High Thermally Conducting Composites Obtained Via In Situ Exfoliation Process of Expandable Graphite Filled Polyamide 6

In this article, high thermally conducting polymer composites were prepared by low temperature expandable graphite (LTEG) filling polyamide 6 (PA6) via an in situ exfoliation process during melt blending. Thermal conductivity of the composites was measured by hot disk method and a very high value of 32.33 W/mK was obtained at the LTEG loading fraction of 70% by weight. Dynamic rheology analysis was applied to determine the structural change by the interconnection of the in situ exfoliated graphite flakes. X-ray diffraction (XRD) analysis confirmed that the exfoliation of LTEG was crucial to the overall thermal conductivity of the composites. Based on differential scanning calorimetry (DSC) data, the introduction of LTEG had little effect on the melting behavior of the composites, but a prominent heterogeneous nucleation effect and greatly accelerated its crystallization procedure of PA6. POLYM. COMPOS., 34:1816-1823, 2013. (c) 2013 Society of Plastics Engineers