Thermal, mechanical and dielectric properties of functionalized sandwich BN-BaTiO3-BN/polypropylene nanocomposites

Abstract

Research attention has been drawn towards the development of polypropylene (PP) based materials, which simultaneously have large dielectric constant, mechanical strength, and thermal stability for power-related applications. This study achieved that by using sandwich structured BN-BaTiO3-BN in modification of PP matrix. The BN-BaTiO3-BN sandwich nanoparticles were prepared via hydrothermal and assembly techniques. Before that, the nanoparticles were surface functionalized using 3-glycidoxypropyltrimethoxysilane. The functionalized nanoparticles were investigated using FTIR and TGA, which confirmed successful functionalization. Molten polypropylene grafted maleic anhydride (PPMA) compatibilizer was used to wrap the BN and BaTiO3 (BT) nanoparticles, which also promoted their compatibility with the PP matrix. The nanocomposites were prepared via melt compounding method using rheomixer. The developed PP nanocomposites showed enhanced DSC properties and thermal stability (above 20 °C compared to the pure PP). In addition, the dielectric constant increased from 2.02 at 100 Hz for the pure PP to 4.68 for PP/5BN-15BT nanocomposite, which is about 132% increase. The nanocomposite also retained an appreciable low loss of about 0.05 at 100 Hz. The enhanced dielectric and thermal properties are required for optimal performance of PP dielectric film capacitor for power applications and miniaturization of electronic components. The various improved properties were attributed to interfacial polarization, interlocking of PP chains and thermal barriers in the PP matrix offered by the nanoparticles.