Dielectric properties of nanosilica filled epoxy nanocomposites

Abstract

This paper presents the development of epoxy-silica nanocomposites and characterized for dielectric properties. The effect of nanosilica loading (0-20 wt%), frequency, temperature and sea water aging on these properties was studied. Transmission electron microscopy (TEM) analysis of the samples showed an excellent dispersion. However, at higher silica loading TEM showed inter-contactity of the particles. The dielectric constant (e 0) increased with silica loading and reached an optimum at about 10 wt%. The e 0 of the nanocomposites showed linear decrease with frequency whereas AC conductivity (r ac) increases. The r ac and e 0 increased marginally with temperature and sea water aging.

Effects of alkyl/vinyl‐modified nanosilicas on negative or positive high voltage direct current breakdown strength and tensile properties in silicone rubber nanocomposites

“…nanosilica's ε' = 4.5-4.9). 23,24 As was expected, the dielectric permittivity of the silicone nanocomposites had more than 3, as shown in Figure 10. As the amount of vinyl groups on the nanosilica surface increased, excess vinyl groups could not participate in the cure reaction, so that the amount of residual polar double bonds increased, resulting in a slight increase in dielectric permittivity.…”

“…It was well‐known that non‐polar polymers always had dielectric permittivity of less than 3 regardless of frequency, and it was also well‐known that the values of nanocomposites were higher than those of the neat polymers because of inorganic nanopowders with higher dielectric permittivity (e.g. nanosilica's ε' = 4.5–4.9) 23,24 . As was expected, the dielectric permittivity of the silicone nanocomposites had more than 3, as shown in Figure 10.…”

The role of interface on dynamic mechanical properties, dielectric performance, conductivity, and thermal stability of electrospun carbon nanofibers reinforced epoxy

“…But when the frequency is very high it becomes very difficult for the bigger dipolar molecules to orient themselves, due to small interparticle distance and agglomeration, with respect to applied field. [61] A remarkable point here is that nanocomposite has a sharper descent in dielectric and frequency relationship at high-PCNFs loadings (5 and 10 wt %). The two factors that govern the overall permittivity of nanocomposites are the polymer chains mobility and NFs concentration.…”

Nanosilica-Toughened Epoxy Resins

“…Renukappa and his team investigated the dielectric properties of a CTBN-toughened DGEBA epoxy resin with various addition levels of nanosilica [ 56 ]. The dielectric constant increased with increasing SiO 2 content with an optimum at 10 wt %.…”