Improved dielectric constant of thermoplastic blend as a function of alumina loading

Abstract

Polycarbonate (PC) and Poly (methyl methacrylate) blends were prepared by incorporating Al2O3 into the polymer matrix using solution blending. The modified blends were characterized by X-ray diffraction, Thermogravimetric analysis, and Scanning electron microscopy. The crystalline to amorphous phase variation was confirmed by XRD with increase in the interplanar distance (d). TGA results indicate that the thermal stability of the modified blend was significantly improved as a function of alumina loading which may be due to interfacial interaction between the alumina particles and the polymers. Scanning electron microscopy studies reveal the presence of alumina particles resulting in plane surface morphology. The modified blends show very high dielectric constant value (105–107) as a function of frequency (in the range 50Hz–35MHz) and temperature in the range (40–150°C). The modified polymer blend demonstrate consistent polarization across the frequency band 50Hz–10kHz. The neutral aggregates formation due to higher concentration of alumina loading demonstrated an influence on AC conductivity. This investigation can be feasible for electronic and electrical engineering application as the dielectric medium.