styrene-ethylene-butylene-styrene (SEBS) composite films containing well-dispersed and highly aligned hexagonal boron nitride (hBN) platelets were achieved by a ball milling process followed by hot-pressing treatment. An ultrahigh in-plane thermal conductivity of 45 W m À1 K À1 was achievable in the SEBS composite film with 95 wt% hBN. The corresponding out-of-plane thermal conductivity was also as high. The hBN/SEBS composite film was further used to cool a CPU connected to a computer, resulting in a decrease by about 4 C in the stable temperature. Percolation thresholds over 40 wt% and 60 wt% in the hBN/SEBS composites were obtained in the in-plane and out-of-plane directions, respectively. This phenomenon has rarely been reported in polymer composites. Molecular dynamics simulations were also conducted to support this percolation threshold. The linear coefficients of the thermal expansion value of the hBN/SEBS composite with 95 wt% hBN was as low as 16 ppm K À1.This was a significant decrease compared to that of pure SEBS (149 ppm K À1). The proposed strategy provides valuable advice about the heat-transfer mechanism in polymer composites containing oriented two-dimensional materials.

Investigation on cure kinetics of epoxy resin containing carbon nanotubes modified with hyper-branched polyester

“…To improve its compatibility with epoxy resin, the surface modication is proved to be an effective way. 11,[22][23][24] Hyperbranched polymers have a lower branching efficiency than dendrimers while possessing many useful properties. [25][26][27] The highly branched architecture minimizes chain-chain ability and low melt viscosity to these polymers, which is compatible with epoxy thermosets.…”

Polystyrene‐poly(ethylene‐butylene)‐polystyrene/asphaltene sands composite elastomer with improved mechanical properties

“…15 Hotpressed hexagonal boron nitride with SEBS endues the material with superior thermal conductivity. 16 These examples clearly prove that SEBS is a good candidate as subtracts for highly tough and stretchable structural materials or functional materials. However, the non-polar and hydrophobic nature of SEBS restricts the good dispersion of the polar ingredients such as organic additives and metal oxides, thus additional modification is usually required for a better distribution of the incorporated ingredients.…”

“…These values are comparable to that reported in the literatures. 13,16,[31][32][33][34][35] These results clearly indicate the strengthening effect of the AS to the SEBS matrix. It should be noted that further increasing the AS content results in an even higher tensile strength, as for that of the sample containing 20 wt% AS is 17.23 MPa, but the tensile strain is decreased to 576%.…”

Vertically Aligned and Interconnected Graphite and Graphene Oxide Networks Leading to Enhanced Thermal Conductivity of Polymer Composites

“…However, the incorporated iron oxide limits the thermal conductivity of the composite fillers and increases the total mass. Meanwhile, other approaches, including hot-pressing [18,46], injection molding [47][48][49], 3D printing [50,51], and electrospinning [52], are also widely applied. The ice-templating self-assembly method, which can construct well-aligned architecture along the ice-growth direction, has been regarded as one of the most promising strategies [3,53,54].…”