The effect of nanographite addition on the physical properties of poly(vinylidene fluoride)/hydroxypropyl cellulose blend

Abstract

In this study, polymeric films of poly(vinylidene fluoride) (PVDF)/hydroxypropyl cellulose (HPC) blend filled with various graphite-nanoparticles (GNP) contents were prepared via solvent-mixing technique. The compatibility between PVDF and HPC polymers was studied. The variations in structure, dielectric and thermal properties were investigated over the frequency range (20 Hz–3 MHz) and temperature range (20–110 °C). The X-ray diffraction and differential scanning calorimetry results reveal that the crystallinity of PVDF was affected by the presence of HPC and GNP. The dielectric results reveal that the great enhancement of dielectric constant ($\upvarepsilon^{{\prime }}$) and ac conductivity (σ_ac) were observed. The dielectric properties were explained in terms of the dielectric polarization mechanism. Both HPC and GNP additions enhance the $\upvarepsilon^{{\prime }}$ of PVDF due to the formation of β-phase polymorph and the interface effect between the GNP and blend matrix. The improvement of the thermal stability was observed due to the regular arrangement of the side chains. The easy processing, high dielectric constant, low tangent loss and high thermal stability of the composites make the composites attractive for practical applications in embedded capacitors.