Hygrothermal effects on the material properties and behavior of thermoplastic polyimide composites
- Univ. of Delaware, Newark, DE (United States). Center for Composite Materials
Thermoplastic polyimides are a relatively new class of polymers that exhibit high-temperature stability and are useful in composite applications. One such material is DuPont`s Avimid{reg_sign} K3B reinforced with Hercules` Magnamite{reg_sign} IM7 graphite fibers. This composite system exhibits excellent strength and toughness, as well as excellent retention of strength and toughness, after prolonged exposure to elevated temperatures. IM7/K3B also resists microcracking at extremely low (liquid nitrogen) temperatures. Further characterization of IM7/K3B thermoplastic composites is focused on evaluating hygrothermal effects on the material properties and behavior. Specifically, the dependencies of T{sub g}, G{sub Ic}, and microcrack resistance on the conditioning time, temperature, and humidity level are being explored. Observations and conclusions from these studies include (1) a reduction in glass transition temperature, T{sub g}, with moisture absorption that is recovered when the sample is redried, (2) development of microcracks in cross-ply and quasi-isotropic laminates conditioned for extended periods in steady-state hygrothermal environments, (3) indications of localized degradation of the material from studies using scanning electron microscopy and ultrasonic scanning on moisture-saturated laminates, and (4) non-Fickian anomalies in the moisture diffusion data that are related to the damage development.
- OSTI ID:
- 237757
- Report Number(s):
- CONF-9510177-; ISBN 1-56676-376-2; TRN: IM9625%%82
- Resource Relation:
- Conference: 10. technical conference on composite materials, Santa Monica, CA (United States), 18-20 Oct 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the American Society for Composites: Tenth technical conference. Composite materials, mechanics and processing; PB: 659 p.
- Country of Publication:
- United States
- Language:
- English
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