Comparison of rheological, thermal and electrical properties of poly(ethylene oxide) composites with micro and nano sized silicon dioxide filler

Polyethylene oxide (PEO) is a water-soluble polymer often used as a model system to observe filler effects. This paper details an investigation into the physical, thermal and electrical properties of polyethylene oxide composites containing micro-(SD) and nano-silicon dioxide (nSD) filler. Three molecular weight host PEOs were used - 100,000 g mol-1, 400,000 g mol-1 and 1,000,000 g mol-1 and the SD was dispersed into the PEO in solution in distilled water, by using controlled shear conditions, and the properties of the resulting materials then studied. Dispersion of the micro- and nano- sized fillers was analysed during the solution rheology phase by means of shear rate - shear stress data collection. The crystallisation and melting behaviour were examined using differenial scanning calorimetry. The AC ramp electrical breakdown strength was also analysed. This paper investigates the effect of SD filler loading and shear history on structural evolution, electrical breakdown behaviour in PEO, and the dependence on filler size.