Dielectric properties, Impedance analysis, and electrical conductivity of Ag doped radiation grafted polypropylene

Abstract

T HE possibility of obtaining relatively high dielectric constant polymer-metal composite by incorporating silver nanoparticles in a polypropylene (PP) polymer matrix using grafting and successive reduction method was demonstrated. Frequency and temperature dependence of AC conductivity and dielectric constant (ε') and dielectric loss (ε'') in pure polypropylene (PP), polypropylene grafted acrylic acid and styrene comonomer [PP-g-(AAc-co-Sty)], and PPg-(AAc-co-Sty)-Ag nanocomposite are studied in the frequency range 50 Hz-5 MHz and in the temperature range 30-70 o C. The experimental results show that the polarity of PP is weak due to deficiency of polar groups. The values of ε' and ε'' increased dramatically with the addition of silver nanoparticles in polypropylene. The obtained AC conductivity follows the correlated barrier-hopping model (CBH) since the frequency exponent (s) and AC conductivity are both frequency and temperature dependent. The calculated value of the maximum barrier height W m for PP-g-(AAc-co-Sty)-Ag is 0.242eV. The dielectric relaxation process is studied in respect of the electric modulus formalism.

Synthesis of (Poly-methyl Methacrylate-lead Oxide) Nanocomposites and Studying their A.C Electrical Properties for Piezoelectric Applications

“…The AC conductivity is frequency dependent and enhanced with an increase of the frequency. This can be accounted for by assuming that there may be charge carriers, which can be transported by hopping through the defect sites along the polymer chain [8].…”

“…There is an interest in dielectric materials because of their wide range of applications in electronic and electrical industry. High dielectric constant, dielectrics, are suitable materials for cable insulation, charge-storage capacitors, electrocaloric cooling, and artificial muscles [2]. Most of polymer materials have very high electrical resistance.…”