Dielectric properties and relaxation behavior of polymethylsiloxane-imide films

Huimin Wang, Xiaoming Tao, Edward Newton

Research output: Journal article publicationJournal articleAcademic researchpeer-review

2 Citations (Scopus)


We have investigated the dielectric properties, dielectric relaxation behavior, electric conduction and kinetic characteristics of polysiloxane-imide films. The addition of siloxane is a very effective way to reduce the dielectric constant (ε′) of polyimides. For example, polysiloxane-imide [BPDA + siloxane] has a very low dielectric constant of 2.66, compared to normal polyimides such as Upilex-S [BPDA + p-PDA] with a dielectric constant of 3.47. The dielectric relaxation behavior of polysiloxane-imide is quite similar to that of fluorine-containing polysiloxane-imide. As frequency increases, the transition peaks of polysiloxane-imide move toward high temperature and the α relaxation strengths decrease. The β peak corresponds to the β dipolar relaxation whereas the α peak is due to the conductive effects in the bulk and the α dipolar relaxation. The activation energy of the α transition decreases with increasing frequency, while the activation energy of the β transition does not vary with frequency. The α peak is reduced with the increase of frequency, while the value of the β peak hardly changes with frequency.
Original languageEnglish
Pages (from-to)91-103
Number of pages13
JournalHigh Performance Polymers
Issue number1
Publication statusPublished - 1 Jan 2003


  • Dielectric relaxation behavior
  • Electric conduction and kinetic characteristics
  • Low dielectric constant
  • Polysiloxane-imide

ASJC Scopus subject areas

  • Polymers and Plastics
  • Organic Chemistry
  • Materials Chemistry

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