Aromatic Polyurea for High Temperature High Energy Density Capacitors

We investigate aromatic polyureas which can be fabricated in the form of thin films through CVD. It was found that the polymer possesses a flat dielectric response (k similar to 4.2 and loss <1%)) to more than 200 degrees C. The frequency-independent dielectric properties ill the investigated frequency range(1kHz similar to 1MHz), low conductance, low dissipation factor (similar to 0.005), high breakdown strength (>800MV/m), high energy density (>12J/cm(3)) and high efficiency suggest this polymer call be a good candidate material for high temperature energy storage capacitors. Breakdown strength was analyzed with Weibull model over a broad temperature range (25 degrees C similar to 180 degrees C). Experimental results indicate that aromatic polyurea is more like a nonpolar linear dielectric material because of its highly cross-linked structures. The experiment results further show that this polymer maintains its high performance even at high temperatures.