Preparation And Properties Of Nano-SiO₂Hollow Spheres/EP Composites

As a fine performance thermosetting resin, epoxy resin （EP） has beenextensively applied in the national defense, chemical and electrical industries forinsulation owing to their outstanding combination of mechanical, electrical, sizestability, durability and chemical stability. However, with the improvement of theelectronic devices to high capacity and small size, the EP as electronic packagingmaterials were putted forward higher requirement.In this paper, nanostructure SiO₂hollow spheres were used to modify the EP.Silica nanostructure hollow spheres were synthesized using template method andthe silica hollow spheres/epoxy nanocomposite was prepared by adding the silicahollow spheres modified by （aminophenyl） trimethoxysilane （APTMOS） into theepoxy resin. The microstructures of the SiO₂hollow spheres and composites wereanalyzed by Transmission Electron Microscopy （TEM） and Scanning ElectronicMicroscope （SEM）. And dielectric property of the composites was characterizedby precision impedance analyzer and breakdown tester. Other properties such asimpact strength, bending strength, thermal conductivity and thermo gravimetrywere evaluated using electronic universal testing machine, thermal conductivitymeter and thermogravimetric analysis （TGA） respectively.Dielectric properties were investigated in terms of frequency andmechanical properties were investigated in terms of filler concentration. Theresults showed that with the increase of the SiO₂hollow spheres content, thedielectric permittivity tended to decrease firstly and then increase. While thedissipation factor value increased slightly with an increase in frequency, it stillremained at a low level. With the increase of the SiO₂hollow spheres content, themechanical properties tended to decrease firstly and then increase too. We foundthat the SiO₂hollow spheres/epoxy composite containing3wt%SiO₂hollow spheres content possessed a low dielectric permittivity, a high dielectricbreakdown strength, a high volume resistivity and a high impact strength andbending strength, but a low thermal conductivity. At the same time, theintroduction of the SiO₂hollow spheres hardly influenced the thermal stabilitybehavior.