Enhancement of thermal conductivity in polyamide-6/graphene composites via a “bridge effect” of silicon carbide whiskers

It is urgent to manufacture a polymer composite that has high thermal conductivity and mechanical properties simultaneously to meet the heat dissipation requirement of electronic devices. In this paper, we report a bridge effect of Silicon Carbide whiskers (SiCw) on the enhancement of thermal conductivity (TC) in polyamide-6/graphene (PG) composites. The composite was made by melting, stirring through an Internal mixer. Experimental results show that the TC of the PG composites increases with additional introduction of SiCw, particularly in the through-plane direction. For example, based on the PG-2 sample (2 wt% graphene in polyamide-6 (PA) matrix), the thermal conductivity enhancement (TCE) of PASC-24 (similar to 2 wt% graphene and 43.2 wt% SiCw in the PA matrix) in the through-plane direction is 199%, while in contrast, the TCE in the in-plane direction is just 5.4%. Meanwhile, the mechanical properties of the composites are synchronously enhanced, indicating that it is a convenient method and can be widely applied in various thermal interface materials (TIMs) and thermal management systems.