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Autoclavable addition polyimides for 371 C composite applicationsStudies were conducted to improve the thermo-oxidative stability (TOS) of PMR type polyimides by the substitution of para-aminostyrene (PAS) for the nadic ester endcap in second generation PMR polyimides (PMR-2). The nadic endcap which provides the PMR polyimides with their relative ease of fabrication, both by limiting the molecular weight of the prepolymer and by undergoing the final addition cure without volatiles, is also the weak link with regard to TOS. A polyimide formulated with PAS endcaps, called V-CAP, utilizes a two step reaction sequence similar to that of the PMR polyimides and can be easily autoclave molded into low void composite materials. Resin studies included two formulations of both PMR-2 and V-CAP, corresponding to n = 9 and n = 14 prepolymer stoichiometry. Unidirectional reinforced T40R graphite fiber laminates were fabricated from each of the resins was post-cured in either air at 385 C or nitrogen at 400 C. Composite specimens were aged in air at 371 C and mechanical properties were measured at 371 C before and after exposure.
Document ID
19910064489
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Vannucci, R. D.
(NASA Lewis Research Center Cleveland, OH, United States)
Malarik, D.
(NASA Lewis Research Center Cleveland, OH, United States)
Papadopoulos, D.
(NASA Lewis Research Center Cleveland, OH, United States)
Waters, J.
(NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1990
Subject Category
Nonmetallic Materials
Meeting Information
Meeting: International SAMPE Technical Conference
Location: Boston, MA
Country: United States
Start Date: November 6, 1990
End Date: November 8, 1990
Accession Number
91A49112
Distribution Limits
Public
Copyright
Other

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