Dielectric enhancement over a broad temperature by nanofiller at ultra-low volume content in poly(ether methyl ether urea)

This Letter studies the dielectric responses of nanocomposites of poly(ether methyl ether urea) (PEMEU) with alumina nanofillers at less than 0.7% volume loading (0.7vol. %). The results show that the dielectric constant K of PEMEU nanocomposites is enhanced by the nanofillers. The enhancement peaks at 0.33vol. % nanofiller loading, from K=3.9 of neat polymer to K=5.5 of nanocomposites from room temperature to 200 degrees C, above the glass transition (similar to 150 degrees C) of the polymer. Except for an enhanced dielectric constant, the nanocomposite maintains a low dielectric loss and a high breakdown strength of 500MV/m at room temperature and 300MV/m at 150 degrees C, respectively. Thus, the nanocomposite with 0.33vol. % nanofillers delivers discharged energy densities of 6.5J/cm(3) at room temperature and 2J/cm(3) at 150 degrees C with better than 90% charge/discharge efficiency, 40% higher than the neat polymer. Published under license by AIP Publishing.