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

Abstract

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.

Dielectric dispersion and relaxation studies of melt compounded poly(ethylene oxide)/silicon dioxide nanocomposites

“…values. The e 0 spectrum of pure PEO is also found in consistent of the earlier reported result of solution-cast prepared PEO film [29,30,38]. Further, inset of Fig.…”

“…These s tan d values are also recorded in Table 2. Further, the magnitude and frequency position of tan d peak of melt compounded pure PEO are found in agreement of the values of solution-cast pure PEO film at room temperature [29,30]. Inset of Fig.…”

“…When the semicrystalline PEO is melted and subsequently cooled, it frequently crystallizes to form a morphology composed of symmetrical super-structures called spherulites [7,12]. The SEM images confirm that these symmetrical structures of PEO grow from a central point when several lamellae form together as a nucleus [29,30,37]. Further, these lamellae grow outwards at a linear rate which depends on the crystallization temperature and affects the chain mobility within the system.…”

“…Our survey of literature revealed that, so far the PEO and SiO 2 interactions and their effect on the polymer physico-chemical properties are characterized by rheological, differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), dynamical mechanical analysis (DMA), X-ray diffraction (XRD) scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements [1,[3][4][5][6][7]19]. Besides these experiments, the dielectric relaxation spectroscopy (DRS) is also a powerful tool for the study of polymer and nanofiller interactions and their effect on polymer dynamics in the PNC materials [20][21][22][23][24][25][26][27][28][29][30][31]. Further, the investigation on dielectric properties of such PNCs can provide the in-depth discussion of nanodielectrics, which is an emerging and fast-moving topic in electrical insulation for microelectronic devices.…”

“…Further, the investigation on dielectric properties of such PNCs can provide the in-depth discussion of nanodielectrics, which is an emerging and fast-moving topic in electrical insulation for microelectronic devices. Survey of literature reveals that the dielectric properties of solution-cast prepared PEO-SiO 2 nanocomposites are recently investigated along with their rheological and thermal properties [29,30]. But the detailed dielectric and electrical properties, and the molecular relaxation processes in the melt compounded PEO-SiO 2 nanocomposites are still unexplored.…”