Enhanced thermal conductivity of PE/BN composites through controlling crystallization behavior of PE matrix

In this article, in order to enhance the thermal conductivity of the polyethylene (PE)/boron nitride (BN) composites through controlling the crystallization behavior of the PE matrix, the crystallization and melting behavior of the PE in the PE/BN composites was investigated. When the BN content was more than 10 wt%, an extra weak exothermic peak (T_h) at 130°C was observed. Moreover, after the annealing of the PE/BN composites at 130°C, the extra weak melting peaks (T_mh) of the PE in the PE/BN composites were also observed and shifted to the high temperature with increasing annealing time, which proved that the T_h was induced by PE crystallization. Meanwhile, the results of temperature‐dependent absorbance IR spectra of the PE/BN composites showed that the crystallization peak (729 cm⁻¹) remarkably appeared at 130.2°C, indicating that the crystallization of the PE in the PE/BN composites can occur at 130.2°C. When the annealing time and temperature were 20 min and 130°C, the thermal conductivity of the PE/BN composite was 16% higher than that of the unannealed PE/BN composites. In addition, the results of the wide angle X‐ray diffraction (WAXD) showed that the BN particles had no influence on the PE crystalline form in the PE/BN composites. POLYM. COMPOS., 38:2806–2813, 2017. © 2015 Society of Plastics Engineers