Thermal and Mechanical Properties of Polypropylene/Boron Nitride Composites

The purpose of this study is to improve thermal conductivity and properties of polypropylene (PP) by adding functionality fillers. Boron nitride (BN) was used for improving the thermal conductivity of polymers. Two types of BN with different particle sizes were used. In addition, two types of PP with different viscosities were used as the polymer matrix. The thermal conductivity, storage modulus and loss modulus increased with the content of BN. The thermal conductivity of PP can be effectively enhanced by adding BN with large particles. Moreover, the melting temperature and crystallization temperature of PP/BN composites were larger than those of neat PP. The degree of crystallization of PP increased with BN. The effect of BN with small particles on the crystallization of PP was slightly stronger than that of BN with large particles. From the SEM observation, the agglomeration of BN with small particles was locally observed. In contrast, BN with large particles dispersed well in the PP matrix. This study found that BN with large particles effectively enhanced the thermal and properties of PP/BN composites. In addition, the above properties were independent of the matrix viscosity.