Dielectric properties and thermal destruction of poly(dimethylsiloxane)/Fe2O3/SiO2 nanocomposites

Thermally stimulated chemical transformation of poly(dimethilsiloxane) (PDMS) adsorbed onto highly disperse Fe2O3/SiO2 was studied using FTIR, thermogravimetry and differential thermal analysis. The influence of active surface sites on this transformation was investigated since iron oxide affects the degradation of PDMS. It was shown that PDMS provides stable (in the 100-500 °C range) hydrophobic properties to SiО2/PDMS depending on PDMS concentration. Differential scanning calorimetry, thermally stimulated depolarization currents and dielectric relaxation spectroscopy techniques were employed to investigate the effects of iron oxide on thermal transitions (in particular glass transition), segmental dynamics and interfacial interactions in PDMS/oxides nanocomposites.