Second-generation PMR-type polyimides (PMR-II polyimides) of enhanced thermo-oxidative stability prepared by substitution of para-aminostyrene (PAS) end caps for nadic-ester (NE) end caps used in prior PMR-II polyimides. Laminates unidirectionally reinforced with graphite fibers and made with PAS-capped resins exhibited thermo-oxidative stabilities significantly greater than those of similar laminates made with NE-capped PMR-II resins. One new laminate exhibited high retention of weight and strength after 1,000 h of exposure to air at 371 degrees C.
Improved PMR Polyimides For Heat-Stable Laminates
NASA Tech Briefs ; 18 , 4
1994-04-01
Miscellaneous
No indication
English
Soluble, thermally-stable aromatic polyimides
NTRS | 1977
|Improved processability of addition polyimides
NTRS | 1977
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