IMF2017

Magnetite nanoparticles were prepared by wet chemical precipitation technique. The particle size was examined by using transmission electron microscopy and found to be in the order of ~100 nm. Poly methyl methacrylate/ magnetite (PMMA/MG) nanocomposites with different concentrations of magnetite were prepared by casting method. The distribution of MG inside PMMA matrix was examined by scanning electron microscopy which indicate fine distribution of the MG particles inside PMMA matrix uptill 10% after which some aggregation was obtained. The magnetic properties of the studied composites revealed ferromagnetic and super paramagnetic. The X-ray diffraction reveals an increase in the degree of crystalinity by increasing MG content. The microhardness of composites was found to increase by the increase in MG content. The dielectric properties of the composites were investigated through the measurements of the permittivity ε' and dielectric loss ε". The measurements were carried out over a wide range of frequency (0.1 Hz and 1 MHz. ) and temperature (30-90 ^oC). e' and e" were found to increase gradually by increasing MG content uptill 10% after which a dramatic increase was noticed. Also it is found that both values increase dramatically by increasing the applied temperature showing positive temperature coefficient. The electrical conductivity σ at 30 ^oC was found to be in the order of 10^-9 S.cm^‑1 which recommends such composites to be used as antistatic materials. On the other hand, the values of s at 90 ^oC was found to be in the order of 10^-3 S.cm^‑1 which behave like semiconductor at such high temperature.