Impact of fabrication process of polyethylene / boron-nitride nanocomposite on morphology and dielectric properties

Nanocomposite (NC) films are extensively investigated due to their improved properties attributed to the interphase formed between the nanoparticle and the matrix. In this work, we focus our interest on Polyethylene (PE) / Boron Nitride (BN) NC. The objective of this paper is to investigate the influence of BN concentration and film thickness on NC morphology and interphase properties. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and its derived mode the Electrostatic Force Microscopy (EFM) are used to characterize the NC morphology and relative dielectric permittivity ($\varepsilon_{r}$). Results show that an increase of the BN concentration has no influence on the crystallinity degree even if a disappearance of spherulites is observed. An increase of the surface roughness is observed as well and is more pronounced for thicker NC films. Moreover, it is shown that the interphase permittivity is lower than the matrix one and the BN concentration seems to have no influence on neither the interphase thickness nor its permittivity.