Research On The Dielectric Characteristics Of Nano-SiO₂、MgO、ZnO Compositing Silicone Rubber

Silicone rubber has became the main material of manufactuing compositesinsulator for its advantage in electrical performance. The insulation performanceof silicone rubber will decline under high voltage for a long time. In order toimprove silicone rubber electrical performance, many scholars begin to payattention to the infulence of nano additives on electrical properties of siliconerubber. A number of studies have suggested that compoundding silicone rubberwith nano additives into nanocomposites can increase the electrical performance.The paper based on Silicone rubber for matrix, nano-SiO2、nano-MgO andnano-ZnO were used as inorganic fillers, selection of silane coupling(KH-560) asmodifiers. Silicone rubber composites with nanofillers loading of2wt%,4wt%,6wt%,7wt%were made by “mechanical mixing method” and “ultrasonicmethod”. The dispersion of nanfillers are investaged by SEM in silicone rubbernanocomposites. Through the breakdown performance test are emphaticallydiscussed different kinds of nanofillers, different nanofillers size, differentpreparation methods and differen nanofillers loading on the influence ofnanocomposites. Through the conductivity test of composite material which wasused to analysis the different nanofillers loading and different kindes ofnanofillers on the influence of the composite materials. Closed to the percolationthreshold, the breakdown voltage of different kinds of nanocomposites decreasedquickly. Pulsed Electro-Acoustic method was used for the measurement of spacecharge.Silicone rubber nanocomposites samples with different kinds of nanofillerswere prepared. We can know that the bigger size of nano-Silica can worseintegration with matrix. The parameters of interface volume proportion and specific surface area were calculated based on the simplified cubic model, Theinfluence of nanofillers loading on the interface volume proportion was discussed.The percolation theory is used to interpret the breakdown behavior ofnanocomposites with the variation of nanofillers lodaing. The percolationthreshold of different silicone rubber nanocomposites is found.Dielectric spectrum test show that nanofillers bring can improves relativepermittivity and dielectric loss of silicone rubber nanocomposites. Closed to thepercolation threshold, The relative permittivity and dielectric loss of Siliconerubber nanocomposites which were doped with different kinds of silicone rubbernanocomposites occurred jump phenomenon. With the increase of nanofillersloading, the conductivity increase. The PEA spectrum indicates that differentkinds of silicone rubber nanocomposites internal space charge can achieve stablestate in short time.