Investigation on dielectric relaxation of PMMA-grafted natural rubber incorporated with LiCF3SO3

Natural rubber (NR) grafted with 30 wt% poly (methyl methacrylate) (PMMA) and designated as MG30 has been added with varying amounts of LiCF3SO3. X-ray diffraction (XRD) shows the samples to be amorphous. Fourier transform infrared (FTIR) spectroscopy indicates complexation between the cation of the salt and the oxygen atom of the CO and –COO- groups of MG30. From electrochemical impedance spectroscopy (EIS), MG30 with 30 wt% LiCF3SO3 salt exhibits the highest ambient conductivity of 1.69×10−6 S cm−1 and lowest activation energy of 0.24 eV. The dielectric behavior has been analyzed using dielectric permittivity (ε′), dissipation factor (tan δ) and dielectric modulus (M⁎) of the samples. The dielectric constant of pure MG30 has been estimated to be ∼1.86.