Dielectric relaxation behaviour in semi-crystalline polyvinylidene fluoride (PVDF)/TiO2 nanocomposites

Polymer nanocomposites based on polyvinylidene fluoride (PVDF) matrix filled with TiO2 nanoparticles (1%, 2%, 3% and 5% by v/v%) were studied by broadband dielectric spectroscopy (BDS) in order to investigate the filler effect on the molecular mobility of the polymer chains. The formalism of electric modulus was used to analyze the dielectric response, thus three relaxation processes were observed. In fact, the first one, which is around -40 degrees C at 10 Hz, is attributed to the glass transition at low temperature. As for the second phenomenon, around 30 degrees C at 10 Hz, it is related to the dipolar relaxations in the crystalline phase. Regarding the third one, around 100 degrees C at 10 Hz, it can be due to the interfacial polarization (IP). The crystallinity ratio decreases and the electric modulus of the interfacial polarization increases with the increase of the TiO2 content. (c) 2012 Elsevier Ltd. All rights reserved.