Thermal characterization of aromatic copolyimide films
Abstract
A series of fully aromatic copolyimides have been synthesized from 3,3,`,4,4`-bi-phenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhyride (PMDA), and 2,2`-bis-(Trifluoromethyl)-4,4`-diaminobiphenyl (PFMB) in m-cresol, BPDA-(PFMB){sub x}-(PMDA-PFMB){sub y}. The molar composition ratios are 100/0, 85/15, 70/30 and 50/50, respectively. The unoriented polyimide films with a thickness ranging between 10 and 20 {mu}m have been characterized by an in-plane orientation of the c-axis in the crystals a well as the molecular chain axis relative to the film surface. This in-plane orientation has been studied by transmission and reflection geometrical modes of wide angle X-ray diffraction (WAXD) and polarized Fourier transform spectroscopy (FTIR), and can be attributed to the rigidity and linearity of the chain molecules. The structural anisotropy leads to anisotropic behavior in the glass transition temperature (Tg), the linear coefficients of thermal expansion (CTE) and the dielectric behavior ({epsilon}` and {epsilon}{double_prime}) parallel and perpendicular to the copolyimide film surface. Possible structure-property relationships are also discussed.
- Authors:
-
- Univ. of Akron, OH (United States)
- Publication Date:
- OSTI Identifier:
- 141939
- Report Number(s):
- CONF-930304-
TRN: 93:003688-1627
- Resource Type:
- Conference
- Resource Relation:
- Conference: 205. American Chemical Society national meeting, Denver, CO (United States), 28 Mar - 2 Apr 1993; Other Information: PBD: 1993; Related Information: Is Part Of 205th ACS national meeting; PB: 1951 p.
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; IMIDES; THERMAL ANALYSIS; CRYSTAL STRUCTURE; COPOLYMERS; DIELECTRIC PROPERTIES; ORIENTATION
Citation Formats
Cheng, S Z.D., Arnold, Jr, F E, Shen, D, Lee, C J, and Harris, F W. Thermal characterization of aromatic copolyimide films. United States: N. p., 1993.
Web.
Cheng, S Z.D., Arnold, Jr, F E, Shen, D, Lee, C J, & Harris, F W. Thermal characterization of aromatic copolyimide films. United States.
Cheng, S Z.D., Arnold, Jr, F E, Shen, D, Lee, C J, and Harris, F W. 1993.
"Thermal characterization of aromatic copolyimide films". United States.
@article{osti_141939,
title = {Thermal characterization of aromatic copolyimide films},
author = {Cheng, S Z.D. and Arnold, Jr, F E and Shen, D and Lee, C J and Harris, F W},
abstractNote = {A series of fully aromatic copolyimides have been synthesized from 3,3,`,4,4`-bi-phenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhyride (PMDA), and 2,2`-bis-(Trifluoromethyl)-4,4`-diaminobiphenyl (PFMB) in m-cresol, BPDA-(PFMB){sub x}-(PMDA-PFMB){sub y}. The molar composition ratios are 100/0, 85/15, 70/30 and 50/50, respectively. The unoriented polyimide films with a thickness ranging between 10 and 20 {mu}m have been characterized by an in-plane orientation of the c-axis in the crystals a well as the molecular chain axis relative to the film surface. This in-plane orientation has been studied by transmission and reflection geometrical modes of wide angle X-ray diffraction (WAXD) and polarized Fourier transform spectroscopy (FTIR), and can be attributed to the rigidity and linearity of the chain molecules. The structural anisotropy leads to anisotropic behavior in the glass transition temperature (Tg), the linear coefficients of thermal expansion (CTE) and the dielectric behavior ({epsilon}` and {epsilon}{double_prime}) parallel and perpendicular to the copolyimide film surface. Possible structure-property relationships are also discussed.},
doi = {},
url = {https://www.osti.gov/biblio/141939},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Dec 31 00:00:00 EST 1993},
month = {Fri Dec 31 00:00:00 EST 1993}
}