Synthesis and Characterization of High-Dielectric-Constant Nanographite–Polyurethane Composite

Abstract

In the face of ever-growing demand for capacitors and energy storage devices, development of high-dielectric-constant materials is of paramount importance. Among various dielectric materials available, polymer dielectrics are preferred for their good processability. We report herein synthesis and characterization of nanographite–polyurethane composite with high dielectric constant. Nanographite showed good dispersibility in the polyurethane matrix. The thermosetting nature of polyurethane gives the composite the ability to withstand higher temperature without melting. The resultant composite was studied for its dielectric constant (?) as a function of frequency. The composite exhibited logarithmic variation of ? from ~ 3000 at 100 Hz to ~ 225 at 60 kHz. The material also exhibited stable dissipation factor (tan ?) across the applied frequencies, suggesting its ability to resist current leakage. © 2018, The Minerals, Metals & Materials Society.