Thermal characterization of aromatic copolyimide films
Conference
·
OSTI ID:141939
- Univ. of Akron, OH (United States)
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.
- OSTI ID:
- 141939
- Report Number(s):
- CONF-930304--
- Country of Publication:
- United States
- Language:
- English
Similar Records
Order structure and crystals of fully aromatic polyimides grown from solutions
Synthesis and properties of the containing aromatic copolyimides
Fluorinated and nonfluorinated polyimides based on 4,4{double_prime}-diamino-p-terphenyl
Conference
·
Thu Dec 30 23:00:00 EST 1993
·
OSTI ID:141730
Synthesis and properties of the containing aromatic copolyimides
Conference
·
Thu Dec 30 23:00:00 EST 1993
·
OSTI ID:141810
Fluorinated and nonfluorinated polyimides based on 4,4{double_prime}-diamino-p-terphenyl
Conference
·
Thu Dec 30 23:00:00 EST 1993
·
OSTI ID:141681