Polyimides
Major condensation polyimids, Dupont’s Avimid N & K
- are marketed as Prepreg polyimids
- Avimid N Tg = 675F (360C), and
- Avimid K: Tg = 490F (254C)
- Linear polyimids are produced which have thermoplastic behavior above the Tg.
- They process like thermoplastics for a few heat cycles.
- Advantages of thermoplastic nature
- Tractable nature of resins when hot facilitates the removal of volatiles.
- Voids, formed as result of the evolution of gases, can be eliminated by applying pressure while heating the resins above Tg.
- Applications
- Wing skins for high performance aircraft.
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