Effects of addition of MgO fillers with various sizes and co-addition of nano-sized SiO2 fillers on the dielectric properties of epoxy resin

Ryosuke Yanashima, Naoshi Hirai, Yoshimichi Ohki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

Complex permittivity (ϵr' and ϵr"), conductivity (σ), and glass transition temperature (Tg) were measured for composites of epoxy resin and MgO fillers with various sizes in a wide temperature and frequency range. The effect of coaddition of nano-sized SiO2 was also examined. It has become clean that Tg decreases by the addition of MgO fillers, and its decrement becomes more with a decrease in filler size. Moreover, Tg decreases if the silica nanofillers are co-added. However, all the three important parameters for electrical insulation ability of polymers, namely ϵr', ϵr", and σ, decrease with the decrease in size of MgO fillers or by the addition of silica nanofillers at high temperatures and low frequencies. This is a very astonishing result, since it seems reasonable that a polymer with a high Tg should have a better insulating ability. Probably, the above-mentioned results indicate that the charge transport becomes more difficult, presumably resulting from the suppression of molecular motion with the decrease in size of MgO fillers and by the co-addition of SiO2 nanofillers. This indicates that the suppression of molecular motion becomes very strong if the filler size is small, making the carrier transport difficult even in polymers with low Tg.

Original languageEnglish
Title of host publicationProceedings of 2017 International Symposium on Electrical Insulating Materials, ISEIM 2017
PublisherInstitute of Electrical Engineers of Japan
Pages650-653
Number of pages4
Volume2
ISBN (Electronic)9784886860996
DOIs
Publication statusPublished - 2017 Dec 4
Event2017 International Symposium on Electrical Insulating Materials, ISEIM 2017 - Toyohashi, Japan
Duration: 2017 Sep 112017 Sep 15

Other

Other2017 International Symposium on Electrical Insulating Materials, ISEIM 2017
CountryJapan
CityToyohashi
Period17/9/1117/9/15

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Keywords

  • Composite
  • Dielectric property
  • Epoxy resin
  • Glass transition temperature
  • Magnesium oxide
  • Silicon dioxide

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

Cite this

Yanashima, R., Hirai, N., & Ohki, Y. (2017). Effects of addition of MgO fillers with various sizes and co-addition of nano-sized SiO2 fillers on the dielectric properties of epoxy resin. In Proceedings of 2017 International Symposium on Electrical Insulating Materials, ISEIM 2017 (Vol. 2, pp. 650-653). Institute of Electrical Engineers of Japan. https://doi.org/10.23919/ISEIM.2017.8166574