Study of structural and dielectric properties of blended poly (vinylidene fluoride) and poly(methyl methacrylate) multifunctional nanocomposites doped with nano-SnO2.

The dielectric constant of polymers is low (low-ε′). A high-ε′ multifunctional nanomaterial must be added to the polymer in order to create a polymer composite with high values of the dielectric constant of the polymer blend. Composites prepared from such high-ε′ polymers are extremely beneficial for many energy storage devices and electrical devices such as transducers, piezo-sensors, hydrophones, microstrip antennas (used in artificial satellites for data detection) etc. In order to achieve the demands and needs of today for the society we prepared and design thin films using PMMA which is blended with poly vinylidene fluoride (PVDF) with high-ε′ value and further mixed with tin oxide (SnO₂) nanoparticles in different weight ratios varies from 0.5 to 4 wt% categorizing sample as SP1—0.5 wt%, SP2—1wt%, SP3—2wt% and SP4—4wt% and these samples are synthesized by casting techniques using magnetic stirrer. The effect of varying SnO₂ content on structure, chain segmental motion and dielectric properties of PVDF/PMMA blend have been investigated using X-ray diffraction (XRD), Infrared spectroscopy using FTIR and Impedance analyzer techniques. The structural characterizations showed that the SnO₂ nanoparticles are immiscibly dispersed in PVDF/PMMA blend matrix, leading to a noticeable rise in the values of dielectric constant and electrical conductivity at constant frequency. On increasing the frequency at constant wt% of SnO_2, a decrease in dielectric constant was observed. Such behavior in a lower frequency range can be attributed to the interfacial polarization effect (IPF) and remarkable increase in the molecular polarization at high frequencies. At high wt% of SnO₂ in the polymer blend, nonlinear behavioral changes occur in the chain segmental dynamics, reflected by the trends of dc electrical conductivity. The electric modulus spectra were used to analyze the relaxation processes associated with the M–W–S mechanism and chain segmental motion in the polymer. [ABSTRACT FROM AUTHOR]