In:
High Performance Polymers, SAGE Publications, Vol. 14, No. 3 ( 2002-09), p. 271-283
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 a relaxation strengths decrease and the;3 relaxation strengths hardly change. The conduction study indicates that the / peak corresponds to the /3 dipolar relaxation whereas the a one is due to the conductive effects in the bulk and the a dipolar relaxation. The activation energy of the a transition decreases with increasing frequency, while the activation energy of the /3 transition does not vary with frequency
Type of Medium:
Online Resource
ISSN:
0954-0083
,
1361-6412
DOI:
10.1177/095400830201400304
Language:
English
Publisher:
SAGE Publications
Publication Date:
2002
detail.hit.zdb_id:
1483713-4
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