Flexible FKM/mRGO nanocomposites with excellent thermal, mechanical and electrical properties

Grace Moni, Anshida Mayeen, Jiji Abraham, Thomasukutty Jose, MG Maya, Rabindranath Bhowmik, Soney C George

Index: 10.1016/j.arabjc.2018.03.015

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Abstract

Nanocomposites having multifunctional properties with simultaneous improvement in thermal, mechanical and dielectric properties along with improved ferroelectric signature are of considerable interest due to the rapidly growing need in the technological aspect. In the present work, microwave reduced graphene oxide (mRGO)/fluoroelastomer nanocomposites with enhanced dielectric performance and ferroelectric characteristics were developed. mRGO was synthesized from natural graphite via GO and was confirmed by analyzing the chemical changes using X-ray diffraction technique, Fourier transform infrared and Raman spectroscopy studies. The addition of the mRGO improved the mechanical, dielectric and ferroelectric characteristics of the nanocomposites by its better dispersion in the polymer matrix as confirmed by TEM and AFM analysis. The enhanced polymer filler interaction was also confirmed by analyzing the Kraus Plot. Nanocomposite with 0.75 phr of filler loading showed optimum mechanical properties with increased Tg of about -12.25 °C. This is an evidence for the enhancement in properties due to the improved filler-polymer electrostatic interaction. Nanocomposites showed several-fold increase in the dielectric constant value compared to the gum sample. Moreover, the nanocomposites have minimum dielectric loss at 1MHz frequency. The incorporation of mRGO created a conductive pathway by the microcapacitor effect and the nanocomposites showed enhanced AC conductivity. Ferroelectric studies revealed that the coercive field (Ec) and the remnant polarization (Pr) of the nanocomposites were increased with filler loading that signifies the improvement in ferroelectric signature of the nanocomposites. The samples show excellent dielectric and ferroelectric properties along with better thermal and mechanical stability, and hence, will be promising candidate for ultra-modern storage devices.