Abstract
The dielectric properties, dielectric relaxation behavior, electric conduction and kinetic characteristics of fluorine-containing polysiloxane-imide were investigated. The fluorine-containing polyimide [6FDA + p-PDA] has a low dielectric constant of 3.04, compared to normal polyimides such as Upilex-S [BPDA + p-PDA] with a dielectric constant of 3.47, due to the addition of perfluoroalkyl groups into the polymer backbone, while fluorine-containing polysiloxane-imide (6FDA + siloxane) has the lowest dielectric constant of 2.43, which is less than 2.5. The introduction of siloxane groups on the fluoric polyimides provides the possibility of obtaining high-performance polyimides with ultralow dielectric constants. The dielectric relaxation spectra suggest that the fluorine-containing polysiloxane-imide (6FDA + siloxane) has a phase separation structure. As frequency increases, the α relaxation strengths decrease and the β relaxation strengths hardly change. The conduction study indicates that the β peak corresponds to the β dipolar relaxation whereas the α one 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.
Original language | English |
---|---|
Pages (from-to) | 271-283 |
Number of pages | 13 |
Journal | High Performance Polymers |
Volume | 14 |
Issue number | 3 |
DOIs | |
Publication status | Published - 1 Jan 2002 |
Keywords
- Dielectric relaxation behavior
- Electric conduction and kinetic characteristics
- Fluorine-containing polysiloxane-imide
- Ultralow dielectric constant
ASJC Scopus subject areas
- Polymers and Plastics
- Organic Chemistry
- Materials Chemistry