Interfacial thermal resistance between high-density polyethylene （HDPE） and sapphire

To improve the thermal conductivity of polymeric composites, the numerous interfacial thermal resistance （ITR） inside is usually considered as a bottle neck, but the direct measurement of the ITR is hardly reported. In this paper, a sandwich structure which consists of transducer/high density polyethylene （HDPE）/sapphire is prepared to study the interface characteristics. Then, the ITRs between HDPE and sapphire of two samples with different HDPE thickness values are measured by time-domain thermoreflectance （TDTR） method and the results are -- 2 × 10-7 m2.K.W-1. Furthermore, a model is used to evaluate the importance of ITR for the thermal conductivity of composites. The model＇s analysis indicates that reducing the ITR is an effective way of improving the thermal conductivity of composites. These results will provide valuable guidance for the design and manufacture of polymer-based thermally conductive materials.