Synthesis of PVC-co-PVAc-co-PVA/Cu Nanocomposites with Improved Dielectric Performance

Abstract

This thesis reports the synthesis of an easy, environmentally friendly, and cost effective polyol method for the synthesis of copper nanoparticles and copper/poly (vinyl chlorideco- vinyl acetate-co- vinyl alcohol) nanocomposite films using solution casting technique. Face centered cubic structured nanoparticles, space group Fm-3m (225) with average crystallite size of 33.5 nm were successfully prepared with characteristics diffraction peaks at 2𝜃= 43.3, 50.5, 73.2° as investigated by XPRD. FTIR also shows characteristics band of Cu-PVP hybrid evident in nanoparticles at 1089 and 629 cm-1 which further confirm the synthesis of copper nanoparticles. Polymeric nanocomposite thin films of 5, 10, 15, 20 and 25 % wt were prepared. Polymer show characteristics broad peak ranging from 10-30°. Spherical nanoparticles were seen to be homogenously dispersed in polymer matrix as investigated by Field emission electron spectroscopy (FESEM). Dispersed nanoparticles in the film possess average size of ~68.67 nm. The improved dielectric constants of nanocomposites was as high as 3.75 at 25 % wt. The insulating effect of PVP, coating the copper nanoparticles along with interfacial polarization results in very low value of dielectric loss ranging from 0.08 to 0.16 with tangent loss values at 0.0025 to 0.0054 and range of value of AC conductivity is 0.4⨯10-6 to 1.2⨯10-5 S/m at weight percentage from 5 to 25 of polymeric nanocomposite film which make these nanocomposites films a promising material for used in charge storage applications.