Study on the structural, dielectric and thermal degradation of poly (methyl methacrylate)-ZnO nanocomposites

Abstract

The aim of the work is to demonstrate the effect of ZnO nanoparticles on the thermal stability and dielectric performance of a PMMA matrix. PMMA-ZnO nanocomposite films were prepared by varying the concentration of ZnO ranging from 1 to 9 wt %. The XRD spectrum reveals the coexistence of hexagonal-phase ZnO and the amorphous PMMA. Optical energy band gap of 3.89–3.93 eV for PMMA-ZnO nanocomposite films is found due to the involvement of ZnO excitonic state transition. Thermogravimetry Technique Analysis (TGA) along with Differential Scanning Calorimetry (DSC) is employed to assess the thermal response of all nanocomposites up to 600 °C. The TG study demonstrates improved thermal stability of PMMA-ZnO films compared to pure PMMA film. In PMMA -ZnO nanocomposite films, all the three-stage degradation have been improved even at high temperature reaching up to 590 °C. Further, kinetic thermodynamic parameters are calculated and interpreted to show significance of ZnO nanofillers in PMMA matrix. High dielectric constant and low dielectric loss for 7 wt% ZnO in PMMA matrix have been found and mechanism of dielectric polarization is elucidated through Cole-Cole plots.